HOLMImpulse: Measuring Frequency- & Impulse-Response

[Ardee]

I have installed the software but when I try to run it I get a message saying it has encountered a problem and needs to close. I'm using XPpro/SP3. Is there any diagnostic information I can post?

[askbojesen]

Originally posted by Ardee
I have installed the software but when I try to run it I get a message saying it has encountered a problem and needs to close. I'm using XPpro/SP3. Is there any diagnostic information I can post?

When the window has closed then
attach the following file:

C:\Documents and Settings\All Users\Application Data\HOLM Acoustics\HOLMImpulse\HOLMLogging.txt

(Or similar path for C:\Documents and Settings\All Users)

[Ardee]

Thanks for the reply askbojesen,

When the window has closed then
attach the following file:

C:\Documents and Settings\All Users\Application Data\HOLM Acoustics\HOLMImpulse\HOLMLogging.txt

(Or similar path for C:\Documents and Settings\All Users)

There is no Holm entry in the Application Data folder and I have searched the c: drive for the file without result.

[Pano]

Originally posted by askbojesen
There is no reason that it should not work on w2000, I did not know anybody was using that in 2009

Not to worry Moondog - I just gave it up last year! Was sorry to see it go, but kept a copy. It's like XP but without the "Fisher Price" interface.

Askbojesen - thanks for posting this software. I'm most eager to try it.

[askbojesen]

No new features/bugfixes except:

• The SSE2 is now disabled per default (Not all computers have SSE2)
  (This might help the users: BDP and Ardee)
• A specific version with SSE2-support
• 64 bit support

See here

[Ardee]

(This might help the users: BDP and Ardee)

Sorry, but both versions give me the same error message as before.

[KSTR]

Originally posted by askbojesen
Not sure that I have read the latest (I am a AES member, but not subscriber), so sent me a link to the article.
I have tested with digital loopback and electric loopback to ensure I have no artifacts. But I might have forgotten something - I have an open mind :-)

I think Earl is referring to this one:
http://pcfarina.eng.unipr.it/Public/...cSound2007.pdf
(Chapter 5)

And of course, big thanks for your software (I can only imagine the pains of windows GUI programming, I never made it beyond the commandline).

- Klaus (BTW, my primary working system still runs unter W2000.... never change a running system... and I have to use some programs that don't run under XP, let alone Vista. Some even require real-mode DOS!)

[askbojesen]

Thank you for the links.

With ref to

http://pcfarina.eng.unipr.it/Public/...cSound2007.pdf
http://www.aes.org/e-lib/browse.cfm?elib=14106

The concerns about the log sine sweep are:

• pre-ringing at low frequency before the arrival of the direct sound pulse
  My problem here is not as big as in the article since I sweep from 10 Hz per default instead of starting at 20Hz
• sensitivity to abrupt pulsive noises during the measurement
  No really solution to this problem! Do not slam the door when measuring
• skewing of the measured impulse response when the playback and recording digital clocks were mismatched
  If the skewing is deterministic I solve this with a phase calibration (DAC-ADC calibration)
• cancellation of the high frequencies in the late part of the tail when performing synchronous averaging
  I do not see this problem (Samplerate converters + Nyquist limit in the DAC-ADC chain is a much worse problem)
• time-smearing of the impulse response when amplitude-based pre-equalization of the test signal was employed
  I make phase synchronized, and absolute gain independent average in frequency domain avoiding this effect

The ideas presented are:

• post-filtering of the time-reversal-mirror inverse filter for avoiding pre-ringing
  Yes, HOLMImpulse does this
• "exact" deconvolution by division in frequency domain with regularization
  Yes, HOLMImpulse does this
• development of equalizing filters to be convolved with the test signal for pre- or post equalization.
  I do not see a reason to do this
• counter-skewing of the measured impulse response
  when the playback and recording digital clocks aremismatched
  Yes, with a DAC-ADC calibration
• employing running-time cross-correlation for performing proper synchronous averaging without cancellation effects
  I have a different solution mentioned above

A little demo: When we have digital clipping we have "nice" odd numbered harmonic distortions, that are seen before the impulse.

[KSTR]

It looks like you have all things adressed, then. And I agree, most of the potential gotchas are rather irrelevant for the way you handle things.

Your SW is running in the background while I'm typing this (no problems so far with my P4-system under XP, W2K not checked yet) and I'm trying to get familiar with it, and then will report begging for additional option/features

One thing found so far: the plots don't use the full area of the pane for some reason, although they scale with window size. Probably because of my 125% scaling of fonts -- many programs have problems with this, because noone seems to use this and thus it is seldom checked for.


Anyway, big cheers for giving us this tool FOR FREE! Very much appreciated! I'll try to raise interest in the german forums.

- Klaus

[gedlee]

Originally posted by askbojesen
No new features/bugfixes except:

• The SSE2 is now disabled per default (Not all computers have SSE2)
  (This might help the users: BDP and Ardee)
• A specific version with SSE2-support
• 64 bit support

See here

Mr Bojesen

That you very much, your cooperation and support are very appreciated and this IS the piece of software that I have been waiting for!!

Much appreciated!