Help a Newbie choose a sub for HT (1 Viewer)

Hi all, I'm new to the forum. I'm designing a home theater room in my basement, and can't decide on a subwoofer.

Here's the setup:

Home theater for 80% movies/sports, 10% music
Room size 14'x14'x9' ceilings, rear wall is a 1/2 wall open to a larger room
Integra 50.1 amp 130 wpc
Paradigm in-wall AMS-LCR x 3; AMS-300 L/R rear surround
Projection 110" diag. screen.

Here's the questions:
If "a sub is for life" should I drop $ for a paradigm Sub 1? (no Sub 2, that's where I draw the line)
Am I better served with 2 subwoofers from another company?
Are paradigm in-wall subwoofers crap (RVC-12SQ)? (I suppose I would buy 2 units)
Is it worth DIY 2 subs just to save the $ but risk the fail in quality?
Finally, anyone DIY in-wall subs?

Thanks for all your responses in advance. It's not like I'm totally willing to throw away cash, but if I'll have a life filled with "boom" with no hassle (option 1 or 2) that might be worth it...

I'm not a fan of in wall speakers, YMMV. I'm a paradigm fan but I gotta say I auditioned a number of Paradigm subs and went with other brands because of their price premium. I ultimately ended up with a Hsu but I recommend you also check out SVS.

I definitely would not recommend in wall speakers of any kind, too many compromises. The most accurate, cleanest sounding subs tend to be servo designs. Rythmik is what I settled on (dual 15"s). They have tremendous customer feedback (check out the forums) and I love that they sonically disappear in your room until needed, then they really bring on the thunder! Ascend Acoustics offers them, as well as direct from Rythmik. Well worth checking out

Highplainsdakota said:

Is it worth DIY 2 subs just to save the $ but risk the fail in quality?
Finally, anyone DIY in-wall subs?

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Why would there be a failure in quality? Go with a proven design and you will guarantee not only output but sound quality. I'd put my sub up against a Wilson Audio Thor's Hammer - http://www.wilsonaudio.com/product_thor.shtml at any time. I use a pair of 15" drivers - https://web.archive.org/web/20070402025330/http://www.tcsounds.com/tc3000.htm with a Behringer professional amp.

Do you mean subs that use the cavity between the drywall and studs for airspace. Won't work. You need an air tight chamber. If you want to add a box between the studs then you are getting somewhere but the depth is too small. In the picture below, the driver on the left is very similar to the older SVS Ultra model. The one on the right is the current offering from Sundown Audio. Things have progressed in the last few years.

Ok, Thanks for the feedback,

If I go with a stand alone sub, I'm going to go ahead and get two. I understand this provides a more seamless integration with the other speakers. That being said, which is ultimately better: More watts RMS, or woofer size? Example: the SVS PB12-Plus is 800 watts RMS and a 12"(plus) woofer. The HSU ULS-15 has 600 watts and a 15" woofer. Prices are similar.

Thanks Robert_J

What is a proven design, just a big enough square box? Does it even have to be square? (then I could build a box between studs extending into the storage room behind for enough room). Which two woofers would you recommend from Sundown Audio? I could probably fit two 12", but they have 6 different models?

You have a storage room behind your theater? Have you thought about an infinite baffle sub? Read "The Subwoofer That Shook The World" - http://www.nousaine.com/nousaine_tech_articles.html%C2 Tom also has a LOT of great information on subs at that site. Too bad no more will be added to it.

An IB sub is simple. There is a baffle of infinite size that separates the front wave of the sub from the rear. In the image below, the 15" subs are mounted on a board and use the room behind them as the enclosure. Basically, it's a big sealed box but the box is so large it doesn't color the sound of the drivers.


Before we get too crazy, let's take a step back. What's your budget? According to the Hsu subs you looked at, it's approximately $2,000. You could get world class bass by DIYing a sub. How large can your enclosures be? Unlike retail subs that have shipping limits, DIY subs can be as big as you need them to be. I mean commercial refrigerator sized if needed. Building skills? If you are building a theater room, then I assume you can build a box. And no, the box doesn't have to be square. Look at the SVS cylinder subs. Cylinders. Air space is the only thing a sub cares about. Tools - do you have them? Router and saws are required. Power - Do you have dedicated 20amp (minimum) circuits to your theater?

As far as my resources:

The house is being bulit, so I can run as many dedicated circuits of any power anywhere. I don't have a router, but plenty of personal DIY capability with building.

Consider my budget unlimited, but sensible. This sounds weird, but I'm totally good with spending what it takes to put good bass in the room. 2 stand-alone woofers? sure, a paradigm sub 1? sure, a whole row of 15" drivers? probably not. I know it would cost less, but it wouldn't meld with the rest of the system (I think I'm putting in pardigm classic series in-wall speakers as I also have a wife to please). She understands if two subs have to be free standing, but didn't want all floor standng speakers. (I also have a small kid and don't want his prying fingers to find their way into expensive tweeters).

