[Brad f]

Hello everyone, I am new to the shack and DIY speaker building, that being said i am a good cabinet maker and are considering building a sub that can at least sound as good or better than a hsu uls 15.
I am using this as a reference for size and sound quality. The driver I have thought of using are the new LMSR 15 from tc sounds and a 1000 watt dayton plate amp. Any comments much appreciated (design and equipment).

 

[Mike P.]

I haven't heard of a LMSR 15, can you post the T/S parameters?

 

[Brad f]

Thanks for the reply Mike. I will try to get the information from TC sounds. I am told this is a new driver
to be released in late December. I just asked for the best recommendation for high quality sub and amp that would meet or exceed the ULS 15 . I don't know if there are other combinations of amps and drivers that would work well, and be more reasonably priced. My knowledge is very low as far as reading specs
on drivers and matching amps therefore I am referring to the ULS-15 as a goal. I was going to purchase it because of price, reviews and size.

 

[looneybomber]

For sealed enclosures, output is a function of displacement (swept volume by the cone of the driver). Increase displacement and you move more air, move more air and you create more sound.

Using a near equal long throw 15 in a box of near equal size of the ULS-15 with near equal power, will result in near equal output.

So in order to achieve your goal of more output, you will need a driver(s) that will move more air than the ULS-15.

Way's of doing this.
1) Use more drivers than the ULS-15 with equal or more power and a larger box.
2) Use a bigger driver (18") than the ULS-15 with equal or more power and a larger box.
3) Use more drivers than the ULS-15 with more power and a slightly larger box.
4) Use a bigger driver (18") than the ULS-15 with more power and a slightly larger box.

 

[Ryan Anderson]

For sealed enclosures, output is a function of displacement (swept volume by the cone of the driver). Increase displacement and you move more air, move more air and you create more sound.

Using a near equal long throw 15 in a box of near equal size of the ULS-15 with near equal power, will result in near equal output.

So in order to achieve your goal of more output, you will need a driver(s) that will move more air than the ULS-15.

Way's of doing this.
1) Use more drivers than the ULS-15 with equal or more power and a larger box.
2) Use a bigger driver (18") than the ULS-15 with equal or more power and a larger box.
3) Use more drivers than the ULS-15 with more power and a slightly larger box.
4) Use a bigger driver (18") than the ULS-15 with more power and a slightly larger box.

IMHO, I believe this is the case with almost all enclosures, the only exception I can think of now is these horns that would be over loaded with drivers with more Xmax. Otherwise, even a pro audio sub that had more excursion, swept volume, would still have more capeable output...generally speaking.

 

[Mike P.]

Brad, what will the sub be used for? HT, music, or both? Depending on what you are looking for, the parameters will dictate what box size will be optimum for the given application.

 

[looneybomber]

IMHO, I believe this is the case with almost all enclosures, the only exception I can think of now is these horns that would be over loaded with drivers with more Xmax. Otherwise, even a pro audio sub that had more excursion, swept volume, would still have more capeable output...generally speaking.

Well for sealed enclosures, the swept volume is the only thing that creates sound. With ported enclosures, there's the driver and the port...which is why sealed vs. ported discussions are so numerous, but there's rarely ever sealed vs. sealed discussions.

But yeah, in general, the more air you move, regardless of the enclosure, the more SPL capability there is.

 

[Mike P.]

Well for sealed enclosures, the swept volume is the only thing that creates sound. With ported enclosures, there's the driver and the port...which is why sealed vs. ported discussions are so numerous, but there's rarely ever sealed vs. sealed discussions.

But yeah, in general, the more air you move, regardless of the enclosure, the more SPL capability there is.

All things being the same, yes. There is also the sensitivity issue to consider.

 

[Tyson]

Build it if you can, there's nothing like the pride of having done it yourself.

 

[looneybomber]

All things being the same, yes. There is also the sensitivity issue to consider.

Well that and efficiency just dictate the amount of power required to reach a certain SPL. Whether it takes 100w to displace 1L of air at 80hz or 1000w, the same SPL will result with sealed enclosures. That's why I have in my post comments about more power but equal sized box, or equal power but larger box. The larger box increases efficiency.

If a person's goal is Xdb at Yhz and they have a limit on enclosure size, the only variables to adjust are swept volume and power. Sensitivity and efficiency are dictated by those choices.

 

[lsiberian]

You can most certainly build a better sub then any commerical one of similar price. TC Sounds drivers are fantastic so that would be a great start.

 

[Ryan Anderson]

But yeah, in general, the more air you move, regardless of the enclosure, the more SPL capability there is.

i agree there. on car audio forums there was a lot of talk about how the square subs only benefitted from the Sd gain in vented enclosures... either way, you can only move so much air, to me you gain just as much sealed as vented or bandpass or anything else so long as you don't begin overloading things

 

[sub_crazy]

LMSR 15?

I did get a response from TC Sounds about the LMS 5400 series and was told it would be only available in a 18" size but maybe the LMSR 15 is a new model for them?

There new e-commerce site should be up in about a month so I can't wait to get more info.

 

[Mike P.]

You can most certainly build a better sub then any commerical one of similar price. TC Sounds drivers are fantastic so that would be a great start.

That remanins to be seen. Hopefully the quailty will be the same with their "new" manufacturer.

 

[sub_crazy]

I don't know this for sure but I believe they are using the same build house as Exodus. When Kevin showed pics of the new M-21 rolling off the assembly line Kyle from TC commented how that place looked like he had been there before in a joking fashion.

The LMS 5400 18" needs to be as good or better than it's predecessor for the price they are asking.

 

[Brad f]

Thanks for the info, so to sum this up spl at a certain frequency can be achieved by more watts in a smaller enclosure. Less watts in a larger enclosure? If this is correct does that mean I should be able to spend less money (on amp and driver)if I fabricate a larger box and achieve the same spl?
What makes a subwoofer speaker sound better than another, is it the voice coil for speed and acurracy? Also I should let everyone know this sub is 90% home theater and 10% music. My room size is 2700 sq ft.

 

[Brad f]

Hello Looney, Thanks for the input. Can you explain swept volume and power? Also how do I know how much DB output I need in 2700 sq ft room.

 

[Brad f]

I haven't heard of a LMSR 15, can you post the T/S parameters?

MIke, I am waiting to hear back from Thilo at TC Sounds. Sounds like the driver is modeled after the
Revo driver but there will be changes to the voice coil. Thats all I know for now. I assume this is a much
better driver than what is in the HSU ULS-15 as the driver is around 450.00 dollars. That being said I don't know how much it would improve the output if I put it in the same size cabinet.

 

[Mike P.]

We'll have to wait for the T/S parameters and model it to see how it will perform in the same size cabinet as the ULS-15.

Swept volume is the amount of air a sub can move. It is the Sd of the sub times the Xmax equals an amount usually stated in liters. The larger the box the less power it takes to reach the maximum amount of air the sub can move.

 

[Ryan Anderson]

I've gotta get used to "swept volume" myself, I'm a nerd, I call it Vd