2. amps-preamps
  3. 182257-2603

Bi-Amping: How can I determine relative output?

Long Story Short:  I have a 50w/channel pair of tube monos, and a 300w stereo solid state amp playing through a set of JBL 4367s. two way monitors.

The tubes are on the horn tweeter and the solid state is on the 15" woofer, crossover is apparently 700hz.

Doing absolutely nothing, some music sounds completely "normal" and some music sounds artificially bass heavy.

The solid state amp has gain adjustments for each channel.

I have a Fluke 115 multimeter, and access to plenty of test tones, but nothing to read SPL.

Is there a way to measure output at the speaker terminals such that I could dial the woofer amp down to "match" the tube amps?

If so, would this be more or less constant as the preamp driving the amps changes  volume, or would it only "match" (to the extent that it actually matches at all) at one volume level?

 

 

 

gthirteen

Showing 1 response by avanti1960

avanti1960
1,545 posts
 

if the a21+ is new, it will sound extremely smooth at 450 hours or so like mine did, so that could be an option.  

you can set an amps gain with a test tone and measure the voltage at  the terminals without speakers attached.  the problem is that tube amps require the load of a speaker or you could damage the amp.  

just play pink noise bands above and below the crossover of the woofer and adjust gain so they sound close.  use tracks 47 to 56 on this disk or download

https://sheffieldlab.com/item.php?item_id=52

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