Measurement Sweep File - Pops, Clicks

[whoareyou]

@juicehifi

I started having intermittent clicks, pops and other distortions during the measurment process. I recently increased number of measured channels from 10 to 13 (7 second sweep at 48Khz), but should that make a difference?
To try and figure out what's going on I listened to the sweep file and I hear the same pops and clicks, but when is sweep file generated? Is this file merely a recording of what happened during the measurment or is something wrong when sweep file is generated?
Edit: Never mind as I see it's generated as part of the measurement.

Still, original question remains as to why I'm having all of these issues after increasing number of channels with ASIO driver?

With ASIO driver I rarely if ever had these types of issues until now.

 

[juicehifi]

This is with 99% certainty hardware related. But see if there's a way for you to increase buffer sizes. Also, lower sample rate may work if you'r runing it high now.

 

[whoareyou]

I run sample rate at 48, so really can't go much lower.

The interesting thing about this is when you review the sweep files having pops, clicks and distortions, there is inappropriate wav output on other channels i.e. when channel 2 is being measured, and should be the onlly signal at that point in time, you'll also see ouput on channel 5. This random noise seems to correlate to length of sweep, where shorter sweep durations seem to decrease the amount of random noise.

Yes, it's possible it's hardware related, but the same hardware works properly with other software, both for measurement and audio playback.

I need to do additional measurements today, so I'll let you know how this goes.

 

[whoareyou]

Ok. I think is sorted out.

I reduced the sweep time from 7 seconds to 5 seconds and increased the memory allocation to 160% .
I was able to take 4 successive measurments without a hint of noise or other distortions.

Thanks to @e1guapo for the suggestion to increase memory allocation for AL.

 

[omousis]

Hello all, I'm interested to know how the memory allocation for AL can be increased, as I face to similar problems :-) Many thanks in advance, Olivier.

 

[whoareyou]

 

[omousis]

Thank you. I tried what you did: increase the memory size and reduce the sweep time... This is not perfect because I still have about 50% of waste but it is still a significant improvement. The question is how clean must be the sweep recording?

 

[whoareyou]

From other thread I see you are using ASIO4ALL with your audio interface..
Is there reason you can't use a native ASIO driver?

 

[omousis]

I thought ASIO4ALL is the right tool for both input and output... I will try the native ASIO driver!

 

[whoareyou]

ASIO4ALL is really only for when you don't have an ASIO driver, or for some reason you need to aggregate devices that otherwise couldn't be used together. If you have proper microphone to use with Focusrite, then use the native drivers. Also, if you can use native ASIO driver, I'm guessing you won't need to increase the buffer size. It will probably just work. Prior to my current interface I used a motu ultralite mk-5 for 10 channels. With standard buffer and 10 channels being measured native ASIO driver was flawless. I only ran into problems when I increased to 13 channels.

 

[AkshaySinghKhanna]

Newbie here but no matter how I measure, I seem to be getting this. My setup includes DPA4060 Mic connected to a USBPre2 ASIO on a PC. Guidance is appreciated please. Not facing issues on REW, Smaart.

 

[omousis]

Unfortunately, the native ASIO drivers Topping DM7 ASIO and Focusrite ASIO do not seem to work together... this is why I use ASIO4ALL.

 

[whoareyou]

Unfortunately, the native ASIO drivers Topping DM7 ASIO and Focusrite ASIO do not seem to work together... this is why I use ASIO4ALL.

I wrongly thought you were using the focusrite as your DAC for a 2 channel setup and you could just switch over to its native ASIO driver.
Since you have a DM7, it seems you have need for more than 2 channels.

Some people have gotten this to work (maybe try WASAPI instead of ASIO4ALL), but eventually got so frustrated with the pops, clicks and bad measurements that I (initially) purchased a Motu MK-5 for measuring multi-channel. Using one interface solved all of my problems.

 

[omousis]

Unfortunately the results using WASAPI were even worse... I'm curious to know what kind of unique interface allowed you to fix all the problems...

 

[whoareyou]

Unfortunately the results using WASAPI were even worse... I'm curious to know what kind of unique interface allowed you to fix all the problems...

It's not really a unique interface other than it's one device with one ASIO driver. Key is that it's only one ASIO driver being used for both input and output on a single unitified interface.

For example, Motu ultra-lite MK-5 has one ASIO driver for both Mic input + up to 10 channels of line-outs.

I'm not familiar with Focusrite, but it seems to provide for 2 line-outs plus microphone input? If that's case, and you require only 2 channels of output, then you could simply select the Focusrite ASIO driver in AL's drop down boxes for both input and output (of course, you'd need to connect to Focusrite outputs for measurement). Once you complete measurements, switch output back to DM7 and use the generated convolution files. If you need more than 2 channels of output, then of course this wouldn't work out for you. Same principle applies for multi channel measurements. You can temporarliy connect to your multichannel interface, and once measurements are completed switch speakers back to your main DAC.


.

 

[omousis]

I see your point... Since I need 8 channels of output, the Focusrite Scalett is not the best match because it has two output channels. I need to upgrade to an 8 channels interface...

 

[whoareyou]

I see your point... Since I need 8 channels of output, the Focusrite Scalett is not the best match because it has two output channels. I need to upgrade to an 8 channels interface...

Unfortunately, that's probably the ultimate solution.

If you go this route, the other benefit that many AL users see is improvement with the measured delay timings. For example, when measuring 2 or 3 times back to back, with microphone in same exact postion, my delays for each measurement would be different. After changing to the Motu, I was amazed that multiple back to back measurements always showed identical delay results across the board.

If you go this route, just remember to change the the advanced options i.e. clock drift, use seperate play and record streams, since everything is now going through one interface.

 

[omousis]

Thank you for these advices. They are very useful. I note that you are using the Motu for both your measurements and the audio DAC. I would need to exchange my Topping DM7 against a Motu for convenience unless I accept to unplug/plug the 8 TRS cable during each measurement session... In this case I could purchase a 8-way Focusrite, which is cheaper than the Motu ultra-lite MK-5!

 

[whoareyou]

I've actually moved on from Motu since I needed more channels, but it proved very reliable for me. The DAC is also pretty good, and imho was very close to the DM7. What I didn't like about the Motu is that it is slow to switch between sample rates. If you just listen to everything at one rate, it's not an issue.

 

[sledwards]

MOTU UltraLite-mk5 18x22 USB Audio Interface

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[omousis]

I've actually moved on from Motu since I needed more channels, but it proved very reliable for me. The DAC is also pretty good, and imho was very close to the DM7. What I didn't like about the Motu is that it is slow to switch between sample rates. If you just listen to everything at one rate, it's not an issue.

I heard about these delays... Did you find high quality DAC with more channels? I would enjoy finding a 2x5 channels high quality DAC...

 

[whoareyou]

I heard about these delays... Did you find high quality DAC with more channels? I would enjoy finding a 2x5 channels high quality DAC...

I'm now using a Hapi MK2 which provides up to 16 channels.

 

[omousis]

I'm now using a Hapi MK2 which provides up to 16 channels.

Do you hear a sound improvement compared to the Motu?

 

[whoareyou]

Yes.

Do you hear a sound improvement compared to the Motu?

Yes.
Also, think DM7 sounded better than Motu but not that big a difference.
Also own an Exasound E38 which I thought was better than Motu, but on par with the DM7, but all of these DACs are relatively close as far as I'm concerned.

Hapi is first DAC I've owned where I thought it really distinguished itself over and above the others. Of course, just my opinion.

 

[omousis]

I agree that a converter chip does not do the whole job... how the DAC is built around is also very important!! Thank you :-)