Trying to track down a muffled/reduced gain from one speaker.
I've eliminated the compression driver as the culprit but haven't been into the crossover yet. Shouldn't a 16 Ohm spec'd speaker measure 16 Ohms?
I've eliminated the compression driver as the culprit but haven't been into the crossover yet. Shouldn't a 16 Ohm spec'd speaker measure 16 Ohms?
Specs here:
https://www.parts-express.com/JBL-2226J-15-High-Power-LF-Driver-16-Ohm-294-472?quantity=1
16Ω is the "nominal impedance" of the driver when measured by an AC signal. I doubt you are doing that with your multimeter! The DC resistance can be as little as half of that. Look at the specs on the page above for Re. This is the DC resistance. It says 10 Ohms, so your 8 Ohm measurement is actually a little low...
https://www.parts-express.com/JBL-2226J-15-High-Power-LF-Driver-16-Ohm-294-472?quantity=1
16Ω is the "nominal impedance" of the driver when measured by an AC signal. I doubt you are doing that with your multimeter! The DC resistance can be as little as half of that. Look at the specs on the page above for Re. This is the DC resistance. It says 10 Ohms, so your 8 Ohm measurement is actually a little low...
There is a fault condition known as shorted turns that is caused by the scraping of the voice coil against the outer magnet pole plate. A weakened suspension or a rotted foam surround are the usual causes. An overdriven speaker can cause the coil to go out of round with the same result.
Best way to know would be to compare your suspect DCR reading to another known good woofer using the same meter. TS parameters for this driver provided by JBL list 10 ohms for R. They also mention a minimum impedance of 12 ohms.
https://jblpro.com/en/site_elements/2226h-j-specification-sheet
https://jblpro.com/en/site_elements/2226h-j-specification-sheet
Just connect the big driver (full range / bass) to the amp directly at low volume, to eliminate cross over fault.
That will tell you if the driver is damaged.
Maybe you can check the tweeter as well, at really low volume, bypassing the cross over.
Check your meter batteries, and short them to verify that zero is actually zero (rare on low ohms range), then measure again, adjusting for the non - zero reading.
That will tell you if the driver is damaged.
Maybe you can check the tweeter as well, at really low volume, bypassing the cross over.
Check your meter batteries, and short them to verify that zero is actually zero (rare on low ohms range), then measure again, adjusting for the non - zero reading.