Are 24 x T60-LAB15s Enough? ;)

[Seth]

Man, the Duratex folks are just fantastic! ... ...They sent a photo, and it looks great!

If it's not too much trouble, I'd like to see that pic. Sounds like an ideal solution for you.

...They also recommended a reflective paint for the shipping container...

Not a bad idea. If it suits the storage yard dress code, seems like just a basic white would be the easiest and best route on that front.

Back to the Dancetronauts setup for a minute, though. Do I count 16 DRs of some sort there? DR280s? It doesn’t seem like their tops have any splay angle, though, so maybe they built them without the splay? Or are they Omnis? And do I count 8 T60s?

There was a little more in depth conversation about that system somewhere and I can't seem to find it. But, from memory it is 16 DR280's and the bottom 8 aren't used. Not sure about the splay and whether they were built without. The sides of them are plexiglass/perspex, pretty neat and visually impressive. Yes, eight 2x12 T60's.

Something to note is the height of the speakers and how clear the sound is at the distance the video was taken from. It just illustrates the importance of getting them up above the crowd.

Also, is that Bill Fitzmaurice I see up there in his space bikini and fur boots, stealing the spotlight again? Classic Bill!

I'm glad I wasn't drinking anything when I read this, I most certainly would have spit it all over my computer. Hilarious

Man, it would be really, really great if those Admark amps pass the test! More than great, actually. Absolutely fantastic!!!

I ordered 3 more test loads and they should be here tomorrow. I might get into some testing this coming weekend, maybe.

We have drivers arriving next week!

Plywood will be here in two weeks!

The era of sawdust is quickly approaching!!!

I'm excited for you! Just guessing Bruce was able to help you out. Your UPS guy is gonna hate you. LOL
I really hope you keep us all posted with progress reports and pictures. I really wanna see this come together!

[Levi]

You betcha! Here you go!

And yep, the dress code includes colors in the beige range of the rainbow. So we'll see if that can happen this year.

I tried searching for more info on their system as well. What I found instead was a thread that said one of their guys was naughty and didn't give credit where it was due... Oh no!

Yep, the plan is to build some simple platforms and to use the stacking brackets on top of them. Gotta set the DR280s properly!

And yes, Bruce is the best!!!

As is this whole community! It is not lost on me that I am standing on the shoulders of giants. This culture of helping out dummies like me is simply amazing. In fact, it fits very well with our overall goal with this system and our camp - to provide folks the GIFT of best experience we can! The emphasis is on GIFT, of course. We will not make any money on any of this. Ever. So thank you all for helping make this happen!

I will try my best to post updates!

[Keryn O'Shea]

All the best to you and your team Levi.. we're stoked for you guys on the cusp of an epic build and event!
I'd be interested in seeing templates & jigs if you get the chance..
The tint/stain for the T60s, does it bead water?

[Seth]

Levi, by some of your responses and conversation I assume you've already read this thread. But, just incase you haven't...
The journey begins.. 16 T60's and 12 DR280's!!

[Levi]

Howdy, folks!

We did about 1500 feet of table saw rips this weekend on over 5000 pound of plywood. What a workout!

That said, I'm having a recovery/turd night. I told myself I'd just take it easy. But the ole brain didn't want to. And now I'm back on the forum! Ha!


Listen.

I'm having trouble crunching the numbers. Call it last minute jitters before making any more sawdust...

If you recall, the original goal was to build a system that can match/beat the gold standard.

To review, that system had 12 x D&B Audiotechnik B-2 Subs for its low end, which I am defining as 60 Hz and below.

I've attached the specs and chart from the manual. Here's what I gleaned from it:

2x18" drivers
"INFRA" mode (provides a little boost in the 32-68Hz range) max SPL, 1m full space - 139db
Power handling capacity (RMS/peak 10ms) 600/2400w
The chart show the max SPL occurs at about 50Hz in INFRA mode, which gains +1db at 50Hz in the chart
Both 40 and 60Hz show about 2db lower than 50Hz


Using that info, here is my math to get a decent comparison:

60 Hz - 100.2 db
1. Starting point - 139 max SPL, full space
2. Add 3 db to bring it to half space, 139 + 3 = 142 max SPL, half space
3. Subtract 6 db to bring 2x18 drivers to 1x18, 142 - 6 = 136 max SPL
4. Subtract 33.8 db to bring 2400w to 1w, 136 - 33.8 db = 102.2 SPL @1m/1w
5. Subtract 2 db from chart, 102.2 - 2 = 100.2 db

50 Hz - 102.2 db
1. Starting point - 139 max SPL, full space
2. Add 3 db to bring it to half space, 139 + 3 = 142 max SPL, half space
3. Subtract 6 db to bring 2x18 drivers to 1x18, 142 - 6 = 136 max SPL
4. Subtract 33.8 db to bring 2400w to 1w, 136 - 33.8 db = 102.2 SPL @1m/1w


40 Hz - 100.2 db
1. Starting point - 139 max SPL, full space
2. Add 3 db to bring it to half space, 139 + 3 = 142 max SPL, half space
3. Subtract 6 db to bring 2x18 drivers to 1x18, 142 - 6 = 136 max SPL
4. Subtract 33.8 db to bring 2400w to 1w, 136 - 33.8 db = 102.2 SPL @1m/1w
5. Subtract 2 db compared to 50Hz, 102.2 - 2 = 100.2 db


Does that all seem right so far?


Here is what I pulled from Bill's chart for the T60 1xLAB12 20" Version

60 Hz - 99 db
50 Hz - 99 db
40 Hz - 97 db


So using this closest apples to apples comparison I could think of, using 1 driver/cab at 1w/1m...

60 Hz - T60 is 1.2 db lower
50 Hz - T60 is 3.2 db lower
40 Hz - T60 is 1.2 db lower


Now to factor in the herd...


12 x B-2s have 2x18s, for a total of 24.

Here are my assumptions about the mouth area of that cab. Looks like the opening is about half of the width, and the full height of the cab. So I used 45"/2 = 22.5" by 22". Subtract an inch for the wall thickness, for 21.5" x 21" = 451.5". But that mouth is for both of the drivers. So divide that by half to get it for one driver, 451.5/2 = 225.75 square inches. Divide by 144 square inches for 225.75/144 = 1.57 square feet.


