Are 24 x T60-LAB15s Enough? ;)

[Seth]

There's currently about 9 Crown XTi 4000's on ebay in the $600ish range.

Benefits to something like that:
- Class D
- Integrated DSP (with delay)
- 18.5 pounds

Although, if you're going to limit to 45V, the XTi 4000 may be a little over kill. You can probably get the job done with the Crown XTi 2000, of which there are currently 5 listings in the $400 range.

[Levi]

Interesting! Out with the old, in with the new!

I have no dog in the fight (yet), I'm just curious.

So, assuming they are high end amplifiers, do you think there is a sound quality difference between class AB and class D? Speaking only for subs.

In this case, our priorities are sound quality, budget, and the surviving long term in an extreme environment.

Again, the 3600VZs seem to be very durable, very affordable, and high quality for subs. But then there's the weight, which isn't a big deal. The power draw and heat matter more, but those are not a deal breaker. Resale value is a good point. It would be nice, but definitely more of an afterthought for our purposes.

Having more efficient class D amps would be awesome, but it seems like they are quite a bit more expensive for the more durable ones, and maybe don't offer as high of sound quality on subs. I don't know. Just an impression I've got from older threads on this forum, and others. Like these:

https://gearspace.com/board/live-sound/ ... macro.html
https://forums.prosoundweb.com/index.php?topic=148950.0

I'll check out the Crown XTi line. Thanks for the suggestion!

Do you happen to have any other class D amps in mind? I know those Admarks look slick, and the price is right, but I can't shake the review I read of one of them giving off smoke at 4 ohms:

https://forum.speakerplans.com/k30-ampl ... page1.html







The more I think about it, though, with the bigger system than we've had in the past, heat coming off the amps might be a bigger issue than I thought.

With our old system, before we had AC cooling the amps at all, there would be constant overheating and tripping circuits, and constant music shutdowns.

Then we started using AC, and things got much better.

First we tried using a single 5000btu window AC. It worked great, but it could not keep up in the hottest parts of the day.

Then we added a 12000btu portable AC with dual hoses to the 5000btu unit. No problems after that.

This year we will make an amp closet of sorts with I'm thinking 4 x 6000btu window ACs. They are more efficient and less of a pain in the butt than the portable ones, and are easier to store and transport.







Once again, Dave Rat to the rescue!

Lesson learned. Peak/burst power can make all the difference!

Here are a few things I noted from the video:

- The modern amp had better peak power, resulting in louder music, while also begin more efficient
- It also had better continuous power, but it seems like the peaks are what really made the difference
- Both amps distorted outside the frequency range that would apply to the T60s
- The fans on the modern amp are quite loud

I'm not sure if you saw it, but Dave pinned an interesting thread in the comments. My head is still spinning, but my takeaways from that are:

- Old amps might be better for subs. Maybe.

"When Crown came out with their later amplifiers and started to talk "burst power" instead of continuous RMS, I talked to their engineers and was told that in some circumstances where low bass was needed, the old systems were actually better. For example on the Katy Perry song, Dark Horse, there is a very long tone, around 60 Hz. that would send any burst type amplifier into low power mode."

"In the amps I tested, the crest put out 400 continuous and the PowerSoft put out 540 watts continuous so even though smaller and lighter, the powersoft still has more output than the crest in continuous measurements as well, so that is another aspect to consider."

- An amp with low continuous power but high peak power can get the job done. "A 1500w amp driving a 1500w speaker is transferring somewhere in the realm of 100 to 200 watts at the most. So all that is really needed is a 200 watt amp with a very high peak power"





Thanks for running through the weeds with me! Very helpful!

Oh, and 800 watts for CoronaOperator's system is just fantastic!





Regarding the duty cycle/pink noise stuff, I don't know what any of it means, either.

It seems like much of the power draw part rabbit hole I've gone down relates to the old school way of using duty cycle, and the new school way of using pink noise.

For example...

Old school - Macrotech 3600vz
New school - Itech 5000hd

From what I can tell, running the amps hard in old school terms means 40% duty cycle. I'm guessing that means on average the amp is working 40% of the time, 60% off. I'm guessing that means no clipping.

In the new school, running the amps hard means 1/8 pink noise. The Itech5000 power draw chart defines that as turned up all the way "just at clip".

My guess is old school = new school at the following level:

50% duty cycle (pink noise) = 1/3 pink noise

and maybe also

40% duty cycle (compressed rock) = 1/8 pink noise

For now, though, I am over the spec sheet game. Gotta get some other things done!





Before I do, though...





What four of five different deployments are you thinking about?

I ask now, because we now have other projects running simultaneously.

The hope is we can be clever and make sure all the different puzzle pieces fit well with one another when the time comes.

