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Old 5th January 2011, 10:47 PM   #681
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Default Exporting THD measurements, other things...

Hi there. Just started using HolmImpulse today. Pretty good stuff, considering the price. Nice work.

Is there any way to export THD measurements? There seems to be options to export frequency and impulse response, but not THD.
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Old 6th January 2011, 12:38 PM   #682
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Default Checking time alignement with HOLM Impulse

I have started to use HOLM Impulse and I like it very much!

I would like to optimize the time alignement of my 3 speakers (VOAt A5, Altec 1505B and JBL 2405) and I measure the 3 speakers separately, but the impulse is automatically set to 0 for each measurement.

Could someone tell me what is the proper setting for having, for example, the medium set as a reference and the bass and high frequency driver distance from this refrence shown in the graph?

Dominique (Germany)
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Old 6th January 2011, 04:24 PM   #683
jtalden is offline jtalden  United States
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Quote:
Originally Posted by dominique-tanguy View Post
Could someone tell me what is the proper setting for having, for example, the medium set as a reference and the bass and high frequency driver distance from this refrence shown in the graph?

Dominique (Germany)
> select; Keep Stream Active (Device tab).
> select; Start Stream (Device tab).
> after making a measurement of the reference driver, select; Time Zero Locked and then, Use-Last Detected (Data Analysis tab).

That should get you started.
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Old 6th January 2011, 06:27 PM   #684
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Quote:
Originally Posted by jtalden View Post
> select; Keep Stream Active (Device tab).
> select; Start Stream (Device tab).
> after making a measurement of the reference driver, select; Time Zero Locked and then, Use-Last Detected (Data Analysis tab).

That should get you started.
Thank you!

Dominique
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Old 23rd January 2011, 12:20 AM   #685
Mikelo is offline Mikelo  Antarctica
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Quote:
Originally Posted by doug20 View Post
How about a HOLM for Dummies? (Me, I feel dummer by the day on this site!!).

I do not want to bog down this thread with really silly and probably easy to answer questions, could we create a HOLM for dummies thread?
I have spent an afternoon looking for something that comes close to HOLM for dummies, but can't find anything that teaches the very first steps. I open up the program and I don't know where to start. Ok, I AM a dummy.

I am trying to do all this with AKG mic, a Mackie mic/line mixer pre, Edirol
PCR-1, and Holm software.

Michael
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Old 23rd January 2011, 12:38 AM   #686
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Hi Michael, I've got this site bookmarked

HOW TO: Measure using HOLM and ARTA - AVS Forum

One thing I haven't seen though is the loopback of the second channel, I do it with my Walin jig, but don't know if it is absolutely necessary or not.. I just did some in room measurements and didn't use the loopback and it worked fine.

What I mean by loopback is that one of the channels is connected back to the soundcard input direct (I do mine after the amp with attenuation) the other channel is the input from your mic preamp. Maybe it is not necessary at all, I'm not sure, it was certainly necessary with speakerworkshop.

Tony.
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Old 23rd January 2011, 04:40 AM   #687
Shaun is offline Shaun  South Africa
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I was not aware that HOLMimpulse has a loopback function. It has an initial DAC-ADC calibration function, but otherwise it is open-loop, AFAIK.
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Old 23rd January 2011, 06:32 AM   #688
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Could well be Shaun! When I first started using it I just hooked it up like I always had with speaker-workshop, certainly didn't see anything in the user-guide so probably it is completely pointless (and may in fact cause problems)..

I thought the first time I used it, it gave different results with or without the loopback, but I'm not sure.. It certainly will make my measurements easier if I don't need to use the second channel.. will try with and without next time I measure!

Tony.
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Old 23rd January 2011, 06:38 AM   #689
Helmuth is offline Helmuth  Netherlands
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Quote:
Originally Posted by wintermute View Post
Hi Michael, I've got this site bookmarked

HOW TO: Measure using HOLM and ARTA - AVS Forum

One thing I haven't seen though is the loopback of the second channel, I do it with my Walin jig, but don't know if it is absolutely necessary or not.. I just did some in room measurements and didn't use the loopback and it worked fine.

What I mean by loopback is that one of the channels is connected back to the soundcard input direct (I do mine after the amp with attenuation) the other channel is the input from your mic preamp. Maybe it is not necessary at all, I'm not sure, it was certainly necessary with speakerworkshop.

Tony.
With room (stereo) measurement you can still use the other channel for feedback. Because you can use one amp output to feed both speakers.

Or you feed the amp left and right channel with one channel of the sound-card and use the other for feedback.
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Old 23rd January 2011, 07:12 PM   #690
Mikelo is offline Mikelo  Antarctica
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Quote:
Originally Posted by wintermute View Post
Hi Michael, I've got this site bookmarked

HOW TO: Measure using HOLM and ARTA - AVS Forum

One thing I haven't seen though is the loopback of the second channel, I do it with my Walin jig, but don't know if it is absolutely necessary or not.. I just did some in room measurements and didn't use the loopback and it worked fine.

What I mean by loopback is that one of the channels is connected back to the soundcard input direct (I do mine after the amp with attenuation) the other channel is the input from your mic preamp. Maybe it is not necessary at all, I'm not sure, it was certainly necessary with speakerworkshop.

Tony.
This helped so much. I was able to calibrate the PCR-1 and now I am wondering if I should calibrate my mic an AKG D190ES. I have a frequency response curve for it from AKG and it occurs to me that I could create a .cal file using the curve. Is that better than nothing?

By the way, the key to getting started here (for dummies) is that the USB audio interface is used as a sound card, and in your computer's setup it needs to be specified as the device for sound, recording, etc.
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