T30/T48/T60

[Seth]

Interesting, thank you for sharing that.
Where did you got that numbers from? Simulating the cab with the drivers TS-parameters and manually adding the stacking and plating-part?
I would be curious to try this out in different frequency points and with different driver-combinations.
I fear i have to get into hornresp. I tinkered around a bit, are the measurements of the T30/T48 available or do i have to measure them out of the plans?

I pulled the numbers from either the advertised curves in the comparisons page or using the "SPL" tool in the forum. You could probably have some fun with the SPL tool. Here's the link... Introducing SPL chart.

I just used a static value of 3dB to account for the V-plate.

I did try to get into HornResp at one point. I was never satisfied that I was using it correctly, it's a bit of a learning curve. It's tough to measure useful dimensions from the plans themselves. I used the sketchup files and measured the centerline of the horn path for section lengths and height and width at the intersections to calculate area at those points.

If you really wanna geek out on it, I encourage you to do so. You could save a whole lotta time and effort though, if you just choose a cab and build it to the specs in the plans. I see you going through all the same thought processes I've gone through in the past, so I get it. I'm happy to see you've already got a good hold on the math side of it. We definitely think alike.

Within the same width not sure if the single 15" would outrun the double 12" loading.

Within the same cab width, the combination with the greatest Vd will have the advantage in peak output potential. But, the difference might only be a couple dB and barely perceivable, if perceptible at all.

If you're handy with spreadsheets you can use this formula to calculate the theoretical increase in maximum output, =(LOG(Vd1*Vd1)*10)-(LOG(Vd2*Vd2)*10) where Vd1 would be the single driver Vd and Vd2 would be the double driver Vd. The result the formula provides is decibel increase.

My way of thought goes the other way around, not how many T30 to fit Output of T48, rather the conclusion i could reach the same level of output of 8 T30 with around half the number of cabs when going for T48.

Here's the same comparison based on single loaded cabs.

Also the stacking would differ, as the stack of 4 would have to sit centered and the DRs would need their own feet.
Nothing which can not be done, sure. But to keep it within the storage space, it wouldn't work as the first intention went. Maybe that intention has just to drop and i will build a 60"somewhat stand for the DRs.

Ideally, you'll want the bottom of the DR's to be at least a foot above the audience, 7-8 feet. Otherwise, instead of broadcasting over the crowd, a portion of what could reach the back is blocked.

The same way my thoughts walk around optimizing the T30 by horning up should go to the T48 to have a comparison that comes closer to true.
Would either of them benefit somehow in extending the plate into more horn?

I've had the same question and curiosity in the past too. Technically, yes. Although, I'm not aware of anyone actually trying it and measuring the results.

I'm sure you know this already, but you are massively overthinking this whole thing. Fun, isn't it. I hope you enjoy your journey as much as I have. I will say though, in the end of it all, I can't really say there's anything monumental that Bill hasn't already thought of and put in the plans. You could save your time and just build single 15" loaded 36" T48's and be on your way. But, I know that thing inside that's not satisfied unless I one up the project somehow. I look forward to this unfolding.

A note as to why 4x the cob count is needed if you decide you really need to impactfully represent content below 40Hz. It's not altogether the speakers or the cabs fault, it's also human physiology. We don't hear all frequencies the same. For lower frequencies to sound as loud as higher frequencies, they have to be much louder. The lower you go, the louder (measured) they have to be to have them sound the same level in your ear. Boundary loading and cabin gain work in your favor indoors. But outdoors, you're only resource is doubling or quadrupling your cab count, depending on how low you want to go. 30Hz? Quadruple your cab count used for 40Hz and you should be good.

Equal loudness contours

It's not a popular method to read SPL charts the way I do, but here's what makes sense to me and the way I think you should do it too. Instead of focusing on getting the most output per cab, start with focusing on the SPL you intend on needing at a certain distance from the stage and work backwards from there. Choose your SPL based on the mids and highs, those are the frequencies that will damage peoples hearing if they're too loud for extended periods of time. You obviously don't want to cause hearing damage to anyone. Then work backwards from there. I'm just going to use 100dB as an example. If your listening position is at 100dB from your DR's, your subs are going to need to be capable of 12 to 16dB more at 40Hz, depending on your taste. If you want 30Hz, 6dB more than that. Then add in 3-6dB for headroom, so you're not running the system at max all the time. In this light, the only point on the response chart that matters for a subwoofer is the bottom frequency you intend on recreating, since subwoofer sensitivity is typically lowest at the bottom frequency compared to higher frequencies. You can then math your way backwards to see how many cabs it will take to get you there, based on each cabs sensitivity/response chart.

