Aeon i Question

MartinLogan Audio Owners Forum

Help Support MartinLogan Audio Owners Forum:

phurley

New member
Joined
Jun 17, 2022
Messages
4
Reaction score
0
Location
San Diego, CA
I'm a newbie on this forum. This is my first post.
I've owned my Aeon i speakers for around 10 years, and I've been very happy with them. But recently the woofers in both speakers have been producing a buzzing sound at moderately high sound levels. This is not a hum, but a crackling sound as if the voice coils were rubbing against the magnet assembly. But there is nothing wrong with the drivers themselves. The problem occurs regardless of whether the speakers are plugged into the wall outlet, and regardless of the amp or original sound source. The problem even occurs if I disconnect a woofer and attach a separate speaker to the crossover. Then the buzzing sound comes from the separate speaker. This strongly suggests that the crossover is at fault. But there are only two components in the woofer crossover: a capacitor and an inductor. Could the capacitor be at fault?
I contacted ML tech support, and Brian Bailey replied to my question. He pointed out that the crossovers are not active (which I knew already), so how could they be producing any buzzing sound? But he was kind enough to send schematics and other info for the speakers.
Has anybody out there in ML land encountered any such problem? If so, please help!
 

Brandon Hartwick

Well-known member
MLO Supporter
Joined
Mar 17, 2022
Messages
247
Reaction score
138
That is a very strange issue, I would open up the back of the speaker and make sure you don't have a wire touching something it shouldn't.

Try bypassing the passive crossover and run the woofer full range and see if the problem persists. This won't sound any good but it will rule out any passive components.
 

phurley

New member
Joined
Jun 17, 2022
Messages
4
Reaction score
0
Location
San Diego, CA
That is a very strange issue, I would open up the back of the speaker and make sure you don't have a wire touching something it shouldn't.

Try bypassing the passive crossover and run the woofer full range and see if the problem persists. This won't sound any good but it will rule out any passive components.
 

phurley

New member
Joined
Jun 17, 2022
Messages
4
Reaction score
0
Location
San Diego, CA
Hi Brandon,

I tried running the woofers directly from the amp, and the buzzing sound seems to disappear.

The woofer crossover on the Aeon i isn't really a crossover. It's a low pass filter, and the single cap is connected across the signal supply lines. If the cap should be shorting at high sound levels, this could produce a buzzing sound. So I'm thinking about replacing the cap on each speaker. I'm definitely not an expert when it comes to capacitors, and I don't know if such a thing is possible. Do these caps ever short circuit?

The interesting thing is that identically the same problem is occurring in both speakers, and the problem has turned up at about the same time in both.

Assuming I try to acquire a pair of 100 mfd caps, do you happen to know where best to get them? I'm 80 years old, and 50 years ago there were electronic stores in every city that sold them. But things have changed, and I've gotten out of touch.

Thanks for taking the time to address my query.

Patrick
 

Brandon Hartwick

Well-known member
MLO Supporter
Joined
Mar 17, 2022
Messages
247
Reaction score
138
That is very interesting that the problem is the same in both speakers and that it appeared at the same time.

What amplifier are you using? Is it possible that it might be in need of a rebuild? I recently worked on a set of crossovers that were killed by a bad amplifier.
 

phurley

New member
Joined
Jun 17, 2022
Messages
4
Reaction score
0
Location
San Diego, CA
That is very interesting that the problem is the same in both speakers and that it appeared at the same time.

What amplifier are you using? Is it possible that it might be in need of a rebuild? I recently worked on a set of crossovers that were killed by a bad amplifier.
I'm using a 60 year old Macintosh MC 2100. I'm sure a rebuild wouldn't hurt it. Do you know exactly what the bad amp did to the crossovers?
 

Brandon Hartwick

Well-known member
MLO Supporter
Joined
Mar 17, 2022
Messages
247
Reaction score
138
I'm using a 60 year old Macintosh MC 2100. I'm sure a rebuild wouldn't hurt it. Do you know exactly what the bad amp did to the crossovers?
The amp in question blew up internally and sent a massive power spike into the crossovers. Some capacitors exploded and the board was burnt through in some places.

You might be able to get your crossover capacitors tested somewhere. Some musical instrument shops actually seem to deal in small passive electronics like this.
 

Tosh

Well-known member
Joined
Dec 17, 2008
Messages
707
Reaction score
43
Location
Silicon Valley
Weird for yours to both be doing it, which kind of points to an upstream problem...

About 20 years ago I heard a pair of Aeon i, and for a couple of minutes it seemed like there was a faint chainsaw effect from somewhere, and it was from those evil tweeters on the rear! Used a toothpick to poke the switch to turn them off, and all was good again.
 
Top