Fridge Buzz gets into Iso Room

So I recently built a 5' x 6' iso room in my apartment and when the compressor is on, the fridge buzz still gets inside. What's the best material to block the frequency of fridge buzz? From inside out (on a 2"x2" frame) I have: Armstrong Ceiling panels doubled up back to back (see cross section and coefficient pics)" 5/8/" Soundboard 1" TUFF-R foam insulation 1/8" HDF

My first guess is that the sound is coming through "flanking paths." There is that gap at top limiting how much isolation you get. Andre

All the walls were prebuilt and joined with 1/4" neoprene rubber insulation tape. There is no floor - just four walls and a ceiling on a carpet. It sounds like it's just coming through the walls, but maybe I need more rubber around the door.

maybe get the fridge up on some Kinetics pads.

With the fridge running, go around the enclosure with a microphone hooked to a meter and note where the noise is the loudest :D Sorry, I was not thinking before. Andre

AVare wrote:

With the fridge running, go around the enclosure with a microphone hooked to a meter and note where the noise is the loudest :D Sorry, I was not thinking before. Andre

You can acheive the same - with a much lower sound level (most cheap meters won't report anything below roughly 50dB) using a mechanics stethoscope. That's what I use when I fine tune and adjust everything in the end. http://tinyurl.com/235tnn Rod

rod gervais wrote:

You can acheive the same - with a much lower sound level (most cheap meters won't report anything below roughly 50dB) using a mechanics stethoscope. That's what I use when I fine tune and adjust everything in the end.

Thanks Rod. It very rare that I disagree with what you write. I think this about the third time. :lol: Your past posts about using a stethoscope are what caused me to have the epiphany. Measure he relative levels of the sound at different locations. And yes, my post started with using a stethoscope. But thinking expense, I recalled that he has all the equipment already in the studio! When I wrote "meter" I was not explicit. I meant "hook up the mic to your recording system, turn down the speakers (to avoid feedback, turn up the gain on the mic so that the level on the meter of the gear when the mic moved along the partition shows a response." No intent to mean an SPL meter. If this keeps up Rod, I'll be disagreeing with you again circa 2010. Respectfully: Andre

AVare wrote:

rod gervais wrote:

You can acheive the same - with a much lower sound level (most cheap meters won't report anything below roughly 50dB) using a mechanics stethoscope. That's what I use when I fine tune and adjust everything in the end.

Thanks Rod. It very rare that I disagree with what you write. I think this about the third time. :lol: Your past posts about using a stethoscope are what caused me to have the epiphany. Measure he relative levels of the sound at different locations. And yes, my post started with using a stethoscope. But thinking expense, I recalled that he has all the equipment already in the studio! When I wrote "meter" I was not explicit. I meant "hook up the mic to your recording system, turn down the speakers (to avoid feedback, turn up the gain on the mic so that the level on the meter of the gear when the mic moved along the partition shows a response." No intent to mean an SPL meter. If this keeps up Rod, I'll be disagreeing with you again circa 2010. Respectfully: Andre

Andre, With all due respect - when it comes to the point of fine tuning - you cannot EVER pick up with any mic that you will find in any recording studio in the world - the sound levels you can with a stethescope. When you purchase sound iso doors from the real deals (picture companies like Overly) their specs called out requirements for field testing using certified techs =- hwever = when I informed them that I would be performning the testing myself (I wanted it done right the first time) they provided me with a copy of their test casette tape (white noise) and insstructions to set up sound source on one side of door (85 dB levels) and use the stethescope to travel the perimiter of the door seals looking for any point where the sound could be heard - - making adsjustments as necessary until no noise could be heard. You don't need to measure the sound levels - just make them go away........ BTW - I used this method to tests the entire perimiter of Studio 15 @ Sonalysts Studios in Waterford CT (15,00 sf - 750,000 cf) including any and all penetrations (cable - HVAC - as well as caulked corners, wall to floor junctions, etc.) and found it to be very effective in taking that last final step in sound isolation. Listening at that level shows up even the smallest imperfection - allowing you to correct as you go. I'll take that over a studio microphone any day of the week. Sincerely, Rod

Thanks Rod. I was starting with no budget. Your system works with world class standards. An example of a pro setup doing similar thing to what described is shown in the image on pdf p6 of: http://www.bksv.com/pdf/bp1755.pdf Respectfully: Andre