60 Hz
The perfect horn area is about 28 square feet, yes? 28/1.57 = 17.8 cabs. So that means up until 17.8 cabs, the B-2 would get full +6db, but from 17.8 to 24, the B-2 would only get +3db, correct? This means the herd gets roughly 100.2 + 24.1 + 0.4 = 124.7 db. Does that seem right?

50 Hz
The perfect horn area is about 40 square feet, yes? 40/1.57 = 25.5 cabs. So that means all 24 driver/cabs would gain the full +6db, right? This means the herd gets roughly 102.2 + 27 = 129.2 db. Yes?

40 Hz
The perfect horn area is about 63 square feet, yes? 63/1.57 = 40.1 cabs. So again that means all 24 driver/cabs would gain the full +6db, right? This means the herd gets roughly 100.2 + 27 = 127.2 db. Yes?



Now for the T60s...

Again, the plan is 32 of them. The mouth area for the 20" version is 19" x 29" = 551 sq in / 144 = 3.826 square feet.


60 Hz
28/3.826 = 7.3 cabs. So that means up until 7.3 cabs, the T60s would gain +6db, then after that only +3db.
99 + 17 + 6 = 122 db

50 Hz
40/3.826 = 10.5 cabs. So that means up until 10.5 cabs, the T60s would gain +6db, then after that only +3db.
99 + 24.9 = 123.9 db

40 Hz
63/3.826 = 16.5 cabs. So that means up until 16.5 cabs, the T60s would gain +6db, then after that only +3db.
97 + 27.1 = 124.1 db


So to compare...

60 Hz - 32xT60s are 2.7 db lower
50 Hz - 32xT60s are 5.3 db lower
40 Hz - 32xT60s are 3.1 db lower


But then there is the power end of it...

How much power can you run B-2 cabs at? I have no idea. Does anyone have a good guess? I know Xmax factors in here as well as the cabs, but I don't know how to figure it. Anyone?

The T60s would be run at 45v, so about 256w each. That would be a gain of +24db, yes?

If the B-2s can run higher, which I'm guessing yes they can, then they will gap will widen further, perhaps by another 3 or 6db. If yes, that would mean they could be about 10db higher at 50 Hz... almost twice as loud! Oh no, they still win!


I'm eager to stand corrected on all this, especially in ways that will make the T60s beat the B-2s... hahaha! So pretty please chime in and correct all my silly errors!









@Keryn

Thank, Keryn! I'll try to document as much as I can.

The stain we used on the old T60s was Sherwin Williams Superdeck. It held up well considering the conditions.

We are still formulating the new staining strategy.

One idea is to leave the birch bare, no stain, and just use the clear Duratex. Let that grain show. That will definitely bead water.

To that end, we ended up getting 120 sheets of 5x5 BB grade Baltic Birch. I sorted through every single one to get the prettiest candidates. I know a lot of guys on here paint over their wood, but we are letting it show, so that was a HUGE extra step. I too the time to pick the A grade parts in the sea of void fillers of the B grade faces. Done deal now, though! We have enough pretty pieces to complete the set!

The other idea is to use an interior stain, since no matter what, we will use the clear Duratex over it. The question there is if we need to add UV protectant to the base stain and/or the Duratex. Still researching that. That option will bead water as well, of course.





@Seth

Thanks, Seth! That is an epic thread! I really appreciate the links. I know there is a wealth of knowledge on this forum, but it can be hard to find if you don't already know what you're looking for.

You know, at the end of the thread, I was hoping that the next chapter would come! With the outdoor system he hinted at. Did he ever do it? I couldn't find anything more on the forum. I even tried to track him down on Facebook, but no luck. Seems like he's still building cabs, though. Just not Bill's. It would be really neat-o to hear his thoughts on the whole thing after all this time!

[Seth]

Levi, take a deep breath, hold, and let it out slow. LOL

Not that you're going to have volume deficiencies (you won't), but I thought "the golden standard" was about the sound quality, a "warm hug" I think you said, and not so much about maximum output potential. Is that not the case?

I read through all your math. I'm really happy there's another "numbers person" on the boards. I didn't sift through it for errors, but nothing stood out as an obvious mistake. Except... Here's the thing, I have a really hard time believing ANY data published by any manufacturer. And all max output figures are bullshit when they're calculated based on "max power". 2400 watts into a 600 watt RMS cab is not a reliable point of data. It's published to compete with all the other speaker cab manufacturers bullshit lies, and they're lying because they want your money. Carries zero weight in this conversation. I'd say you should use their response chart, but it's been referenced to 0 instead of actual measured numbers. Why do you suppose they didn't just post their 1W/1M half space measured response measured in SPL? Why not spell out their real world performance capabilities plainly, in simple terms? It's all a bunch of bologna. Go ahead and twist their BS into some numbers if it gives you something to do and you enjoy it. Just know, it makes just about the same sense as working a pile of poop into a stylish vase on a potters wheel... it's still just poop.

I feel like I've gone over this before, but I don't want to go back through the thread to find out, so forgive me if I've said it already. In comparing sensitivity charts from one cab to another, I only look at the sensitivity at lowest frequency I expect the system to faithfully reproduce. And here's why, if you take a look at the target response curve I recommended (I'll put it up again)...



... you can see the bottom frequency needs the most output, but the native response of most any cab is lowest at that point. So, to create that frequency (again, I'm just going to use 40Hz in this conversation, but the point is greatly amplified for frequencies lower than 40Hz) based solely on the target chart it'll take 5.6 times more voltage (31.6 times the power if the impedance was the same) to create 40Hz than it would to create 125Hz. But, that doesn't even take into account the cab response, of which 40Hz is -8dB compared to 125Hz. Which means it will actually take 14.1 times the voltage at 40Hz than it does at 125Hz tuned to that specific target response curve. Now, music isn't linear, so it doesn't work out the same as doing a sine sweep, but the point is who cares what the sensitivity is at 50, 60, 70, and beyond when the major limiting factor to the maximum output potential of the system is the sensitivity at the frequency that will need the most "effective" EQ boost/least EQ cut?

I wouldn't worry one bit. When the bass is clean, it seems there's never enough. But you'll have more than enough to do what you want to do. Your time and mind space is much better spent on figuring out the optimum deployment and identify a few different strategies to test when it comes time to blow up the local high school football field or wherever you can find enough open space to test and tune that rig.

Yes, 45V is +24dB over 2.83V. If they were mine, I'd probably limit them at 50V. I can't recall any account of anyone blowing one.

