HOLMImpulse: Measurements in practice

[Mike Gergen]

I'm using the EMU 1212. Make certain you have the latest version of Patchmix and drivers. I had trouble too with the older revs.

[askbojesen]

Originally Posted by ilardi

Thank you skeptic43, panomaniac and breez. Another question. I have been measuring near field response in a small, vented speaker that I have built. The nearfield response of the woofer does not show the notch, that a vented speaker should show. The impedance curve I measured with WT3 looks textbook so I can't figure out why the response shows just a small inflection at fb, not at ll what I would have expected from D' Apollito. I figure I must be doing something wrong-but can't quite figure out what. Again any suggestions would be very much appreciated.

Hi, can you attach the measurement as a file.zip
HOLMImpulse > File > Save Measurements

Then I can see your settings

[flexus]

Originally Posted by Speedskater

I think that you are right. I bet he planned on doing so, but somewhere along the line he ran out of time or enthusiasm.

when i bought his book it wasnt deliverable at first - the reason was: "he writes a new one..."
i asked twice, but nevertheless ordered Testing loudspeakears cause i needed it at this moment.
i´m very happy with this book. the dislikes are the same as from the others, no comparisons. but hey.. revolutions are no childrens birthdays (holmimpulse is on the way to it btw) maybe with the next book we will get the all inclusive solution.

[Cut-Throat]

First time post here. I have never measured any speakers before, but would like to just get a Freq. Response Graph for my 3 Way speaker system.



I downloaded the HOLMImpulse software on the recommendation of someone on one of my Audio Forums. I am very Computer Savvy as that was my profession. However, Even though I have been involved with Audio for 30 years, my audio knowledge is probably at the neophyte level compared to all of you here. I have never measured the Freq. Response of my Speakers, but have built some crossovers based on Calculators.

I downloaded the User Guide and was looking for some very basic Instructions on how to use this program. In terms of the hardware that I need to set it up and what functions to run in HOLMImpulse to get some very basic freq. Measurements and start learning from there by doing. Nothing in the User Guide seems to address the basics.


Are there any of these instructions available in text or in help form on the program? I am guessing that I need an External Sound Card, A microphone, some cabling, And my amplifiers, pre-amplifers and my Laptop. I do have an EX-TECH SPL that has some jacks on it, that could be used as a Microphone in some Measuring software (Not sure if HOLMImpulse is one of those) - Recommended Hardware would be a plus as I do not have an external Sound card yet or Microphone etc. I don't mind spending some money on this, as I really would like to be able to do this. Just for my personal Audio Hobby.


Any help from you will be appreciated.

[Pano]

You'll find the HOLMImpulse a great software and easy to use once you get it running.

Stuff you need.

• Microphone. Many of use use the Berhinger mic Or the Dayton mic which is pretty much the same thing.
• Mic stand. Find online or at any music shop
• XLR mic cable
• Mic preamp with phantom power.
• Sound card. M-Audio and others make USB and Firewire cards that have the mic preamp and phantom power built in. That's what I use.
• Drivers for the soundcard. If it has ASIO drivers, use those.

That's about it. Of course there are other ways to do it, but this is pretty simple and all off the shelf. Please ask if you have further questions.

[Cut-Throat]

Originally Posted by panomaniac

You'll find the HOLMImpulse a great software and easy to use once you get it running.

Stuff you need.

• Microphone. Many of use use the Berhinger mic Or the Dayton mic which is pretty much the same thing.
• Mic stand. Find online or at any music shop
• XLR mic cable
• Mic preamp with phantom power.
• Sound card. M-Audio and others make USB and Firewire cards that have the mic preamp and phantom power built in. That's what I use.
• Drivers for the soundcard. If it has ASIO drivers, use those.

That's about it. Of course there are other ways to do it, but this is pretty simple and all off the shelf. Please ask if you have further questions.

Thanks for your reply!

Is USB 2.0 fast enough or should I get a Firewire Connection?

[Andreas]

Originally Posted by Cut-Throat

Thanks for your reply!

Is USB 2.0 fast enough or should I get a Firewire Connection?

Holmimpulse works fine even with USB 1.1.

/Andreas

[Pano]

Yes it does! You will be limited in bandwith, but I have not found that to be a big deal. I run everything at 48K. That's fine for me.

[Cut-Throat]

Thanks for all your replies!

I have a question on the microphone. I have an Extech 407727 SPL meter. I have heard that it is possible to use an SPL meter for a Microphone on some measuring software. From the manual:

Analog Output:

A 3.5 mm phono output jack is provided on the meter for connection to external test equipment. An AC rms voltage is provided (0.707v maximum) which is a linearized representation of the analog pointer reading. Connect this output to a datalogger, chart recorder, etc. for datalogging purposes.

I don't mind buying another microphone, if it will work better, but If this will work just as good, I might as well save a few bucks.

As far as the external soundcard, is there a certain desirable model to have? Or doesn't it make much difference? I don't mind spending a few bucks here either, if it makes some sense.

[ilardi]

Originally Posted by askbojesen

Hi, can you attach the measurement as a file.zip
HOLMImpulse > File > Save Measurements

Then I can see your settings

Thank you Ask. Unfortunately, when I go to save the file I get an "Unhandled Exception..." and the file that is saved has 0 kb. (I also get an unhandled exception whenever I quit the program). I've reinstalled HolmImpulse several times but I still get this whenever I quit the program.

Attached is a text file into which I have pasted the details of the unhandled exception.

Thanks in advance for any suggestions you can provide.
Terry