We can actually test and discuss the deployments later on, but it would be helpful to know ahead of time what they might be, so we can do the best we can to make the all the other things adapt, such as shade, the DJ booth, the bar, etc.

Also, on a very practical note, we have to create a few maps that lay out different parts of our camp by the middle of June I think. This matters because we have a finite amount of land, and every year there never seems to be enough! Adding to one section means subtracting from another. So if the speaker layout requires extra space, we would need to know before locking in everything else. I'm not sure what you're thinking, but if it involves a major change from the one straight row of subs, then it's something we need to plan for. Like how much further over we need to drop our shipping containers, which in turn determines where our access lanes will be, and where the showers and generator go, and where Chris and Sally can set up their personal camp, and so on.

Oh, and this includes where to put the DR280s as well!

[Seth]

I know those Admarks look slick, and the price is right, but I can't shake the review I read of one of them giving off smoke at 4 ohms:

https://forum.speakerplans.com/k30-ampl ... page1.html

It wasn't the amplifier that was smoking. The 4Ω resistor he was using as a test load (in leu of speakers) was smoking.

"Note: Test was halted due to the 4-ohm resistor. The 4-ohm resistor began delivering a heavy dose of smoke. The objective of this test was to determine how long the amplifier would maintain it's output voltage under a 4 ohm load before ramping into protection or reducing it's output (Whichever came first). Since the resistor began to give off heavy smoke, the risk of an electrical fire was too high. The test was halted and further measurements were put off to a later date. The amplifier's thermal rating (55 Celsius) once the test was halted, is still within it's normal thermal status. The K30's overheating warning begins at 69.1 Celsius."


Later in the thread, the OP/tester wrote:
"I will say this. In the United States, the users are not complaining about the K30 failing."

and

"Matching the output voltage of the QSC and K30, the QSC offers a more richer tone in the low mid section whereas, the K30 supersedes the QSC on dynamic Attack. With both amplifier's output voltage matched using a 55 Hz sine wave and, were evaluated -20 dB from clipping, the K30 shines over the QSC from a percussion perspective. However, from a male vocal standpoint, the QSC sounds more prominent than the K30."

and

"Approaching the one year mark and, the K30 is working without any issues. I am planning to buy a few more to cover the complete low midrange section and shift the QSCs up to midrange. In certain parts of the States and, the Caribbean, these amplifiers are becoming very popular due to its price -vs- performance ratio on the underground scene."

There's a lot more good info in that thread, most notably his recommendation to power it with 240V.

[Seth]

Levi, I'm headed out of town for the weekend, visiting the Mom's. If I don't find the time to better reply to your last post more thoroughly this weekend, you can expect a reply early next week.

[Seth]

So, assuming they are high end amplifiers, do you think there is a sound quality difference between class AB and class D? Speaking only for subs.

In this case, our priorities are sound quality, budget, and the surviving long term in an extreme environment.

Again, the 3600VZs seem to be very durable, very affordable, and high quality for subs. But then there's the weight, which isn't a big deal. The power draw and heat matter more, but those are not a deal breaker. Resale value is a good point. It would be nice, but definitely more of an afterthought for our purposes.

Having more efficient class D amps would be awesome, but it seems like they are quite a bit more expensive for the more durable ones, and maybe don't offer as high of sound quality on subs. I don't know. Just an impression I've got from older threads on this forum, and others. Like these:

https://gearspace.com/board/live-sound/ ... macro.html
https://forums.prosoundweb.com/index.php?topic=148950.0

I'll check out the Crown XTi line. Thanks for the suggestion!

If it were an install, I'd have no problem running the 3600VZ's. And contrary to what I said about resale value, those seem to be holding their value very well. Don't get me wrong, they're bad ass amps. I just don't think they're the right amp for this particular job. If you could get 8 of them, maybe.

Sound quality... To be really really honest, some of the older guys that have had a lot more time on class AB amps may be able to give you a more experience based opinion. My opinion though, is that I want an amplifier to amplify the signal without adding anything to it. There's a lot of vintage gear that is desirable for what the hardware adds to the sound and what it usually adds is distortion. I guess any variance in the signal would technically be distortion. Anyway, those qualities usually occur near the maximum limits of the preamp or final stages of amplification, sometimes called a soft clip. That's what people like about old tube amplifiers.

My opinion of class D amps is they are clean sounding. When people start characterizing what one amp sounds like compared to another, I associate it to people who like wine a lot. "It's got a hint of this, a note of that, the nose is unbelievably floral, the finish... I'm not that picky about wine, but I am picky about sound and I think most people describing what they hear from one amp to another are being supremely picky and more than likely imaginative in what they say they're hearing. Even the budget Class D amps I've owned in the past sounded great. My guess is there's not one person on this forum (or any forum) that could walk into a venue that's been professionally tuned, run well below maximum output, and tell you whether the amplifiers are class AB or Class D.

