THTLP

For livingroom sound better than in a theatre.
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V8DER
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Joined: Sat Oct 15, 2022 12:16 pm
Location: FAIRFIELD CT

THTLP

#1 Post by V8DER »

Good day,

My first post. I am going to attempt to build a THTLP Front firing mouth option. I would like deep bass and I believe according to the document the wider the THT the deeper the bass. I am shooting for 30” wide standing upright in a corner. What is the difference or advantages between the Ultimax 15 and RSS 390-HF-4 as far as performance/digging deeper?

Thank you your help.

Grant Bunter
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Re: THTLP

#2 Post by Grant Bunter »

V8DER wrote: Sun Oct 16, 2022 12:06 pm Good day,

My first post. I am going to attempt to build a THTLP Front firing mouth option. I would like deep bass and I believe according to the document the wider the THT the deeper the bass. I am shooting for 30” wide standing upright in a corner. What is the difference or advantages between the Ultimax 15 and RSS 390-HF-4 as far as performance/digging deeper?

Thank you your help.
Hi, and welcome to the forum :)

I think you've misread, but it's not that big a deal.
It should say something like "the wider you build, the greater low frequency sensitivity increases".
That's not playing lower, just the lower frequencies can be louder.

The design dictates response, and the design revolves around TS parameters for drivers. If the driver doesn't have suitable TS parameters, it won't work as well as one that has. In short, both the drivers you mention are fine, and you wouldn't notice the difference. There's more than one driver there, because it offers options for budgets etc.

Have a great time, show us your build and ask whatever you need to know...
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...

V8DER
Posts: 5
Joined: Sat Oct 15, 2022 12:16 pm
Location: FAIRFIELD CT

Re: THTLP

#3 Post by V8DER »

Grant Bunter wrote: Sun Oct 16, 2022 2:56 pm
V8DER wrote: Sun Oct 16, 2022 12:06 pm Good day,

My first post. I am going to attempt to build a THTLP Front firing mouth option. I would like deep bass and I believe according to the document the wider the THT the deeper the bass. I am shooting for 30” wide standing upright in a corner. What is the difference or advantages between the Ultimax 15 and RSS 390-HF-4 as far as performance/digging deeper?

Thank you your help.
Hi, and welcome to the forum :)

I think you've misread, but it's not that big a deal.
It should say something like "the wider you build, the greater low frequency sensitivity increases".
That's not playing lower, just the lower frequencies can be louder.

The design dictates response, and the design revolves around TS parameters for drivers. If the driver doesn't have suitable TS parameters, it won't work as well as one that has. In short, both the drivers you mention are fine, and you wouldn't notice the difference. There's more than one driver there, because it offers options for budgets etc.

Have a great time, show us your build and ask whatever you need to know...
Oh! So the wider it is, the louder it gets. I do not need this to make my ears bleed 😂 I do want chest pounding bass for home theater. Thank you for clearing that up, I appreciate it.

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Tom Smit
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Location: Sarnia, Ont. Canada

Re: THTLP

#4 Post by Tom Smit »

Welcome to the forum!
TomS

V8DER
Posts: 5
Joined: Sat Oct 15, 2022 12:16 pm
Location: FAIRFIELD CT

Re: THTLP

#5 Post by V8DER »

Tom Smit wrote: Sun Oct 16, 2022 9:57 pm Welcome to the forum!
Thank you

V8DER
Posts: 5
Joined: Sat Oct 15, 2022 12:16 pm
Location: FAIRFIELD CT

Re: THTLP

#6 Post by V8DER »

I ordered a Dayton Audio UM15-22 15 for the THTLP build. I am undecided on the width. This is probably going to be a slow build as I am still working, but almost done with my Klipsch KPT clones. I wish I found this site sooner. The SLA/TLAH looks impressive, oh well.

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Seth
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Re: THTLP

#7 Post by Seth »

V8DER wrote: Tue Oct 18, 2022 2:08 pm ...I am undecided on the width...
Full recommended width or the widest you can.

In my opinion, increased peak volume potential isn't the important benefit of increased cab sensitivity. The wider you go, the less power you'll need for any given volume.



Here's an 18" THT and a 30" THT. The 5db difference at 35Hz means the 18" cab will require 3.2 times the power compared to the 30" cab to create that frequency at any particular volume. If a 30" cab is at 100 watts, the 18" cab would require 320w to match the output.
Last edited by Seth on Tue Oct 18, 2022 9:30 pm, edited 1 time in total.
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

DaveMacKay
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Joined: Tue Aug 03, 2021 3:10 pm

Re: THTLP

#8 Post by DaveMacKay »

Very interesting. And impressive.

Do you have a similar graph for a 15" (minimal-size) THTLP?

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Seth
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Re: THTLP

#9 Post by Seth »

Here's a 15" and a 30" loaded with LAB12's... not LP's though.




All the available charts are listed here.
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

DaveMacKay
Posts: 88
Joined: Tue Aug 03, 2021 3:10 pm

Re: THTLP

#10 Post by DaveMacKay »

Thanks!

V8DER
Posts: 5
Joined: Sat Oct 15, 2022 12:16 pm
Location: FAIRFIELD CT

Re: THTLP

#11 Post by V8DER »

Seth wrote: Tue Oct 18, 2022 5:12 pm
V8DER wrote: Tue Oct 18, 2022 2:08 pm ...I am undecided on the width...
Full recommended width or the widest you can.

In my opinion, increased peak volume potential isn't the important benefit of increased cab sensitivity. The wider you go, the less power you'll need for any given volume.



Here's an 18" THT and a 30" THT. The 5db difference at 35Hz means the 18" cab will require 3.2 times the power compared to the 30" cab to create that frequency at any particular volume. If a 30" cab is at 100 watts, the 18" cab would require 320w to match the output.

Wow, thanks for that information. I appreciate it.

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