Bass reinforcement for very large room

My main system resides in the great room of our open-concept house - essentially a 30x30 open area (entryway, family room, dining room, kitchen) with 15' ceilings.

My second system resides in the 11x15 master bedroom.

Recently I have become especially aware at how much better the much more modest system in the BR sounds - it is weighty and more authoritative. Why? Because no matter what sort of main speakers I use in the large room, it seems they cannot produce enough space for that very large space. In contrast, the BR speakers, with smaller drivers and lesser bass extension, pressurize the room and fill it with sound so easily.

The speakers (now) are Hyperion 938s. They are a quite-capable full-range speaker, solid to the low 30s or so. (The 'lack of weight' that plagues the great room is something that surely extents all the way up to the upper-bass, probably 125-150 Hz, so the speakers' extension is really not too vital. IOW, if they were flat to 20 Hz it wouldn't be much different.)

I am thinking subs are the only/best way to cure this. I could use some kind of EQ - but that would undoubtedly result in great driver excursion and an extreme load on my (modestly-powered) amplifiers. I think I need a lot more driver *area*. In other words, in this case there's no replacement for displacement. (And, by the way, I am no 'bass fiend'.)

I've had subs before. I don't like them because it seems they just never integrate *perfectly*. Especially if they must be relied on all the way up to 100 Hz or higher (which is something I've never even tried).

I don't really have any questions per se and am really just ruminating out loud, but if anyone has any thoughts to share, be my guest. (Moving might be my best bet.)
hi, just curious what size speakers are you using to fill the 30x30 room? i have jbl 4435 studio monitors, and it fills a 40x30 room and pressurizes without difficulty.
Read this:
Sounds like your speakers need more power A room that size will need 350-1000 watts/ch depending on the speakers sensitivity. A quality sub for two channel audio would help but no HT crap. Rel studio would come to mind
>My main system resides in the great room of our open-concept house - essentially a 30x30 open area (entryway, family room, dining room, kitchen) with 15' ceilings.

Modal issues dominate the bass region for nearly all systems and with identical length+width which are an even multiple of height yours are going to be worse than most.

I doubt you'll be able to solve your bass problems without multiple sub-woofers (where placement will fill in some of the nulls and average out the peaks) and/or bass traps (which will reduce the size of peaks and nulls).

The Earl Geddes/Duke LeJune multi-sub reference given by Jdombrow is a fine starting point.
I agree with Drew about the multi sub solution. Integration with the mains can be achieved in this large room and seems easier when there are several subs working at lower capacity. I fought this issue in a room that has large size (15x30 with hall and another room off the sides making for something like a 25x35)When just one sub it had to work too hard and was difficult to integrate, never filling the room. Two was better, and then I stumbled into a deal on a third sub, and that took it to another level. Good luck
While obviously I'm on record as a proponent of multisubs, small rooms are more prone to modal problems than large rooms and so in general multisubs offer more of a qualitative improvement in small rooms than in large ones, counter-intuitive as that may seem.

I haven't run into a situation quite like what Paul describes, but I don't doubt him in the slightest. It is quite possible that a multisub system would work well. I'd suggest setting up at least two subs near the main speakers and crossed over high enough to fill in the weak upper bass energy. If any additional subs are placed well away from the main speakers, they should be rolled off low enough and steep enough that they don't betray their presence by letting lower midrange energy through.

Another possible solution in this case is to use a dedicated midbass sub to fill in the upper bass region. Hsu Research makes such a product. Also, take a look at the new line of subs coming out from GedLee (Earl Geddes' company). I think they include at least one model that's meant to be crossed over fairly high.

Paul your pissin in the wind get the right loudspeaker for your space go big and horn its the right choice for such a space anything else and you will be buying again in a few short months. In my large room 25x35 open to much of the house 12ft h. I use a giant bass horn with 3 way front horn monitors. I have no issues with loading such a space. After all this is what a horn system does best why you dont see direct radiators used much in large venues. Have a great holiday and happy listening.
Apachef1 - you didn't read carefully enough.

Drew, RW, Duke - no doubt that many subs are best. I neglected to provide one important fact - I'm not really expecting the sound/bass to fill the entire space. We listen 10' away on the couch and it just needs to sound good there. The rest of the space is "background-music" territory. Also, I was being vague with 30x30x15 - the space is quite irregular and there are no room node issues.

Two bigger subs along the back wall with the speakers is probably how I need to go. They just need to be good air-movers and I will need to spend a lot of time dialing them so I can get some fill all the way up to the 80-100 Hz region.

John - on the contrary I have not been pissing into the wind - I learned my lesson on that matter a good four months ago and don't plan to try it again, certainly not in the winter.

Seriously - I have tried some horns. Horns do have their issues. 10' is too close for big horns to gel. Etc.

