There is no longer a spring in a spring mass equation that normally defines how this driver should work. The big thing is why does this phase plot start at -90 and not +90? I scratched my head, I checked my test setup and could not explain it. I still have the RC network in there that hits 30 degrees of positive phase shift at 10khz through 20khz. Now, ignore the big phase change at the end. Only so much processing power left you know. For me though, a full analog path can be done so I'll go that way so I don't have to think too much. Also, many of us actually DO have old versions of Cool Edit Pro (like me). I'm sure many people will be interested in knowing that. Thanks so much for posting about the free VST plug-ins that can do this. I say that jokingly as I have seen your other posts. Or, if you still have a 32-bit Windows machine going, try to turn up a copy of good old "Cool Edit Pro" before it became "Adobe Audition" - its "FFT Filter" function that allows you to freely draw your curve has a very "analog-ish" phase response, and does a rather good iRIAA on A/D transfers made through an analog RIAA preamp.Ĭhris, I'm thrilled you found us here on LatheTrolls as a new(old)bee. If you have time to put a signal flow chart together that would help us as well.Ĭhris-zwarg wrote:That said, there are several freeware or shareware "VST" EQ plugins that allow one to choose between linear-phase and quasi-analog (phase-lagging) filtering. It could also go through the whole signal chain. It could be run on the output to input on the PC to see what delays are being generated there and it could be applied to compensate. In your manual - look for "Delay Locator / Delay Tracking". Oh, that brings up another thing - be sure to read up on how to do a system delay measurement and apply it. A high reading (near 100%) says the readings can be trusted, low % readings may indicate a problem like not applying the system delay measurements correctly. It's a good thing to do until you get a good feel for what you are looking at. There is also a "Coherence" function that you could turn on to see if the measurement data is stable and if it can be trusted. I'm not saying it is correct to use it, but if the phase polarity turns out to be inverted, and after you fix it and it still starts at zero try moving 0 up to +90 and see if the chart starts to look correct. there is a phase function that lets you move the 0 reference where you want. Next, reading some info on your program (Rational Acoustics Smaart 7), which is crazy expensive. At the first resonant frequency the phase should be zero and start to go negative from there. As the low frequency response curve rises, the phase plot should go down. Ideally, the phase should start at +90 degrees at low frequencies.įirst, look into the polarity of the signal path from the feedback coil to preamp to your PC. But it also seams to be offset starting in the low frequencies by -90 degrees. Ciuens, I'm looking at this phase plot and I'm a bit puzzled.
0 Comments
Leave a Reply. |