[Marflinger]

You could probably have some fun with the SPL tool. Here's the link... Introducing SPL chart.

Ah, thank you for that. I've seen the spl-tag but did not understand the link to the tool. This also only renders a graphic, do you (or anyone else) know if the data points are available for that? or do i have to read it out of the graphic manually?

You could save a whole lotta time and effort though, if you just choose a cab and build it to the specs in the plans.

Yeah sure, but as you noted i am kind of on my way through the rabbit hole. I'm aware of that, i do that on purpose. If my goal would be to save me time and trouble I would just buy a system that is already built.
My rabbit hole has the shape of trying to understand it as far as possible within a certain amount of learning and try&error. We'll see when that amount is reached, not yet.

For me the whole comparison-thing doesn't seem to be close to the possible accuracy, as it is always something left out.

The key points (i think) would be the design of the cab in terms of the rear chamber and the horn path, to get the response caused by the housing. This, combined with the driver spec (as Sd, Xmax and power intake) that is used inside gives a view on the speaker, single Variant.
And from there it gets somehow foggy. The stacking of more than one cab seems to be somehow not really calculateable; as it changes the response curve and the total sensitivity.
The coupling with Plates is also done in a somehow foggy manner, with just adding x db. I assume (maybe because I am stupid) the Plate acts very different when coupling two together vs. coupling 6 together.

Probably, these approximations with "add 3db for plating" and "add 6db for doubling the amount of cabs" are already as precise as it is possible in a reasonable manner. The rest will have to be measured when built.
I'm curious if there are any measurements available from people that built stacks with plates? So far i couldn't find any, preferably mdat data for importing to REW or some other format that has the datapoints in it.
I'm aware of the many different circumstances that alter these results, would be interesting to see anyway.

Ideally, you'll want the bottom of the DR's to be at least a foot above the audience

The top one yes, the bottom one on each side has to fill the front area. There will be a pair on each side (at least).

start with focusing on the SPL you intend on needing at a certain distance from the stage

This somehow differs, as i dont have a stage scenario. Here a sketch to show you what my target constellation looks like:

Screenshot 2026-01-03 080658.png (9.85 KiB) Viewed 76 times

The red area somehow the target to deliever to. side length around 20 meters.
Sort of centered the DJ in FOH position (Just without having a house in the front), as i hate it to have a different monitoring than the actual PA, and as i hat the person-culture when it should be about the sound...and so on, many thoughts went into that.
I am super fine with a dropping spl, the further you are in the back. simplyfied by the line on the left, this gives everyone the option to have it as loud as they want to, and the ears of the dj are not f*cked after 20 minutes.

This sketch is to true dimensions of the T30 (here with the maybe extended moreHorn) to get a scale to that.

It's not a popular method to read SPL charts the way I do

Thank you for repeating that part, I've read the thread linked where the point was the same.
I'm aware of the human hearing curve, but in this scenario about reproducing sound i would take a different position on that:

SPL is the sound emitting side, the Fletcher-Munson-Curve is the percieving end.
This is kind of widely used, inside music production metering over frequencies always has a slope that shifts the lower end to adapt to that.

Two key points on that for me:
The reproducing on the speaker side is not targeted at getting a linear output when i set the gains per band according to the fletcher-curve; if you do that to all bands this will be pretty wild. Sure, the low end has to be somewhat exaggerated compared against the rest, but my goal is not to meet the fletcher curve but rather to get it to a somewhat balanced level.
I respect that as a goal, but it is just not mine. Balanced for me is probably around the half of the fletcher-curve-distance.
Not because I'm just stinky or whatever, but because the other key point: The lower it gets, the more of the bass is not percieved by ear but by the body itself through the resulting vibrations. So the hearing becomes only one part of the truth.
And again, compared to what ppl are used to every part of pushing this further will be percieved as an improvement.
Don't want to throw around critic, i highly respect that goal and i am sure the results from that are very good. But i am in another rabbit hole for now at least^^

I've had the same question and curiosity in the past too. Technically, yes. Although, I'm not aware of anyone actually trying it and measuring the results.