Hearing is a funny thing. We hear what we want to hear or what we think we should be hearing. I've got a few stories, Bruce has some, and I'm sure many of the other guys do as well, about dialing in just the right amount of reverb or an instrument level and "really" hearing it... but later realizing it was muted or on a completely different mix. Point is, if I played a class ab amp for you, then played a Class D amp, you'd hear what you think you should hear even if they were technically indistinguishable.

I have no issue with Class D amps. I'm curious to hear what some of the other guys have to say in the matter.

Do you happen to have any other class D amps in mind?

Anything with at least 500WPC at 8Ω from any of the well known manufacturers Crown, Crest, QSC, Ashly, Lab Gruppen, Powersoft, etc.

My hat's still in the ring for the Admark 410, but I have no issue with whatever direction you choose. I like that you're aiming at high end amps. If you're getting 2 channel amps, I'd highly recommend you get 8 of them. That link I posted for the Admark 410, I took a look at it the other day and they've sold out of every other model and just have the 410's in stock.

This year we will make an amp closet of sorts with I'm thinking 4 x 6000btu window ACs. They are more efficient and less of a pain in the butt than the portable ones, and are easier to store and transport.

I'm picturing a little box barely larger than the amp rack made of double layered 2" XPS foam insulation, 4" thick on all six sides, with window AC units hanging front and back. I'd imagine 10-15kBTU would be sufficient, depending on amplifier choice.

...I'm not sure if you saw it, but Dave pinned an interesting thread in the comments. My head is still spinning, but my takeaways from that are:

- Old amps might be better for subs. Maybe.
"When Crown came out with their later amplifiers and started to talk "burst power" instead of continuous RMS, I talked to their engineers and was told that in some circumstances where low bass was needed, the old systems were actually better. For example on the Katy Perry song, Dark Horse, there is a very long tone, around 60 Hz. that would send any burst type amplifier into low power mode."

"In the amps I tested, the crest put out 400 continuous and the PowerSoft put out 540 watts continuous so even though smaller and lighter, the powersoft still has more output than the crest in continuous measurements as well, so that is another aspect to consider."

- An amp with low continuous power but high peak power can get the job done. "A 1500w amp driving a 1500w speaker is transferring somewhere in the realm of 100 to 200 watts at the most. So all that is really needed is a 200 watt amp with a very high peak power"

I'm not sure there would be such a large difference when the plan is to be no higher than half power potential. Neither case would be tapping into what the amps capabilities are at their limit.

Thanks for running through the weeds with me! Very helpful!

I'm happy to help, Levi

What four of five different deployments are you thinking about?

I ask now, because we now have other projects running simultaneously.

The hope is we can be clever and make sure all the different puzzle pieces fit well with one another when the time comes.

We can actually test and discuss the deployments later on, but it would be helpful to know ahead of time what they might be, so we can do the best we can to make the all the other things adapt, such as shade, the DJ booth, the bar, etc.

It sounds like you're leaning toward lining them all up for a 20" high, 5x80 foot long dance platform. If the vision of that and creating the space and ambience is paramount to the best configuration for sound, I won't criticize. I get it. I would definitely have them on their sides if you want people to dance on them, instead of 32" high. The sides will have more internal support compared to the top or bottom of the cab.

What I'd love for you to try is the above configuration with and without some delays, then flip every other cab end for end and delay for cardioid cancellation to the rear, then that configuration with added delays for steering the sound/beamforming.

Then go double deep, creating a 10 foot deep by 40 foot wide platform. Front row of subs mouth forward, rear row mouth back, delayed for cardioid cancellation to the rear.

Then 8 stacks of 4 cabs on their sides, creating a 6.6 x 20 foot wide straight wall, with and without delays. Then curve that wall, with and without delays.

And then, two stacks spread as wide as you could go.

Then choose the configuration that best fills the desired space.

Oh, and this includes where to put the DR280s as well!

Intuition only, need to research more, but centered in the space about 30 feet apart seems reasonable for 100 x 100 coverage. Perhaps Bill has some input on this. I seem to remember reading the DR280 has 90º horizontal coverage, but can't find that info now. If so, you'll want those as far away from the closest dancing location as possible to cover as much of the space up front as evenly as possible. Another really good reason to get those bottom cabs up high and firing downward, good coverage up front.

[Levi]

Hope you had a great time with your mom!




Funny you mention that, we can get 8 of the 3600VZs! And the idea was to run 4 subs per amp. Before when I was floating the idea of max cabs per amp, that was more just exploring what we might do if something goes wrong.




