Ionovac distortion

[rdr]

How about Russell's site http://www.roger-russell.com/ionovac/ionovac.htm
where he seems to have measured high distortion. I have had a pair for many years and wonder who out there has had experience with them. It now seems to me that I should crossover at over 10 K instead of the 6 K I have been using.

[bear]

It should be fairly trivial to use a modern FFT computer/soundcard software measurement system to retest. Even one of the inexpensive Behringer or similar measurement mic will likely give useful results.

I'd try it.

Also, it would be useful to know if a higher slope xover reduced the measured IM figures or not. I suspect it would. How much is the question.

_-_-bear

[rdr]

Yes I am about to do some testing. Russell did IM measurements. I am trying to revive an old harmonic distortion meter (Heath IM12). Wonder if TrueRTA will do it? Don't know, jus downloaded the freebie. As early high end systems using the Ionovac did crosover above 10 k I suspect I will find I will also have to.

[bear]

Dunno about that software.

Speakerworkshop, iirc has FFT. Or is it Soundworkshop, I forget, it's freeware tho'.
There's lots of them...
Any of these softwares with FFT and preferably MLSSA will do fine at this point to get in the ball park.

Forget the old Heath, imho.

You want far more information that that old box will provide.

You need a decent microphone for measurement.
Linkwitz' site show how to do it on the cheap...

Then, test something other than the ionophone/vac first and get some sort of baseline results... see if ur of the same, greater or less magnitude for distortion, waterfall, and impulse responses... not to mention frequency response.

_-_-bear