Simple Stereo Measurements With REW on Windows 10

[billm256]

Hello,

I’m a new user of REW and am impressed with its capabilities. However, the vast capabilities are my reason for asking for help, i.e., how do I cut thru all the stuff I don’t need and implement my relatively simple requirements described below.

Sound System: Stereo, no sub, no surround, Speakers are Linkwitz LX521.4s, a 4-way system. Each driver is individually amped with an upstream MiniDSP 2X8 DSP providing Crossover and EQ, so I have full config control of EQ. Typically a single listener is positioned “optimally” or at least symmetrically and predictably.

Measurement Equipment: Ancient Dell Windows 10 PC. MiniDSP UMIK-1 calibrated mic. On the computer, REW detects Java I/O drivers and gives me WASAPI and Hi-Def options. Not sure, but I’ve tentatively chosen Hi-Def Speakers and the Mic, as opposed to WASAPI with Output and Input Volume Control by REW enabled.

Objective: Measure speaker responses at the listener and tweak the DSP accordingly.

I’ve spent a lot of time in REW Help but still have uncertainties about how to proceed, e.g., WASAPI or not, REW I/O volume control or not. And 151 pages of forum posts to search for answers is daunting.

So, recommendations on posts or tutorials that are reasonably consistent with my simple requirements will be greatly appreciated.

Thanks,

Bill McDonald

 

[skid00]

Room Measurement Tutorial for Dummies Part 1

There are few more things transformative in audio than learning how room acoustics works. You never look at any system the same again. Like moving from film photography to digital, measurements give you instant feedback on what your system is doing. Even if you choose to not make any changes...

www.audiosciencereview.com

 

[billm256]

Thank you, I'll check it out.

 

[John Mulcahy]

WASAPI or not, REW I/O volume control or not

Using the EXCL device entries avoids possible Windows processing that can cause issues (e.g. stereo mic inputs can have automatic noise cancellation applied to them). With EXCL volume control usually isn't available but in any case all REW is presenting is the Windows volume controls. It doesn't matter whether you let REW access them, but it is best to set the UMIK input to its 0 dB gain setting (around 53%) which REW will do if allowed.

 

[billm256]

Thank you, I'll check it out.

Using the EXCL device entries avoids possible Windows processing that can cause issues (e.g. stereo mic inputs can have automatic noise cancellation applied to them). With EXCL volume control usually isn't available but in any case all REW is presenting is the Windows volume controls. It doesn't matter whether you let REW access them, but it is best to set the UMIK input to its 0 dB gain setting (around 53%) which REW will do if allowed.

Great info, thanks John. I was heading the other way.



Bill

 

[MediumRare]

@billm256 would love to see your FR results (and more, such as ETC) when you have them. I’ve heard your speakers at Axpona and they’re very interesting.

 

[deercreekaudio]

Hello,

I’m a new user of REW and am impressed with its capabilities. However, the vast capabilities are my reason for asking for help, i.e., how do I cut thru all the stuff I don’t need and implement my relatively simple requirements described below.

Sound System: Stereo, no sub, no surround, Speakers are Linkwitz LX521.4s, a 4-way system. Each driver is individually amped with an upstream MiniDSP 2X8 DSP providing Crossover and EQ, so I have full config control of EQ. Typically a single listener is positioned “optimally” or at least symmetrically and predictably.

Measurement Equipment: Ancient Dell Windows 10 PC. MiniDSP UMIK-1 calibrated mic. On the computer, REW detects Java I/O drivers and gives me WASAPI and Hi-Def options. Not sure, but I’ve tentatively chosen Hi-Def Speakers and the Mic, as opposed to WASAPI with Output and Input Volume Control by REW enabled.

Objective: Measure speaker responses at the listener and tweak the DSP accordingly.

I’ve spent a lot of time in REW Help but still have uncertainties about how to proceed, e.g., WASAPI or not, REW I/O volume control or not. And 151 pages of forum posts to search for answers is daunting.

So, recommendations on posts or tutorials that are reasonably consistent with my simple requirements will be greatly appreciated.