Oh yes, this is what i was looking for.
I just don't see a way to get that approximation how far the "technically, yes" could be valid without hornresponse or just building and measuring it.
As Bill said, on the T60 there is no reasonable benefit due to the hornpath being super long within the cab already; there are probably limits to every cab that make no sense to exceed.
Probably i will have to build it and extend the horn further and further and measure each extension to see where the benefit ends.
My Neighbours will love me for that, maybe i should drive far away to do so

I can imagine, that the benefit will be so little, that no one cared to really do it. Probably way simpler to just add more cabs.
In my mind, the benefit becomes somewhat viable due to the low cost on storage space, so i tend to try that.

As far as i got hornresp, i do not see a way to take the multiple cabs scenario down there. Or should i take the ouput of the single cab, and place it into a MEH for figuring that? Anyone who knows more about simulating of that extension?
There is the mouth adaptor, but i don't see the option to fire multiple cabs in there.

And has anyone simulated T30 and T48 within hornresp who would be so kind to give away the measurements of the segments for the hornpath?
If not i will measure that from the model and post here to have it at least checked - if i am allowed to.
Or is that effect of coupling and plating just not simulateable within hornresp? Is there any other software to do that?


And, within the available data (also within the spl tool), i could not find a chart for the results of any version of the T48 coupled and plated. Are there any available?
Because looking at the one from the T30, it shows a super flat response from 30 to 50. The single T48 has a way steeper slope on that area, and i am curious if that will add up to a similar flat response when coupled and plated.
Beneath the less needed power, this response difference seems to be one of the tipping points i could take a decision on. The flat T30 is very attractive to me so far.

Overall, the T48-variant would come at probably lower cost in terms of amping power and money when using the same amount of drivers per cab.
[In the above sketch, the T48 would sit in one cluster in the middle, tops seperated at the corners)

Keeping it within the 30" width, both have the maximum Sd with a dual 12" and as they probably fit the same drivers (other recommendations in the plans, i will look for that) there will be a somewhat compareable Xmax the cabs will be limited on.
As the drivers, sidenote that the PRV are not really available here and by importing them from the US they will be the most expensive option. So i will stick to the european available ones for comparing.
For now i will keep it to the approximations available for stacking and plating and look for the maxed combination in each variant, and try to get the horn path out of the models somewhat close to reality.

[Marflinger]

To the Hornresp-gaming around...

I did something, based on assumptions.
The first part of the Horn i assumed as the throat chamber, as i would run out of segments way too fast otherwise.
According to the hornresp-forum, this is somehow valid. Also ignoring the driver entry point, as offset position would cost another segment to handle.

So far, so good and somehow reasonable result compareable to other spl graphs here.
Interestingly, hornresp can do the multiple speaker maximum output as well; and giving the driver data it gives you maximum spl for these combinations.

So i did the T30 for now, results so far:
30"wide cab
Dual 12" loaded with the LaVoce SSF122.50L, single cab:

Screenshot 2026-01-03 105016.png (9 KiB) Viewed 73 times

Chamber resonances masked.

Now going for single cab maximum output:

Screenshot 2026-01-03 105157.png (10.23 KiB) Viewed 73 times

Red parts are where limits are met (Xmax or powerhandling in this case)

And now it becomes interesting:
Doing 4 by 2 stacked together, sensitivity:

Screenshot 2026-01-03 105520.png (9.25 KiB) Viewed 73 times

Same with MaxSPL for that stack:

Screenshot 2026-01-03 105624.png (10.88 KiB) Viewed 73 times

So far all without the Plate.

