Wave Generator gain bug (or peak bug)

Chester01 · Feb 8, 2005, 10:38 PM

If you connect the wave generator to a peak plugin, it will be set to output -3 db at default, Peak will read -3.5, why? I dont know which plugin is at fault here. Just something I have noticed

eyagos · Feb 9, 2005, 03:42 AM

The error is in peak plugin: It is not exactly linear. If you set -12dB in wavegen you'll see -12dB in peak.

Chester01 · Feb 9, 2005, 05:06 AM

I noticed that when setting the wave generator to 0.0 db also (peak is at 0.0) however I do not see how this means the peak plugin is at fault?

townkat · Feb 9, 2005, 11:58 AM

i made a test with soundforge
-wavegen 1/2 outputs into wmm recording, voulume set to default -3 - soundforge reports -3.6left, -1.7right channel; this depend alot on wich wavegen output is used
-soundforge generated syn at 0.0db-peak reporting -0.7 left;-0.7right
Considering Soundforge an pro app seems that both plugins are not well calibrated, but seems that peak have an smaller error.
cya

townkat · Feb 9, 2005, 11:52 PM

I belive for peak it may be because of the log function from the kx dsp being an aproximation of log and not the exact value and peak plugin use the log function to get its peak level , for wavegen probably is a similar reason
cya

Chester01 · Feb 10, 2005, 12:16 AM

just curious, is there a way to have a more accurate log function? or is this 10k1/2 chip limited?

eyagos · Feb 10, 2005, 01:03 AM

The LOG instruction, combined with a little interpolation, gives very accurate ressults.

PD: But Peak uses the LOG function, and there is no need of using it. I never use it in my VU-meters.

Feb 8, 2005, 10:38 PM	#1
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	Wave Generator gain bug (or peak bug) If you connect the wave generator to a peak plugin, it will be set to output -3 db at default, Peak will read -3.5, why? I dont know which plugin is at fault here. Just something I have noticed __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Feb 9, 2005, 05:06 AM	Thread Starter #3
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	I noticed that when setting the wave generator to 0.0 db also (peak is at 0.0) however I do not see how this means the peak plugin is at fault? __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Feb 9, 2005, 11:58 AM	#4
townkat DriverHeaven Lover Join Date: Sep 2003 Location: Romania Posts: 123 Rep Power: 0	i made a test with soundforge -wavegen 1/2 outputs into wmm recording, voulume set to default -3 - soundforge reports -3.6left, -1.7right channel; this depend alot on wich wavegen output is used -soundforge generated syn at 0.0db-peak reporting -0.7 left;-0.7right Considering Soundforge an pro app seems that both plugins are not well calibrated, but seems that peak have an smaller error. cya __________________ mixy kx plugins http://mixy.0fees.net/

Feb 9, 2005, 11:52 PM	#5
townkat DriverHeaven Lover Join Date: Sep 2003 Location: Romania Posts: 123 Rep Power: 0	I belive for peak it may be because of the log function from the kx dsp being an aproximation of log and not the exact value and peak plugin use the log function to get its peak level , for wavegen probably is a similar reason cya __________________ mixy kx plugins http://mixy.0fees.net/

Feb 10, 2005, 12:16 AM	Thread Starter #6
Chester01 HardwareHeaven Senior Member Join Date: Jan 2004 Location: St. Cloud, MN Posts: 492 Rep Power: 0	just curious, is there a way to have a more accurate log function? or is this 10k1/2 chip limited? __________________ COMP: Dual Intel PIII 733 Mhz; GeForce 4 Ti 4600; 1.128 Gb RAM; SB0350 (Audigy 2 ZS Platnium) STEREO(I UPGRADED):Crown Audio K1 and K2 amplifiers (4000 watts at .1% THD ), JL 13w7 Subwoofer (6.5 CF) (2) 18" PR's, Klipsch SB-1's, some cement blocks for speaker stands...

Feb 9, 2005, 03:42 AM	#2
eyagos DriverHeaven Addict Join Date: Dec 2002 Posts: 259 Rep Power: 0	The error is in peak plugin: It is not exactly linear. If you set -12dB in wavegen you'll see -12dB in peak.

Feb 10, 2005, 01:03 AM	#7
eyagos DriverHeaven Addict Join Date: Dec 2002 Posts: 259 Rep Power: 0	The LOG instruction, combined with a little interpolation, gives very accurate ressults. PD: But Peak uses the LOG function, and there is no need of using it. I never use it in my VU-meters.