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PostPosted: Thu Aug 01, 2019 1:41 am 
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Location: Ypsilanti, Michigan U.S.A.
Excellent, thank you.

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PostPosted: Mon Aug 19, 2019 7:48 am 
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I'm a noob to this forum, so I apologize for any obvious questions. I've looked around a decent amount, but still had a question about this:

Soundman2020 wrote:
Quote:
might be with a full-range monitor placed on the floor in a corner, and the opposite ceiling corner being used for the measurement mic, as this will provide some extra gain from boundary proximity, and also verify the room modes fairly well.
I often do that in live rooms and booths, yes, because there's no fixed positions for the sound source and receiver (ear, mic) in a live room. That does give you a pretty good feeling for how the low end is behaving, especially modes. But I don't usually do that in a control room, since it isn't going to tell me much that I didn't already know from the "standard" test, and also because in a control room, there's a very precise fixed location for both the source (speakers) and receiver (listening position). Since the entire purpose of a control room is based around the listening position(s), that's what I'm most interested in: the room response at the listening position. For a control room, I might do another series of tests that I call the "walking mic" test (which I'll post a description of at some point soon), as that tells me a lot more about the SBIR issues and the modal issues, as well as about possible changes in the mix position, but I don't see much of a need to do the "diagonal corners" test that you describe: That's really useful in live rooms, but not very much in a a control room. (There's one exception, which has to do with very high precision room tuning, but I won't be going into that here, as it's not even applicable to most home studios).

Quote:
Thanks again for your efforts, and looking forward to future posts regarding this topic.
:thu:

- Stuart -


Is there a good tutorial on measuring live rooms specifically, similar to this one? Or would the opposite corners strategy be the only difference in testing compared to this? I'm really curious since I'm wondering if you would need to test a variety of speakers considering different speakers I'd expect would have a different frequency response, and when recording you would be using a variety of them in a live room depending on the application, right?


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PostPosted: Sat Aug 24, 2019 6:09 am 
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Location: Ypsilanti, Michigan U.S.A.
Preparing to run my first analysis and I'm stuck on the soundcard calibration section. Yep, the very beginning.

I have a Blue Sky Pro Desk 2.1 monitor system and I am not sure if I have everything set "flat" as the instructions indicate.
The sub-woofer does have "Variable Cutoff Frequency" controls and I'm not sure if that is applicable or not.

Also a little confused with the instructions for setting up my multi-channel output. I'm on a Mac OS X.


[url]http://abluesky.com/products/prodesk-2-1//url]

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Small Personal Recording Studio
I compose and record almost everything on my own.
Guitars are recorded direct via Axe-FX III.


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PostPosted: Mon Aug 26, 2019 1:52 am 
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Attempting to proceed and having a problem with the input signal when calibrating my sound card.
It will not show an input signal if I set the sample rate to 48kHz. Everything is set to 48 on my interface, etc.

If set to 44.1 I do get an input signal.

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I compose and record almost everything on my own.
Guitars are recorded direct via Axe-FX III.


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PostPosted: Mon Aug 26, 2019 4:37 am 
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Well, I finally got an input signal at 48k but the measuring results may not look to good. Not sure how to correct this.

Attachment:
REW Capture 1.jpeg


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Small Personal Recording Studio
I compose and record almost everything on my own.
Guitars are recorded direct via Axe-FX III.


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PostPosted: Mon Aug 26, 2019 5:03 am 
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When I have my interface monitoring set to mono, I get better results. Not sure if this should be done though.

Attachment:
REW Capture 3.jpeg


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I compose and record almost everything on my own.
Guitars are recorded direct via Axe-FX III.


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PostPosted: Mon Aug 26, 2019 8:53 am 
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Quote:
Well, I finally got an input signal at 48k but the measuring results may not look to good. Not sure how to correct this
You have a feedback loop in your system somewhere. Probably you have monitoring engaged and feeding back into the inputs, or some such.

