I have a den set up for home theater. 23x21x10 (all real wood walls (not paneling) and tile floor. I currently own a Yamaha rx v3900 with M22's for fronts a vp100 for center 2 M3ti's for surrounds and a 10" velodyne sub. I realize this seems small for the room but I get a really nice sound. What I am looking for is more bass but I have a pretty tight budget. wandering what the least expensive axiom sub I could consider would be and if I could chain it with the Velodyne for extra punch. Does not have to be Axiom, but preferred.

Probably the least expensive option for you would be an EP350 through the Factory Outlet, if you stay with Axiom. You could also look at HSU, SVS, Outlaw, Elemental Design, Paradigm DSP's to name a few good alternatives.

Where is your subwoofer placed in your room? The cheapest option for getting more bass would be to place your single sub in the corner or near the corner furthest from other openings into other rooms.

Also, it sounds like your room is very reflective. One way to tighten things up is to put a throw rug or carpet piece between you and your speakers. Or, adding bass treatements and panels to your room makes a great difference in flattening out your room response in the lower frequencies.

As Adrian mentioned, adding additional subs in your room, normally across on the opposite wall can make a great improvement.

Thanks, the room does have a rug in the middle between the fronts and the seating area. There is also quite a bit of furniture and wall hangings to soften the room. The sub is 3 1/2 feet from the right front corner of the room (right if facing the projection screen). I can completely close off the room from the rest of the house but cannot move the sub any closer to the corner (ext. door).

Just a clarification you say you want more punch which usually comes from the midbass frequencies and is usually has more impact when the source is placed near to and facing your seating. So when you say “punch” are you in fact talking about the chest thumping feeling or the deeper rumble of the low bass or both.

I ask because IMO adding another mid-range sub in a room that size won’t help either cause very much. As Randy said your best bet is first to try repositioning your sub in the corner the way he described playing with it’s distance to the walls to emphasize different frequencies. If you have a calibration disk with a low frequency sweep you could pop it in when you play with the subwoofers positioning to see what effect the position has on different frequencies and also to know for sure which frequencies you’re looking to improve.

Another thing you could try is moving the sub close to and in front of your seating. Midbass frequencies are best produced near field to give that chest pounding feeling. Understand though that if you over do the midbass you’re not getting a flat frequency response though many people are willing to sacrifice it for the punch in the chest feeling.

If more midbass is in fact what you are after you might look into a midbass module like this:

MBM-12 Mid-bass Module

If the deep rumble is what you are after then you might consider a tactile transducer like one of these.

BUTTKICKER LFE KIT

I make these suggestions since you already have a sub and adding another similar sized sub is only going to give you +3dB to +6dB improvement at best depending on how you place it and maybe not even that much in a room that big.

Cheers,
Dean

To clarify "punch" what I really meant was tighter bass. Not really concerned about knocking pictures off the wall. Want better musical performance. What I was originally trying to figure out is with the large room would adding an extra sub or new sub allow for both musicality and the rumble.

I've been intrigued by the concept of a mid-bass module for that extra punch in both music and movies. I briefly read the link on the MBM-12 module above. Thanks for that Dean.

My question is... because it is designed to work in the 50 to 150 Hz range, would the upper range o the 150 Hz mark become just a bit less non-directional than a normal 80Hz and lower sub configuration? It recommends a near listener position and shows an example of being situated behind the listener. It might be a bit odd if you felt the 'punch' of a bullet shot behind your seat when the surround track called for it to be somewhere else. It's normally the higher frequencies that accompany a deep bass sound effect that give you an illusion that a deep bass rumble is coming from where it should be in relation to the action but I'm not sure where that mix really starts to kick in.

To this point perhaps, I noticed that the review including the HSU demonstration had the MBM-12 running from 50 to just 80 Hz. I wonder if they choose it simply for sound quality or to keep it non-directional?

Perhaps is still just too non-directional under 150 Hz to worry about? I'm not sure, thus I ask.