Having the better system will come down to deployment and tune (and music selection). You'll have enough cab, no doubt.

The fate of the thread I posted... you know as much or more than I do. I noticed he put his tel number in there. I didn't think it was important enough to call and ask. Although, if I ever get out to Boston again, I'd consider giving him a call and seeing what he's up to now-a-days.

Oh, and the "perfect horn" calcs look good, except the mouth area is only applicable to the bottom frequency. Frequencies higher than the bottom roll-off frequency will resonate further up the horn and have a smaller "effective" mouth area.

This thread needs pics. A huge pile of plywood? That's darn near pornographic for us guys around here. Are you kidding me? Post that shit up!

[Seth]

Also, scaffolding like this would be a good idea for the DR's
https://www.amazon.com/Metaltech-SAFERS ... B00XLI0AVW

[Levi]

Math update:

Ooopsies!

Looks like I forgot to add +1db to the B-2 50Hz level. I say this because the non-INFRA curve is at 0 at 50Hz, which I'm guessing is what the spec table refers to at the max SPL peak of 139db. INFRA is at +1db over the non-INFRA at 50Hz. So... dot, dot, dot... that means a single T60 is now 4.2db (not 3.2db) lower at 50Hz, and the herd 6.3db lower at 50Hz. With the likely higher power level that the B-2s can run at, it seems like even with all these T60 cabs, we still will be -10db at 50Hz. Very discouraging...



Okay, and breathing! Lol



Agreed, the gold standard out there is the sound quality, warm hug, etc.

A big part of that involves output levels, though, correct? All other things held constant, output can make the difference between hearing a track, and feeling a track, yes?

I'm thinking about it from a numbers/max output perspective, because of some benchmarks that I've come across, on this forum and others, use numbers to help describe that gold standard.

On this forum, Corona Operator mentions 132db at 50Hz for his T60s indoors. That definitely seems possible with clever placement indoors to get a free +6db or even +12db corner. Outdoors is proving much more difficult!

On some car audio forums, I've seen guys reference 135db and up at 30Hz, and 145db and up at 50Hz. Granted, they are within 1-2 meters, and in a completely enclosed space, so that's pretty easy to achieve, relatively speaking. Those are levels in which they say their whole body vibrates and even their arm hairs stand on end, which is probably less a "warm hug" and more of an "scalding hot anaconda squeeze". So that's probably not what we're looking for here.

If reproducing the quality of that gold standard system can happen at much lower levels, then great! But as you can probably tell, I'm a little skeptical.

The marketing data from manufacturers is silliness for sure. But it has to be rooted in some kernel of truth, yes? Even if that kernel is what happens just once for less than 10ms? Otherwise there would be some lawsuits, yes?

I look at it like I look at all those sugary breakfast cereals, being part of a healthy breakfast... Yes, I guess they can be, if everything else is ridiculously healthy, and you have a very very small portion, and the very definition of healthy is a bit skewed, and so on.

The reason I am focusing so much on it here, is that the murky max output level for the B-2 is at around 50Hz in their chart. Whereas in Bill's chart max output is at 85Hz and up. That's a big difference! Especially since this application needs that 50Hz "warm hug".

I guess I am just trying to find some sort of north star with these numbers (i.e. poop pots).

And...

More importantly...

If we set these numbers, and poop pots, and this whole armchair exercise aside, my ultimate skepticism and reason for these reindeer games is my personal experience.

I have heard and felt this gold standard system many, many times, for many, many hours. And every time I am absolutely blown away by the quality. By comparison, it just seems like our previous system had no low end! Just mid bass and up, that's it! And that is starting to make sense if I look at from the math perspective, and my numbers are correct... At 50Hz they maybe have +10db! Whoa!!!

Maybe it's just not possible to do this with 12" drivers in folded horns? Maybe the gold standard is using 2x18" bandpass subs for a reason? Because nothing else got them there?

Oh, brother...



Yes, I remember that target response curve!

But doesn't that EQ argument support the B-2 over the T60?

System wide, these T60s will cover 30-75Hz or so. Then the mids in the DR280s will take over up to 1200Hz, and then the compression drivers up from there.

If my math is right (which hopefully it is not!), the B-2s seem to have the T60s completely outgunned in that 40-60Hz range by 3 to 6db. At that upper end of the decibel spectrum, that is a huge difference, yes? I mean, for us to keep up, that would mean another doubling of T60 cabs to 64, or even 128, yes? Which would be absolutely insane! (But also pretty cool, right? But also that will never happen. Lolol)




Thanks for reminding me about deployment! Did you ever get to messing around with any of those modeling programs? Our default is to just have one big row of T60s. This is because that coverage pattern would fit to the vast majority of our events. (I'm basing this off the Dave Rat video.) Maybe we will mess around with some delays to widen the coverage a bit, but we don't want to do that at the expense of quality. Either way, though, that high school football field doesn't stand a chance!




I hear you on the 50v limit instead of 45v. Using this calculator (https://www.aetechron.com/calculator-Volt2dB.shtml), it seems like that would give an additional +0.9db of output. Which is great! The thought on limiting to 45v was to have a little more protection. These cabs will be outdoors in high temps. A few will probably be in direct sunlight. And they will often be playing for 12+ hours straight. So we thought maybe we'd back it off a bit to give a little extra buffer there.



Thanks, it's a long thread, I must have missed his number! I'll look again and give it a shot. Why not?



Yes, that makes perfect sense that higher frequencies will resonate further up the horn. I just wasn't sure how to do that math. Do you think that would change anything, though? Would the T60s get more output than my numbers allow?



Goddamnit, you're right! It's been such a scramble up to this point that I should slow down and enjoy the ride a bit. I will have your porn soon!



Oh, and that scaffolding is a good idea. We have some at the shop. But I just don't think it will meet our sexiness standard. We plan on building nice wood platforms that will support the DR280 brackets. The plan is to have the bottom edge of the lowest DR280 at 6.5 feet.

[Bill Fitzmaurice]

To review, that system had 12 x D&B Audiotechnik B-2 Subs...
I've attached the specs and chart from the manual.

You didn't, because there are no real specs there. The one chart they provided, which shows piss poor response BTW, is useless, as it doesn't show SPL.

If my math is right

It's not even close. You have no real data to work with.

Whereas in Bill's chart max output is at 85Hz and up.

You haven't been paying attention. That's with one cab. This is 2.8v into sixteen cabs:

And this compares them to sixteen B2 subs:

[Levi]

Thanks, Bill!



