Saturday, August 31, 2013

Door re-test with iPhone, shows 4dBA improvement only

Since I didn't measure the door beforehand with my wonderful Galaxy (not Samsung, Galaxy brand SPL meter from 6 years ago, recommended and sold by Home Theater Shack for use with their famous equalization program) microphone, but only the iPhone, I need to trot out truly comparable before-after measurements, with a huge disclaimer.

The disclaimer is that currently I measure background noise level of 39.0 dB (+/- 0.5 db).  So that sets a limit on even how low infinite sound blocking could achieve.  Actually, I now measure dBA under same conditions as before in the room as 42.0dBA, compared with 46.0dBa previously.  In other words , only a 4dB improvement (comparing apples and oranges by using the Galaxy for the after-measurement showed 9.5dB improvement).  But since the ultimate noise floor is 39.0 dB, that then suggests that the unbiased estimate of the true noise level would be about 39dB (summing 3dB higher to 42dB, assuming no correlation), and more like a 6dB improvement.  It sounds to me more like the larger 9.5dB improvement I estimated earlier.  Anyway, it is showing over 30dB of total noise reduction now (well, from the listening position) which is pretty good.  Before the new door but after the wall upgrade it wasn't seeming like much more than 20dB reduction, as indeed it was measuring (much of that coming from the preceding wall improvements; the door is off axis from the hall that leads to the living room, so actually this isn't a test of the door per se.  Instead, it is intended as a realistic relevant test from the listener to the non-listener.  This is what I seek to maximize here.)

Anyway, with the current best measurement showing 

1 comment:

  1. Hello, I also have an Aragon 8008 BB amplifier -- mine was made by Mondial Designs in 1998, before Klipsch entered the picture. Unfortunately, my amplifier is having some problems, as it won't turn on after sitting for 5 years.

    When I first turned it on after 5 years of sitting, the 12 amp ceramic fuse where the power cord enters the amplifier blew. I replaced with a 10 amp fuse, which immediately blew again, and there was slight smoke rising from the top of the amplifier. (A horrific sight.)

    I'm not an electronics expert, but I assume there is a short somewhere inside the amp. Any ideas? Is the amp killed? I opened the top cover and everything looks pristine, no visible damage, no leaking capacitors, etc.

    I hope no serious damage occurred from this latest smoke incident. The amp has only about 50 hours of use on it, before its 5-year slumber, and is treated with utmost care, having not a single scratch or blemish.

    In your other posting at the below link, you posted a schematic, is that for the Klipsch 8008 version?

    Do you have a 8008BB schematic authored by Mondial Designs? I'm certain the repair shop will ask for the schematic of this beast, and given the weight, I'll have to bring it for repair locally, as it would not survive shipping. I had no idea an amplifier of this caliber could just stop working.

    Hope you can help!