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andyc56 last won the day on April 6 2019

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  1. Sorry, there isn't any way to export miniDSP XML configuration files. I've tried to avoid the situation of writing code that's specific to the make and model of the DSP device, as I didn't want to get stuck writing new code every time a new model is released. That's why the interface is somewhat generic in nature (sample rate, biquad count etc). To be honest, my enthusiasm for the project isn't what it was when I first started it a few years back, so I've kept it mostly in maintenance mode, except in cases where I can learn something interesting or generally useful by implementing a new fea
  2. It's been ages, but I've finally gotten a fix for the "stacking" problem in the latest MSO version. An article (PDF) that I recently found detailed how to impose global constraints in the Differential Evolution algorithm without causing convergence problems. I implemented it and it seems to be working well so far.
  3. Here is a link to a Harman study about target curves.Hopefully it will work.
  4. I noticed when reading this article on room gain that there appears to be a few character encoding or decoding errors on the page. It' looks like what was intended as an apostrophe or similar character ended up undergoing some sort of illegal conversion somewhere along the line. It is in the text: "The difference between the two measurements will show the effect the boundaries and acoustics of the space has on the subwoofer�s basic raw response as delivered to the listening position." and "Based on these results, we can then gauge what other subwoofers� maximum headroom and basic
  5. I recently got into a discussion with REW author John Mulcahy about this, and it turned out to be very fruitful. There are several different conventions for "Q" for PEQ filters of different hardware vendors, and some question of how this parameter relates to bandwidth, and even how bandwidth should be defined in the first place. I wrote an article about it to hopefully clear up some of the mystery about different conventions for different DSP vendors.
  6. I haven't tried to do any simulation of finite word length effects on the coefficients. If they were 32-bit floating-point, I guess I could use Matlab's single-precision floating-point arithmetic to get an idea of the error. But with oddball-sized integer coefficients, it seems that would be a PITA to figure out. I'm not a digital filters guy anyway, so I had to read a book on them by Antoniou (the op-amp gyrator guy) to understand what was going on. I had to shake out some mental cobwebs going back to the 1970s. I seem to recall that someone on AVS, it might have been notnyt, had som
  7. I'm having trouble splitting up quotes, so I'll just paste them into regular quote blocks. That's really weird. So just applying a single EQ to a single channel doesn't give the expected measured response? I don't know what could be causing that. Edit: Can you try this with just a PEQ and no all-pass filter in the path? I'll go back and re-check the biquad coefficients for the all-pass filters using Matlab. Internally, MSO computes the filter responses as analog filters. When it computes the biquad coefficients, it uses the bilinear transformation to get the z-domain trans
  8. At the moment, there's no way to constrain the maximum allowable total PEQ boost in a given channel, just individual boost. I've always used MSO with all PEQs set to a maximum individual boost of 0 dB per the default. In this way, if there are any notches in a combined response, it must try to fill them in by minimizing cancellation. I'd suggest giving that a try. You can often fill in response notches by a surprising amount without any boost in any PEQ at all.
  9. This is the first I've heard of FreeDSP, so I'll have to spend some time going through the web site. I can export biquad coefficients in the same format that REW does for miniDSP. These have the miniDSP oddity that the a1 and a2 coefficients in the file are actually the negatives of the coefficients in the transfer function. I haven't used SigmaStudio, so i don't know if it expects the inverted a1 and a2 the way the miniDSP software does.
  10. You're welcome! A while back, you were talking about raising the max allowable center freq of PEQ filters for horn sub EQ. I can look at how to do that while discouraging the high max center frequency usage for more typical applications. Maybe have a special PEQ type that allows it.
  11. Hi, I've had some strange problems when trying to do a loopback measurement of the frequency response of my UMC-200 pre-pro at line level with ASIO4ALL on a Windows 7 machine with AMD processor using HDMI. I was able to get a good sweep again (but only temporarily) by changing the REW output channel to a different one, then changing back to the desired channel again. I don't know if this is the same problem you were having, and I don't know what the sweep would have sounded like, since it was a line-level measurement without a mic. All I know is that it gave me a really crazy looking fr
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