Okay, its been a rough couple days. I just got done drawing the schematic and looking at the words and measurements again. Just one note, do all measurement in the resistance mode, not in the diode mode as the diode mode really doesn't tell us anything. You don't need to disconnect one end of the resistors to check each resistor. So with no drivers attached, between the midrange terminals on the crossover board, you get close to 2.2 ohms, but it's not a dead short correct? For the tweeter terminals, you get close to 0 ohms, but not a dead short correct? At the mid/hi amp inputs, you get essentially OL after holding the probes on the terminals for few seconds, correct? What happens when you reverse the leads on the mid/hi amp terminals? Does the meter go to (-) xxx.x ohms then to (+) xxx.x ohms before going to OL? This is a dumb question, but just so I understand everything. When you use only one amplifier to power the speaker in the full range (bi-WIRE) mode, the (+) terminals of the inputs are connected together. And separately, the (-) terminals of the inputs are connected together, correct? The photos are gone, but don't think we need it again. From your DC voltage measurements at the amps, they look healthy. Please answer all of my questions in order, so we don't get confused, thanks.
testing a crossover
hi guys and girls i have a
problem with my 3 way wilmslow-audio mirrage speakers , I am hoping you can help me with the problem,.
Lately my power amp went pop and i sent it away for repair,when i
received it back {repaired} it went pop again,on sending it back to
the repair technician ,he has come back to me ,and asked me to take
some ohms readings on the speakers, on testing the speakers , i run
these speakers using 2 power amps{Arcam Alpha 10s,using one for low
pass{bass} and the other for MID/HIGH,this is the amp which keeps
blowing,on the high /mid,on testing the terminal the bass{low pass}
read {left speaker]7.9 ohms ,right speaker bass 6.8ohms, But on the
left and right speakers hi/mid ,both read 0.0 ohms,{which we all know
is wrong}
BUT the strange thing is,when the blown amp was away,i only used one
power amp to run both speakers in bi wire config,and they worked
ok,all being a bit lack of bass and tightness,but still sound great.
So i stripped both speakers and checked the drivers,all 6 drivers
where good no shorts reading approx correct ohms for age,{Speakers
disconnected from x over}.can any one help with this,i would be so much in debt.
kind regards Mark
problem with my 3 way wilmslow-audio mirrage speakers , I am hoping you can help me with the problem,.
Lately my power amp went pop and i sent it away for repair,when i
received it back {repaired} it went pop again,on sending it back to
the repair technician ,he has come back to me ,and asked me to take
some ohms readings on the speakers, on testing the speakers , i run
these speakers using 2 power amps{Arcam Alpha 10s,using one for low
pass{bass} and the other for MID/HIGH,this is the amp which keeps
blowing,on the high /mid,on testing the terminal the bass{low pass}
read {left speaker]7.9 ohms ,right speaker bass 6.8ohms, But on the
left and right speakers hi/mid ,both read 0.0 ohms,{which we all know
is wrong}
BUT the strange thing is,when the blown amp was away,i only used one
power amp to run both speakers in bi wire config,and they worked
ok,all being a bit lack of bass and tightness,but still sound great.
So i stripped both speakers and checked the drivers,all 6 drivers
where good no shorts reading approx correct ohms for age,{Speakers
disconnected from x over}.can any one help with this,i would be so much in debt.
kind regards Mark
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- 119 posts total
CORRECTION, sorry. The last test on the mid/hi amp terminals on the crossover board; when I asked to to test and then reverse the meter leads and test again. The multimeter should be set on the "diode" test mode, not ohms. The readout should display some voltage then go to OL. When you immediately reverse the leads, the display should read -x.xxx volts, then change to +x.xxx volts before going to OL. Hope your meter has a diode test function, but it's not absolutely necessary. This test just shows that the caps are charging in both directions. I still can't explain why the system worked with one amp when the mid/high amp was in repair... This is troubling. |
You can find all the photos here https://systems.audiogon.com/ Without drivers connected, The HF measurement should equal to the DC resistance of the 0.22mH inductor. The MF measurement should equal to the DC resistance of the 2.5mH inductor + 2.2Ω. |
Hi guys, sorry for the very late reply in my/your quest to sort this out,ive done a couple of thing since, taken advice on multi meter/s, fitting fully charged battery's in the digital and analogue multi meters,both tested by using an 8ohm resistor, I use for running in component/gear, just incase, removed all wire to and from the x over and cleaned the board,and flowed every joint,so there no chance of dry joints and shorts,also i have done a continuity test from every component lead to pcb tracks,all joint good, please find results of questions asked. multi meter set to ohms- between mid pos and neg 2.7 ohms between tw pos and neg 0.002 ohms mid/high inputs OL {held on for 5 secs}nothing changes mid/high inputs {reversed} OL{held on for 5 secs}nothing changes when run with one amp,in bi-wire mode both pos are NOT connected the same goes for the neg wires,the amp has 2 sets of switched speakers terminals,i use one set for the bass and the other set for the mid/high,so the two speaker cables do not touch each other resistor showing short{5w2R2J},which i measured using continuity mode,just above IP neg,when doing an ohms test is reads 2.3ohms Diode test on mid/high -OL when reversed is flashes 2.2xx,then goes to OL every time i reverse leads it flashes something {2.2xx}not sure its voltage,it doesnt tell me that |
- 119 posts total