HF driver diagram failure, defect or too much power

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maxolini

maxolini

Member
Joined 2018
#1
Guys,
Last Friday gig one of my tops just go dull, so I noticed and when in front of the cabinet, I immediately knew what happened, I lost the HF driver.

The tops are :
Yammy DSR112, the plate amp have all the DSP and limiting , so why the driver fail?

Metal fatigue, too low XO point (too much LF power), or just too much power.

Factory DSP suppose to prevent any harm to the drivers!
PXL_20250506_012759162.jpg
PXL_20250506_012816544.jpg

I saw pics on the net where the diaphragm shattered like this or more.

See the pic

Like 8 months ago the original driver died, at that time it you can see the glue of the coil bubbled and more dark suggesting power failure.

But why? I have seen people who play them with the limiter light stuck on ,
And nothing blow.

Do I have a bad plate amp that is outputting DC or not limiting right?

I'm puzzled.
 
#3
Does the driver have any sort of capacitor for protection? Is it directly connected to an amplifier in an active configuration?
That sort of damage does not look like excessive power in the HF range. That looks like a large low frequency spike taking out the driver.
 
#4
No , those speakers are discontinued and Yamaha do not have anymore drivers.

I just ordered DZR's 7yr warranty.

Question is what that failure was,as I don't saw Browning or bubbling on the coil but actual diaphragm shatter
 
#6
Interesting failure mode, doesn't look like any of the broken diaphragms I have seen. Appears to be where one of the coil lead in wires are, also looks like there is some distortion of the former right there. Crossover point is 1.7khz according to the specs.

Is it possible that they suffered a mic feedback issue?
 
#7
Maybe somehow low frequency got into the amp, despite the active crossover. Maybe it put out a large(ish) 120Hz hum for a couple seconds due to amplifier misbehavior.

Or maybe 1.7 kHz crossover really isn’t high enough or steep enough for it.
 
#8
diyuser2010 said:
Interesting failure mode, doesn't look like any of the broken diaphragms I have seen. Appears to be where one of the coil lead in wires are, also looks like there is some distortion of the former right there. Crossover point is 1.7khz according to the specs.

Is it possible that they suffered a mic feedback issue?
Click to expand...
No mic feedback , I have pushed them harder other times ,that night was around 40% power, no limit light
 
#10
An amplifier input connector can fail and inject a large hum signal. A DSP driver could have a lapse of reason and send the driver to an early grave. The best practice is to have some form of LF limiting capacitor in series with the driver. Cutoff can be about tow octaves below the crossover frequency.

Power blips and brownouts have been known to take out midrange and tweeters on multi-amp configurations. I have looked right at the face of the venue engineer as a power drop happened and you could see the fear as we knew the new 2" exit driver was clapping against some sort of stop and breaking.
 
#14
#16
wg_ski said:
Two octaves lower, or 40 to 47 uF. If you want better protection use 2nd order L-R (with an inductor too) and make it one octave lower. This failure really does smell of diaphragm hitting the phase plug.
Click to expand...
i called the manufacturer and sent the pics and they told me THAT!!! right away
he said
" ohhh very common on people who do not adjust they crossovers correctly"
Click to expand...
that is the diaphragm hitting the phase plug" LOL!!!
 
#17
#18
daqvin_carter said:
I see no sign of charring on the voice coil in that first picture so I would be willing to say excessive power in the HF range was not the problem.
Click to expand...
but those plate amps in the active speakers specially on the high end prosummer , have limiting and DSP.

i read stories of guys that got the limiter pegged in all night
( red light constant on )
and no fryed drivers

so, power surge or brown out
or the amp is shattering HF drivers now
 
#19
wg_ski said:
Two octaves lower, or 40 to 47 uF. If you want better protection use 2nd order L-R (with an inductor too) and make it one octave lower. This failure really does smell of diaphragm hitting the phase plug.
Click to expand...
so what frequency i need to calculate the protection cap
40uF gives the below
too low uh ?
a 10uF cap gives me a 2KHz cut off

1746735011865.png
 
#20
maxolini said:
Actually it is a Brazilian manufacturer
PRV
Click to expand...
Ok then you should not be surprised that the driver failed, you simply cannot throw a different driver in there and expect it to last... even if it supposedly has a higher power handling capability. The driver, the horn it is mounted on, and the amplification and processing are all parts of a very closely matched system, Yamaha wes really pushing the limits of what was possible with these boxes so there is no room for experimentation and as you are finding out it is not possible to even match what they achieved with a different driver. If you still have the original drivers get new diaphrams and put them back in.
 
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