Distortion noise coming from my speakers measuring with REW

[meek81]

So when I use ASIO in REW to do sweeps of any of my front speakers (L,C,R) there is this noise that comes through the speakers as the sweep begins and through the sweep as well, the noise sounds like a digital machine gun firing that’s the best way I can describe it lol, does the same thing when I measure my subs as well. I’m using hdmi through my laptop and when I switch to Java drivers the distorted noise goes away. I tried different hdmi cables but the noise is still present but only when I use the ASIO drivers.. any idea what might be going on?

 

[John Mulcahy]

That might be caused by the REW sample rate being different to the sample rate in the Windows audio properties default format setting.

 

[meek81]

I see I’ll have to check it to see where I have it set at.. I followed Austinjerry’s REW guide but maybe I entered something wrong. What should the sample rate be set at in windows audio properties? And I’m assuming it’s the mic properties correct?

 

[John Mulcahy]

For replay, which is where you said the problem happens, it would be the rate for the HDMI connection. 48 kHz is typical.

 

[AustinJerry]

I see I’ll have to check it to see where I have it set at.. I followed Austinjerry’s REW guide but maybe I entered something wrong. What should the sample rate be set at in windows audio properties? And I’m assuming it’s the mic properties correct?

Page 14 of the guide recommends setting the Windows Audio sample rate to 48KHz, which matches the sample rate of the UMIK-1. The newer UMIK-2 supports a 96KHz sample rate, so the Windows Audio setting should be set to the same value.

 

[hotwheels_04]

This is the sound im experiencing also!

First time user here, initially bit rate for hdmi and mic the same, then changed hdmi higher to see if it made a difference. Either way i matched windows settings to rew. Pink noise is fine, other set up test tones good. Note i am using an anthem arc mic.

 

[hotwheels_04]

I see I’ll have to check it to see where I have it set at.. I followed Austinjerry’s REW guide but maybe I entered something wrong. What should the sample rate be set at in windows audio properties? And I’m assuming it’s the mic properties correct?

Did you end up sorting this?

 

[meek81]

Did you end up sorting this?

Well I checked to make sure windows and REW match up and they are both set to 48KHz, I just haven’t had time to run some sweeps to see if the distortion is still present. I have some time off from work on Wednesday so I’ll run some sweeps then and see if it’s still doing it, I just think it’s weird that it distorts when using ASIO but not when I use Java??

 

[meek81]

Page 14 of the guide recommends setting the Windows Audio sample rate to 48KHz, which matches the sample rate of the UMIK-1. The newer UMIK-2 supports a 96KHz sample rate, so the Windows Audio setting should be set to the same value.

What if I tried 16KHz In windows and REW? Or would that mess with umik measurements since it’s sample rate is 48KHz?

 

[hotwheels_04]

Well I checked to make sure windows and REW match up and they are both set to 48KHz, I just haven’t had time to run some sweeps to see if the distortion is still present. I have some time off from work on Wednesday so I’ll run some sweeps then and see if it’s still doing it, I just think it’s weird that it distorts when using ASIO but not when I use Java??

Ahh ok. Yes so its the asio part of it it sounds like. I tried setting up in java but couldnt get it set up properly.

 

[meek81]

So I am at a loss as what to do here… I am still getting popping and cracking sounds from my speakers and subs when taking REW measurements using ASIO. I have tried everything I can possibly think of, I even tried using a lower buffer of 256 instead of the 512 in the preferences tab in ASIO but no change, popping and crackling sounds still present. I’ve triple checked my umik and AVR settings in windows and all is as suggested in @AustinJerry REW set up guide, Java works with no issues but can only measure L R speakers but not my center… so I don’t know what xover would be best when trying to align it with my subs. Help please?

 

[John Mulcahy]

If buffer size is an issue it should be made larger, not smaller. It would be best to use the same crossover setting for left, right and centre assuming they are similar, to minimise any change in the character of sounds that pan across.

 

[AustinJerry]

So I am at a loss as what to do here… I am still getting popping and cracking sounds from my speakers and subs when taking REW measurements using ASIO. I have tried everything I can possibly think of, I even tried using a lower buffer of 256 instead of the 512 in the preferences tab in ASIO but no change, popping and crackling sounds still present. I’ve triple checked my umik and AVR settings in windows and all is as suggested in @AustinJerry REW set up guide, Java works with no issues but can only measure L R speakers but not my center… so I don’t know what xover would be best when trying to align it with my subs. Help please?

While I agree that getting ASIO working properly would be the best solution, you can still be reasonably productive using the Java drivers. To measure the center channel, set the AVR sound mode to Dolby Surround (or Dolby ProLogic II, depending on what your processor has), and then output the measurement sweeps to both the left and right speakers. Identical signals to left and right using Dolby Surround are routed to the center channel. And to measure the sub channel, do the same, but unplug the center speaker cable. As long as the center is set to Small, low frewuencies below the crossover are routed to the sub channel.

Being able to measure left, right, center and subs using Java should be quite useful.

 

[Bestboy4]

@meek81 I am experiencing the the same thing. Java sounds perfect, but ASIO sounds distorted and clipped. I have adjusted output levels, and tried different sample rates and bit depths to no avail. It is very frustrating to finally get the functionality of speaker selection via ASIO, but then have unusable tones. Having to disconnect speakers is a real pain

 

[Bestboy4]

Hey I figured it out ya'll. You have to increase the buffer size for ASIO. See here

 

[AustinJerry]

Hey I figured it out ya'll. You have to increase the buffer size for ASIO. See here

My ASIO buffer remains at the default it set upon installation--512 samples. I haven't been experiencing any noise issues. I wonder what is different about our setups? Interesting to hear from @meek81 as to whether increasing the buffer size resolves his issue as well.

 

[meek81]

Interesting.. I am plugging my laptop up now to see if increasing the buffer will resolve my issue as well, I will report back shortly.

 

[meek81]

@AustinJerry @Bestboy4 it worked! Turning up the buffer to 704 worked! I no longer have those cracking and popping sounds coming from my speakers when measuring with ASIO.

 

[AustinJerry]

Thanks for confirming. I'll add a note to the REW Guide for users experiencing similar issues. I trust @John Mulkahy will see this result as well.

 

[John Mulcahy]

If buffer size is an issue it should be made larger, not smaller.

 

[meek81]

@John Mulcahy yes and making the buffer larger indeed does work, I had it set to the default of 512 and then turned it up to 704 per @Bestboy4 recommendation as he was having the same issues, and sure enough the distortion was gone.

 

[weilerhot]

outstanding. I love it when forums just magic up the answer!