This problem is a problem of bass, so going with horns all-around is not really the solution. It would be if I wanted HIGH SPLs and wanted them all throughout this space but that is not what we do.

Now, one of your big horn-loaded bass systems might be something... but wouldn't fit.
Time to stop fooling around with the 'little' guys. Go directly to the JBL Everest speakers. Big room, big speakers. These speakers were in the Kimber room at RMAF 2009. They are not horned loaded base, they use conventional 15 inch base units in a dual configuration, the mid and top is horned loaded so I think it would overcome your issues.
Does your amp have enough power? I have the same Hyperion 938 speakers in 15x25 room with ceiling sloping from 12' to 20' and can get really loud powerful bass with Rowland 102 (class D) amp (150W at 6 Ohm). If it is a bass node (valley) you should be able to find too much bass (peak) walking in the room.
I have my secondary system in a small room similar to yours and I know exactly the effect you are talking about with the bass pressure in the room. I love that little system. It is my warm cozy winter room. I don't believe you would be able to achieve the same effect in the space you describe no matter what speaker or sub/subs you changed or added. There are many things you can try to improve your setup but it will be impossible to duplicate your small room. Ideas to change your existing space, add walls, french doors, clerestory or transom windows or move. I have a large opening into a kitchen/dining area above an existing partial wall/plant shelf that I want to enclose but use the transom windows to let light in from the skylights in the kitchen. I don't want to move so I keep trying. Good luck.
Buconero117 - New speakers? YOU'RE THE DEVIL! YOU'RE THE DEVIL!!!!

Kijanki - have tried 200W SS and digital amps - tube amps have more & better bass.

Turns out there ARE bass nodes - there is a spot over in the dining area that has mucho bass response. Damn!

Well, there's one REL sub on the way already. We'll see what can be done. Neither the listening position nor the speakers can really be moved.
I'm not sure you need two subs. Scheme with two subs is often used when you need to equalize bass in large listening area (home theater with many rows of seats). For fixed listening position one sub properly placed should be ok especially one that can equalize (with microphone) itself like JL Audio Fathom F113.

Do you still like your HPS-938? There is some "ease" and something very relaxing in their presentation but they are also very snappy and dynamic at the same time.
One more thought - have you tried to rotate bass units? it shouldn't affect imagining since crossover cuts at 220Hz. I assume you have standing wave along the room. Directing bass units inward toward sidewalls might change it (but it looks ugly). Your room amplifies 20Hz (1150/30/2) - too low to get any audible benefit. Nodes in the room will move with frequency and if you have strong nodes then bass is perhaps uneven as well. Bipolar speakers don't make nodes in the room. You can get the same effect firing two bass units in opposite directions - standing waves will cancel but it will look very weird.
12-22-09: Kijanki writes
> Bipolar speakers don't make nodes in the room.

Bipolar speakers most definitely stimulate room modes - I measured over 10dB peak around 70Hz in one room with a pair of Definitive BP8s.

In the modal region conventional speakers are omnidirectional (a 100Hz wave is 11' long and wraps around any speaker you can fit in your living room like it wasn't there). Apart from the force cancellation you get which reduces structure borne vibrations having the drivers on opposite sides instead of one surface doesn't make a difference you can't get by moving a box with drivers on one side.

Dipoles with the front and back waves 180 degrees out of phase do interact differently, producing measurably weaker height and width modes although you need to equalize at 6dB/octave and use multiples to get sufficient head room (with 15" separating the drivers, at 40Hz it takes 4 drivers to play as loud as a single driver in a closed box).
Drew - Are you talking about peaks and valleys caused by standing waves or just room resonances? I read that Planars and Electrostats are praised for the lack of nodes/standing waves - I guess this is the 180 degree back wave type. I never had this type of speaker in my room.
The reason dipoles do not excite as many room nodes are the nulls to the sides. Directly to the sides, the waves fully cancel and there is no output. (Yes, I've had dipoles along with everything else.)

Kijanki, I think the 938 is a very good all-around speaker. Superb, actually.

Your idea of rotating the cabs would probably not work all that well since all cabinet bass is largely non-direction under, say, 60 Hz or so. Also, the speakers are each more than 3' from the side walls already (but I have them very near the front wall for bass reinforcement).

I did read carefully. Your problem is two fold. First your speakers should be able to fill the room. If they are not like you claim the problem my be not enough power and headroom to fill the room adequately. Have you listened to these speakers in a smaller room and achieve a different result with the same equipment?

You seem to want to hear people tell you about multi sub applications more than what the underlying problem may be. I'm in full agreement with the multi sub concept for your application but that may bring a whole new set of issues.

Multi sub applications become very placement sensitive and you will need to experiment. Be flexible when trying to achieve bass that will be time aligned to your main speakers.

