Garage Loudspeaker Lab

[Ivan Beaver]

Re: Garage Loudspeaker Lab

Good news, Ivan - I question things as readily as you do. Funnily enough, I just encountered the situation you listed above yesterday and I explained exactly that to the sophomore who was curious as to what I was doing.

That is why you have to use other parts of the programs to help figure out what the REAL problem is.

It may show the RESULT of the problem in the amplitude response-but not the CAUSE. Sometimes you need to look elsewhere.

And THAT is where the "knowing how to measure" part comes in. Of course it ALSO helps to have a good understanding of what phase is-what the various relationships are and so forth.

So many pieces are all "interconnected", you can't just "learn one part" without knowing the others and what they mean and how they can affect various "things" in the overall outcome.

Learning what you can and cannot do something about is a large part of the "understanding" Some things you just leave alone-no matter how ugly they may appear on one measurement. You may not be able to do anything about it.

 

[Mark DeArman]

Re: Garage Loudspeaker Lab

So, besides loudspeakers my other hobby is Radar signal processing. I got the bug after I build one of those MIT Kit radars a few years ago.
There are a TON of parallels to loudspeaker transfer function measurement.

http://ocw.mit.edu/resources/res-ll...etic-aperture-radar-imaging-january-iap-2011/

The MIT radar is a fun project to work on with your kids too. It's very easy to build and understand how it functions.

Anyway, my latest bit of gear which I picked up for cheap, is this vintage HP pulse generator. The construction is just amazing. I love the old HP stuff. They just don't make them like this anymore.

Edit: Added the finished repair photos. Replaced the BNC crap with nice Agilent SMA connectors. Cleaned out the garbage dust buildup from the analog boards and magic, pulse looks good again.