Good wine analogy! Mmmm... [he smacks his lips] just the right amount of distortion... What a fine vintage! Now, where's the cheese whiz? Lol




I called Crown technical support (again) to get their take on this as well. As he saw it, it is possible to make the new class D amps sound like class AB. However, depending on a guy's familiarity with DSP, it can take a LOT more work tinkering with the DSP settings within the amp. In that regard, the old class AB can be considered plug and play.

Our conversation went further as well. He was very curious about the system overall. Particularly, our DSP. After learning that we were trying to accomplish everything with a dbx Driverack PA2, as well a a Midas32, he was both shocked and impressed. His hypothesis is that we were able to optimize sound quality by running everything a higher volumes, to mask any combing that was occurring. He also had some cool stories about Dave Rat using the BSS stuff to perform some wizardry, and that Dave has recently switched back to analog.

Anyway, his overall take was that we could have a great rig with the 3600VZs if we ran 4 per amp. But also, we should look into the VENU360s (that you mentioned a few pages back). But then he paused, and remembered that back in the day, most of the guys using the Macrotech amps paired them with the dbx Driverack 4800s. 4 channels in, 8 channels out. If we put each 3600VZ on its own channel, we'd have a really great setup. Even better, since we are going to tune the system by walking around with a tablet, he said we should probably just look at the 4820 instead of the 4800. Same specs, it's just that the 4800 is more expensive because you can adjust the settings with the screen on the front of the unit. Since we wouldn't really need that, just go for the 4820.

So... we found a killer deal on a couple used ones that are in excellent condition, and voila! Add 2 x dbx Driverack 4820s to our assets!

If we explore our deployment options now, we should really be able fine-tune this system! We can use one 4820 just for the subs. The other we can use to power shade the DR280s. And we can use the old PA2 just for the sound in our booth, which will likely be doubled in size (now about 40-50' long by 20' wide) to allow for a house party vibe inside of it during smaller parties. (And if that's the case, maybe we should forget cardiod operation? We'd want sound on the stage in that case.) And depending on the placement of our DR280 line arrays, maybe we should have a couple of channels for our old Omnitops, using them for center fills? ...This thing just keeps getting more and more complex! Ha!




That said...




We are still at a crossroads with amps.

8 x 3600VZs are a default option, and a good one at that. We'll have to put adapters on them to take them from 30amp plugs to 20 amp receptacles on the power conditioner, but if we are only running them in with 2 subs per channel, the 3600VZs will still deliver full output.

However, class D amps are still appealing. If it ain't broke, make it better, yes? More efficient/less heat, lighter weight, those are great benefits. But here is something that occurred to me overnight. If we use the 410s, with 4 channels each, and we get 8 of them, we can have complete control over the low end. 32 channels, 32 subs, each with its own channel and DSP... On paper that sounds really impressive! I think.

And so here we are, yet again! Another fork in the road. With optimal sound quality as our north star, up to this point, we have made every decision to stay on course. Max width cabs, premium drivers, etc.

So I ask, would having the granularity to control each sub on its own channel be worth doing? Maybe it could have a noticeable impact on sound quality? Compared to controlling them in groups of 4? Yes, no, maybe so?

My guess is no? No one's ears are that good? But like with all the other forks in the road, I'm hoping that if we take the harder, more time/money/work path, by the time we finally get to the destination, the compounding of all these little marginal improvements will be very noticeable and very awesome! A new gold standard perhaps!

That said, when it actually comes to tuning the system, walking around with a tablet and tweaking the settings on the 4820s, it seems like it could be real chore to adjust the DSP on the amps as well. Back and forth, and back and forth, without a real time A/B comparison. Well no, I guess we could use walkie talkies, and have the tablet guy out front chirping at the amp guy in back to press buttons. Up, up! No, down, down, down! Up! Down! Goddamnit, I said up! Up! Up! Down!!! Over. Or, is there an app for those 410s to adjust them remotely? I didn't see one, but I didn't look that hard either. Nothing in the "manual", anyway.

Thoughts?




For the amp closet, I'm not sure yet. The two main ideas are wither a small box like you said, or a larger one that we can walk around in.

Small box is a great idea! Minimal footprint and materials. Maybe it would work best with QSC style amps that have back to front airflow. That way, the AC could be mounted in the back of the box, and it would be easy to just open the cabinet and adjust settings if needed. Maybe the airflow direction doesn't matter, though. As long as the hot air is cooled back down by the time it got back around to the intake on the front of the amp, it would be fine. Maybe?

Big closet would be great, too. Be able to escape the elements a bit while tinkering, and have more workspace.

I gotta think on that a little more.





We are not set in any configuration yet! The big long dance platform idea just keeps coming up is all. But now is the time to play with ideas, before we start cutting wood for the booth.

