The Dude Posted February 7, 2021 Share Posted February 7, 2021 While dialing in the peqs and delays, Chris noticed a drop in high frequency to little or no output. I could still here some high frequency, but it was down 8 db and when increase the gain on that channel I would get no additional output. So today I decided to perform some exploratory surgery and see if I can find something wrong with the diaphragm. For identification purposes, we are working on a BMS 4590. First thing I did was check the resistance which I had confirmed 8 ohms (should be fine on a 16ohm driver). Then I proceeded to remove the driver from the horn and disassemble it. Upon inspection I noticed the leads and ribbon like material have separated. Could this be my problem and if so, what could have caused on a new diaphragm? You may have to zoom in on the picture Sent from my SM-G986U using Tapatalk Quote Link to comment Share on other sites More sharing options...
LTusler Posted February 7, 2021 Share Posted February 7, 2021 Maybe open up your other one and have a look at it? Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 7, 2021 Share Posted February 7, 2021 If you've got a volt-ohm meter (VOM), that would be a quick check of continuity. Generally, these ring-radiator diaphragms are pretty rugged, so I'd suspect that it was a manufacturing issue if you see an open circuit on the voice coil. IIRC, this driver is not very old. Chris Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 If you've got a volt-ohm meter (VOM), that would be a quick check of continuity. Generally, these ring-radiator diaphragms are pretty rugged, so I'd suspect that it was a manufacturing issue if you see an open circuit on the voice coil. IIRC, this driver is not very old. ChrisShowing 8 ohmsSent from my SM-G986U using Tapatalk Quote Link to comment Share on other sites More sharing options...
Bacek Posted February 7, 2021 Share Posted February 7, 2021 What kind of electronic crossover do you use? Yesterday noticed same for tweeter while measuring and setting. Looked like something hanged on XO, restarted it and it was fine. 1 Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 7, 2021 Share Posted February 7, 2021 That means the diaphragm is probably good. Check the output voltage from the amplifier using your VOM. If you see voltage, then it's either a hung-up diaphragm within the driver (very doubtful), something in the settings of the crossover (most likely). Quote Link to comment Share on other sites More sharing options...
mustang_flht Posted February 7, 2021 Share Posted February 7, 2021 ... Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 7, 2021 Share Posted February 7, 2021 The diaphragms leads have been damaged by a transient -----but the main diaphragm itself seems to be fine -------you might have to redo the leads with new wiring to be able to get the diaphragm working right -------I would check both driver' s diaphragms to verify if both sides have identical damages -- here 's what the leads should look like 1 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 What kind of electronic crossover do you use? Yesterday noticed same for tweeter while measuring and setting. Looked like something hanged on XO, restarted it and it was fine.Hypex Fushion Fa123,You saying shut it off and turn it back on?Sent from my SM-G986U using Tapatalk Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 That means the diaphragm is probably good. Check the output voltage from the amplifier using your VOM. If you see voltage, then it's either a hung-up diaphragm within the driver (very doubtful), something in the settings of the crossover (most likely). .030 with fluctuations, seems on point with the other side.Sent from my SM-G986U using Tapatalk Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 The diaphragms leads have been damaged by a transient -----but the main diaphragm itself seems to be fine -------you might have to redo the leads with new wiring to be able to get the diaphragm working right -------I would check both driver' s diaphragms to verify if both sides have identical damages -- here 's what the leads should look like Maybe a bad solder on the ring terminal?Sent from my SM-G986U using Tapatalk Quote Link to comment Share on other sites More sharing options...
Bacek Posted February 7, 2021 Share Posted February 7, 2021 6 minutes ago, The Dude said: Hypex Fushion Fa123, You saying shut it off and turn it back on? Sent from my SM-G986U using Tapatalk Yes it costs nothing and turn it as last item in chain after amps or what ever you have more (connected computer ex.) Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 7, 2021 Share Posted February 7, 2021 40 minutes ago, The Dude said: Maybe a bad solder on the ring terminal ? easy fix Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 11 minutes ago, Bacek said: Yes it costs nothing and turn it as last item in chain after amps or what ever you have more (connected computer ex.) So going with your advice, I decided to switch through Pre sets and noticed an increase in high frequency as measurement shows has returned. Maybe a setting with preset 3? Not sure, but does this confirm our diaphragm is working properly? @Chris A not sure if your remember how it looked with first measurement, but this is back to where the spl once was. However, I now am back to nasty phase and GD measurements. I think I will add our filters one at a time until I see if something changes this. Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 7, 2021 Share Posted February 7, 2021 16 minutes ago, The Dude said: Not sure, but does this confirm our diaphragm is working properly? Yes. It's working now. I would try the third round Left Belle-BMS-3.xml, then zoom way in on your SPL response plot within REW. You're currently zoomed way, way, out. You might have cleared the issue by dissembling the driver and reassembling it. It wasn't working beforehand: Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 4 minutes ago, Chris A said: You might have cleared the issue by dissembling the driver and reassembling it I don't think that was it as I was getting the same readings with no output until i switched presets. Quote Link to comment Share on other sites More sharing options...
OO1 Posted February 7, 2021 Share Posted February 7, 2021 6 minutes ago, The Dude said: I don't think that was it as I was getting the same readings with no output until i switched presets. so nothing wrong with the diaphragms- -----good news Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 7, 2021 Author Share Posted February 7, 2021 so nothing wrong with the diaphragms- -----good newsDoes not appear soSent from my SM-G986U using Tapatalk Quote Link to comment Share on other sites More sharing options...
Chris A Posted February 8, 2021 Share Posted February 8, 2021 Try the right loudspeaker presets on the left. Chris Quote Link to comment Share on other sites More sharing options...
The Dude Posted February 8, 2021 Author Share Posted February 8, 2021 13 hours ago, Chris A said: Try the right loudspeaker presets on the left. Same issue, since all of our work was on preset 3, the amp defaults to preset 3 when the right side config is loaded and then the high frequency drops off. Weird. Quote Link to comment Share on other sites More sharing options...
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