My assumtion was now, to just extend the hornpath to the front of the plate, and assume the final mouth area as the area from the plate.
There is a slight bend in that last horn segment, but i think this is the closest i can get there for now.
Assuming the original V-Plate, the results show as this:

Sensitivity for four cabs:

Screenshot 2026-01-03 105903.png (9.16 KiB) Viewed 73 times

Max SPL for that stack including the V-Plate:

Screenshot 2026-01-03 105952.png (10.87 KiB) Viewed 73 times

And now extending the Plate, another meter deep horn added:
Sensitivity:

Screenshot 2026-01-03 110403.png (9.04 KiB) Viewed 73 times

And MaxSPL

Screenshot 2026-01-03 110509.png (10 KiB) Viewed 73 times

Not sure if i am doing this right.
Does anyone see any errors on that?
I can share the calculations for the horns, here a overview of the hornpaths of the variants:

Screenshot 2026-01-03 110622.png (8.88 KiB) Viewed 72 times

[the maximized moreHorn, the normal V-Plate and the single cab.]
I took the full volume of the V-Plate as this:
Red Path is the Cab without anything, blue is the V-Plate-Path and pink would be the overkillhorn-path, in this case outer width around 3 meters.

Screenshot 2026-01-03 110834.png (6.22 KiB) Viewed 73 times

[Seth]

In the fifteen or sixteen years I've been active on this forum, there haven't been any useful discussion about using HornResp. Just my experience that you'll have to rely on other forums for that informati0on. You could try sending a private message to user Wylandright206. You may also consider reading through some of his post history too. Intelligent guy.

You may have seen this thread already. It's worth a read if you haven't.
Outdoor DJ Tuba 30 vs Titan 48

I'm about the only person on this forum that's usually willing to dive down a rabbit hole like this with someone. But honestly, my mind is in other places and I just can't continue to delve deeply beyond this point. You're off to a good start. There's nothing patently wrong with your direction. I look forward to seeing your journey unfold. Enjoy the ride.

[Seth]

Ideally, you'll want the bottom of the DR's to be at least a foot above the audience

The top one yes, the bottom one on each side has to fill the front area. There will be a pair on each side (at least).

You want the bottom cab of any size stack above the heads of the crowd. Off axis attenuation benefits the people up close, unblocked line of sight to all cabs benefits the people in the back. You could power shade the bottom cabs if you plan to run separate amplifier channels to the top and bottom cab so you're not blowing heads off up front. But, then you lose the benefit to people in the back. Also, since they're DR's and have built in splay, I'd consider elevating them a little more if practical.

[Marflinger]

I'd consider elevating them a little more if practical.

Thank you for that hint, will keep that in mind. First full flown setup will take a ton of testing and measuring, so thank you in advance.

You may have seen this thread already. It's worth a read if you haven't.
Outdoor DJ Tuba 30 vs Titan 48

Did not see this thread, but quotes from this thread in others.
So far it seems to be the common way to go with the T48, most of the time with the comment of (if space isn't a problem). Kind of the point where I am at.

But honestly, my mind is in other places

No worries, i totally get that. You've already brought me further down that hole then i thought i would get, so thank you for that

Just my experience that you'll have to rely on other forums for that informati0on.

First of all i would need to get deeper into hornresp as it is. I walked through the manual in the evening, there is a lot more to cover. Kind of a steeper slobe to get in there, but i think i will figure it out far enough.
The previous screenshots for the T30 measurement have errors in them i found now, i think i messed up the measuring of the horn path for instance. Also it could be worth it to set the input driver point correct.
Tried the same idea on the T48-path, the result is super wrong by eye already. I got to get into the unfolding of the path to have that somehow correct. Not sure how to cover the widths of the path in the very tight folding points.

But, what my gaming around found interesting so far:

The horn extension to get the V-Plate deeper shows a very little effect (around +2db) for the cost of putting together a horn with a mouth of 3m by 1,60m. Well, probably not worth the hassle.
The V-Plate as original thought does around the same addition; but to have it installed the hassle is near zero compared to the big variant.
So the big variant will drop out; i will try it once i figured the hornpaths correct, but i don't think this will change anything on that effect.

I still want to have a somewhat close simulation to compare the T30 and the T48, but actually i tend to go for the T48 probably (In case the simulating matches the approximated results).

So still, if anyone has an unfolded hornpath, or hornresp-data for the T48/T30, i would be very interested.
I will try to figure that out by myself at first, the weather will allow me to finish the first two DRs soon and then i will have a conclusion maybe.

there haven't been any useful discussion about using HornResp

Could you get deeper into that, briefly? Because the common idea here is, that the software is somehow bad or faulty? Is there other software? Or what is the point?
It seems a totally fitting tool, esp for the choice of drivers before build it seems very handy to me to just plug it in there and look for the results.

