Best Way To Dampen Bass In Townhouse?

no, there is no solution for this, at least not within your constraints...

What volume level setting on your AVR are use using to watch movies?

TURN THE BASS DOWN! I live in a townhouse so I feel your pain. But I did have a nice chat with my next door neighbor who wanted to know what was shacking his room when I was watching Inception. Once I explained what he was experiencing we had a laugh and I promised to keep it down when he was home, which fortunately isn't all that often since he works a lot at night.


Ian

Option #1
Buy a $100 sub from Best Buy!

Option #2
Invite your neighbors over whenever you watch a movie!

Seriously though, other than turning the mid-bass volume down you don't have much in the way of options. Depending upon how friendly you are with the neighbors, you could tell them that you'd like to test out your system and find a volume level that you and they can both live with or find out what times of day/night they aren't around or wouldn't mind you blasting your system. Other than working it out with them, I can't think of any non-structural modifications you can make.

Will bass traps help keep sound from leaking out of the room?

^^^

no...

Though I have to admit to some doubts about it's effectiveness, Audyssey is touting their forthcoming LFC product as a solution to sound leakage between walls. It isn't available yet, but might be worth keeping an eye on.

http://www.audyssey.com/audio-technology/audyssey-lfc

I wonder if LFC will be available on receivers with MultiEQ XT 32, or on lesser receivers?

PS I also have some reservations about the effectiveness of LFC...

Pure speculation on my part, but in reading the description on the Audyssey site, LFC appears to require a good bit of processing power. Given that, it may only be available on AVR's that have also have the processing power to support XT32.

It sounds interesting, but the question remains, how more effective is it in terms of preserving the dynamics any more then a midnight mode.


Ian

Audyssey, the gift that keeps on giving, or should I say the gift that keeps on taking

No telling what they can do with psychoacoustics

Just speculating, but my guess is that they employ an aggressive "night mode" DRC combined with generic room material models.

Psychoacoustic models... so now instead of hearing frequencies at low volumes (turn it down) they just simply won't be played at all - or intermittent at best - to trick the brain they are being heard.

You could try putting them on an Auralex Subdude platform and see if it helps but really the only solution is to lower the volume.

Wouldn't that make the bass louder (better)?

Tighter maybe ( highly debatable) but at least it would decouple from the floor. Maybe.

Buy 3 Auralex Subdudes, put one under the sub and the rest under each tower. I did this when I lived on the 2nd floor apartment and I used to watch movies all the time beyond 4am and the bass simply did not travel through the floors and walls due to this method. I ended up selling my towers when I moved to a basement apartment but I still use the one on my sub just to play it safe. It does also give the sub tighter bass which makes it easy to control how much bass gets to neighbors.

Another thing that helps is an AVR that will EQ your sub, something with Audyssey XT32 for example Onkyo 818. These AVR's give you far more control over the bass in the sub and all speakers. I'm sure with this combo of a new AVR and subdudes you would be satisfied with a solution.

I'm going to add that bass traps could help with this problem. It is non-intuitive, but bass traps can increase your perceived bass levels without actually turning the volume up.

If your seating position is in a null mode, a point where the bass reflections interact to cancel each other out, then adding bass traps can make that null mode go away by reducing the strength of the reflected waves. Which means you can turn the volume knob down, which will reduce how much bass your neighbors hear, but still keep the level of bass effectively the same at your seating position.

Again, that's only the case when your seating position is in a null mode to begin with. But it is pretty common.

Not really. Just because you add a bass trap to the corner, it is not going to remove the null or peak at the seating position. If you want to remove the null or a peak then you have to position the bass traps so that the null/peak is removed and this I believe is done by adding bass traps at a proper distance from the back wall or side walls (and of course the ceiling) based on the offending frequency. Why? Because the bass trap will prevent the reflected wave from the walls from causing a null or peaks also work. It also depends on the thickness of the material.

In general bass traps at the corners will reduce some reverberations (boominess) so you will feel the bass is tighter. It is not going to solve the volume issue. I have bass traps (OC 703 panels in the form of a stack of trangles) at corners and also have the 2x4 panels at the back wall though not exactly at a correct distance based on the wavelength. The back panels are mainly to prevent any high frequency reflections.

The subdude is just a waste of money. It is just a piece of foam and MDF. All it does is reduce the vibrations going to the floor. They are not going to prevent the bass from hitting your neighbors. Low frequency travels in all directions. So unless the room is sound proofed, there is no way to prevent bothering your neighbors. Just turn down the volume.

Using bass EQ (Audyssey or Antimode) is the cheapest solution to tame the bass, if it is boomy and the response is not flat. Bass traps, if bought from online stores are ridiculously expensive and DIY is not easy. It is a lot of work to cut them into triangles and stack them. Also just putting a 2x4 panel on the wall is not going to magically remove the peak or null. They have to be placed at a proper location and away from the wall. A lot of people just hang those panels on the walls. That way the bass is not really trapped between the panel and the wall. It just gets reflected back to the room?

^^^

bass traps do not "trap bass in between the panel and the wall"...

no acoustic panel, period, traps sound waves between the panel and the wall...

they ABSORB.... or in the case of diffusors, diffuse...

that being said, they won't help the op...

Well I didn't mean "trap" literally. They would prevent the sound waves from getting reflected by the walls back into the room by absorbing the sound. That is what I meant. No? For this reason, I guess it is better to move the panels away from the wall, even if one cant place them accurately based on the wavelength of the offending frequency. Some suggest leaving some air space between the panels and the wall, whether is like a triangular stack or rectangular panels. But in pretty much every picture I have seen, the panels are hung on the walls like a picture.

Anyway, the bass trap is not the solution for the OP's problem so I will not digress anymore. Neither is the subdude or gramma or what ever gizmo they are selling to make money. If the OP wants to use the subdude anyway, just get some pieces of PC packaging foam (the thick dark grey foam) if you know someone who works for a software company and a piece of MDF. There you go that is your subdude. No need to pay $50 for that. Check out the one I did in that Aurlex Gramma thread.