Sorry man, I attached what was available to me... That's all I have to go on! If I had more details, I would share them!

I think we are in the same boat, here. It's frustrating to deal with inadequate/misleading information! And think - you know enough to sift through it! I definitely do not, so it's all the worse for me!




I'm curious, what about that chart's response is piss poor? Let me be clear, I am not defending it. I am only wondering what your trained eye sees, as opposed to my untrained eye. Is it that it lacks a lengthy flat plateau?

My untrained eye sees a classic negative parabola like in algebra class back in the day. With a relatively high amplitude, and the vertex shifted to the right and up. Fun!

In the context of sound, that means a very limited response, yes? One that in practice is difficult to work with if you want to do anything outside of those limits. So the B-2 would not be very useful outside of that very narrow range on either side of the vertex. It's kind of a one-note wonder, yes?

This leads me to think that cab was purposely designed to deliver a very narrow 45-60Hz band. But it comes at a cost - it can't really do anything else. It's a specialized insect. That makes me think they designed it specifically to deliver the "hug", and nothing else. I don't know how the "INFRA" mode works, but it seems to amplify that narrow band, and add to the hug. It's like they started with that in mind, knowing that they would throw in plenty of other cabs to fill in at all the holes around it. Does that seem plausible?




More generally speaking, how do you yourself compare commercial cabs, then?

I know you look at as many specs as possible. You have to, yes? But if they are bullshit, how do you sift through it?

For example, in your Tuba 60 charts, I noticed you compare a T60 2xLAB12-30" to an EAW SB2001 (but with 2.0v instead of 2.83v). What was the process there? Was that in simulation software? Or did you have access to one and measure with a microphone and all that?

Also, what is the SB2001 exactly? Is it a folded horn? Also, its "unprocessed" chart in the manual looks like quite the roller coaster ride! Yikes!

I see another comparison chart with the JBL 728. Wow, looking at the JBL 728 manual, I'm impressed! It has a workable chart! Apples to apples! But, that chart has different values than what is on the T60-1x12-20" comparison chart... Seems like the values in the T60 chart are actually higher than what JBL has in their own manual... That's interesting! So maybe that means you had access to one and measured it with a microphone? And for once, a manufacturer understated performance? Or maybe there's a difference because they use 1w/1m instead of 2.83v?

I ask how you sift and compare, because for someone like me, that could be a Rosetta Stone of sorts.

As in, I can see real data on the T60 and the SB2001 in your chart, a true apples to apples comparison. (Which is so great!!! I can't emphasize enough how helpful that is, so thank you for putting that together!) Then, I can find the EAW SB2001's bullshit spec sheet, and compare it to the B-2's bullshit spec sheet, and have a better sense of things that way. It probably won't give me crystal clarity, but it's better than what I'm dealing with now, which is more in the mud at midnight category.

Let's take my efforts to find a commercial version of the T60, with a bullshit spec sheet. I haven't found anything close enough yet. It's easier to find for the T30/T45, though. Like these:

https://cerwinvega.com/el-36d.html
https://eaw.com/documentation/bh760-specs-rev1/

The Cerwin says max SPL 141db. The EAW says max output of "Peak" 145db and "Long Term" 139db. No chart of any kind for the Cerwin, so that's a dead end guessing where its max would be. Same for the EAW 760. Nothing, not even in the manual. That makes me want to give a little credit to D&B for at least publishing a bullshit chart in the B-2 manual. That gives me at least some idea of what's going on there. Also, I can probably conclude that if there was a bullshit spec sheet on the T60, it would also have a max SPL in the 140s.

On that note...

Wouldn't it be fun to create your version of a bullshit spec sheet to throw into their silly world! I think it would be a hoot! Throw in some bikini models, some race cars, maybe even some assault rifles and stuff. Oh, and flags! Flags, flags, flags! Flags for days! You know, the whole package!!!




My shitty math... Thank you for confirming! Again, I was hoping my math was incorrect. The fact that it's not even close is encouraging to hear!




Come on now, of course I'm paying attention!

My issue is not attention. My issue is a lack of understanding. I do not have the background you guys have, which is why I'm here asking questions to begin with! And I'm soaking up what I can along the way. I am an amateur and will never make money from this, after all. I've noticed in forums on other websites you have provided clueless guys like me links to resources that help them learn. Perhaps you know of some good ones to share on this subject? I can't be the only one who has asked questions like these, can I? It can help anyone else in my shoes that is following along now, or years later when this thread is ancient history. I know I would have loved reading a thread like this if it already existed! Then I wouldn't be asking so many questions - they've already been asked and answered for me!

Also, all I have to go on are the charts on this forum. That's why I said 85Hz, because on that chart, the curve flattens out at 85Hz all the way to the end of the chart at 200Hz. Can you see why I said that? Because I am paying attention, my man! Plus, I said it in the context of comparing one T60 to one B-2. Not the herd. So please cut a guy a little slack, yeah?

On that note, though, wouldn't a herd of B-2s also benefit in the same way the T60s do? Maybe not to the same degree, though? That's my guess, anyway.





Thank you for the chart on the 16 x T60 cabs! That is the first place I've seen a chart for 16 x T60s. (The one you posted a while back in #23 is for 8 x T48s.) But is it for 1x12 cabs? 2x12? Ah, never mind, I see when I download it, that the file is entitled "16 2x12". Got my answer there. What width, though? 30"? Probably yes. 30" seems to be default width when talking about 2x12.

Referring to the single cab T60 2x12 chart, here is what I see in the 40-60Hz "hug" range, for 1 x T60-2x12:

102.5 db at 40Hz
104 db at 50Hz
105 db at 60Hz

Referring to that 16 cab chart, I see that in the 40-60Hz "hug" range, 16 x T60-2x12s have about:

111.5db at 40Hz
111db at 50Hz
111.5db at 60Hz

Given my limited understanding of adding speakers and the effect on output, that is quite surprising. Shouldn't those numbers be much, much higher? I thought at the very least, with doubling power alone, there would be +12db. And that's not counting the gain from the increased cone displacement...

Or maybe that chart is only factoring in the cone displacement? Yep, that seems to be the case. It verifies that in a herd, the response really flattens out. Sweet!

That said, though, that pulls me back to this 132db at 50hz metric. If Corona Operator has his "hug" starting there, it seems like we just won't make it there. Not outdoors anyway, and not at any great distance.