Good point about putting them on their sides instead of upright! That makes a lot of sense with the extra bracing. (And 20" is a way friendlier height for getting up/down than 31.5".) However, with the 20" wide version, the plans call for 2 sets of braces instead of just 1 set like with the 15" wide. We are planning on doing 2 sets in each cab. Do you think that would make upright vs. side a wash, then? Even Stevens?

80' length on their sides... That might be way better for extending the width of our coverage area, yes? The 1.5" gap between the cabs, due to the rubber feet and casters, might be more of a trip hazard than it's worth, though. Do you think so? Not necessarily a deal breaker, but something to think about.

Cardioid operation... Instead of flipping cabs, could we accomplish the same thing by reversing polarity?

Man, those are all cool ideas for deployment! I wish we could try them out right meow! It's kind of a bummer, because I don't think the timelines will match for these projects running simultaneously. At the very latest we need to cut wood on the booth by mid June. However, we'll see how many subs we can build and what amps we can get before then! The race is on!

Also, at some point I get a couple of Sketchup pics of what we are playing with for the whole space, see what might be the best fit from that perspective.





DR280 placement...

Yes, you are correct. 90 degrees horizontal dispersion. https://billfitzmaurice.info/forum/view ... hp?t=17529

If the DR280s are further apart than 30-40', would you entertain the idea of Omnitop 2x12s for center fills? Our old ones are piezos, with 2 x 3012HO drivers. We have 4 of them that work for sure. The other two might need some TLC.

[Levi]

Oh, and I almost forgot!

Wood porn!

Driver porn!

Enjoy!

[Seth]

Seems to be a few more drivers in that pile than I expected. Sup wit dat?

Hope you had a great time with your mom!

Thanks Levi. I had a very enjoyable time with both of them.

Funny you mention that, we can get 8 of the 3600VZs! And the idea was to run 4 subs per amp. Before when I was floating the idea of max cabs per amp, that was more just exploring what we might do if something goes wrong.

I think I grossly underestimated your budget for this project. LOL
If you take this route, you can use the BTU data you posted earlier to pencil out the needed A/C capacity to move enough heat out of whatever enclosure you choose to build for the amp rack. The smaller the enclosure, the less outer surface area to soak heat from the environment and easier to seal up to keep the playa dust out. If there's a few inches clearance around the rack, a small fan would be ample in circulating the air around inside so it wouldn't matter if you wanted to put the A/C's on the back and the amps cooled front to back. I'd paint the enclosure white and keep it as small as possible while allowing enough space for the air to freely circulate inside.

Good wine analogy! Mmmm... [he smacks his lips] just the right amount of distortion... What a fine vintage! Now, where's the cheese whiz? Lol

Cracking me up, Levi. I can see it landed well.

I called Crown technical support (again) to get their take on this as well... ...back in the day, most of the guys using the Macrotech amps paired them with the dbx Driverack 4800s. 4 channels in, 8 channels out... ...we found a killer deal on a couple used ones that are in excellent condition, and voila! Add 2 x dbx Driverack 4820s to our assets!

FUCK ME!!! You guys move quick! Good thing, with the deadline sneaking up! A quick scan of the manual looks like it has everything you need, except it limits you to 8 channels of delay instead of 16. Not sure whether that's a big deal or not. Probably not a deal breaker.

...If we use the 410s, with 4 channels each, and we get 8 of them, we can have complete control over the low end. 32 channels, 32 subs, each with its own channel and DSP... On paper that sounds really impressive! I think.

You'd need four of the DSP processors just for the subs to get that level granular control. Although since the same delays would be used on each side of center, you could get the control you desire with two of them on sub duty.

From an amplifier point of view, they would also not need power conditioners and you could (should) power them with 240V. It would certainly give you a ton of backup options if there were any issues.

So I ask, would having the granularity to control each sub on its own channel be worth doing? Maybe it could have a noticeable impact on sound quality? Compared to controlling them in groups of 4? Yes, no, maybe so?

My guess is no? No one's ears are that good? But like with all the other forks in the road, I'm hoping that if we take the harder, more time/money/work path, by the time we finally get to the destination, the compounding of all these little marginal improvements will be very noticeable and very awesome! A new gold standard perhaps!

If I had the option financially, I would. Just another level of bulletproofing (and cool factor). Although, 2 cabs per amp channel should be sufficient with either amp choice. It would be control of groups of two (not four). Oh, wait... yeah, four with the new DSP processors.