Generally speaking anything below 60 - 80 hz is pretty difficult to locate. 150 hz may be easier to locate than that, but not a whole lot easier. I guess if you found it was too easy to locate, you could always cross it over lower. It's the 60 - 80 hz boost that you're really after with one of these units anyway, right?

80hz and lower is pretty much nondirectional and this is where that punch lies, 50-70hz. This is where the MBM is supposed to work well and enhance that usual crossover point which could have a slight dip between the roll off of the mains to the sub. I run my M80s at 40hz to avoid this I also found running the A1400 greatly improved that mid bass punch opposed to my 3808 alone.

I’m also intrigued by the concept of these and have been looking into them for some time. What got me started was the move from my apartment where my M80s were 6-8 feet away to the house where they are now 11-12 feet away. In the apartment the punch I got from the M80s at that distance was scary. But now farther away it’s not the same. There’s still a lot of kick coming from them but it’s just at the farther distance room modes are interfering with the feeling in all but my EBM styled music.




Though I haven’t used one IMO the bass would be to localizable if the MBM was placed anywhere but in front of the listening position since most things producing it would be on screen. I base this on having tested my EP500 in various location behind my seating. It just never feels right back there.

One of the reasons I keep my M80s crossed at 40-50Hz is to get more of that directional punch than I feel with higher crossovers. Problem is I like having them under the screen for imaging and soundstage across all my seats but that puts them to far away for the near field punch they can give. So the only real solution I see is to place the source of the midbass closer and in front of me. Both are doable since no one but me has veto power on where things go.

MBMs do have there detractors and some of the issues are brought up in this thread:

http://www.avsforum.com/avs-vb/showthread.php?t=768725

Some people just see it as a gimmick. Some people also see the QS8 design and more apropos the Buttkicker as gimmicky but IMO neither is. Specifically the by having the Buttkicker very near field (touching the seating) it can provide a rumble that no subwoofer can w/o overpowering the rest of the LFE.

Another concern is that using a MBM requires integrating another set of drivers and crossovers into the mix which I think is a valid point. I don’t have a problem integrating my Buttkicker but then it’s crossed at 40Hz and below which I think might be a litte more forgiving than 50Hz and up potentially to 150Hz (though I thing it can be cut out lower). Also I don’t use my Buttkicker for music as it adds nothing the EP500 can’t already do. If I get a MBM it would be for movies since the M80s are fine even for the most intense EBM I listen to.

I have no doubt that I will something like this eventually it just depends on how soon I get my butt in gear and start doing tweaking again. Right now I’m just to busy enjoying things and tweaking speaker possitioning to tackle the joint issues of evening out my rooms bass and increasing my bass punch. It might turn out that room treatments might help bring out more of the punch or I may decide to pull my M80s out again though that’s not very likely.

I’ll post anything else I find and hope that anyone else who gets a chance to experience one of these would also.

Cheers,
Dean

Then I suggest that you play with your current subwoofer to see if you can get better performance by tweaking. Changing its location will have an huge impact on what room modes it excites and may help “tighten up the bass.” Also playing with the distance settings can also help. Don’t count on your receiver to set the correct subwoofer distance. Even if you measure it and set it correctly it wouldn’t hurt to play around with the distance settings. A friend, who use to engineer audio, and specialized in doing cannon sound effects took one listen to my auto settings during “Master and Commander” and said my subwoofer distance was off. He tweaked the distance some and the cannon shots went from “Booooooooom” to “Boom.” I would just focus on doing this for your primary seat and if it works then you could look at adding another subwoofer to smooth out the bass response across all your seating.

Something else to consider is bass traps. Might be no matter where you put your sub traps might help it’s overall performance.

Also I’ve found that for very large rooms having full range tower speakers for mains can help produce better bass than a subwoofer + bookshelf combo. Though this somewhat depends on speaker distance/position relative to room size. It’s also possible a completely different subwoofer would make a difference.

However, before doing anything else I would play around with your present subwoofer to see if you can get any improvement.

Cheers,
Dean

Dean thanks for your help. I am crawling around now and moving the sub. Also checking the distance and will just play with a few things and see what I can come up with. Your input is priceless.