Tall shelving in the corners where the speakers are near.
I stuck together (glued/screwed/stacked) cheaper self assembled shelving that winds up 88" tall on sides in corner. I have windows behind with full drapes. The shelves really cut the echoing. and the bass booming. i would try a live end dead end with furniture. shelves. pictures. wall decorations nearer speaker end...
Stuff to alter the square shaape problem.
Use normal stuff instead of wierd audiophile stuff. Shelves, pictures. (Even pictures with deep frames and sand inside!!)
Furniture on side walls...
Soundproofing and room correction are two different animals. Soundproofing a room deals with adding mass such as adding another room inside a room. That of course would be somewhat costly. So unless you own the apt it would not be worth it. Now sound correction is much easier on the pocket book and there are many ways to accomplish this. The problem right off is your room is a perfect square with high ceilings.The rug will do very little with controlling sound. The best move would first to tame bass with upper corner traps and bass traps where the walls meet. You should use no less than 4" panels as long as WAF gives you the nod. Use panels in white.I say in white because the room is small so not to close it in. Once the bass is taken care of, most things will fall into place sound wise.Buy her a nice piece of Jewelry. That will give you a stronger handle with room acoustic.
Elizabeth makes some great comments. Go slow, one object at a time so you can sense the change. As to the WAF 'canvases on the wall', best to try some ceiling to floor lined drapes in key spots. If you pull the drapes out from the wall two inches, things like echo busters etc. can be mounted behind them so all that is seen is the drapes. JC Penney makes some great look drapes that are very inexpensive. Hey, you could even use that hideous foam carpet padding on the walls, covered by the drapes.
Also, measure the sound in your room, step by step. There are some great free software programs that can be used so you can 'see what your hearing'.
There is not that much one can do to soundproof an apartment that does not involve some construction work. What you are already planning is almost all you can do in that area. The use of carpeting, particularly with a very good pad that is designed to reduce sound transmission is the most important thing you can do. Wall treatments may reduce the amount of higher frequency transmission, but, bass is almost unstoppable without major work. An acoustic isolation platform under the speakers (instead of spikes or couplers) can help with isolation and actually improve the sound (e.g., Symposium Svelte Shelves) of the system.
Major work can be as little as adding another layer of sheetrock to the existing walls. There are adhesives that are designed to provide some acoustic isolation between the two layers ("Green Glue") and these are quite effective.
If you can't really isolate the walls, your best approach is to get your system/room to resolve and provide satisfying sound at LOWER volume levels. It appears that you are well on the way in those respects. I personally like the way Devore speakers sound at lower volume. Tube traps can do a lot to improve the sense of clarity and articulation in the system. Tapestries on the wall can tame higher frequency slap echo (try these first, without any special, ugly, acoustic treatments). Go slowly with acoustic treatment panels because it is easy to over do them and make the room sound sterile. Bookshelves and record racks make terrific sounnd diffusers (particularly if all the records are not pushed in all the way so that they create an irregular pattern.
Choice of speakers can also dramatically affect the amount of sound transmission. When I switched from electrostatic speakers to regular dynamic speakers I notice that there is a LOT more sound spilling out of the listening area with regular dynamic speakers. With dipole speakers (electrostics, planar speakers), the back and front waves are out of phase and cancel at the sides. This means that the soundfield is much more focussed in the area between the speakers. In particular, electrostatics work well in apartment situations because of this dipole cancellation and their ability to sound good at lower volume (bulky size and placement demands are the downside).
Thanks everyone for the answers. I'm going to go slowly and just do the acoustic pad under wall to wall carpeting then put in record shelving and a tapestry or two, plus drapes on the windows. If my neighbors complain, then I'll look into heavier-duty stuff. I own the place, and it's a Condo, so I can do what I want, but I'm just not going to do more sheetrocking, as it's already a smallish room. Something on the ceiling seems good, but what?
I suggest you consider something like the Tact gear.
So I had a small chat with my neighbors yesterday who said they can hear the bass from my stereo. I was listening at not-overly loud levels, although for me that may be louder than for them. I'm clearly going to have to address this. That, or give up listening, which I don't see doing.
I'm looking into having a sheetrock ceiling put up with insulation between the original ceiling and the lowered one. I'll also have acoustic padding put on the floor with wall-to-wall over it. I just simply don't have the extra room (sorry for the pun) to put up additional walls, so I'm really looking for recommendations on what I can do with the walls now to make it better: canvases with acoustic batting in them? Corner mounts? Bass traps? What?
Also, anyone have any experience with putting their speakers on platforms to prevent bass traveling? That seems to be the biggest issue here.
You need to get a book on acoustics and soundproofing. It is pretty hard to isolate bass frequencies.
Most of what you can put on the walls and ceiling will attenuate higher frequencies, but lower frequencies are tough. I don't think bass traps will actually lower the amount of bass transmitted to another apartment appreciably, but, if they, and other acoustic treatment improves the sound, you would tend to want to listen at lower levels than before.
As i mentioned before, the use of another layer of drywall with "green glue" between the layers will provide some bass isolation. This should not take up that much more room (compared to a second wall). There is quite a bit of discussion of green glue if you google the term, such as the following:
A friend had a professionally designed (Rives) dedicated listening room installed in his home and a lot of that stuff was used in the construction.
I bet that the extrasheet rock on the ceiling (with green glue in between) and a really good pad under a thick carpet will do quite a bit to reduce noise transmission. This would absorb some of the energy and provide extra mass, which also inhibits transmission of sound. Doing the walls too, would help, even if the big problem is with transmission to higher and lower floors rather than next door, because bass energy transmitted into the structure travels everywhere.
An energy absorbing platform under the speaker or speaker stand should provide some isolation from direct transmission of vibration from the speaker itself to the floor. Even if it only provides a little help, it is better than nothing, and besides, it often improves the sound of the system.
One more reference to Green Glue. I recently heard an NPR broadcast about environmental noise. The guest, who recently wrote a book, actually mentioned Green Glue as one of the modern technological marvels that helps in reducing noise. A transcript can be found here:
Thanks so much Larry, really helpful! I'm going to start bit by bit so I can get a sense of how the things I add change things for the better.
First definite changes will be platforms for my speakers, then wall to wall carpet with acoustic padding underneath. Then I'll some bass traps and wall/corner treatments and make sure the door seals well.
My neighbor is fine with me being in their space to see how much sound is transferring, so I can get a sense for how I'm doing with the treatments. Last resort will be dropping the ceiling.
One thing that I am thinking in the back of my head is that I may have too much speaker for the room. I have Devore 9's, and the room is roughly 12 x 12. Should I try the super 8's?
I have heard both DeVore speakers in somewhat small rooms and really like both. I don't think there would be that much difference between the two for your sound transmission problems. The BIG difference would involve the use of a fundamentally different kind of speaker, like the Quad electrostatics or Magnepan speakers (for the dipole cancellation reasons I mentioned before). The current Quads sound pretty good at low volume too, helping your problem even more. But, I can understand your desire to stick with the DeVores; they are really nice sounding speakers.
Well you cannot easily block low frequencies... that takes mass, lots of it and space.
You can however remove the low frequencies from your main speakers and divert those notes to woofers / sub-woofers right next to your listening spot.
This will diminish the level at which you play the woofers and of course the level to the adjacent domociles. A 6 dB reduction in energy should be easy to get.
This is going to require either a very low turn over frequency or some time dalay for the woofers... easiest to do in the digital domain.
I agree with schipo, your treatments may alter the sound, but they will do little to "soundproof" the room and protect the neighbors from 2 am listing sessions. !