Room Acoustics


Just tested my media room using the Rives test disc (pink noise) and a RS analog SPL meter.

Couple of things:
- I kneeled behind the meter, which was set on a tripod in my so-called sweet spot for two channel. Certain midrange frequencies were very sensitive to my location and movement.
- For the heck of it I put some FG acoustical treatments (4'x2') at the first reflection points. Plotted the data and found that it impacted some frequencies but appeared to create more spikes a troughs than without!

I am interested in how some of these room treatment companies can quote you a package without measurement!

I'm going to repeat the test from all seven seating locations. Expect to see some wide variation.
quicke
You may want to smooth-out the bass response in your room with bass traps and then work on the other freq. to make the job more easy. Upper freq. will be very easy to deal with unless you have a reverb-chamber for a room.

Dave
Sogood is right..do the bass first (www.realtraps.com) and look at treating all the first order reflection points which are left, right, ceiling, floor. The purpose of the first order reflection points (using either absorption or diffusion depending on your room) is to prevent the delayed echo from reaching your ear. This will clean up the imaging in a huge way. Unfortunately the rives cd test sweap has big gaps and is useful for basic idea but you really need to use something like EFT to sweep a frequency in small increments.
Most "mild" room treatments utilizing thin layers of foam and / or "stuffed" cloth materials, etc... are actually very non-linear in their absorption of frequencies. I commented on this many, many years ago in the Agon archives and posted links to actual absorption curves for commonly used devices. I did this after someone inquired about purchasing some of these devices and told them that they would actually be creating more of a problem. In plain English, most of those types of devices are a big mess.

If you want to treat a room and end up with results that are actually better / more linear than what you started with, rather than just shifting problem areas to different frequency regions, you have to treat the room as a whole. Once again, i recommend that folks pick up and read some books by F. Alton Everest BEFORE spending money on products that you can do a better job of buildng yourself and impliment them in a manner that is more suitable to obtaining optimum results. Not all rooms are the same, nor do they require the same type and quantity of treatments. If they did, they could design speakers that worked within those constraints and did so perfectly. Sean
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