Welcome to the MusicPlayer Acoustics forum! Our purpose is to discuss room acoustics, bass traps and other acoustic treatment, and related topics.

If this is your first visit, please read the ACOUSTICS FAQ . This detailed article explains the basics of acoustic treatment, and answers the most common questions we are asked.

The FAQ is admittedly quite a bit to read, but when you are done you will know a lot about room acoustics and treatment! You can also use the Table of Contents, or search the page in your web browser, to quickly find the topics discussed. Then if you have any follow-up questions you are most welcome to post them here in the forum.

Thanks.

--Ethan Winer

Many people ask about substituting MDF or Masonite or some other material for the front panel of the wood panel bass traps in my PLANS article. You can use other materials, but the mass must be similar to that of the 1/8 inch and 1/4 inch plywood used in those plans. See the panel absorber section of this calculator:

Acoustic Calculator

Many people ask about the difference between the wood panel traps shown in my article Build a Better Bass Trap and rigid fiberglass panels mounted straddling the corners. In my opinion wood panel traps are great in larger rooms, but are less appropriate for rooms the size of a bedroom.

The great thing about panel traps is they absorb well at low frequencies without impinging very much into the room. The less than great thing is they are tuned, and absorb well over a range of about an octave only. So for a complete treatment solution you need at least two types: low-bass and high-bass. But that means you need twice as many traps altogether, since each trap absorbs only half the range. In contrast, bass traps based on rigid fiberglass absorb a much wider range, so treating all the corners puts full-range absorption in every corner.

As I see it, the best way to treat a small room - say, less than 15 by 20 feet - is to use broadband absorption such as rigid fiberglass panels in all the corners, including the ceiling corners. This is usually enough to make a very big improvement. But if more trapping is still desired you can then put wood panel traps on the walls alternating the low-bass and high-bass types. For very small rooms, smaller than 10 by 16 feet, you'll do fine using rigid fiberglass only.

One of the most common questions asked here is "Where do I buy rigid fiberglass?" Besides the suggestions for finding a dealer described in the Acoustics FAQ linked above, this company has outlets in various cities around the US:

http://www.spi-co.com/servicecenterdirectory.cfm

And for folks in Northern California there's the Western MacArthur Company in Oakland. Special thanks to Adam Sullivan for putting together this web page:

www.greatmagnetrecording.com/owens_corning.html

Also see THIS "sticky" thread that lists a number of local suppliers.

Often it's useful to post a photo or drawing of a room for others here to comment on. In order to do that you need a web host to store the files, then you can add [img] and [/img] around the picture's web address to display it inside your post. If you don't have a web site, this site will host images for free:

www.imageshack.us

I have never used this site myself, but others report good results.

NOTE: Regardless of where you host your images, please reduce them to a reasonable size. When images are wider than 500 or 600 pixels it's impossible to view them in context, and it's also difficult to read any of the text.

Another way to convey simple room shapes is with ASCII art - dashes and underscores etc. However, the forum software combines multiple blank spaces which "collapses" the drawing. The solution is to use the code and /code tags. The tags go inside [ ] square brackets like other tags, but I can't show it here because it will be interpreted instead of displayed!

Here's a drawing without using code and /code:

+--------------------------------+
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Here's the same drawing using code and /code:


--Ethan

People often express concern about the safety of fiberglass, wrongly believing it causes cancer. This is not true - fiberglass is safe, if irritating to the skin when handling it. The full report is on the American Lung web site:

http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35439