One final caveat: I'm building this house, but may be moving again in 10-15 years, and that may give a stand alone sub the edge as I can take it with me. The storage room is an L shape wrapped around the left and screen wall of the theater room. I read the post on the IB, and don't need 12 subs, but I get the idea. The storage room door is in the left wall of the theater (that's where my rack of components will go), so if that doesn't foil the "separate enclosure" part it will work. (perhaps like a IB with a port?)

What about building it and finding out the sound is bad because it's in the wrong place? I've heard subs are particular based on their placement.
Again, I'm a competent DIY'er with little knowledge of subs. That's why if I'm willing to spend the $2-3K for the right set up, it might outweight the "risk" of getting it wrong. That being said, I would like to explore this as a possibility. Thanks for all the answers.

by the way, that set up looks awesome.

OK. I saw another thread on IB designs, and "Holy $&@*" that looks awesome. That certainly might be doable with my set-up and seem reasonable to the wife. Important point here is that it only has a small drywall opening. It doesn't look from the other designs people have posted that it matters where the mannifold is located in the room. Is that right?

The real question is: Will this work if the door to that room opens into the theater. What happens if it's open? Could it ruin the subs or just sound bad? I could spring for a solid door there in order to help with the pressure differential.

Also, I see people are using all different brands of speakers. What would be the ideal speaker to use if I put in 2 15" or 4 12"? Again my room dimensions are ~1800 ft3 for the theater, but the rear half wall opens into another 3,500 ft3 game room. (I don't care what the theater sounds like in the game room, as long as it's good where you sit. Thanks!

Choosing the wrong place for a sub is a risk but using some testing tools and a $100 sub will find the best place. It's a small investment for a mufti-thousand dollar sub system. I just put subs in front under my center channel. I I needed more, I'd just add more.

An IB sub using a manifold would accomplish a few things. 1. You can use a metal grill over it and keep the kids hands away from the driver. 2. No boxes in the room so there would not be any clutter. Very high WAF (wife acceptance factor). 3. Easy to build. 4. Cheaper than a retail sub.

What's a manifold? http://www.facstaff.bucknell.edu/esantane/movies/ibsub.html%C2 This. The drivers oppose each other so the forces cancel each other out. Crank up a driver and try to hold it while playing. It's like a jack hammer. But when they work against each other, there are no external vibrations. Scroll down on that link to the picture of the speakers and amps. See the 2 small openings in the wall? That's where the sub sound comes out. Put a nice grill over them and you will never notice them until you turn up the volume. Also, read the guy's comments on sound quality.

Prices - Fi Car Audio IB subs - http://store.ficaraudio.com/ib3-series/ $224 to $274. I'd go with 15's at least and use a pair of them.
http://psicaraudio.com - The IB subs are built on their Platform 1 system and start at $225. You can get all kinds of custom features that you need. David is a great guy to work with. And he learned his speaker building skills from Scott who owns Fi Car Audio.
Acoustic Elegance - http://www.aespeakers.com/drivers.php?driver_id=71%C2 $350 but these are hand built. Subs of this quality are using in boutique speakers selling for $50,000 and up.
Stereo Integrity - http://stereointegrity.com/index.php?id=61%C2 Yes, it's a 24" sub but you would only need 2 and it would perform better than 6 or 8 15's. Nick also has other options available.

This is not the complete list of subs that are suitable to use. There are literally hundreds available. At one time, I was going to try some older Cerwin Vega V-Maxx (orange surround) 15's but ended up selling them.

Amps - Behringer EP series or iNuke DSP series. The EP amp is just an amp. The iNuke DSP series adds Digital Signal Processing. EQ will make a good sub sound great. It will make a great sub sound fantastic. My sub was a boomy mess when I first built it. Now it's awesome. I use an EP-2500 amp with a Behringer digital parametric EQ. The iNuke DSP amps combine the 2 into a single chassis and allow fine tuning via a PC interface.

What happens if it's open? Close it.

Again my room dimensions are ~1800 ft3 for the theater, but the rear half wall opens into another 3,500 ft3 game room. - To pressurize your theater, you have to pressurize that entire space. I suggest 4 15's or 18's.

And it helps when I include the missing link above to the IB install. http://www.facstaff.bucknell.edu/esantane/movies/ibsub.html

This is all sounding great except for one or two things:

I was going to install a component rack for amps, receiver, PS3, etc. in the left wall between the storage room and theater room for access. This would probably disrupt the separate enclosure pressurization idea. I suppose I could wall it off behind, but I'd have to figure out another way to keep them all cool.

The larger game room behind the semi-open theater room has stairs at the back going upstairs into endlessly larger spaces. I know it's ideal to have the room closed off, but is it absolutely necessary? By that I mean is it not worth doing this and I'll always have crappy bass in a room like this?

Hi guys,

I'm going to sum up the above posts and remaining questions:

Infinite Baffle (IB) system is better and cheaper than any other option. Two 15" drivers are minimum, but four 15" or two 18" are better. Inuke amp with eq. is ideal for this set up. Shouldn't matter where the manifold enters the room (could test that theory).

