Posted by: tfabris
Frequency Test MP3s - 12/04/2000 10:32
Since I just moved my Empeg to a new car, and I'm working on the speakers now, I'm messing with my EQ settings again.
At some point, I realized that having tracks with predefined sine wave bursts would help. So I fired up CoolEdit and made some. I'm sure this sort of thing exists elsewhere on the internet, but it was so easy to do in CoolEdit that I didn't bother to look. Also, doing it myself allowed me to customize the frequency centers to match the Empeg's default ones.
If anyone is interested, here are the files:
Frequency Test - Band Centers.mp3 (File size: 1 meg)
Frequency Test - Sweeps.mp3 (File size: 377 k)
Some things you should know about these test files:
1) My voice (which announces the frequencies) is recorded poorly. There are some strange artifacts that sound like MP3 compression artifacts on the voice. Actually, those are the artifacts from the noise reduction algorithm I applied to the voice sections- it was recorded with a bad mic in a room with three noisy computers running, so I had to noise-reduce the voice. But the frequency bursts were created digitally as pure sine waves and weren't post-processed.
2) I compressed these using AudioCatalyst on its highest VBR quality setting. Up through 9khz, they sound great. But the 18khz bursts came out heavily artifacted, so just ignore those. I guess we have to take Xing's claim about it being able to capture high frequencies with a grain of salt. By the way, if anyone wants to know what worst-case high-frequency compression artifacts sound like, listen to those 18khz bursts.
Tony Fabris
Empeg #144
At some point, I realized that having tracks with predefined sine wave bursts would help. So I fired up CoolEdit and made some. I'm sure this sort of thing exists elsewhere on the internet, but it was so easy to do in CoolEdit that I didn't bother to look. Also, doing it myself allowed me to customize the frequency centers to match the Empeg's default ones.
If anyone is interested, here are the files:
Frequency Test - Band Centers.mp3 (File size: 1 meg)
Frequency Test - Sweeps.mp3 (File size: 377 k)
Some things you should know about these test files:
1) My voice (which announces the frequencies) is recorded poorly. There are some strange artifacts that sound like MP3 compression artifacts on the voice. Actually, those are the artifacts from the noise reduction algorithm I applied to the voice sections- it was recorded with a bad mic in a room with three noisy computers running, so I had to noise-reduce the voice. But the frequency bursts were created digitally as pure sine waves and weren't post-processed.
2) I compressed these using AudioCatalyst on its highest VBR quality setting. Up through 9khz, they sound great. But the 18khz bursts came out heavily artifacted, so just ignore those. I guess we have to take Xing's claim about it being able to capture high frequencies with a grain of salt. By the way, if anyone wants to know what worst-case high-frequency compression artifacts sound like, listen to those 18khz bursts.
Tony Fabris
Empeg #144
