mmm
i don't get it
there are only 1 set of terminals on the driver
not 2
how can i test "between the coils" then ??
please explain more so i can get on with that
i have measured 3.8-4.2ohm with on the driver connections at rest
as soon as the move the cone with my hand though,
that all goes to havoc ...goes up to a few Mohms ...
is that normal ?
then i tried the inductance on my multimeter
gives pretty much nothing at rest
and changes alot when i move the cones ..
let me know what's next
i don't get it
there are only 1 set of terminals on the driver
not 2
how can i test "between the coils" then ??
please explain more so i can get on with that
i have measured 3.8-4.2ohm with on the driver connections at rest
as soon as the move the cone with my hand though,
that all goes to havoc ...goes up to a few Mohms ...
is that normal ?
then i tried the inductance on my multimeter
gives pretty much nothing at rest
and changes alot when i move the cones ..
let me know what's next
My mistake, I assumed it was a dual voice coil unit, just ignore the 'between the coils' bit.
4 ohms doesn't sound like a shorted coil. Maybe the electrical side of things is OK. If you don't feel rubbing, then the driver may not be broken.
BTW, avoid moving the coil with an ohm meter connected as this applies a voltage to the meter which could possibly damage it..
4 ohms doesn't sound like a shorted coil. Maybe the electrical side of things is OK. If you don't feel rubbing, then the driver may not be broken.
BTW, avoid moving the coil with an ohm meter connected as this applies a voltage to the meter which could possibly damage it..
JinMTVT said:
Try a different amplifier. Maybe the Bryston has issues with the lowZ reactive load.
Put flying leads on the speaker terminals (clip leads if you have) and momentarily connect the driver to a 12 volt car battery, one polarity and then reverse and again. See if the cone moves. If it does not your driver is totally skee-rude. You should see a small spark as the lead is removed from the battery and hear a fairly loud click from the speaker cone.
ok .the Bryston plays just perfectly fine on my other loudspeakers ..
is there any measurements i could seriously do on the drivers to have an idea of the possible causes ??
still waiting for advices..
i'll probably unmount the other driver this week end
and see if i can ge tit to play on another amp
anbd take some measurements at the same time!
anything will help as far as the measurements go ..
is there any measurements i could seriously do on the drivers to have an idea of the possible causes ??
still waiting for advices..
i'll probably unmount the other driver this week end
and see if i can ge tit to play on another amp
anbd take some measurements at the same time!
anything will help as far as the measurements go ..
JinMTVT said:
OK. Get yourself a tape measure and take he diameter and depth measurements so you will know what to buy at the store to replace these blown drivers. You have had plenty of technical advise already about what `measurements` and procedures you can use to evaluate the failure mode of these drivers already in this thread from folks wishing to help which you seem to ignore. Good luck.
i just tried them on the Bryston 4B again , on single channel but with the 2 drivers in paralell ...( 2ohm)
played a bit louder...but at everything maxed out or almost , it was probably 1/4 as loud as my 2 12" in my current setup
but the sound seems correct
can there be any problem that causes that kind of behavior?
can drivers really be that ineficient??
played a bit louder...but at everything maxed out or almost , it was probably 1/4 as loud as my 2 12" in my current setup
but the sound seems correct
can there be any problem that causes that kind of behavior?
can drivers really be that ineficient??
heres the problem
84 dB 2.83V/1m
that means u need over 1000w of REAL power to get these to 104db/spl
might be ok in a small space like a car, but i still don't see why they make drivers this hard to drive
also that 84 dB 2.83V/1m may be 8th space efficency in witch case your screwed
i like to hear my bass
84 dB 2.83V/1m
that means u need over 1000w of REAL power to get these to 104db/spl
might be ok in a small space like a car, but i still don't see why they make drivers this hard to drive
also that 84 dB 2.83V/1m may be 8th space efficency in witch case your screwed
i like to hear my bass
Naudio said:heres the problem
84 dB 2.83V/1m
that means u need over 1000w of REAL power to get these to 104db/spl
might be ok in a small space like a car, but i still don't see why they make drivers this hard to drive
also that 84 dB 2.83V/1m may be 8th space efficency in witch case your screwed
i like to hear my bass
And there is really no excuse for the outrageously poor efficiency either since large magnet structures (high field strength in gap) are what is required to make high efficiency possible (besides some other no brainer factors like not physically damping the cone so it cannot move!), and this driver certainly does have a large magnet structure.
Hi Bob,
One thing that needs to be considered is that often, woofers are sold on magnet size and their ability to dissipate power. Selling intelligent woofers for car applications halted many years ago.
Same for amplifier sound quality. Most are not listenable these days by our standards. The poor young fellas don't have any idea anymore.
-Chris
One thing that needs to be considered is that often, woofers are sold on magnet size and their ability to dissipate power. Selling intelligent woofers for car applications halted many years ago.
Same for amplifier sound quality. Most are not listenable these days by our standards. The poor young fellas don't have any idea anymore.
-Chris
Hi Andrew,
Well, no. I took a different path.
When I was young, "Mind Blasters (?)" were the high power rage. Echo boxes and 8 tracks. I installed a pair of efficient 12" woofers on some plywood where the back seat used to be. A '67 Cutlass with a monster trunk (box). At about 4W, it pounded. Later on I installed an "MGT 2100". Supplies of +/- 34 VDC. You want to believe that car was loud. Later on I actually designed proper boxes using 8" woofers (about 2,000 cu in each) with mids and tweeters. From there I was always loud and clean. Even when the other poor guys were using "Fosgate PR-250(?)" amps. Those supplies were only about +/- 22 VDC and they couldn't figure out why I had more power, and cleaner power.
Ever see a "Linear Power" amplifier? Some of those ran +/- 45 VDC supplies and higher. Too bad the amps didn't sound good. They believed that MJ15015 and MJ15016 were audio outputs. The amp sections were enough to make big noise. Did warranty on those briefly.
-Chris
Well, no. I took a different path.
When I was young, "Mind Blasters (?)" were the high power rage. Echo boxes and 8 tracks. I installed a pair of efficient 12" woofers on some plywood where the back seat used to be. A '67 Cutlass with a monster trunk (box). At about 4W, it pounded. Later on I installed an "MGT 2100". Supplies of +/- 34 VDC. You want to believe that car was loud. Later on I actually designed proper boxes using 8" woofers (about 2,000 cu in each) with mids and tweeters. From there I was always loud and clean. Even when the other poor guys were using "Fosgate PR-250(?)" amps. Those supplies were only about +/- 22 VDC and they couldn't figure out why I had more power, and cleaner power.
Ever see a "Linear Power" amplifier? Some of those ran +/- 45 VDC supplies and higher. Too bad the amps didn't sound good. They believed that MJ15015 and MJ15016 were audio outputs. The amp sections were enough to make big noise. Did warranty on those briefly.
-Chris
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