Fun With HolmImpulse (Show and Tell)

[auracle]

Just started playing around recently with HolmImpulse - ah...... yet another measurement toy!!

Thought it might be interesting to have a little HolmImpulse Show and Tell right here on PE. The attached pics are of a build I've been testing to find baffle reflections (pair of Neo 3's and Vifa PL18's in MTM). Not exactly sure what I'm looking at - the 5 cm time/distance gap doesn't seem to have much of a correlation with anything I can find on the baffle. Perhaps these are driver related artifacts. Does anyone have impulse plots using HOLM they'd like to share? - maybe point out in detail what to look for to spot diffraction or reflection issues.....

[DDF]

Just started playing around recently with HolmImpulse - ah...... yet another measurement toy!!

Thought it might be interesting to have a little HolmImpulse Show and Tell right here on PE. The attached pics are of a build I've been testing to find baffle reflections (pair of Neo 3's and Vifa PL18's in MTM). Not exactly sure what I'm looking at - the 5 cm time/distance gap doesn't seem to have much of a correlation with anything I can find on the baffle. Perhaps these are driver related artifacts. Does anyone have impulse plots using HOLM they'd like to share? - maybe point out in detail what to look for to spot diffraction or reflection issues.....

Hey dummy,
em, auracle, are there still teething pains with Hlmimp?

I started following the DIYAudio thread but got drowned in the sea of usual puffery and sidetracking those threads always take.

At one time there was question raised over one or more of its key algorithms.

[auracle]

Hey dummy,
em, auracle, are there still teething pains with Hlmimp?

I started following the DIYAudio thread but got drowned in the sea of usual puffery and sidetracking those threads always take.

At one time there was question raised over one or more of its key algorithms.

LOL @ "puffery"!


Speaking of puffery, yes, Geddes had his usual bout of puffery at the beginning with his usual "you don't understand my genius" and "if it doesn't separate out the pre-ringing, I'm not interested..." yada, yada yada. Askbojesen (DIY) has been extremely attentive, patient, understanding, and responsive to everybody's wishes (demands). A couple weeks after the puffery went bye-bye, Geddes was singing HolmImpulse's praises - now, it's like the best thing since sliced bread. In any event, I had a few bumps of my own getting started. Some were self induced (living up to my new "I'm With Stupid" moniker) and some indicate that the software is still in its infancy.

It seems that if you intend to use more than 48khz of sampling with a 32 bit Windows box - you're going to have issues. I was and still am getting into situations where I get severely distorted test signals and the expected garbage back out in the response plots. As others have indicated, it's likely caused by background processes running in Windows that are making demands on CPU utilization ( I think I have a dual core unit which makes matters worse). If you have the newer 64 bit XP - you probably have the best, most reliable setup.

In any case, I'm extremely pleased with what it seems to be doing. The graphs attached to this thread are full range sweeps through the crossover to both driver sets measured about one meter on axis level with the tweeters. The ringing I'm seeing is consistent with the driver's capabilities - which as far as I'm concerned are absolutely stellar.