Measurement setup advice

[Thooms]

Hi all,

As my active crossover/amp project is approaching completion, I'm starting to think about building a pair of speakers to go with it.

Looking at drivers, I'd really like to build a 2 way using the Peerless HDS / Scan Speak D2608 tweeter along with a Peerless 830875/830883 or Seas L18/U18..

To do this however, I'm going to need a measurement setup.

Now, I know what you're all going to ask - I have no experience with crossover design or measurement equipment.

This is where I need my help! I'm on a budget here so will be building a mic (I may be able to borrow a calibrated one for comparison) and preamp using a Panasonic condensor capsule, like most of the other entry-level measurement microphones.

However, what free software can I use to take measurments? I've looked at a couple but they all seem hideously expensive. I have a PC with a full duplex sound card.

Does anyone have any free software they can recommend? It can be Mac or PC based.

[ThomasW]

https://www.htguide.com/forum/showthread.php?t=26544

[BobEllis]

I like Holm Impulse for measurement. There are some nice tutorials over at DIYAudio.

Do the Linkwitz mod on your capsule. It makes a world of difference. Noise is reduced running it from 9V rather than the sound card's bias. The way you mount your capsule impacts its frequency response. Use as small a wand as you can. Using a generic calibration curve I got results that pretty much matched my drivers' published curves so I felt that was good enough for a while.

I bought a calibrated mike from Cross Spectrum Labs. Relatively inexpensive (compared to building and getting your homebuilt mike calibrated) and well worth the cost if you plan to do more than one project. They need phantom power, though. You'll need to add that if you don't have it available from your sound card.