Simulating T48 in hornresp

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Evarist2
Posts: 24
Joined: Mon May 29, 2023 9:46 am
Location: Belgium, West-Flanders

Simulating T48 in hornresp

#1 Post by Evarist2 »

Hello everyone! I am back on a new account, my previous was called "Evarist" but I forgot my password sadly...

I have now decided I wanted to start building the T48s (48x24x24) as I now have more time, and a bigger budget. However getting the Eminence drivers here for a fair price is hard (I am located in Europe: Belgium). So I wanted to try to simulate the T48s in hornresp, however I am encountering some issues (I am still new to the subject of loudspeaker design, but I am catching up).

I saw that Seth has done it before, so maybe he could provide his to me? It would help out a ton, as I would also learn from it.

Thanks in advance!

Grant Bunter
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Re: Simulating T48 in hornresp

#2 Post by Grant Bunter »

What you are referring to is pretty much a problem anywhere in the world outside the USA.
Because of that, many of us waste countless hours looking for drivers based on what we consider to be reasonable cost, but they are compromises. Often said here; Buy once, cry once.

I wonder if you have plans yet?
Eminence isn't the only option, my older plans have options for drivers for those from Europe.
There's also an entire thread about where to get what in Europe as well.

Are you trying to reverse engineer the cabs so you can try other drivers?
Change the design, change the outcome.

Get into the theory later. For now, build your cabs, with recommended drivers, as designed.

I'm hoping Seth helps you, but not by giving you what he has done. You will learn far more getting through it yourself...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Evarist2
Posts: 24
Joined: Mon May 29, 2023 9:46 am
Location: Belgium, West-Flanders

Re: Simulating T48 in hornresp

#3 Post by Evarist2 »

Grant Bunter wrote: Mon May 29, 2023 4:16 pm What you are referring to is pretty much a problem anywhere in the world outside the USA.
Because of that, many of us waste countless hours looking for drivers based on what we consider to be reasonable cost, but they are compromises. Often said here; Buy once, cry once.

I wonder if you have plans yet?
Eminence isn't the only option, my older plans have options for drivers for those from Europe.
There's also an entire thread about where to get what in Europe as well.

Are you trying to reverse engineer the cabs so you can try other drivers?
Change the design, change the outcome.

Get into the theory later. For now, build your cabs, with recommended drivers, as designed.

I'm hoping Seth helps you, but not by giving you what he has done. You will learn far more getting through it yourself...
Hello!

Yes, I have bought the plans of the T48. I am not trying to modify the plans, just look how they work, and why certain decisions have been made. The drivers I want to try, are in the spec range listed in the plans, so normally it should be fine.

I agree, Seth shouldn't just give me the hornresp project, however a bit of guiding couldn't hurt. If I am given the right resources, I can definitely learn it. However the problem I had recently was having resources. Cruising along the forums shows me a lot of different opinions, and not much theory (and facts). This forum however with the section Bill created has given me the most. Hence why I chose to buy the plans.

RCF is a pretty good brand, so I was looking into their drivers. Also B&C.

Grant Bunter
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Re: Simulating T48 in hornresp

#4 Post by Grant Bunter »

Evarist2 wrote: Mon May 29, 2023 4:28 pm I am not trying to modify the plans, just look how they work, and why certain decisions have been made.
It's one thing to learn how to use a sim programme.
It's quite another thing to know how to vary the result to achieve a better outcome.
Bill designs or has designed a number of large company name cabs, and that's worth reasonable money, so he's never going to tell us everything he knows!
Needless to say, designing with sims, but then introducing tweaks based on all that experience is the gold.
Way before sims were invented, someone experimented until they knew how to fold a trumpet/tuba/trombone etc for the best results.
And the same can be said for horn cabs, the magic is knowing where to fold them, vs where the sim says to fold them.
Evarist2 wrote: Mon May 29, 2023 4:28 pm The drivers I want to try, are in the spec range listed in the plans, so normally it should be fine.
Well, the thing is this: If a driver has the spec range as listed, then the result will be the same as any of the recommended drivers.

It's not the driver that dictates response, it's the design. Remember that.

If you supply a spec chart, and ask Bill via the forum, he will give you a voltage displacement limit as well.
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Seth
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Re: Simulating T48 in hornresp

#5 Post by Seth »

Hey Evarist, welcome back.

Seems there's a couple different questions on the table
1) Identifying a suitable driver
2) How to model the T48 in hornresp

The first one is easy. Just find a driver that suits your budget and meets all the required specs stated in the plans. That's all you need to create amazing, breathtaking results.

I completely understand the desire to really geek out and choose a driver based on modeling results. I'm the same way. But, honestly, it's not worth the effort.

