testing crossover

[valhallax]

i also have a set , supposedly from a 1215..the values on the caps are 28uf and 18uf1215 crossover

[bfish]

Without EQ, 288s naturally start to roll off around 5kHz (plot on p2);

http://www.altecpro.com/pdfs/vintage...0HF%20Horn.pdf

Unless your meter has a capacitance function (uf) and most don't, you've no way to test the caps. No biggie, for $5.37 ea, you can replace them if you think they've drifted.

http://www.partsexpress.com/pe/showd...number=027-434

If you want to EQ the "g system" HF without giving up your 8553, just build a pair of 30923 EQ networks for $40-50, and install them after the 809s. Art J has posted the schem here.

[valhallax]

okay, ive gone through several past posts concerning crossovers, everyone says to test the vatiables in the crossover before you even install it. the thing is..no one says how? ive got a multimeter. do i clip the leads to the caps and test? what setting on the multimeter?
thing is, i took the rta over to my ex-father-in-laws, and this 8553 eq, and no eq will fix a screwed up crossover. he is still very happy with the sound...lol
its a set of a-5's and the frequencies above 5000hz are about gone. im using 809 crossovers here and ive another pair on the shelf, id like to test them before i go over and just swap them out. got some 1209's as well but the holes a different size. and i should keep them for myself.
for what its worth, this is my g system, gone thru most of the prior letters in the alphabet but this is granpa's set. 416-8c 288-8k 805 horns. the cabs are pretty sturdy yet, so bracing has been done. when i changed out from 418-8h mi speakers, to the 416's the guy was very much impressed by the difference, and now you can really feel the bass notes...the whole house shakes! the vent has been changed to the recommended 75sqin.

[donaldpatten]

To test an XO I 1st listen to it. I trust my ears as my best measurement tool. If you have an RTA and a Pink Noise source , or a MAC with FAST software you can do frequency response or FFT analysis.
Listen at a very low level, are the speakers working? Then play softly the Pink Noise or FFT test signal. Connect the RTA or FFT analyzer to the XO input with the speaker connected and playing the test signal. Check the analyzer display. It should be a flat line. Turn off the test signal and the display will show the noise level. For good testing the noise should be at least 20 dB down.
Turn the test signal on and connect the tester to the Woofer terminals and check the display , with the speaker connected . Repeat for the other speakers and drivers.
Don