That said, when it actually comes to tuning the system, walking around with a tablet and tweaking the settings on the 4820s, it seems like it could be real chore to adjust the DSP on the amps as well. Back and forth, and back and forth, without a real time A/B comparison. Well no, I guess we could use walkie talkies, and have the tablet guy out front chirping at the amp guy in back to press buttons. Up, up! No, down, down, down! Up! Down! Goddamnit, I said up! Up! Up! Down!!! Over. Or, is there an app for those 410s to adjust them remotely? I didn't see one, but I didn't look that hard either. Nothing in the "manual", anyway.

Thoughts?

When tuning the system, you'll put a few microphone stands out in the listening space at specific locations. Run a sweep, move the mic to the next stand, run a sweep, move the mic to the next stand, run a sweep, review the data, make your changes, and start over again. You won't really be walking around making changes by ear so much, other than final touches after it's mostly done by data.

It looks like there may only be PC control software for the 4820's.

Good point about putting them on their sides instead of upright! That makes a lot of sense with the extra bracing. (And 20" is a way friendlier height for getting up/down than 31.5".) However, with the 20" wide version, the plans call for 2 sets of braces instead of just 1 set like with the 15" wide. We are planning on doing 2 sets in each cab. Do you think that would make upright vs. side a wash, then? Even Stevens?

On their sides (20" high), the perimeter is supported on the panels, where standing upright the perimeter of the panels people would be dancing on would rely on the sheer strength of the glue (and any screws you decide to use).

80' length on their sides... That might be way better for extending the width of our coverage area, yes? The 1.5" gap between the cabs, due to the rubber feet and casters, might be more of a trip hazard than it's worth, though. Do you think so? Not necessarily a deal breaker, but something to think about.

If you planned to use them on the sides, I'd put the feet on the sides and the small end, for when they're stood upright for storage and transport. You could easily create cutouts to allow the castors to recess into neighbor cabs, allowing them to sit together flush. In the mouth, you can also screw one cab to it's neighbor to keep them together. You can do that for stacked cabs too. Just make sure the screws go into the mouth area or dead space (not the horn path).

Cardioid operation... Instead of flipping cabs, could we accomplish the same thing by reversing polarity?

No. The process works because of the distance between radiating planes. Where sound traveling from the rear firing sub reaches the front firing sub at that is perfectly delayed to sum. Yet, in the opposite direction provides cancellation centered on the frequency in which half a wavelength is the distance between the two radiating planes. If you just reversed polarity of every other sub on the same plane, it would create a cancellation everywhere at all frequencies.

Man, those are all cool ideas for deployment! I wish we could try them out right meow! It's kind of a bummer, because I don't think the timelines will match for these projects running simultaneously. At the very latest we need to cut wood on the booth by mid June. However, we'll see how many subs we can build and what amps we can get before then! The race is on!

I did a little fiddling with one of the simulators and it looks like the wide option will have wider coverage at the cost of peak output potential. The tall wall stack will have greater output potential with more centralized pattern.

One is 15 cabs (2x18" ported) wide. The other is 3 high, five wide. Note that the SPL scale on the top one (wide array) indicates the red area as max 108dB and the bottom pic (tall array) red area maxes at 115dB. A considerable difference, indicating the wide array would require more than 4x the power to reach any particular volume the tall array may be set at. Yet, the hot spot is smaller.
These numbers are purely for identifying trends and patterns and aren't correlated to the output potential of the T60 in any specific way. The square on the right is 100' by 100'.

If the DR280s are further apart than 30-40', would you entertain the idea of Omnitop 2x12s for center fills? Our old ones are piezos, with 2 x 3012HO drivers. We have 4 of them that work for sure. The other two might need some TLC.

I'll have to put a little thought and research into this subject

[Levi]

Good eye! We have a few extra LAB12 and 3012HO drivers as backups! Just in case maybe something happens. Seems like something always happens. No quick run to the store out there!





Budgets are funny. Some categories have gone way over. Luckily, others have been way under! Overall, with the net difference we have been able to throw any surplus right back into sound quality. Plus, in the past week or two, I've come to terms that I will be making cuts in my own personal budget because I want to, no, at this point, I have to, see this thing through! If that means frugal living for the rest of the year, so be it!




These are all great points for the amp house! Thanks!




Good point on the processors! We would need both of them (at least) just for subs if that level of control will make a difference. I didn't think that one through. I guess I was thinking that broad brush strokes could be used with the 4820s, then there could be finer adjustments downstream in the 410 amp settings. Would that be possible? Do the Admark/Ronin amps have all the settings for all the things? Impossible to tell from the limited documentation on their website.

Also, if it makes sense, we could start watching for another used processor deal. If we use both 4820s for the subs, then how many channels would be best for the tops? 6 at least for each of the 6 DR280s. Maybe more if the Omnitop center fills become a thing. Right?





240v? ...Oh no, another potential fork in the road! Lol.