I'm with Grant and his recommendation to build the cabs and choose the drivers independent of modeling. And yes, learn to model if you want to model. But, I highly recommend you keep the two projects separate.

I know myself, and if you're anything like me, that advice will likely fall on def ears. So, here's what I did to model the T48...
1) Learned to use sketchup and unfold the sketchup file. It takes some thinking to keep the dimensions (for the most part) true and accurate. Try it a few times. Don't give up. Just figure it out. Then use the measure tape tool to measure the resultant segments.
2) Learn to use hornresp. Out of 10, I have a mastery level of maybe 3 or 4 with hornresp. I'm not convinced I've been modeling my measurements correctly. Although, they seem to be (subjectively) reasonably close. I certainly don't want to pass on any poor habits.

It's a little unfortunate, but this site is primarily about the construction and use of the finished products. You'll have to research and source the info about SketchUp and hornresp on YouTube and forums that are more specifically about the subject matter you seek.


Really though, my highest, honest-to-goodness bit of advice... build your cabs and put suitable drivers in them. Then learn all the stuff that would have otherwise eaten up the time you just used to make your cabs.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Evarist2
Posts: 24
Joined: Mon May 29, 2023 9:46 am
Location: Belgium, West-Flanders

Re: Simulating T48 in hornresp

#6 Post by Evarist2 »

Seth wrote: Tue May 30, 2023 12:01 am Hey Evarist, welcome back.

Seems there's a couple different questions on the table
1) Identifying a suitable driver
2) How to model the T48 in hornresp

The first one is easy. Just find a driver that suits your budget and meets all the required specs stated in the plans. That's all you need to create amazing, breathtaking results.

I completely understand the desire to really geek out and choose a driver based on modeling results. I'm the same way. But, honestly, it's not worth the effort.

I'm with Grant and his recommendation to build the cabs and choose the drivers independent of modeling. And yes, learn to model if you want to model. But, I highly recommend you keep the two projects separate.

I know myself, and if you're anything like me, that advice will likely fall on def ears. So, here's what I did to model the T48...
1) Learned to use sketchup and unfold the sketchup file. It takes some thinking to keep the dimensions (for the most part) true and accurate. Try it a few times. Don't give up. Just figure it out. Then use the measure tape tool to measure the resultant segments.
2) Learn to use hornresp. Out of 10, I have a mastery level of maybe 3 or 4 with hornresp. I'm not convinced I've been modeling my measurements correctly. Although, they seem to be (subjectively) reasonably close. I certainly don't want to pass on any poor habits.

It's a little unfortunate, but this site is primarily about the construction and use of the finished products. You'll have to research and source the info about SketchUp and hornresp on YouTube and forums that are more specifically about the subject matter you seek.


Really though, my highest, honest-to-goodness bit of advice... build your cabs and put suitable drivers in them. Then learn all the stuff that would have otherwise eaten up the time you just used to make your cabs.
Hey Seth! Thank you so much for your answer!

I really, really want to get the modeling down. So I will definitely keep trying. However I will follow your advice to keep it a seperate project, that way I can start building the cabs faster. The main reason I wanted to do it, is to compare the performance of the driver to the T48 loaded with an Eminence 3015LF. That way I knew I was making the right decision.

Thanks for pointing out that I should unfold the horn, I thought of doing it while I was calculating lengths, and areas. Will make stuff easier (however the unfolding might be harder...).

I hope I can start building them soon, contacted my cousin who is a woodworking professional. He is going to help me out a bit with tooling. Cannot wait to start and document the parties I do with them around here!

Again, a big thank you to anyone who replied. You guys have massively helped me out!

Bruce Weldy
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Re: Simulating T48 in hornresp

#7 Post by Bruce Weldy »

Evarist2 wrote: Tue May 30, 2023 7:05 am
I hope I can start building them soon, contacted my cousin who is a woodworking professional. He is going to help me out a bit with tooling. Cannot wait to start and document the parties I do with them around here!
Just don't let him convince you to use cabinet grade plywood. Stick to the plans on wood selection.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Evarist2
Posts: 24
Joined: Mon May 29, 2023 9:46 am
Location: Belgium, West-Flanders

Re: Simulating T48 in hornresp

#8 Post by Evarist2 »

Bruce Weldy wrote: Tue May 30, 2023 7:18 am
Evarist2 wrote: Tue May 30, 2023 7:05 am
I hope I can start building them soon, contacted my cousin who is a woodworking professional. He is going to help me out a bit with tooling. Cannot wait to start and document the parties I do with them around here!
Just don't let him convince you to use cabinet grade plywood. Stick to the plans on wood selection.
We are sticking to that, we are following the plans strictly!