No matter if answered or not, thank you for guiding me so far

[Seth]

there haven't been any useful discussion about using HornResp

Could you get deeper into that, briefly? Because the common idea here is, that the software is somehow bad or faulty? Is there other software? Or what is the point?
It seems a totally fitting tool, esp for the choice of drivers before build it seems very handy to me to just plug it in there and look for the results.

No matter if answered or not, thank you for guiding me so far

You're quite welcome. I'm going to be following along and I'm happy to respond to short direct questions. I may occasionally be inspired to go into depth from time to time as well. I see the effort and thought you put into your posts and questions. I just don't have it in me to soak up the depth of some of the deeper stuff and dive in to meet you down there. I really am happy to help where I can.

As far as HornResp... It's my understanding that it's the modeling software that Bill has used in developing his designs over the years. So, it's not that the software is bad or faulty. I think it hasn't gained popularity as a point of discussion in this forum for a couple reasons. One is that, it's only a few of us here, like yourself, that are geeked out enough to have the desire to understand things that deeply. And secondly, of that handful, maybe one has actually successfully learned and grasped how to use the software successfully due to it's steep learning curve.

In the past I've asked Bill directly, specific questions about how to use the program and while he was encouraging in spirit, his responses were ultimately unhelpful. Whether it be that he just didn't want to take the time out of his day to go down that rabbit hole with me or perhaps that he wants to keep the integrity of his designs and not actively assist me in unraveling and reverse engineering his intellectual property. No matter the reasoning, I respect his choice and am deeply grateful for the knowledge he does openly share.

This forum is pretty much dedicated to choosing a design, building and construction of the cabs, optimum system deployment, and electronics settings. Not too much discussion in the way of horn theory. I recall being frustrated about that way back in the day. I'm the kind of guy who wants to learn, understand and know how and why stuff works too.

[Seth]

PM me your email address and I'll send you a link to download the spreadsheet I've created in making sense of some of this stuff. It's not super organized, but you're likely to find some of it enlightening. The equations are solid.

[Marflinger]

in unraveling and reverse engineering his intellectual property.

To be honest, i don't get that part.
Maybe i am just to far away from that, but wouldn't be the only benefit i could gain from that to draw a plan and build a box...like the plan i already bought from bill to build this box? This seems to be a circle to me, but happy to be enlighted.

For me this seems quite benefical in terms of deciding about the width of the box and the used driver there, as i can simulate the differences and look at the numbers.
Sure, this is also only an approximation, the real result will still differ. But this is kind of as close as it gets in terms of guessing the result?

The other way around, to ask for a simulation of the box in several widths with several drivers seems to be the wrong way, first of all as in diy and second the inhumane workload i request others to do by that.

So it seems to be the right way for me, are there any concerns about that from you bill? I also don't want to battle any limits you've set for the useage of your concepts. I see that scenario within the personal use that is granted (as far as i understand that).

I'm the kind of guy who wants to learn, understand and know how and why stuff works too

Ah yes, there we are. Well yeah, this is kind of my point. I would add that i want to have this understanding, to be able to at least feel like i've made a decision based oin my understanding - even if the decision turns out wrong, it was my own understanding that led me there.

PM me your email address and I'll send you a link to download the spreadsheet I've created in making sense of some of this stuff. It's not super organized, but you're likely to find some of it enlightening. The equations are solid.

I sent one, that idles in the outbox and doesn't move to the sent folder. We'll see if it moves from there, i will find another way eventually.

[Bruce Weldy]

Time for the grumpy old sound man to throw a little cold water on the discussion.

If you spend half of the time on learning how to properly EQ your system once it's built as you have on trying to choose a cab, you'll end up with a much better sounding system regardless of the sub you choose.

You and Seth are obviously twins separated at birth.....and that's good to keep some intellectual stimulation going for the rest of us ludites. BUTTTTT.....don't build the world's fastest race car and not be able to find the door to the gas tank.

Bottom line, it boils down to extension and sensitivity. Outside, you typically will go with the louder box. Inside, you can give up a little loud for some low. However, the difference between 35hz and 40hz is not going to make anyone either rave about or demean your system. If it sounds good, it sounds good.

So, my advice to you is - pick a box, build a box, make some noise. You'll be pleased whichever way you go.

Or, the paralysis of analysis will keep you at the keyboard instead of the tablesaw.