Also, please move all of your posts about this to your own personal thread, instead of having them here on this thread, which is about using REW in general, not specific individual cases.

- Stuart -

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PostPosted: Mon Aug 26, 2019 9:44 pm 
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Soundman2020 wrote:
Quote:
Well, I finally got an input signal at 48k but the measuring results may not look to good. Not sure how to correct this
You have a feedback loop in your system somewhere. Probably you have monitoring engaged and feeding back into the inputs, or some such.

Also, please move all of your posts about this to your own personal thread, instead of having them here on this thread, which is about using REW in general, not specific individual cases.

- Stuart -


Thank you Stuart. I have created a separate thread for this. I'm not able to delete my posts here. Do I need to send a request to have them deleted?

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I compose and record almost everything on my own.
Guitars are recorded direct via Axe-FX III.


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 Post subject: Extech 407730
PostPosted: Wed Sep 11, 2019 7:38 am 
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Location: Los Angeles, CA
So can the Extech 407730 be used for calibration given its limited frequency response?

This is the handheld meter I ended up purchasing, so just checking if I should return it and opt for another?

Thanks


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PostPosted: Mon Oct 28, 2019 6:49 am 
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Quote:
So can the Extech 407730 be used for calibration given its limited frequency response?

Why do you figure it has a limited frequency response? It has slow and C weighting settings and that's all you need it to do. It should work fine.

Greg

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PostPosted: Sun Feb 09, 2020 7:16 am 
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Hi there, I purchased the Extech 407730 for this test as it was recommended as one of the devices in the instructions. However I noticed after going through all the subsequent postings that the 407730 only has frequency response down to 300hz. I have a subwoofer in my studio setup and was wondering if I should get a different one that has a lower frequency response? I see someone already posed that question, however I wanted to know if it makes a difference with me having a subwoofer.

Also I have a couple questions about testing with the subwoofer in the setup:

- When we are doing the tests of the L/R speakers for their own separate tests, should they go through the subwoofer (with subwoofer volume at 0)? Or should I bypass the subwoofer for those tests and wire them directly to my soundcard? I assume they should go through the subwoofer as the crossover would affect the volume of the monitors even at 0 volume?
- In your additional instructions about calibrating the volumes when having a subwoofer, are you saying that in step 3 we should play around with the volumes of L/R/S at around 77db each, and keep adjusting until all 3 are giving out combined 86db?


Thanks!


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PostPosted: Sun Feb 09, 2020 8:01 am 
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Quote:
However I noticed after going through all the subsequent postings that the 407730 only has frequency response down to 300hz.

That's as low as C weighting calls for. This meter is more than adequate.

Greg

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PostPosted: Sun Feb 09, 2020 8:12 am 
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Location: Cork Ireland
Hi Greg, that 300Hz comment caught my attention. I'd guess you meant A?
Also, I think it odd that any SLM would be restricted to measurements over 300Hz.
Attachment:
frequency-weightings.jpg


On a General REW note. Calibrating the Soundcard was perhaps necessary, or desirable for critical timing measures, in some distant past. But no longer afaik.
REW, FuzzMeasure, etc. work perfectly well with single channel USB mics.


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PostPosted: Sun Feb 09, 2020 5:25 pm 
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Sorry, yes.

My meter is "flat" only down to 125Hz as well.

Greg

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PostPosted: Mon Feb 10, 2020 5:45 am 
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Thanks Greg for the reply. And sorry, just read the posting rules and of course didn't have my location entered, which is now there.

I'm still not clear about how I should set the volume on my subwoofer when doing the testing. I'd like to get as accurate measurements as possible before posting the results on the site, so want to make sure I'm doing it correctly. If the subwoofer is only playing frequencies less than 80hz (which is what my crossover is set at), and the SPL doesn't pickup these low frequencies, how would I set the subwoofer volume? I'm using two KRK rokit 8's and a KRK 10s subwoofer in my studio setup.

Thanks!


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