Re: Feature Request: External sweep with REW

This is something I have been wanting to try, although I think I can just use the RTA and a pink noise track for my purposes.

The goal is to confirm if the output from my sources is flat. Specifically, I have a FLAC media player with an optical out. It has no input so I can't route the REW live signal into it. But I could make a pink noise WAV file and load that onto the player, and then run the optical cable into my sound card. I think the only caveat is I must use REW on a PC to access the optical input on my sound card, correct? I prefer the Mac version but don't recall seeing the optical input as an available option in Mac REW.


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Super. Sometimes it takes a few tries.

 

You can loop back from anywhere you want to in your system, as long as you take proper care for signal levels. Even at the AVR speaker output (be REAL careful there!).

 

Any progress implementing a convolver in REW?
I'm really curious to get at detailed analysis of my system with Audiolense XO corrections. I have done the pink noise/RTA test and it looks really promising, but it would have been very interesting to see a frequency sweep, waterfall, impulse response, excess group delay +++ I do not have a jriver license (trial period has expired) and don't want to spend 50$ for a single measurement

 

Re: Feature Request: External sweep with REW

Doesn't audiolense let you measure with the filter in place?

Alternatively you could convolve the sweep with your filter offline and use this as the external measurement sweep.

 

Audiolense only gives a simulated response, which is supposed to be quite good. I could do something like you suggest, do you think it would be possible to simply play a 20-20000Hz sweep through my SBT and at the same time do a measurement with REW? I guess there would be some timing issues, but that might be alright?

 

I would expect the audiolense simulation to be exactly correct if you haven't moved the mic at all. If you want to measure the results across multiple positions then you need to actually measure.

My point is to use an offline convolver (e.g. convolver.sourceforge.net) and feed your convolved sweep in like http://www.hometheatershack.com/for...shack.com/forums/rew-forum/76226-umik-1-timing-reference-phase.html#post1419514

 

Thanks a lot The latest beta version(7) of REW has implemented exactly what I needed. I can generate a testsweep with a time reference and store it on my music server. I can then play the file though my Squeezebox with the correction file installed in the Inquz convolver. The measure procedure waits for the time reference tone before it starts recording. It worked like a charm

 

I am an "old hand" with REW but quite new with using JRiver as a player and active three way crossover. Using WDM as the device for REW works, but all my sweeps are choppy and the measurements "may be corrupted". I made a few trials of the WAV method described above, and it does work. In my case, I tell REW to output to an unconnected port so it's happy I have to manually start the sweep WAV in JRiver; it takes a bit of luck to get the timing right, but it will read a good sweep.