So I’m thinking, should I somehow treat drywall for better acoustics in listening room? For example add another layer of drywall with green glue or mass loaded vinyl between. Or maybe hang some heavy stuff on drywall to dampen vibrations.
There are a lot of different opinions about drywall in listening room. Some people say it can vibrate/resonate and fill room with unwanted frequencies. Other people say, that drywall is a gift if it divides two rooms like in my situation. Because low frequencies (below 100 Hz) pass through to bedroom and bedroom acts like giant bass trap reducing all most problematic low end frequencies. And frequencies above 100 stay in listening room, but they are easily treatable with ordinary bass traps. Actually the sub-bass-traps can be added in bedroom and they should work perfectly if this theory works.
Also I hear “boomy” sound if I hit my drywall with hand. Some people say it is bad, because the same “boomy” sound/frequency can present when listening music. But some other people say that it is very good, because drywall acts like big resonator and reduces bass in this “boomy” frequency range.
So guys, what do you think? Should I treat/rebuild this wall or leave it as it is? I know there is a lot of information about drywall soundproofing, like decoupling, adding more layers, etc. Soundproofing can reduce sound in bedroom, but at the same time it can ruin acoustics in listening room. So my preference is better acoustics in my listening room and NOT soundproofing for bedroom.
The best thing you can do is buy an instrumentation microphone (such as the miniDSP UMIK-1) and get a copy of REW to record the sound characteristics of your room. Then you can really find out how the room is influencing the sound. When you know that you can take proper measures to control the influence of the room rather than relying on nothing more than guesswork.
REW certainly can give insight into room resonances etc…and it is quite interesting to see the nulls and peaks vary as you vary your listening position… or even speaker positions and furniture…
A cheap alternative which can give some insight is to get an audio test track from a streaming service or elsewhere and play a frequency sweep loud. If you have bass resonances or other resonances that will become quite evident.
I‘ve read DBL manual. Solid back wall is recommended but not mandatory. The manual says: “If possible choose a site where the back of the loudspeaker will be against a solid wall”. I assume the same recommendation is for SBLs and Credos. A lot of people have placed these speakers near light wall with wonderful results.
I will say that Credos and Intros were an exception to the rule, as these were designed to be in a free space also, depending on the room of course. You can get either of those models to work in a free space with fairly good results.
Yes, I have Umik mic and REW software and will post results later.
Does anybody know how to distinguish drywall resonance (if any exists) from room mode? Does the resonance have some special distinctive feature that I can find using REW software?
Blue plasterboard (used for sound insulation) should produce better results than regular plasterboard. The blue ones are quite heavy, and come in two thicknesses.
I have used the blue plasterboard behind my speaker’s to great effect. I used it for sound insulating between rooms and put 2 layers on one side.
I used my sbl’s against this and they liked it and preformed much better than against a normal plasterboard wall and even better than the soild wall that they once sat in front off, as the twin blue plasterboard gives a nice dense wall and my soild wall being a light weight block probably wasn’t as dense
I’d put the loudspeakers to the wall at the right side of the room. It will result in similar reflections for the tweeters, and have a solid wall behind them.
In the setup you propose I would be afraid that the right loudspeaker sounds louder and or different than the left one.
As Dunc writes, both. Great sound insulation (we also used two boards, in our case it’s a party wall), and also for against-the-wall speakers as the blue boards add quite some mass to your wall. They are quite heavy…
It’s quite likely that it will cause a sharp deviation in the minimum phase plot around the same frequencies as it comes onto it’s resonance (but it’s not certain to do this).