Just putting two subs near the back wall next to your main system may or may not cut it and could also cause a cross cancellation between the two subs and/or your speakers.

I you're having some issue with your speakers and room interaction I personally would spend more time with speaker placement and room inter-action to achieve the best possible sound from your Hyperion 938s before spending a lot of money only to find out you may still have the same issues now only compounded more.

You may also find out the Hyperion 938s are just not going to interact well with your room

I'll be totally honest a previous poster mentioned horns for such a large room and he is really not off base at all. Horns become very easy to place in a large room like yours and you will get room filling sound like no other type of speaker. (I'm not an owner of horn speakers) It really sounds like you may be limited on speaker placement WAF issues and the like. If thats the case you may be fighting a loosing battle in such a large space

Good luck I would be interested in what direction you go and the results.

Classic Audio Reproductions T1 or T3 will do the trick.
Apachef1, it seems you failed to note that I am not interested in pushing those drivers to the limits of their excursion, causing distortion. The realization that I have come to is that even a three-way floorstander is not capable of truly pressurizing a space of this size. Adding "more power" is not part of a solution to the problem I presented both for the reason of driver excursion *and because I'm not desiring higher SPLs*. I never said the music is not loud enough at the listening seat - it most certainly is.

Cancellation between subs and speakers is obviously something that has to be dealt with in setup.

I'm not interested in changing the sound of main speakers, which in general I like, especially by a move as radical as going to horns. I'm confident that's not necessary.

Adding a pair of large subs isn't going to really pressurize this space as happens in a small room either, but it's bound to be an improvement. I'm pretty confident that quality stereo subs carefully setup and crossed high enough to fill in even the 40-80 Hz area is worth a good try.
Tvad, it is very generous to offer me a pair of the excellent Classic Audio horns. I would prefer the T1 but will not complain about either. If I did go to front horns it would be those speakers, or possibly one of John K's custom offerings. Or - if you were really going to splurge - the Cogent field-coil horns, which are the best speakers I've ever heard.

They still needs lotsa help below 60 Hz tho.
good luck dude!
They still needs lotsa help below 60 Hz tho.
Paulfolbrecht (System | Reviews | Answers)
Not the Classic Audio T1 or T3.

They need no bass reinforcement whatsoever.

This guy should of just posted that he is interested in multi sub applications instead of all this other BS he has going on here! He's just wasting everyones time who may have recommendations for the core of the problem.

Its his money and someone will be ready to take it
Apache, was that really necessary? Your childish response strikes me as the time-waster here. Just couldn't handle being told politely that you did not grasp the nature of the problem? This sort of nonsense is one of the reasons I don't post much around here.

Let me explain things to you in a little more depth. Your recommendation for "more power" was intended to do - what? Radically alter the frequency response of the speakers? Of course it would not do that, but my explanation of the issue makes it clear it is primarily a frequency response issue. Adding more power just might improve dynamics, which isn't what I complained about, but it sure wouldn't fill in the low-mid bass region unless I *also* turned the *volume up*, which I had/have no reason or intention to do.

Manufacturers (good ones at least) voice speakers with the notion of some room-reinforcement of bass in mind. Most speakers do sound 'thin' in an extremely large acoustic space, which is what we have here. Thus, the problem could be stated as replacing the room-reinforcement that occurs in a small-medium room, which means somehow boosting that bass. That means more driver area for producing bass one way or another.

Tvad's idea of going to horns with 15" bass drivers is not bad, as they have so much direct-radiating area that it might make a difference, but I don't think it would really solve the problem completely and is not viable for financial and other reasons.
You have been very closed minded to anyone with advise other than multi sub applications. I told you I agree with the idea and you keep referring back to one suggestion of more power.

Another poster made the same recommendation.

You are being very condescending to people offering advise that you may not agree with. Do yourself a favor and get some social skills before opening up a topic with good natured people only trying to help you

The end!
Tvad & I know one another a bit and I'm pretty confident he saw my tongue-in-cheek suggestion that he buy me the horns for what it was.

The fact is that your advice didn't speak to the issue at all and I don't think you cared for that being pointed out, however gently.

I stated in the OP that I was simply ruminating on the issue and not seeking any & all advice in the world including changing the entire system.
Paul - 938s, in spite of quite large bass cabinet, are rated only 35Hz. It could be lower but I think they tuned port to get less distortions and not the extension. Sub in that case will serve dual purpose. Sub that equalizes itself and has phase adjustment should be able to reinforce existing bass and add extension. There is an article/study on the web about positioning 2 subs in home theater environment - if you don't have it I might be able to find it.
Kijanki, you are correct; it is not like they are flat to 20 Hz. But even if they were I think they would sound a bit thin here.