Questions still on the table:

How closed of a system does the baffle side have to be? (could I have a hole in the wall of the baffle room so my components can be reached with a remote?) (Do I have to install an inside/outside weatherproof door from one room to another to get a good enough seal?)

How closed of a system does the theater room/connecting rooms have to be. (technically my entire house is open due to the open stairwells going from basement to upstairs. I'll need a lot of drivers to move ~30,000 ft'3 of airspace!)

How big does the manifold opening into the room have to be? If I install four 15" drivers in a long manifold that is upright, can I just connect the bottom side to the theater room instead of a long box extending into my storage room? Should I make a 45 degree baffle inside to "bounce" the sound wave into the room?

Finally, is it better to have four 15" or 18" or two 24" drivers (SI for example)? ie. is the bass more responsive with smaller drivers despite the difficulty in moving as much air?

Thanks again for all the advice.

Alright, I've answered some of my questions with more research, and will post it here for others to see/verify:

Manifold opening into the room should be at least 1/2 the combined Sd (area) of the drivers. Check

How closed of a system does my IB room have to be as far as connection with theater room?: apparently there should be a canceling of sound in a node where the two pressure differentials meet, so as long as I don't sit nearby that, I should be OK... I'd like someone to verify this if possible.

IB room needs to be at least 4 times, and should be 10 times the combined Vas volume of all drivers... (that was surprisingly not that big, even for 4 18" drivers) Check

How many/large drivers do I need for my space, since it is partially open to a larger room (total of 7,110 cubic feet) and possibly much much more if the open stairways 25' away matter. I'm trying to design a door into the plan to cut those off, but wife wants it open. Doesn't understand the negative effects on the bass! Some say it matters most that you sit near the manifold (same basic room) and you'll still get plenty of effect. Any thoughts?

Thanks

You have summed it up well. It's basically a trade-off on the open room vs. closed. You will lose the tactile feel of pressurization. Meaning when Optimus Prime punches a Decepticon, you will hear it but the thump in the chest will be smaller than if you were in a closed room.

I was going to install a component rack for amps, receiver, PS3, etc. in the left wall between the storage room and theater room for access.

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The Behringer amps have a loud fan. I mean Cessna taking off loud. I'd make sure it is in the other room completely. Also, you can put a back on your amp rack and only have a few openings for wires. I'd put as much equipment in the other room as possible and use an RF to IR remote system. I'm looking at getting a now discontinued Harmony 890. I've used the IR only 880 (same remote style) for years and it's great. The buttons are getting a little hit and miss plus pointing it to the back of the room is getting old.

Back on subs. If it turns out that IB isn't your thing, then go big and ported. Build a box and keep it in the storage room. Just open the studs to allow the front of the box to face into the room. You can go small and sealed - or big and ported - http://www.danmarx.org/audioinnovation/tcsounds.html . This is an example of what I am describing. The speakers and subs are set into the wall openings - http://www.seaton-sound-forum.com/post/new-convert-to-seaton-sound-3162799?trail=60

How about choice of subs? Four AE 18" push 17.53L (Xmax = 18mm); Four FI 18" push 29.04L (Xmax 30mm); 4 SI 18" push 21L (Xmax 22.5). How much better are the Acoustic elegance subs vs the Fi or SI? Are the reported Xmax values accurate across the board? Is FI the obvious winner just due to more L of air pushed or is there a DEFINITE audio benefit to the acoustic elegance?

Look up Acoustic Elegance, LLC on Facebook. Look at the June 27 posting of the motors with the copper sleeves. This and the shorting rings reduce inductance and distortion. This impacts the higher frequencies more than the sub bass region. That's why these features are more prevalent in AE's woofers in the uber expensive systems.

On the other side, distortion only starts to appear when you are pushing a sub close to its limits. Keep the subs basically loafing instead of working like crazy and you will keep distortion down as well.

Yes, xmax is accurate on these subs. I'd go with PSI first because I know the owner and his shop is less than an hour from me. I'd choose Fi second.

Since you are comparing xmax on subs, look at the XXX from RE Audio. It's not cost effective but it will definitely move the most air of any 18" sub on the market. And this sub was designed by Scott of Fi Car Audio. David of PSI was the president of RE for a while. Nick of SI works in the same location as Jacob of Sundown.

Ok, Great. Lots to look over.

Another question: Four 18" into one cube manifold or Two 18" into each of two different manifolds?

I suggest 2 manifolds with 2 subs each. That way you can get them between the studs. I was able to build a manifold for a pair of 18's from a single sheet of MDF. I have four IB subs using TC Sounds, TC 9 motors (originally from old Elemental Designs Audio subs) and some custom drop-in recones that Scott designed for me.

Sounds good. I think I'm gonna have to be another convert to the IB! I'm going with 4 18" drivers in two manifolds that exit 1' x 2' just under my screen inside my left and rights. Not sure which drivers yet, but I'm researching the information posted above. Thanks guys!