I recently moved and now have a huge room, 9500 cu ft, that needs some bass. Currently I have an Aerial Acoustics SW12 with 10Ts, and they don't even come close to what they did in my smaller room.

I've been thinking about a pair of SVS PB13 Ultras, but recently ran across a pair of 18" TC sounds LMS in ported boxes.

However, the DIY subs don't have tuning or power, so I'd have to supply that. Otherwise the builder is very good.

Here's the dilemma. The SVS gets rave reviews with flat response down low. But the TC Sounds LMS 18s will move a lot more air.

If the cabinets are competently made, which I think they are, should I just go for the TC Sounds and fork out for the crossover and amps? That said, I looked at this review, which seemed to indicate the PB13s were very very close to the TC Sounds 18s and thus might be more of a sure bet --

http://www.hometheatershack.com/forums/home-audio-subwoofers/6656-subwoofer-tests-fall-2007-a.html

Any advice would be greatly appreciated!

If you really have access to LMS-18's then go for it. They are simply the finest sub driver ever made....period. Anyone in the DIY circle will tell you the same thing. If you don't want them, please forward the seller and the price and i'll take em...

The Ultra13's are great as measurements will show you.... but sealed the LMS's will easily topple them, I would go sealed, make sure the boxes are the proper size and you won't need stuffing. Just do your homework....

Now, keep in mind that to power those 18's you will need 2 extremely large amps to drive them properly and you should also add some sort of EQ to bring up the low end unless you are in a small room that will naturally boost the bottom end.

You better know what you are getting into when it comes to how much money it will take for amps and those drivers.... SMALL FORTUNE sums it up pretty well.

I want 3 of those - all in I'm looking at $10K - that aint no lie.

Why sealed vs tuned....I can't recall exactly but I think the guy said they are ported and tuned to 15 hz...

I only have read this stuff and have no in depth knowledge, but I thought a sealed cabinet dropped the output by 6 db? and really does nothing for the bottom end?

Again, the ported SVS PB13 ultra seems to spank just about everything else on the bottom end, although the LMS 5400 might be the one it can't top.

Does anyone know the cubic feet the PB13 or the LMS 5400 can move? If the accuracy is similar, that is a big factor given the huge volume of the room.

I think the LMS 5400 can move something like 7 liters of air.

We don't know how much air the PB13 can move because it is considered classified information. But it will move a lot. My guess is low 6 liters.

There is no contest between the PB13 and LMS5400. The PB13 does have more output +or- 10Hz at its tuning point, but anywhere else the LMS5400 takes over. The LMS5400 is simply the best driver ever made. It probably have better sound quality too.

There is no contest between the PB13 and LMS5400. The PB13 does have more output +or- 10Hz at its tuning point, but anywhere else the LMS5400 takes over.

I thought according to the link which the OP posted, the LMS sealed 100L got 98dB at 12.5Hz, the PB13U @ 10Hz tune got 92dB.

To the OP : Anyway, if you are gonna be spending good $$$ on the LMS, spend some $$ on PR, Acoustic Elegance and DIYcable sells some good stuff (the CSS are actually AE stuff). Just a couple of hundreds more and with a pair you will be on the way to heaven. There is like 6dB more at tune, that is like a free additional driver and free amp/2X power.
A bigger box than 200L means lower tune (shifts the SPLs down more), but do consider that a 100L box is quite small and perhaps have a better WAF.

What are your goals?

Ahhhh sorry I guess I didn't take from your post the cabinets were already constructed. I'm just a big fan of sealed, and if it takes more power and some EQ I have no problem with that...

I have dual 18 LMSs and they are fantastic.

However, I would go sealed and save the floor space.

To the OP : Anyway, if you are gonna be spending good $$$ on the LMS, spend some $$ on PR, Acoustic Elegance and DIYcable sells some good stuff (the CSS are actually AE stuff)

What is PR?

I have dual 18 LMSs and they are fantastic.

However, I would go sealed and save the floor space.

I thought the ported cabinets let you go lower... What size is a sealed enclosure vs the ported one? Might be worth just redoing cabinets?

What is PR?

I thought the ported cabinets let you go lower... What size is a sealed enclosure vs the ported one? Might be worth just redoing cabinets?

A PR is s Passive Radiator. It essentially acts like a port but without the air flow and port resonances. Usually allows for smaller enclosure as well. They are non-powered, ala passsive but radiate like an active driver at/near their desired tuning point which is controlled by weight.

With sealed you go as low as you want. You can EQ to taste. The LMS can handle just about anything you throw at it so unless you have a HUGE room two of these will bring down the house even in a small sealed setup.

Additional help, just ebay 2 Crown CE4000s and call it a day with small sealed config, sweet and simple. (100L would be good as you can see in HTS).

Drop by the DIY forum, there's much fun there!

Why sealed vs tuned....I can't recall exactly but I think the guy said they are ported and tuned to 15 hz...

I only have read this stuff and have no in depth knowledge, but I thought a sealed cabinet dropped the output by 6 db? and really does nothing for the bottom end?

Again, the ported SVS PB13 ultra seems to spank just about everything else on the bottom end, although the LMS 5400 might be the one it can't top.

Does anyone know the cubic feet the PB13 or the LMS 5400 can move? If the accuracy is similar, that is a big factor given the huge volume of the room.

In a sealed Box, the LMS 5400 with some EQ will surpass the output of the SVS and continue down to single Hz output. Two of them with adequate amplification are capable of structural damage to your home. The SVS is a great sub no doubt but no match for the LMS 5400....not even close. Yep..Flame away fanboys!

You seem to be centered around the amount of air the driver can move so lets examine it. One LMS 5400 has almost twice the surface area of the driver in the PB13. The maximum linear excursion for an LS 5400 is 38mm but the SVS drivers Xmax is not published. Even if it was equal to the LMS (not likely given the Sd, Bl and surround design), the LMS still moves more air...lots more.

There really is not much of a comparison. The LMS will yield better SQ as well.

It just comes down to preference, expectation and preference.

Do you want something with a built-in amp and related features that is pre-finished and ready to go?

Or

Do you want something that you can change out the amplification and design to your specs?

If you have access to a the LMSs at a reasonable price, then I would strongly consider them.

If you have access to a the LMSs at a reasonable price, then I would strongly consider them.


Agreed, they are rare to find available.....

These drivers can handle some serious amp power as well.... up to 5000w each.

IMO I think they are worth the long time investment, and you can easily say that you have hands down one of the best subs period....

Ya'll's comments are very very much appreciated. The LMS looks like the sure winner.

A final question: Audyssey AS-EQ 1 looks like a great thing. I know it's not out yet, but do you think it can replace a Parametric EQ--eg tune a barebones sub in a box, or would it be best used with a tuned sub?

You will be able to use the AS-EQ1 for this project....

Although before you jump into that, I would suggest finding out how the subs in room response is. Get some rough measurements by plotting out response with test tones on a sheet of paper, Its a bit time consuming, but hey it doesn't cost anything and you can get a idea where you sit for starters.

The signal chain for adding any of these EQ's like the SMS-1, AS-EQ 1, Behringer, antimode or what have you, would be to come out of your AVR/Pre-Pro Sub out, into the EQ of your choice then into the amp that powers your sub.

I run SMS-1 for my systems, I am interested in SVS's new EQ but I also will be running 3-4 subs, and I still have yet to see a response from them about how/if it will handle multiple subs. it is stated for 2 seperate subs...... so would be ideal for your situation.