One reason I would not change speakers to something that would do that is that the SE tube amps that I tend to favor will never control large woofers going down to 20 Hz.

(Another is that I think the speakers that it would take to really do what I want here would weigh 200+ lb and be extremely expensive. And most would still not properly do it.)

So, those are the reasons that external bass augmentation is the best solution.

Even most speakers that do go down to 20 Hz would not solve the real problem, which is just that there is essentially no room reinforcement to speak of, and extra output in the 20-80 hz region (or so) is what's necessary.
Ever considered Altec Model 19?
It sounds to me as though you should quit listening to music and finish up your home theatre with some subwoofers. Your house has the acoustics of a mens bathroom at Disney World. What's your room treated with? It sounds like you may live in California with no furniture? I can tell you have wall to wall carpeting or a ton of area rugs on organic rolled oat floors.
Yes, Tvad, I will procure a pair of those Altecs.
Paul. I apologize for my snide remarks I posted last night. A little too much Holdiay cheer for me I guess. Good luck in remedying the problem.

Were you the one who told off Aunt Stacy at the party, too? Her passive-aggressiveness can be trying, yes, but damn.

Seriously, don't sweat it, but thanks. It's best to keep it light here.

And guess what? Today, the system sounds wonderful out in the big room. Sometimes that sense of pressurization is really nice, or necessary, and sometimes it just isn't. For whatever reasons (probably mostly psychological).

[Que Charlie Brown Christmas theme.]
I had a fairly big room (33 x 13) when I lived in New Orleans, and it had doors leading into multiple adjacent rooms. The bass impact was noticeably improved when I closed all the doors. Mentioning just in case.
You have your speakers 3' from the side walls with a room width of 30', so they are 24' apart? That doesn't make sense. Speakers need to be close together for good dynamics and tone and energizing the room. And I don't know that having the speakers close to the front wall for bass reinforcement is going to give you the best bass in that room. The best spot for bass in a room that size could be out 12' or something. Maybe your issues are related to speaker placement. Sure, a square room isn't good either. And the suggestions to use multiple subs like the audio kinesis products sound like a solution. And bass trapping as well. But speaker placement is king. You might want to try the speaker placement some people use at shows in square rooms where speakers are placed straddling a corner of a room instead of symmetrically along one wall.
Hard to say but since you have tried subs before and don't like them - I'd say that the bass is not your problem.
Altec model 19 a good idea...
Bmckenney, I mispoke there really: one speaker is 3' from side wall. But the other "side wall" is just a 1' jog in the wall - it comes out just 1 ft. And then another 5' later it jogs a bit more for the bedroom door and then the foyer. But the actual wall is 15' from that speaker.

So, in another words, the speakers are in a 15' "alove" along that wall, which is essentially open on the right side. The speakers are about 8' apart, with the listening distance at 10' as I'd said.

That wall is the only possibly location for speakers. It's how the house is built. The living room is open on the right (foyer/dining room) and the rear (dinette & kitchen).

Shardone, I have tried subs only for very low bass, crossing them sharply at 30-35 Hz. So I think that using subs (and good ones) crossed higher but at lower level might fill in that light-sounding midbass nicely.

I probably somewhat exaggerated (unintentionally) the problem here in the OP. It's not like the room sounds terribly thin or awful - as a matter of fact it sounds great most of the time on most material. But it is lacking that very full/pressurized bass feel you get in smaller rooms. There is "enough" bass to shake the floor on some material, but it's not the same. I've been listening in this room for years, and had not "noticed" this problem, nor had others comment on it, until I acclimated myself to the effects of listening in the smaller room.
I don't quite understand your room(s) dimensions. It sounds confusing. Pictures would help. I have no experience with setting up speakers in a huge room, but I believe if you have big enough speakers you can energize it just like you can a smaller room. If I'm wrong, then sorry.

I know what you mean about an energized room, and I know what you mean when its not. And it is all about speaker placement. But if you have L-shaped room or alcoves or whatever you have, and placement constraints because of the wife or living spaces, then you're screwed. And you can have these same issues in smaller rooms too, IMO. I don't agree that medium and small sized rooms will be always energized at all. I've heard enough that suck so badly, including at dealers who just don't get speaker placement, that I know small rooms will sound like your big room. So I feel its therefore just as possible to load a large room like a small room.

If you have appropriate speakers for the room, size wise etc, you're not done. You need to place them properly.
Smaller room - let say 15x15 will amplify 40Hz (1150/15/2=38Hz) creating effect of bass pressure while 30x30 room amplifies 20Hz not present in music material therefore sounding more flat (natural).
You will save yourself a lot of grief by inserting an Audyssey MultiEQ in the system to smooth any Sub you install...and smooth out any other room gremlins. It's amazing how that device will change the entire sound (for the better).