Alas, 240v will likely not be available to us from our main generator. This is because we run it in three phase "low wye", which is 120v per phase (208v line-to-line with the phases offset by 120 degrees). We can switch the alternator settings to run dual/split phase at 120v per phase (240v line-to-line with phases offset by 180 degrees). If we do that, though, we lose access to 1/3 of the generator's potential output. We need that extra output for the rest of our camp. And since none of our other end loads require 240v, the three phase low wye makes the most sense from a camp-wide perspective. It's crazy to think about, but even with this new system that will have double the subs of our previous system at its peak, all of sound will still only account for about 15-20% of our total power usage. Relative to air conditioning, sound is super duper efficient!

Maybe we can upgrade the generator to a bigger size and run split phase? We have a 70kva reserved. I think that is about 7,000 pounds to tow. We are already in the pintle hitch category with the 70kva. Heavy. The truck that is towing it will have another 6,000 pounds on its flatbed. It might be maxed out. Especially since because the next step up in generator size is 125kva, which I think is about 10,000 pounds. Not completely sure. I'll check though.

That said, though, do you think the 410s could run off of three phase? My guess is probably not. But that would be a way to get to 208v. Which would be way better than 120v, but not as good as 240v of course.





Thanks for the tuning tip! We will have to get a mic stand. All this stuff, and no mic stand... Or maybe we do, and that blasted squirrel got a hold of it. I'll check.





On their sides... Man, this sounds very promising!

For storage and transport, working with 3x30" instead of 4x20" is a much better use of limited trailer and shipping container space. Much better.

We are planning to use 18 pocket screws per side panel (9 on top, 9 on bottom) to help sturdy them up! And good idea - we are also planning on using feet on both sides of the casters so they will behave when upright or laid flat.

Plus, I could make half of them with the feet/casters on one side, and half the other, so they could be symmetrical. That might look cool!

My only hesitation with creating cutouts is aesthetics. They would be flush, but the black feet would stand out like a sore thumb with the lighter colored stain.

Using screws to keep neighbors together sounds promising as well! We'd avoid ratchet straps altogether. But maybe it would be better to use bolts with hurricane nuts/inserts for longevity. But then we'd need to use locking bolts to avoid them rattling loose. That said, if they if are their sides, 30" is pretty stable. And level enough. And easy. So in the end, it might be best just to lay them flush next to each other without fasteners. Or would that risk rattling?





Very interesting point about cardioid operation! Fascinating! As you can tell, I've never really done it before! That could be a really cool effect!

However, if we are actually craving output on both sides of the subs, we might not end up doing that come burn time. It would definitely be fun to test, though! Especially since we may decide to change the deployment later on. Maybe we'd want to have that cardioid option down the road! Or maybe even this year, who knows? Always good to have options!





Thanks for modeling those scenarios! From the looks of it, we would probably benefit from more even coverage, rather than higher peak output. Especially if we can still somehow get the 50Hz hug going. Probably not, though. 7db is a huge difference! So maybe a narrower double stack is the way to go... Oh, the options!

And now that I think about it, that's probably a big reason why the D&B gold standard system is able to deliver at 50Hz. The B-2s are stacked on their sides for more narrow coverage, yet higher output. Yeah, science!!!

[Seth]

Good point on the processors! We would need both of them (at least) just for subs if that level of control will make a difference. I didn't think that one through. I guess I was thinking that broad brush strokes could be used with the 4820s, then there could be finer adjustments downstream in the 410 amp settings. Would that be possible? Do the Admark/Ronin amps have all the settings for all the things? Impossible to tell from the limited documentation on their website.

The Admark K410 does not have integrated DSP. If needed, you could use the two 4820's on subs and the PA on the DR's.

I suppose the option still exists to route the signals back in/out of the M32 if additional delays were to model significantly better. But, so far I only seem to be able to model 2x18 cabs, essentially the width of two T60's. So, I might not even be able to model any finer than that. We'll see.

That said, though, do you think the 410s could run off of three phase? My guess is probably not. But that would be a way to get to 208v. Which would be way better than 120v, but not as good as 240v of course.

I contacted the rep at the number provided on the Admark website and he indicated they would work on 3 phase.

I've got a follow up on that with the seller I linked to before, VIP Pro Audio, to see if they'll also confirm. I'll see if they're able to physically verify. Do you have any way to test them on 3-phase prior to game time?

Thanks for the tuning tip! We will have to get a mic stand. All this stuff, and no mic stand... Or maybe we do, and that blasted squirrel got a hold of it. I'll check.

Get three or four. Cheapies are fine. That way, the stands can stay put and subsequent data is from the same exact 3-4 locations in the listening space.

My only hesitation with creating cutouts is aesthetics. They would be flush, but the black feet would stand out like a sore thumb with the lighter colored stain.