Go make some sawdust! It's way more gratifying.....

[Bill Fitzmaurice]

In the fifteen or sixteen years I've been active on this forum, there haven't been any useful discussion about using HornResp.

There are plenty of DIY forums with HornResp sections, for those who want to design their own. Our purpose is to provide plans to those who don't want to design their own.

[Seth]

Time for the grumpy old sound man to throw a little cold water on the discussion.

If you spend half of the time on learning how to properly EQ your system once it's built as you have on trying to choose a cab, you'll end up with a much better sounding system regardless of the sub you choose.

You and Seth are obviously twins separated at birth.....and that's good to keep some intellectual stimulation going for the rest of us ludites. BUTTTTT.....don't build the world's fastest race car and not be able to find the door to the gas tank.

Bottom line, it boils down to extension and sensitivity. Outside, you typically will go with the louder box. Inside, you can give up a little loud for some low. However, the difference between 35hz and 40hz is not going to make anyone either rave about or demean your system. If it sounds good, it sounds good.

So, my advice to you is - pick a box, build a box, make some noise. You'll be pleased whichever way you go.

Or, the paralysis of analysis will keep you at the keyboard instead of the tablesaw.

Go make some sawdust! It's way more gratifying.....

100% agree.

In the fifteen or sixteen years I've been active on this forum, there haven't been any useful discussion about using HornResp.

There are plenty of DIY forums with HornResp sections, for those who want to design their own. Our purpose is to provide plans to those who don't want to design their own.

Here too. Well said. 100%

[Seth]

in unraveling and reverse engineering his intellectual property.

To be honest, i don't get that part.
Maybe i am just to far away from that, but wouldn't be the only benefit i could gain from that to draw a plan and build a box...like the plan i already bought from bill to build this box? This seems to be a circle to me, but happy to be enlighted.

I want to be clear. That is just one of a handful of possible reasons I could make up in my mind. It's not anything that has ever been said directly, conveyed, or communicated in any way.
Purely an imaginary potential explanation on my part. No factual basis whatsoever.

For me this seems quite benefical in terms of deciding about the width of the box and the used driver there, as i can simulate the differences and look at the numbers.
Sure, this is also only an approximation, the real result will still differ. But this is kind of as close as it gets in terms of guessing the result?

I totally get this. It would be amazing if the website had a page where we could comparatively fiddle with cab width, driver parameters, and cab count combinations. But fact is, the site doesn't have that functionality at current time.

The other way around, to ask for a simulation of the box in several widths with several drivers seems to be the wrong way, first of all as in diy and second the inhumane workload i request others to do by that.

Take a deep breath. The things you and I are compelled to understand aren't actually required to get the results we desire. All anyone has to do is choose the lowest frequency they want to reproduce, choose a cab that will produce that frequency, build them as wide as possible up to the maximum width, then double cab count until the desired output is accomplished. It's really just that easy.

It took me more than ten years, starting from where you are now, to come to that conclusion. It'll likely take you the same time to learn what you need to learn and come to the same conclusion. Funny thing is, that's pretty much the same advice the forum members offered me right up front. So, ten years... just to understand their advice was spot on from the get-go.

Thanks BTW, to Bill, Bruce, and others for your suffering my curious mind all these years. You've definitely played an amazing part in my journey and I appreciate you.

I'm the kind of guy who wants to learn, understand and know how and why stuff works too

Ah yes, there we are. Well yeah, this is kind of my point. I would add that i want to have this understanding, to be able to at least feel like i've made a decision based oin my understanding - even if the decision turns out wrong, it was my own understanding that led me there.

I experience trust issues too. Nothing wrong with doing your due diligence. I'm not offended if you don't want to blindly trust the opinions I share with you. I'm definitely in support of you asking all the questions you have and seeking out the answers wherever you happen to find them.



Bruce is absolutely right, you and I share the same desire in depth of understanding stuff. There's nothing wrong with it. At the same time, there's also nothing wrong with just following the steps of how to do things without actually understanding why things are the way they are. The vast majority of people just want the results and care very little about how or why the results occur. Nothing wrong with that either.

I look forward to watching your journey unfold.

[Tom Smit]

I toyed around with Hornresp in the past because I was curious and wanted to understand, but, I have to dedicate my time to other things.