Let's say we do 50v, for about a +25db increase from power. At 50Hz, 111db + 25db = 136db at 1 meter. 136 > 132, so awesome it's a warm hug! But as soon as we get to 2 meters, we lose 6db, correct? Down to 130db. No more hug. So to get the hug, you need to be within 5 feet or so.

Maybe that's where the B-2 bandpass really comes into play then. I don't know how that works. Maybe there's a port or something to really focus on 50Hz? Whatever the mechanism, it seems specialized to throw everything it can at 50Hz. Designed specifically to make your chest thump and the hairs on your arm stand up straight. And nothing else.

Knowing a little more about all these sound dynamics, I will definitely pay more attention this year to the intensity and distance of any hugging systems I come across! Ask what's under their hood and all that.




Oh, and you added that second chart on 16 B-2 subs as I was typing this out. Thank you so much!!! Wow, it is really amazing to see them compared like this. Pretty stinking close! So maybe the only thing a herd of 12 x B-2s has on a herd of 32 x T60-1x12-20"s is one little decibel or so! Well, maybe more if they can run significantly higher than 50v. Maybe 70v or something crazy, I don't know. I'd imagine it couldn't be more than 1-2db all in, though, with everything factored in. 12xB-2 cabs instead of 16... but running them at a higher voltage... Seems like it would be a wash. Cool!!!




Also it sounds like I need to learn how to use the Hornresp program everyone is using. That seems to be the go-to for definitive answers. I will put it on my list! But I probably won't get to it for a long while. Plenty of building to do first, of course!



Lastly, maybe there's a sticky on the forum that has bunch of educational resources listed, so that you don't have to keep explaining all this low level stuff to a bunch of dummies like me... Maybe there is one already? If not, there could be a "Bill's Complete Idiot's Guide to Speakers & Stuff - Read All of This Before Asking any Dumb Questions". Hmmm... Got a nice ring to it!



Thanks again, Bill!!!

[Seth]

I see you've posted again since I've been writing this. I haven't read your latest post yet. This is in response to your post earlier this morning.

Math update:

Ooopsies!

Looks like I forgot to add +1db to the B-2 50Hz level. I say this because the non-INFRA curve is at 0 at 50Hz, which I'm guessing is what the spec table refers to at the max SPL peak of 139db. INFRA is at +1db over the non-INFRA at 50Hz. So... dot, dot, dot... that means a single T60 is now 4.2db (not 3.2db) lower at 50Hz, and the herd 6.3db lower at 50Hz. With the likely higher power level that the B-2s can run at, it seems like even with all these T60 cabs, we still will be -10db at 50Hz. Very discouraging...

The data they have available is so darn... not helpful. So much so, that I can't make heads or tails of it. I think part of it is, they seem to be presenting the info as a powered system with DSP corrections. Infra setting? That's not a native cabinet function. But, to reluctantly dip my toe into the nonsense with you, you added the 1dB indicated in the chart for the Infra setting, however forgot to note that their rated "maximum output" is -3dB for the Infra setting.

Agreed, the gold standard out there is the sound quality, warm hug, etc.

A big part of that involves output levels, though, correct? All other things held constant, output can make the difference between hearing a track, and feeling a track, yes?

I'm thinking about it from a numbers/max output perspective, because of some benchmarks that I've come across, on this forum and others, use numbers to help describe that gold standard.

On this forum, Corona Operator mentions 132db at 50Hz for his T60s indoors. That definitely seems possible with clever placement indoors to get a free +6db or even +12db corner. Outdoors is proving much more difficult!

You're going to have concert output levels at your fingertips. And like a professional concert, you aren't going to need to max out everything you have to get what you need.

Outdoors, you'll need 2-4 times the rig you'd need indoors to make the same SPL. IIRC, Corona Operator ran two 30" 2x12 T60's in his club. Four to eight cabs should match that output outdoors. You're building the equivalent of twice that, and then some given increased sensitivity of the max width cabs. You should be able to get that performance at less than half power. I just ran some quick numbers, I don't think there's any mistakes but could be (I'm not in the mood to spell it all out at the moment), but you could possibly have 150dB potential all the way down to 25Hz. That seems like a lot, I'll rerun the numbers again later and double check. In any case, given proper placement and system tune, you're going to have "shit your pants" output potential.

If reproducing the quality of that gold standard system can happen at much lower levels, then great! But as you can probably tell, I'm a little skeptical.

I'm fairly confident that quality you've been missing has been due to your previous deployment and system tune, not max volume potential. With the system you're building, you should probably monitor SPL levels and possibly set limits so you don't permanently damage anyone's hearing.

The marketing data from manufacturers is silliness for sure. But it has to be rooted in some kernel of truth, yes? Even if that kernel is what happens just once for less than 10ms? Otherwise there would be some lawsuits, yes?

Maxes are always calculated. I wish there were lawsuits. That would be great for the industry if they all started being straight shooters. But, to your point, I'm sure there's a sliver of something pure and true in the stinky pile. I'm not willing to dig that deep into it though. I gave it a double look, downloaded their brochure and owners manual, searched for a genuine response chart, and tried to make sense of their numbers. They just don't add up. I thought about emailing them and asking for a 1W/1M SPL referenced response chart, but I'm just not willing to go further down the path in comparing the two.

You are already building at least twice the rig you'll likely need to get amazing results. I highly recommend you step away from the comparison game and focus on things that can help. But, I've been in your shoes before and I know what it's like wanting proof in the numbers. I hate it when people say "trust me", so I'll just ask you to have some faith, you're on the right path.

I have heard and felt this gold standard system many, many times, for many, many hours. And every time I am absolutely blown away by the quality. By comparison, it just seems like our previous system had no low end! Just mid bass and up, that's it! And that is starting to make sense if I look at from the math perspective, and my numbers are correct... At 50Hz they maybe have +10db! Whoa!!!

More and more, I suspect your system tune and/or deployment were just not good.

Their numbers are HIGHLY suspicious. If their sensitivity was really 105 at 50Hz, they'd absolutely have it plainly plastered everywhere, on their site, in the manual, brochure... 105dB is an unbelievable number for that frequency. +10dB over what you're building? No way, no how.

Yes, I remember that target response curve!

But doesn't that EQ argument support the B-2 over the T60?

Here's what I like about their response curve, it wouldn't take much EQ to create the target response curve. But again, I'm not willing to go further down this rabbit hole and I suggest you refrain as well. Their marketing and portrayal of performance potential is working really well. Snap out of it! It's bullshit.