Sexy black trim dots. Yeah, that's what they are. Instead of cutouts for the wheels, you could assemble the cabs with a bevel on that end, I think.

Using screws to keep neighbors together sounds promising as well! We'd avoid ratchet straps altogether. But maybe it would be better to use bolts with hurricane nuts/inserts for longevity. But then we'd need to use locking bolts to avoid them rattling loose. That said, if they if are their sides, 30" is pretty stable. And level enough. And easy. So in the end, it might be best just to lay them flush next to each other without fasteners. Or would that risk rattling?

Not sure if they'd rattle. I don't think so. I was thinking more about keeping them from moving from exterior forces/people.

Thanks for modeling those scenarios! From the looks of it, we would probably benefit from more even coverage, rather than higher peak output. Especially if we can still somehow get the 50Hz hug going. Probably not, though. 7db is a huge difference! So maybe a narrower double stack is the way to go... Oh, the options!

And now that I think about it, that's probably a big reason why the D&B gold standard system is able to deliver at 50Hz. The B-2s are stacked on their sides for more narrow coverage, yet higher output. Yeah, science!!!

Yeah, no problem. I'm enjoying the ride.

I think the best way to determine the best deployment solution is to do what we can in software, but ultimately you'll need to test to really know what is the best configuration to meet your expectations in person. Then you can put some reality to the numbers. Maybe wear a diaper on that day.

You said the D&B subs were in a semi circle, or curved array, correct? I'll practice a little more with the software and see if I can churn out some better results on more configurations.

[Seth]

If 50Hz is a warm hug, 40Hz is a hand job and anything lower than that is... even better. I'll be very curious to see how much usable extension this system will effectively have outdoors. If it's capable of solid, visceral low 30's, I don't think there would be too many "competitors" out there that could even begin to provide that experience. Would have to have the music library for that sorta stuff though. EDM has the most sub 40Hz content of any genre I'm aware of, but it's still kinda rare to find music content that low unless you're specifically looking for it. If you plan to have various DJ's throughout the week, tell them to bring their low low.

[Levi]

Oh gotcha! I don't why I assumed it had DSP. Probably because it just looks fancy.

Yes, good idea on the Midas. Always great to have access to more gear than we potentially need!



Hey, thanks! I never really considered that they'd have any kind of tech support at all.

Good question. I think I could figure out a way to test on 3 phase. The only tricky thing I could think of is the cord from the genny to the Admark.



Will do on the mic stands! Great idea, thanks!



Funny you mention the software. The Crown tech support guy said that in some of these big budget places, that's all they do! Enormous systems in stadiums and what not, they use software to do the whole thing. No testing at all until the installation is complete. How about that? Amazing! We'd still test the shit out of everything in person, of course. Just thought that was really interesting.

You know, whether modeling with software, or testing in the field, I feel like should wear a diaper everyday. Always be prepared!



The B-2s were in a straight line. Here's the best photo I could find. Pretty much every other shot is at night with all the fire and lasers. And/or with a huge crowd in the way. Man, this thing was really something to behold! A masterpiece!!!

Visceral lows, warm hugs, and hand jobs? And better?! Oh boy, this is very exciting to hear!!! Lolol

And great point, after we confirm with testing, we will definitely spread the word about the low low!

[Levi]

Also, look at us! Over 100 posts now. This thread will be quite the case study down the line!

[Seth]

Also, look at us! Over 100 posts now. This thread will be quite the case study down the line!

Couple of chatty Cathy's. LOL

[Seth]

Hey, thanks! I never really considered that they'd have any kind of tech support at all.

Right? Even responded in less than a minute on WhatsApp. Although, 5:30pm Tuesday evening in California is 8:30am Wednesday morning in China. So, he was probably already on his third cup of coffee.

Good question. I think I could figure out a way to test on 3 phase. The only tricky thing I could think of is the cord from the genny to the Admark.

Prior to this, I've never dealt with any 3 phase stuff. After a little research and getting up to speed, I'm certain it will work. It's just a 208V sinewave. Nothing special about it being 3 phase service in this case. Not like a three phase motor that actually uses the three phases. I wonder if it would be wise to put all the amplifiers on one 208V circuit or better to spread them out a little among the 3 available? Seems like it may be good to spread the load out a little. Would be pretty simple to make a little in rack distro with 3x208V circuits along with one or two 120V circuits. However, I hope the amp rack is close to the genset... four conductor 50A rated power cords are not cheap! Shewwweee!

You know, whether modeling with software, or testing in the field, I feel like should wear a diaper everyday. Always be prepared!

Man, this thing was really something to behold! A masterpiece!!!

Wow! It sure is! Amazing visual appeal.