out of spec crossovers...

[DrWho]

Does anyone happen to have any measurements of the output result from

out of spec crossovers? It seems to be all the rage to update

crossovers lately and like a good college engineering student I am

still a bit skeptical (even after hearing a marginal difference).

So does anyone have available some measurements to compare the before

and after effects from updating an "out of spec" crossover?

And has anyone ever taken into account that the impedance of the

drivers might be changing over time too? I can't imagine the behavior

of a driver being identical to 30 years ago so shouldn't that reveal

itself at least partially in the impedance of the system?

I'm pretty much just trying to quantify the differences because I think better with numbers...

[BS Button]

Does anyone happen to have any measurements of the output result from out of spec crossovers? It seems to be all the rage to update crossovers lately and like a good college engineering student I am still a bit skeptical (even after hearing a marginal difference).

So does anyone have available some measurements to compare the before and after effects from updating an "out of spec" crossover?

And has anyone ever taken into account that the impedance of the drivers might be changing over time too? I can't imagine the behavior of a driver being identical to 30 years ago so shouldn't that reveal itself at least partially in the impedance of the system?

I'm pretty much just trying to quantify the differences because I think better with numbers...

I recommend you start drinking, heavily.

[J.4knee]

Does anyone happen to have any measurements of the output result from out of spec crossovers? It seems to be all the rage to update crossovers lately and like a good college engineering student I am still a bit skeptical (even after hearing a marginal difference).

So does anyone have available some measurements to compare the before and after effects from updating an "out of spec" crossover?

And has anyone ever taken into account that the impedance of the drivers might be changing over time too? I can't imagine the behavior of a driver being identical to 30 years ago so shouldn't that reveal itself at least partially in the impedance of the system?

I'm pretty much just trying to quantify the differences because I think better with numbers...

Measurements, no I do not have any. However when you concede that you even heard a difference should merit some consideration, after all if the driver impedance had changed in the before it was not magically corrected by the after. I will grant you though when discussing changes and mods a good many improvements justified by what people hear is more likely due to anticipation and placebo.

[colterphoto1]

Bob Crites uses a meter with ESR (equivalent series resistance?) to test the capacitors for RESISTANCE, which in my limited understanding is the worst audible change they take on as they age. I think this is like a $500 test piece.

M

[PrestonTom]

Dr,

An interesting question. I recall BEC listed some values once, perhaps they were typical.

I am about to refresh my caps (K-Horns) and I was asking folks around work if they had anything that could measure ESR. No luck. Actually it is hard enough just borrowing and LCR meter....

I assume the increased ESR would essentially (and primarily) decrease the output level of the tweeter. But I have not thought this through.

As a tangential thought, what are the possible non-linearities that might be measured. For instance, with an inductor one can measure saturation, is there something comparable (and still within the audio range) for capacitors. I can not imagine that either capacitance or ESR would change as a function of level (or frequency). But I am just guessing.

Good Luck,

-Tom

[Hardhead]

"So does anyone have available some measurements to compare the before and after effects from updating an "out of spec" crossover?"

Sure! I can give you some measurements, although I didn't simply update my crossovers; I did a full upgrade. On a scale of 1 to 10, before I upgraded my crossovers to ALK's, my Heritage speakers sounded, oh, about an 8. After I changed them, they were a 10. Is that the type of measurement you were looking for?

If the difference you heard from updating crossovers was only marginal, perhaps you should hear some ALK's in a pair of Klipschorns. Upgrading makes the more significant sonic difference, not updating.

[johnyholiday]

GE PIO spec. just a uf of a start

http://www.geindustrial.com/publibrary/pubLibResult.jsp?famId=7&prdTypeId=29&subTypeId=394&pubType=Specifications%20-%20General&src=cwc

[DrWho]

I'm talking something more like RTA measurements of the actual speaker output before and after the crossover gets switch....

[JJkizak]

You might have to talk to Dean or Al to supply full freq response, impeadence, harmonic distortion, and typical capacitance and inductance measurements. Hearing wise it made a huge difference in my old speakers.

JJK

[meagain]

I'm talking something more like RTA measurements of the actual speaker output before and after the crossover gets switch....

Hmmm.... I have this Behringer DEQ. I could measure our old stock 1981 AA's vs. Deans 'super AA' and take pictures. Might be interesting. But I think when Jeff sent his old xovers to BEC, he ran tests and posted them. I think he then showed a pic/diagram of the new? Forgot what the thread was called.