Thanks,

Bill McDonald

Here is a Tech Video of ours - Making and interpreting measurements to build the foundation for a proper sounding system. We hope this helps with your learning curve.
Using Key Measurements to Verify Basic System Setup

 

[billm256]

Using the EXCL device entries avoids possible Windows processing that can cause issues (e.g. stereo mic inputs can have automatic noise cancellation applied to them). With EXCL volume control usually isn't available but in any case all REW is presenting is the Windows volume controls. It doesn't matter whether you let REW access them, but it is best to set the UMIK input to its 0 dB gain setting (around 53%) which REW will do if allowed.

Hello John,

I'm extremely frustrated with your website! I've tried to reply to two helpul responses to day. I spent considerable time composing one response.

In each case I'm disallowed with an ambiguous message about spam or posting links before I've passed some threshold. In neither case did I do either! In the first, my advisor sent a link, I did not. All I said was, "Thanks, I'll check it out." In the second, no spam, no language, no links. I did attach a couple of .mdats per my advisor's request. What's going on?!

I wonder if this post will be allowed.

Sincerely,

Bill McDonald

 

[billm256]

@billm256 would love to see your FR results (and more, such as ETC) when you have them. I’ve heard your speakers at Axpona and they’re very interesting.

Thanks for your interest!

Yes, interesting speakers, pure dipoles, front baffles designed for optimum room interaction without concern for cosmetics (although many think they’re attractive), each driver individually amplified, i.e., no intervening xover. Several years ago, Peter Aczel said, “I have not tested or even briefly listened to every high-end loudspeaker out there, but of all the speakers known to me none equals the Linkwitz Lab LX521. . . .” His review is available online, just google “the audio critic web zine”, navigate to the table of contents, and Peter’s review is one of his last, i.e., near the top. The review also has a section on measurements. Some will find his other articles over many decades interesting, informative and refreshing, as he was a highly-knowledgeable and honest realist who frequently debunked prevalent audio-.

My individual problem is these speakers need significant breathing room; they need to be at least a meter from any wall. My room is barely able to accomplish this. Also, the room is highly asymmetrical, much open space on the left and completely closed on the right, including a 4’ wall facing toward the R speaker.

Despite these challenges, I am extremely happy with the LX521.4s; they are by far best speakers I’ve owned. (But always striving for perfection.) Incidentally, they are so good at filling the room with sound, I recently retired my surround speakers and an 18” Velodyne servoed-sub. I.e., now a pure 2.0 system, and I’m much happier with the current sound, including even the bass, than I was before the retirement!

So, I finally got around to measurements yesterday, results are attached. Other than my rolling the bass off sharply below 30 Hz (I watch movies that sometimes have destructively loud and deep bass), these were taken with Siegfried Linkwitz’s recommended xover and eq settings. This is my first attempt; my thinking may evolve, and my measurements may improve.

My next step is to eq variations between L/R. I currently listen w/R down by 3 dB to position voices in the center as appropriate. First examination of my measurements indicates some R channel peaks in the frequency range I assume voices or their harmonics occupy. I’ll see if I can reduce these and will test primarily by listening to determine if the voices center without my 3 dB cut.

Again, thanks for your interest. Any advice or observations will be appreciated.

Bill McDonald

 

[billm256]

Here is a Tech Video of ours - Making and interpreting measurements to build the foundation for a proper sounding system. We hope this helps with your learning curve.
Using Key Measurements to Verify Basic System Setup

Thank you, I'll check it out.

 

[billm256]

Hello John,

I'm extremely frustrated with your website! I've tried to reply to two helpul responses to day. I spent considerable time composing one response.

In each case I'm disallowed with an ambiguous message about spam or posting links before I've passed some threshold. In neither case did I do either! In the first, my advisor sent a link, I did not. All I said was, "Thanks, I'll check it out." In the second, no spam, no language, no links. I did attach a couple of .mdats per my advisor's request. What's going on?!

I wonder if this post will be allowed.

Sincerely,

Bill McDonald

Ok, I took another clean run at both posts and both were successful this time; they were exact copies of the ones which previously failed. I'm still frustrated and doubt I'll waste more of my valuable time fighting w/this website.

Thanks for your good work and capable product, but you might want to tell your webmaster to do a better job of vetting posts.

Bill

 

[John Mulcahy]

Ok, I took another clean run at both posts and both were successful this time; they were exact copies of the ones which previously failed. I'm still frustrated and doubt I'll waste more of my valuable time fighting w/this website.

Thanks for your good work and capable product, but you might want to tell your webmaster to do a better job of vetting posts.

Bill

It's not my site.