Make realistic goals based purely on the performance you need and aim to achieve them. Drivers are bought, paid for, and delivered. Lumber has been cut. it's not like you can reasonably take any other course at this point. And you're on the right course for phenomenal results. Don't second guess yourself to death. Completely unnecessary stress at this point in the game. You've chosen your bull. Now get on that beast and ride it!

Our default is to just have one big row of T60s.

There's about four or five different deployments I'd like you guys to try. We'll discuss more as it draws in closer.

I hear you on the 50v limit instead of 45v. Using this calculator (https://www.aetechron.com/calculator-Volt2dB.shtml), it seems like that would give an additional +0.9db of output. Which is great! The thought on limiting to 45v was to have a little more protection. These cabs will be outdoors in high temps. A few will probably be in direct sunlight. And they will often be playing for 12+ hours straight. So we thought maybe we'd back it off a bit to give a little extra buffer there.

You know, those are all really good points. 45V is definitely not a bad choice. In either case, I highly doubt you guys are going to need to ride the limiter to get the performance you need. I think you'll have more than enough. (if there is such a thing. LOL)

Oh, and that scaffolding is a good idea. We have some at the shop. But I just don't think it will meet our sexiness standard. We plan on building nice wood platforms that will support the DR280 brackets. The plan is to have the bottom edge of the lowest DR280 at 6.5 feet.

You would do much better to get those things up more. Bottom cab 8-10 feet up or more would be ideal. Having them high will allow better coverage up close, better throw out far, and keep them reasonably far away from anyone's head/ears. I'm very serious about taking ownership and being responsible about peoples hearing. This rig will easily do damage if your not mindful and purposeful about it. Most people don't know any better, or aren't in a clear enough mind state to know better. Especially young people. We've gotta save them from them selves. LOL

[Bill Fitzmaurice]

I'm curious, what about that chart's response is piss poor? Let me be clear, I am not defending it. I am only wondering what your trained eye sees, as opposed to my untrained eye. Is it that it lacks a lengthy flat plateau?

Exactly. A bandpass speaker can have a reasonably wide bandwidth with reasonably flat response, or it can have high sensitivity. It can't have both.

[Levi]

Thanks, Bill and Seth!

I am satisfied! You'll hear no more nonsense about bullshit specs from me, I promise. Thanks for indulging me. Confidence renewed, I am really looking forward to getting back to into the sawdust! Good timing, too, because my body feels fully recovered! Time to ride that bull!



@Seth

Good point on the -3db for INFRA! I mixed it up assuming the -3db was a choice between the D12 or A1, instead standard vs INFRA. Doh! Thanks for pointing that out!

150db?!!! Holy smokes! Wouldn't that be something!

Can't wait to get to the deployment and tuning stage! Should be a ton of fun!

Thanks for the suggestion on the DR280 height! We will build it up to be at least 8 feet high. If the majority of our desired coverage area is about 80' wide and 100' long, what do you suggest for the height of the platform? Also, any thoughts on the distance between the line arrays?

And yes, don't worry, we will tune this system to proper levels. No hearing damage will occur because of us!




@Bill

Thanks for the info about the bandpass tradeoffs! Always great to learn!

[Levi]

Amplifiers!!!




Don't worry, guys, I haven't been completely unproductive chasing bullshit speaker specs during the past couple days.

I've also been chasing bullshit amplifier specs, too!

Ha! So there!

I went down a bit of a rabbit hole on amps. Really trying to understand the power tables, cross-referencing those with power/thermal draw sheets, comparing class A vs AB vs D vs H amps, etc.




Right now, I think we are just going to copy HifiBob. He seemed very satisfied with the Crown Macro-Tech MA-3600VZ amplifiers with his system. Here's the download page:

https://www.crownaudio.com/en-US/produc ... ech-series

I have also attached a few screenshots of the more relevant pages, as far as I can tell anyway.




The plan is to get at least 4 used ones. We found a good price. Less than $1000 each. The risk I suppose is that the used ones have all the complications that come with used gear. However, I've been assured that they have had one owner. They were used for touring, but have been kept in cases/racks the whole time.

It seems like these things are really heavy duty, built to last, which inspires extra confidence in buying them used. And apparently you can spot weld with them? Lol

The only downsides I can see is that they are heavy - 55lbs - and maybe aren't as efficient as say, class D amps. They are class AB. Or, as the anniversary brochure states, they are class AB+B. Whatever that means.

But apparently class AB sound better than D? Or H? I don't know enough to know. Maybe someone here does?

Anyway, the extra weight isn't really a concern, since it's not like we are doing events all the time. It's mostly just the once per year.

The lower efficiency isn't too much of a concern either. With how efficient these T60 cabs are, and since we have plenty of power to spare, that's not a biggie.





That said, does anyone feel like getting into the weeds on amps?

A few questions have come to mind. Keep in mind we will only be using these to run the T60s. For the DR280s, we already have a Macrotech 1200 for the compression drivers, and a Macrotech 2400 and/or 5000 for the mids.



1. What amp class is best for these T60s? A, AB, D, H? Does it even matter? Could you hear the difference?






2. How many T60-1xLAB12 cabs could you run per 3600VZ amp in parallel? Seems like our inputs are 45v, 5.625a, 8ohms, and 253.125w. Does that mean 4 cabs per channel would be just fine and dandy? Think there's enough headroom there for transients?







3. How hard do you think you can push the 3600VZ? If you were in a pinch?

This will be a story of bottlenecks, for sure.

The first bottleneck I can think of is...

What the maximum amperage that can continuously flow through each channel?

For instance, our generator has a maximum current of about 150 amps per phase. You can get more wattage by running it a higher voltage, but no matter what the voltage is, we are limited to 150 amps per phase. Bottleneck. That limit is based on the gauge of the wiring and components inside, how much heat they can take before failing and staring a fire or something.

What amperage do you think the 3600VZ can do? I see in parallel-mono it can dive into the 1 ohm range and pump out a minimum 3550 watts. I'd have my answer if I knew what voltage they use to generate the numbers in this table. Does anyone know that? Crown's tech support did not. Somewhere online I think I read that 70v is the industry standard... Is that it? Or maybe 60v? Thoughts?

