Some of you may recall Monsoon audio -- for a time (late 1990-early 2000s) --- they became hot sellers due to their PC-related sat/sub models.
They sound quite good (mine are about 21 years old, but I retired them after about 2 years due to subject of this thread).
Both sats have a "buzzing" distortion over most of their freq range. They sound as if they are "blown" but BOTH being blown would be rare.
I think I've read that their powerful magnets can attract dust and that clogs their diaphragms.
The drivers are RIVETED shut so disassembly would be somewhat destructive. Don't want to do that just yet!
But I am open to other suggestions. E.g., how delicate are the film diaphragms to, say, compressed air blow-out?
They sound quite good (mine are about 21 years old, but I retired them after about 2 years due to subject of this thread).
Both sats have a "buzzing" distortion over most of their freq range. They sound as if they are "blown" but BOTH being blown would be rare.
I think I've read that their powerful magnets can attract dust and that clogs their diaphragms.
The drivers are RIVETED shut so disassembly would be somewhat destructive. Don't want to do that just yet!
But I am open to other suggestions. E.g., how delicate are the film diaphragms to, say, compressed air blow-out?
Monsoon was a Vancouver company and we ended up with 5 pallets of warranty returns, we were able to resurrect a huge number of system and i liquadated the rest as parts. Eastech in Malaysia bought them, i m sure just for the licince from Emminent for the push-pull electrodyanamic planar.
MM1000 with the 1st gen big planar..
The problem could be the drivers, but that is unlikely. They usually just die when the voice coil breaks. Or the amplifiers. It uses a stereo chip am, so both channels would go at the same time if PS or other problems occur.
But the 1st place i would look is the flaky connector of the controller to the woofer box.
dave
MM1000 with the 1st gen big planar..
The problem could be the drivers, but that is unlikely. They usually just die when the voice coil breaks. Or the amplifiers. It uses a stereo chip am, so both channels would go at the same time if PS or other problems occur.
But the 1st place i would look is the flaky connector of the controller to the woofer box.
dave
The problem is almost certainly the drivers.
I hooked two Cambridge Audio sats to the Monsoon sub/amp system. No distortion.
I hooked up the two in-question Monsoon MM-1000 planar sats to the Cambridge system. Distortion audible thru the sats, as was the case with their default Monsoon sub/amp system.
I did blow out the planar vents gently with bottle compressed air. No difference.
For those curious about the Monsoon controller/amp section: (the tda7393 is for sats; 7396 is for sub)
I hooked two Cambridge Audio sats to the Monsoon sub/amp system. No distortion.
I hooked up the two in-question Monsoon MM-1000 planar sats to the Cambridge system. Distortion audible thru the sats, as was the case with their default Monsoon sub/amp system.
I did blow out the planar vents gently with bottle compressed air. No difference.
For those curious about the Monsoon controller/amp section: (the tda7393 is for sats; 7396 is for sub)
Last edited:
Been awhile since i disassembled a set of those. Rivets you say? You might need to carefully drill those out to look for a problem.
Do inspect the lead wires first. Very unlikely they are the issue. May be frayed or the copper tarnished to the point where it is not doing a very good job.
Pictures?
dave
dave
Do inspect the lead wires first. Very unlikely they are the issue. May be frayed or the copper tarnished to the point where it is not doing a very good job.
Pictures?
dave
dave
Sorry, MM-1000 is doomed.
PM-9 has potential but needs a tweeter past 5kHz....
https://www.diyaudio.com/forums/pla...soon-planar-magnetic-drivers.html#post1089598
PM-9 has potential but needs a tweeter past 5kHz....
https://www.diyaudio.com/forums/pla...soon-planar-magnetic-drivers.html#post1089598
If the panels are doomed, if you can figure out how to defeat the OB filter (1st order boost below 1kHz) you can attach a box speaker.
The filter to the woofer is 200 Hz or so, be nice to lower that a bit. The woofer is decent.
We have used a lot of the woofers from the PM-9. Really quite a nice one. The box is a bit small.
dave
The filter to the woofer is 200 Hz or so, be nice to lower that a bit. The woofer is decent.
We have used a lot of the woofers from the PM-9. Really quite a nice one. The box is a bit small.
dave
Not fixing .... but not selling them either ...
I'm done with these speakers unless someone can offer a simple solution (one that does not involve de-riveting, or so much work).
Too bad ... the MM-1000 are quite nice sounding. And some accounts I've read involve them being used with good amps and subs ... and that being the ideal use for them ... well beyond "PC speakers" category.
Yeah ... I think I saw your account here on DIYA, years ago, and recall the magnet peel issue.
I'm done with these speakers unless someone can offer a simple solution (one that does not involve de-riveting, or so much work).
Too bad ... the MM-1000 are quite nice sounding. And some accounts I've read involve them being used with good amps and subs ... and that being the ideal use for them ... well beyond "PC speakers" category.
Right, the nickel coating peels off and then the ferrite magnets crumble into dust.
For less buzz you could cross them over higher (I used an active xo to try this), but then there's still not much top end past 5kHz.
For less buzz you could cross them over higher (I used an active xo to try this), but then there's still not much top end past 5kHz.
As I noted, the buzzing happened within the first two years of their purchase (purch'd 1999, IIRC). They were in daily use then. In firing them up recently, I have not really noted any increase in buzzing. So nickel issue may be related to activity rather than environment (humidity, O2, etc.).
Do you (anyone) have pictures of an un-riveted driver?
Is there any way to repair w/o de-riveting? (As noted, I did gently blow deep into driver vents with canned compressed air -- but no effect!)
Is it similar to Infinity's EMIT planar drivers?
Is that a picture of the current state of disassembly… you have gotten far enuff.
The EMITs are electrodynamic planars as well, but single sided magnets i believe, vrs the push-pull in the Monsoons.
Trace the voice coil, looking for any gaps or pieces missing.
dave
The EMITs are electrodynamic planars as well, but single sided magnets i believe, vrs the push-pull in the Monsoons.
Trace the voice coil, looking for any gaps or pieces missing.
dave
BTW: I am assuming (??) Monsoon fixed the issue after their "1st gen"? Not sure whether that includes the MM-1000, which I believe was only sold in Monsoon's early years.
Hi Dave - Did you measure the 1st order boost below 1kHz and if so do you remember it is stopped anywhere in the lower frequencies? I just found a new old stock set of 4 Monsoon MM-2000 planar speakers and will be using a MiniDSP active crossover to do some tweaking to the sound. Thinking it won't be too hard to get the bass right on the Monsoon's with the MiniDSP before it gets picked up by a subwoofer.
Thx,
Greg