VO-BB - 20 YEARS OLD!

[Ed Gambill]

Correct your DC Off set, that will help.
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[Brian Hudson]

If interested in home studio acoustics recommendations check out this blog.
http://voiceover-casting.com/blog/home-studio-acoustics/

[Brian Hudson]

Be careful of using DC offset as this article I read states:
The Problem

An input capacitor is not required in the amps on this site in the ideal situation. They receive an incoming AC signal (music), and they amplify it for the headphones. Very straightforward.

But in real life, music sources have some DC offset: the AC signal is shifted by some constant DC level. The amplifier multiplies the source’s DC offset by the amp’s gain, and adds some offset of its own. If this total offset is large enough, it can damage headphones, so a source that has an acceptably low DC offset can still become a problem when used with an amplifier.

DC offset is a problem because it can heat up the driver coil to the point where damage occurs. Even if that does not occur, DC offset robs the driver of some of its dynamic range, which raises its distortion. With excessive DC offset, this can cause the driver to overextend, damaging it.

A conservative limit is 20 mV across the driver. If your amp has a gain of 10, then the source must have a DC offset of no more than 2 mV, and that’s assuming that the amp has no DC offset of its own.
Article found here
http://tangentsoft.net/audio/input-cap.html

[Jason Bishop]

You're dead on FF with the blackout curtain info!

Mine are 3-4 inches away from the wall/window and are large enough to accordian instead of laying (or is that lying?!) flat.
The wall/corner behind my mic (see new avatar) has 2" auralex foam covered in thick fabric (to appease the wifey) which is mounted on 1/4" wood panels.
The wall behind has insulation pumped into it and behind that is a clothes closet, so lots of attentuation there.
Then I also have the thick coverlet/duvet that closes around me & my desk which hangs off the hospital/cubical curtain track I mentioned.
In effect, when the curtain is pulled, my 14x14 airy room becomes a 6x5 recording space with -60db of noise floor.
There's also carpet on the floor and jackets hanging off the office door and if I really need it, a queen murphy bed which can fold down to absorb sound.
I still have some hard surfaces (see gear in avatar) so the sound isn't too dead.
The only sound I can't control is the UPS truck rumbling by or the occasional power boat in the intercoastal.

Later,
Jason
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[Ed Gambill]

I use Sound Forge and have for many years. The file you posted has an off set from the 0db base line. In this case DC Offset has notiing to do with the output of audio. Is has everything to do with the wave file crossing through 0db. Read the following from Sound Forge Help Fole:

DC Offset
DC offset occurs when hardware, such as a sound card, adds DC current to a recorded audio signal. This current results in a recorded waveform that is not centered around the baseline (-infinity). Glitches and other unexpected results can occur when sound effects are applied to files that contain DC offsets. Sound Forge software can compensate for this DC offset by adding a constant value to the samples in the sound file.

When you are editing you want to make sure the cuts occure at the base line so as to avoide glitches.
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Esse quam videri "To be rather than to seem"
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[Frank F]

Brian,

Just a quick note regarding your article. It's close.

When doubling drywall (gypsum board) it is not just buying a sheet which instead of being 1/2" inch is 1". The real key is in "de-coupling" the room. to wit; using the proper thickness of drywall, (walls and ceiling) with wall-damping material between the studs and drywall, sealing ANY opening, adding RC-1's (Resilient Channel) damped, and "wall-damp, then adding a second sheet of drywall in the opposite orientation, keeping some distance between the sheet and the floor/ceiling/side walls, sealing ANY opening and the seams between the ceiling/floor/side walls, etc. THEN, and only then will you get an increase in isolation. As for the resonant frequency, this will depend upon other factors, not just the make-up of the drywall - although this method is a good start.

Foam diffusers are not all they are touted-to-be even when hung properly. In addition foam diffusers are usually considered "broadband" diffusers, not dealing with bass at all (or in a very limited fashion is when working in a small room). Bass or "boominess" is one of the bigger problems when dealing with the relative small area of a home VO studio.

No offense to UCSC media arts program, but until you have really worked designing a small studio which has dual uses (recording and listening/editing/mixing), you will not be able to divide the differences between art and science. Acoustics are a blend of both disciplines and; just for fun - personal preferences are added into the mix when working with the acoustics of a home VO studio.

Toodles

F2
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Be thankful for the bad things in life. They opened your eyes to the good things you weren't paying attention to before. email: thevoice@usa.com

[Brian Hudson]

Great reply Frank.

Just to clarify there is gypsum board available that is 3/4 of an inch thick.
Doubled would give you almost 1 1/2 in. of sound proofing, and costly.
Unfortunately most aren`t trying to spend the big dollars to get a great sound.
I/we only wanted to offer good solutions within reasonable price ranges.

But if you wouldn`t mind Frank I would like to add your response to the comment section of that blog post. With your permission, and, of course referencing VO-BB as well.

Kind regards,
Brian

[KaseyKruz]

I did a quick search after remembering something I saw on TV on a home improvement show about noisy neighbors in a townhouse.
http://www.quietsolution.com/html/quietrock.html
This seems to be designed with the application in mind.
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[Brian Hudson]

Great post Kasey.

Brian