Once I get the amperage limit, then I believe I can know how hard I can push it. For instance, for simplicity of calculations, if it can do its name in wattage - 3600w - and their numbers are based on 60v, well then they used components that can handle 3600w/60v = 60 amps. But I'm not sure how the electricity flow in parallel-mono is that both channels together, or for each channel? If in mono, is that one channel really beefed up, and the other not so much? I don't know. I do know that from our power grid that 6awg with 90*C THHN jacketing can handle 75 amps. But the jacketing can make all the difference. For instance, if you jump down to 75*C jacketing, ampacity drops to 65 amps. 60*C jacketing drops to 55 amps. What does the wiring look like in the 3600VZ? What gauge is it? And is there jacketing? Probably not, so it can vent and cool off?

I'll run two scenarios for fun.

Scenario 1 - 60v and 60amps per channel. If I run the T60s at 45v, and each channel can handle 60 amps each, then max I could do is 0.75 ohms. That would mean 10 2/3 cabs per channel. So up to 10 cabs per channel in practice, 0.8 ohms, 56.25 amps (5.625 each), 2531.25 watts per channel. Nope, no way. There's probably a bottleneck somewhere before reaching that level.

Scenario 2 - 60v and 30 amps per channel. If I run the T60s at 45v, and each channel can handle 30 amps each, then max I could do is 1.5 ohms. That would mean 5 1/3 cabs per channel. So up to 5 cabs per channel in practice, 1.6 ohms, 28.125 amps (5.625 each), 1265.625 watts per channel. Hmmm... Maybe.

The next limitation I need to consider is the conservation of energy. Even though they were designed for a 30 amp circuit, these 3600VZs will be plugged into 20 amp circuits. At 120v, that is a maximum of 2400w going into the 3600VZ. They cannot output more than 2400w. Actually, a little less due to inefficiencies like heat loss. So 10 cabs and 2531.25 watts per channel is not possible, and neither is 5 cabs and 1265.625 watts per channel - the 20 amp circuit will trip!

This is where I get mixed up, though. I know that there isn't a constant load on the output side of the amplifier, at least not in the same sense that a motor or heating element load that is engineered for 60Hz on a generator. Music is a variable load. Maybe not as much for a lot of EDM with relatively consistent tempos and beats, but still way more variance than something like a box fan or oven. Plus, there are transients to consider, that could demand big draws from capacitors inside the amp.

That makes me reconsider to a maybe on the 5 cabs per channel... I guess that just depends on the music?

Anyway, back to bottlenecks. I bring this up because my next step is going to try and backdoor into the limit by using the 2400w power into the amp. If my nominal max is 2400w from the 20 amp circuit, and the ampacity is high enough inside the amp, then I could get away with 45v, 8/9 ohms mono, 50.625 amps, and 2278.125w. That's 9 total cabs.

Again, this is an exploration of what might be possible if we get in a pinch out there in the desert. I have no idea if we'd ever actually do that try to put 9 cabs in whatever configuration on one 3600VZ.

Now that I think about it, it seems like, since we are ultimately limited by the 20amp breaker on the power conditioner, a Macro-Tech 2400 would be the perfectly sized amp for this setup. Put 8 cabs on it, do that times 4, and that's a wrap! If you guys think that would be enough headroom, that is. Which I certainly hope so, otherwise I guess we need to split the system up into 8 amps x 4 cabs. Or some combination in between.

However, since the deal we found is for 3600s instead of 2400s, that seems like the way we'll need to go.

Also, my guess is HifiBob had full 30 amp circuits to plug his 3600VZs into, not 20 amp circuits, so he had a whole extra 1200-ish watts of headroom there. We'd only have 400 ish watts. That might be a little close for comfort?






4. What is the relationship between the power/thermal draw spec sheet on the input side of the amplifier, and the power tables for the output side of the amplifier?

For instance, on the Minimum Power table, the fully utilized minimum power of 1800w at 2 ohm stereo load at 1kHz per channel, does that match up with a 40% duty cycle on the power draw table?

Also...

I'm confused on the relationship between pink noise and duty cycles. The concept of a duty cycle is simple - 50% means half on, half off. Pink noise is a lower-frequency-weighted collection of signals across the whole spectrum. Like a waterfall. But I haven't yet been able to connect the dots. My guess is that pink noise can be so demanding that it makes amplifier amplify signals half the time, or more, on average. But even as I type that, I don't really know what I'm saying.

Does a 50% duty cycle mean 1/3 pink noise (heavy clipping)?

Does a 100% duty cycle mean full pink noise (100% clipping)?

Is there such thing as 1/2 pink noise?

Where does 1/8 pink noise (no clipping) fit in? 40% duty cycle?

I've tried the Wikipedia page of pink noise, and it's a bit dense. Also, I'm a bit dense. So maybe I just need to walk away from this one. The idea with this question was to get a good handle on this relationship, so I can balance the power grid properly. I can do that without knowing the answers, so I guess I'm just curious is all.

[Seth]

Personally, I don't think I'll ever own a class AB amp again, unless someone gave me one, or I found one in a dumpster.

You seem to have already sussed out the main drawbacks of Class AB amplifiers, power draw, weight, and heat. I might add in there resale value.

If you want to use AB amps, I'd recommend not loading them down too much. One or two cabs per channel. The one's I've used get stupid hot when loaded down with a low impedance load.

I'm not really sure what that "duty cycle" deal is all about. Maybe percent of maximum potential? Dunno. But, I do understand BTU and loaded down to 2Ω (honestly 4&8Ω aren't too different) at whatever they're calling 50% duty cycle, the heat dissipated is equivalent to running a 700 watt heater. A lot of wasted energy and a lot of heat when you consider you're talking about 4 of them, I'd be surprised if the additional heat didn't outrun the A/C's capability in the RV.

It's not impossible. But I'd much rather see you spend the same money on new class D amps.

1. What amp class is best for these T60s? A, AB, D, H? Does it even matter? Could you hear the difference?

2. How many T60-1xLAB12 cabs could you run per 3600VZ amp in parallel? Seems like our inputs are 45v, 5.625a, 8ohms, and 253.125w. Does that mean 4 cabs per channel would be just fine and dandy? Think there's enough headroom there for transients?

The amp is rated 1800 watts into a 2Ω load. Every doubling of speakers on the amplifier channel halves the impedance load. One cab 8Ω, two cabs 4Ω, four cabs 2Ω. Four cabs per channel will work if you can supply the amp with enough power and airflow to keep it from overheating.

