A while back I attended an AES presentation by an Audio Precision representative about audio specifications. In one of our listening tests we experienced something first hand that you may have experienced yourself; why does some gear with awful specs sound great, while some with great specs sound awful? One point is that specifications generally do not provide enough information or leave important information out. A THD+N specification might be impressive at 0.005% however, what if the test was taken at only 1 kHz with an A-weighted filter? The THD+N might be SUBSTANTIALLY higher in the low frequency and we may never know. It may also help to know which harmonic(s) account for the majority of the THD.
This is simply the tip of the iceberg. Below the surface is a solid mass of misleading, incorrect, and flawed specification testing. Luckily, for us audio nerds there are a few (free!) resources that can help us better understand how to interpret and what should raise red flags when reading testing specifications.
Get Yer Feet Wet
The Rane notes library provides a wealth of accurate and free resources for audiophiles (aka nerds). At this point everyone an their dog has read the Rane paper on audio system grounding. Seriously, I read it to Lola last night. Their Audio Specification paper provides a nice overview of the key specifications, measurement techniques, and how they should appear in the final spec sheet. Good bedtime reading with your dog…or cat if you one of those people.
Dive in Head First
If after reading the Rane paper you still desire more audio specification knowledge, you’re one crazy bastard. Good for you. Luckily, the good people at Audio Precision in Oregon have just what you need. The Audio Precision website has a fabulous White Papers section. They have a book entitled “The Audio Measurement Handbook” for downloaded that provides an in-depth resource of all things audio measurement.
If you’re still craving for more after that, then you have a problem!