The formula for parallel resistance is 1/Rt= 1/R1+1/R2+1/R3....If any one or more of the paralleled resistor is 0 ohm, it is a short circuit and the total resistance should be 0 ohm.
https://www.electronics-notes.com/articles/basic_concepts/resistance/resistors-in-series-parallel.ph...
Since he measured almost 8 ohms then the total resistance will be 1/8 ohm + 0 ohm or 0.125ohm.
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
The best way I know of to test a crossover is to generate an impedance graph. You can use DATS V2 (or is it now up to V3) or you can build a jig and use Room EQ Wizard’s app for this. But... if you are bi-amping it is possible the two crossover sections are not properly separated. If the voltage in one section can touch the voltage in another, at all then you can cause the amps to fight each other. If the internal crossover is completely separated, including separate grounds internally then no problem. OTOH, if the ground is not separated internally and 1 amp has reversed outputs or balanced outputs then you run into the problem above. |
@likklegerry - Anymore info from you? Are you using internal passive crossovers? |
Hi Guys,thankyou so much for all your help,but i still dont see a solution to this problem,in my opinion there is shorts in both xos,please see below- LEFT SPEAKER / RIGHT SPEAKER speaker terminals with everything connected on both speakers MID/HIGH 0.0 ohms / MID/HIGH 0.0 ohms BASS 7.9 Ohms / bass 6.8Ohms DRIVER TEST DISCONNECTED FROM X OVER TWEETER 8 OHMS / 7.9 OHMS MID 6.3 OHMS / 6.2 OHMS BASS 6.1 OHMS / 6.0 OHMS CONTINUITY TEST ON X-OVER WITH DRIVERS REMOVED USING DIODE FUNCTION between positive and negative on x over HF 000.2 {dead short} / 000.2 {dead short} MF 000.5 / 000.5 LF OL. / OL. MID HIGH INPUT IP OL. / OL. BASS INPUT OL. / OL. OL. BEING NO CONTINUITY TEST TESTED AT/ON X-OVER SPEAKERS CONNECTED OHMS HF 0.0002 OHMS / 0.002 OHMS MF 0.0001 OHMS / 2.0 OHMS LF 6.4 OHMS / 6.3 OHMS ive also now removed one lead from all the caps on one xo,and tested them with a cap meter,all caps are the correct uf ,within spec,can anyone tell me where to go from here, thankyou again for all your kind help.regards Mark |
- 119 posts total