Background: Many years ago (15+), I assembled a set of speakers based on the Zaph Audio design that used Seas metal drivers. I was happy with how they came out and sounded. I didn't do any fancy testing of the crossovers or final speakers, only made sure sound came out of all 4 drivers and both finished speakers sounded about the same. They have to date remain the pair of speakers I most enjoy.
I currently am using them in my living room for a 50/50 combo of TV and audio. Wiim Ultra with inputs from HDMI arc(TV) and an AirportExpress via optical (audio) with amplifier duties via a used Rotel RMB-1066 I picked up a number of years ago that was gathering dust waiting for me to get around to trying to build a pair of LXmini+s.
I was using 4 of the 6 channels of the Rotel (A and C) bridged to 2 channels for the past year or so. Last week, I noticed the left channel was significantly quieter than the right. I did some testing and determined it was the left (A) channels of the Rotel. During part of the testing, I had the left speaker connected to the B channels of the Rotel both bridged and unbridged. When I was done, all 4 A and B channels seemed to be no longer working. Note I was careful to never let the speaker leads from the amp touch while the amp was powered.
In case it was something wrong with the speakers and to get audio for the TV room back, I put the speakers off to the side and connected an even older pair of Boston Acoustic CR6s I have had since college connected to the still working C channels of the Rotel.
What is my question? Did the left Zaph speaker kill 4 of the 6 amp channels? I recall an old Kenwood reciver I had also had the left channel die slowly - it would be out and then of I turned up the volume it would come back. It eventually died completely.
I assumed I may have either mis-assembled one of the crossovers, a crossover component died over the years, or one of drivers had died. For the first time in 15 years I decided to do some slightly more detailed testing and ordered a Dayton Audio DATS v3 to run an impedance sweep of both speakers. I assumed I would see either really high or near zero ohms for some portion of the frequency band.
This is what I got:
Compared to the original Zaph measured response:
To my very untrained eyes, my speakers look to be close enough to the design to be okay and not the problem. Would the forum agree? Anything else I should check before potentially killing another amp? I do have a UMK-1 mike and have used REW for some subwoofer tuning in my home theater if that would be worthwhile.
I currently am using them in my living room for a 50/50 combo of TV and audio. Wiim Ultra with inputs from HDMI arc(TV) and an AirportExpress via optical (audio) with amplifier duties via a used Rotel RMB-1066 I picked up a number of years ago that was gathering dust waiting for me to get around to trying to build a pair of LXmini+s.
I was using 4 of the 6 channels of the Rotel (A and C) bridged to 2 channels for the past year or so. Last week, I noticed the left channel was significantly quieter than the right. I did some testing and determined it was the left (A) channels of the Rotel. During part of the testing, I had the left speaker connected to the B channels of the Rotel both bridged and unbridged. When I was done, all 4 A and B channels seemed to be no longer working. Note I was careful to never let the speaker leads from the amp touch while the amp was powered.
In case it was something wrong with the speakers and to get audio for the TV room back, I put the speakers off to the side and connected an even older pair of Boston Acoustic CR6s I have had since college connected to the still working C channels of the Rotel.
What is my question? Did the left Zaph speaker kill 4 of the 6 amp channels? I recall an old Kenwood reciver I had also had the left channel die slowly - it would be out and then of I turned up the volume it would come back. It eventually died completely.
I assumed I may have either mis-assembled one of the crossovers, a crossover component died over the years, or one of drivers had died. For the first time in 15 years I decided to do some slightly more detailed testing and ordered a Dayton Audio DATS v3 to run an impedance sweep of both speakers. I assumed I would see either really high or near zero ohms for some portion of the frequency band.
This is what I got:
Compared to the original Zaph measured response:
To my very untrained eyes, my speakers look to be close enough to the design to be okay and not the problem. Would the forum agree? Anything else I should check before potentially killing another amp? I do have a UMK-1 mike and have used REW for some subwoofer tuning in my home theater if that would be worthwhile.