3. How hard do you think you can push the 3600VZ? If you were in a pinch?

In a pinch, you could wire all 32 cabs series parallel and run them on one channel of one amplifier. It would limit output potential of the system though.

Without limiting the system performance, four cabs per channel. Assuming you have the appropriate mains power circuit and ability to keep the amp cool.

What the maximum amperage that can continuously flow through each channel?

This is something that's seldom talked about and isn't really that important. The amperage through each channel isn't the same as amperage consumed by the amplifier.

For instance, our generator has a maximum current of about 150 amps per phase. You can get more wattage by running it a higher voltage, but no matter what the voltage is, we are limited to 150 amps per phase. Bottleneck.

150amps should be considerably more than enough for the system itself.

What amperage do you think the 3600VZ can do? I see in parallel-mono it can dive into the 1 ohm range and pump out a minimum 3550 watts. I'd have my answer if I knew what voltage they use to generate the numbers in this table. Does anyone know that? Crown's tech support did not. Somewhere online I think I read that 70v is the industry standard... Is that it? Or maybe 60v? Thoughts?

The square root of (watts x ohms) = volts
3550 watts at one ohm is 59.58 volts
1800 watts at 2Ω is... 60 volts

70 volt audio systems are a completely different animal than what we use for car audio, home audio, and PA. It's what is typically used in large commercial buildings with long wire runs and many speakers (cleanup on isle 4 Bob).

If in mono, is that one channel really beefed up, and the other not so much?

Parallel mono is kind of a rare feature, it combines the amperage capabilities of each channel into one without increasing the voltage.

What's way more typical to see is Bridged Mono, which combines the voltage of the two channels resulting in twice the voltage swing.

What does the wiring look like in the 3600VZ? What gauge is it? And is there jacketing? Probably not, so it can vent and cool off?

All power wires that someone may come into contact with, or that otherwise need to be electrically insulated are jacketed. I don't know for sure, but if it's designed to use a 30A circuit, it's probably 10 Gauge.

I'll run two scenarios for fun.

Scenario 1 - 60v and 60amps per channel. If I run the T60s at 45v, and each channel can handle 60 amps each, then max I could do is 0.75 ohms. That would mean 10 2/3 cabs per channel. So up to 10 cabs per channel in practice, 0.8 ohms, 56.25 amps (5.625 each), 2531.25 watts per channel. Nope, no way. There's probably a bottleneck somewhere before reaching that level.

Scenario 2 - 60v and 30 amps per channel. If I run the T60s at 45v, and each channel can handle 30 amps each, then max I could do is 1.5 ohms. That would mean 5 1/3 cabs per channel. So up to 5 cabs per channel in practice, 1.6 ohms, 28.125 amps (5.625 each), 1265.625 watts per channel. Hmmm... Maybe.

Here's how you want to do this:
- Identify nominal power output per channel in watts
- Multiply that figure by the amplifiers efficiency percentage and add the two together. The specific amp efficiency will differ from brand to brand, but just for the sake of conversation it's fairly close to use 65% for class AB and 85% for Class D.
- Now that you know how much power the amp will consume, you can divide the figure by wall voltage to get your maximum nominal amperage.

Typically amplifiers are rated based on 1/4 to 1/8th of their maximum nominal. You should see it on the sticker on most any newer amplifier.

Here's a quote from another thread a few years back that illustrates it better:

I measured my rig with a kill-a-watt meter (4 dr250's and 2 dual tuba 60's) and it measured 800 watts at full volume using class D amplifiers (with DJ equipment)...

The next limitation I need to consider is the conservation of energy. Even though they were designed for a 30 amp circuit, these 3600VZs will be plugged into 20 amp circuits. At 120v, that is a maximum of 2400w going into the 3600VZ. They cannot output more than 2400w. Actually, a little less due to inefficiencies like heat loss. So 10 cabs and 2531.25 watts per channel is not possible, and neither is 5 cabs and 1265.625 watts per channel - the 20 amp circuit will trip!

Unless special fast trip breakers are used, most any circuit breaker will allow short periods of over amperage without tripping the breaker. I've heard rumors or that number being upwards of 80 amp blips through 15amp circuit breakers.

This is where I get mixed up, though. I know that there isn't a constant load on the output side of the amplifier, at least not in the same sense that a motor or heating element load that is engineered for 60Hz on a generator. Music is a variable load. Maybe not as much for a lot of EDM with relatively consistent tempos and beats, but still way more variance than something like a box fan or oven. Plus, there are transients to consider, that could demand big draws from capacitors inside the amp.

Amplifiers have a fair amount of energy stored in capacitors. That energy can be released quickly on transients, but it wont usually transfer over to a sharp transient draw of amperage on the power cord end of it, the capacitors in the amplifier create a little buffer between the amplifier input and output. So, it isn't exactly a 1:1.

That makes me reconsider to a maybe on the 5 cabs per channel... I guess that just depends on the music?

I wouldn't, four per channel is already a less than ideal solution.

Another minor reason to limit cabs per channel is if you end up wanting/needing to use a bunch of delays in the sub array setup. Not thinking it's super critical, but it is consideration worthy.

4. What is the relationship between the power/thermal draw spec sheet on the input side of the amplifier, and the power tables for the output side of the amplifier?

For instance, on the Minimum Power table, the fully utilized minimum power of 1800w at 2 ohm stereo load at 1kHz per channel, does that match up with a 40% duty cycle on the power draw table?

Also...

I'm confused on the relationship between pink noise and duty cycles. The concept of a duty cycle is simple - 50% means half on, half off. Pink noise is a lower-frequency-weighted collection of signals across the whole spectrum. Like a waterfall. But I haven't yet been able to connect the dots. My guess is that pink noise can be so demanding that it makes amplifier amplify signals half the time, or more, on average. But even as I type that, I don't really know what I'm saying.

Does a 50% duty cycle mean 1/3 pink noise (heavy clipping)?

Does a 100% duty cycle mean full pink noise (100% clipping)?

Is there such thing as 1/2 pink noise?

Where does 1/8 pink noise (no clipping) fit in? 40% duty cycle?

I've tried the Wikipedia page of pink noise, and it's a bit dense. Also, I'm a bit dense. So maybe I just need to walk away from this one. The idea with this question was to get a good handle on this relationship, so I can balance the power grid properly. I can do that without knowing the answers, so I guess I'm just curious is all.

I have no idea what any of that means, other than what I've written already.