Rich4349
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Location: Kankakee, IL

Re: Simulating T48 in hornresp

#9 Post by Rich4349 »

Bruce Weldy wrote: Tue May 30, 2023 7:18 am Just don't let him convince you to use cabinet grade plywood. Stick to the plans on wood selection.
I thought 1/2" , 7-11 ply, B/BB Baltic birch WAS cabinet grade? (As opposed to construction grade.)
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!

Bruce Weldy
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Location: New Braunfels, TX

Re: Simulating T48 in hornresp

#10 Post by Bruce Weldy »

Rich4349 wrote: Tue May 30, 2023 9:01 am
Bruce Weldy wrote: Tue May 30, 2023 7:18 am Just don't let him convince you to use cabinet grade plywood. Stick to the plans on wood selection.
I thought 1/2" , 7-11 ply, B/BB Baltic birch WAS cabinet grade? (As opposed to construction grade.)
Cabinet grade refers to Birch with a thin veneer. Only time I ever see Baltic Birch used for cabinets around here is drawers. Most folks like the pretty veneers to stain for their cabinets.

If you go to a big box store and ask for baltic birch, they will sell you birch veneer....because they've never heard of baltic birch.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Seth
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Re: Simulating T48 in hornresp

#11 Post by Seth »

Rich4349 wrote: Tue May 30, 2023 9:01 am
Bruce Weldy wrote: Tue May 30, 2023 7:18 am Just don't let him convince you to use cabinet grade plywood. Stick to the plans on wood selection.
I thought 1/2" , 7-11 ply, B/BB Baltic birch WAS cabinet grade? (As opposed to construction grade.)
The whole "cabinet grade" and "veneer" thing get's kind of confusing. I don't know about other places on the planet, but out here in California I've seen really nice Radiata (unfortunately not in ½") described as "cabinet grade" and I've seen Baltic Birch described as "Veneer Ply". I think they refer to it as veneer ply because the ply's in Baltic Birch are very thin compared to standard plywood. But, that's just a slightly educated guess. And all of the Baltic birch I've ever seen, if you look very closely like the plans say to do, the outer layers are slightly thinner than the inner layers. So my first thought was this aint the shit I'm looking for... but it is.

The stuff you want to avoid is thicker inner ply's with a nearly thumbnail thin outer veneer, where the only purpose of the outer veneer is to make the wood look good. There are 2 issues I'm aware of with using the looks good on the outside veneer stuff: 1) There are usually tons of voids. And 2) the glue they use to adhere the veneer onto the base ply is shit. So, when you glue a panel to the veneer surface with kick ass glue, the other side of that veneer is essentially glued on with spray adhesive... negating the bad ass glue altogether. Like welding something onto something else that's held to the main part with Velcro. Where, with the Baltic Birch the outer layers are slightly thinner than the inside ply's, but the adhesive they use is the same structural quality throughout.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Grant Bunter
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Re: Simulating T48 in hornresp

#12 Post by Grant Bunter »

Seth wrote: Tue May 30, 2023 9:13 pm I don't know about other places on the planet
Glad you brought that up. The OP is in Belgium.
I wonder if plywood there has the same problems as in the USA?

I have a feeling, IIRC, that the OP should look for Finnish ply, rather than Baltic Birch.
By far lighter, as internal panels (which is where it should be used as it gets dents and dings quite readily), will be Poplar ply, which, again IIRC, is more widely available in Europe...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
Seth
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Location: Sacramento, California, USA
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Re: Simulating T48 in hornresp

#13 Post by Seth »

Grant Bunter wrote: Tue May 30, 2023 10:01 pm Glad you brought that up. The OP is in Belgium.
I wonder if plywood there has the same problems as in the USA?

I have a feeling, IIRC, that the OP should look for Finnish ply, rather than Baltic Birch.
By far lighter, as internal panels (which is where it should be used as it gets dents and dings quite readily), will be Poplar ply, which, again IIRC, is more widely available in Europe...
Excellent points.

Personally, if I had Poplar available at a reasonable price, I'd use it. Maybe put a couple coats of fiberglass resin on prior to final finish to toughen it up a little bit. Never tried it, just a thought.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Bill Fitzmaurice
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Re: Simulating T48 in hornresp

#14 Post by Bill Fitzmaurice »

Grant Bunter wrote: Tue May 30, 2023 10:01 pm I have a feeling, IIRC, that the OP should look for Finnish ply, rather than Baltic Birch.
Finland is on the Baltic Sea. That's why birch ply from Finland and northern Russia is called 'Baltic'. Most Poplar ply comes from Italy, just a tad further south.

Evarist2
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Joined: Mon May 29, 2023 9:46 am
Location: Belgium, West-Flanders

Re: Simulating T48 in hornresp

#15 Post by Evarist2 »

I will soon check out what birch we have available over here. I think we should be able to grab some baltic birch for a fair price, as we are a bit closer to the source.

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