Martin Logan subwoofer failure..... mild rant

Uncle Bambi

Funky Tut
So - about 4-1/2 years ago, I spent large on a nice subwoofer. I brought home a ML Depth-i and have been enjoying it ever since.

Yesterday, it started to make loud, angry noises while the speaker cones moved violently in and out. I shut it off, disconnected everything, and then turned it back on. Same deal. Looks like either the power supply or amp has failed.

I call the retailer where I bought it from, he looks it up and tells me it is out of warranty... warranty being 3 years. I call ML, hoping I can convince them of doing a one-off warranty repair, but they decline. :(

Now - I realize the warranty is 3 years and I am 1-1/2 half years out. I get that ML is not obligated to do anything, and I'm not really mad at them for declining. What I am kind of peeved about is that a high-dollar piece of equipment didn't last very long, under very normal use. That kind of pisses me off, to tell the truth. It just seems that every new production audio gear I've bought turns to crap in a very short time..... my top of the line Onkyo A/V receiver, as an example. I have 40 year old Sansui and Pioneer stuff that still hums right along, but the newer stuff goes south in 2-4 years.

Oh, well. The retailer is an authorized ML service center, and they say they can pull it apart and give me an estimate. I'm kind of stuck - this thing cost a bundle, and I'd hate to toss it and buy a new one......

OK - I feel a bit better now. Maybe I'll haul it down this weekend and let them see what they can do.
 
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Its a lottery, and shit happens. Plenty of vintage gear failed long ago,. Some got repaired and others are deep in landfills. Much of today's gear will one day be vintage just as some of it will be electronic compost.
Quality is quality, no era has a monopoly on it, Martin Logan is far from mass market crap.
Hopefully its a cheap fix.
 
The reason vintage is still working at this point is partly because all the stuff that went bad early on got disposed of, what is left is the one in a dozen so to speak. I share your frustration, I prefer to buy used, because most of the initial failures are absorbed by someone else. And used is much more affordable.

Hopefully yours only requires a recap or something inexpensive. Maybe pull the amp and see for yourself if there are any bulging or leaking caps, or other obvious signs of damage.

A poor connection on the input could play havoc I should think as well. Good luck, I hope you can get it back to full function soon. It sounds like it worked very well so far.
 
recently had a velodyne sub go belly up after about 5 years. no warranty. Maybe not same class at ML but Velodyne did fix it for about 1/4 of the replacement cost. Think a capacitor or more went bad.
 
the problem as i see it is that most all subwoofers are built with cheap plate amps (even high end sometimes) that and the amps should never be built into the subwoofer cabinet were all the vibrations will shake them apart in a few years.
 
Plate Amps

the problem as i see it is that most all subwoofers are built with cheap plate amps (even high end sometimes) that and the amps should never be built into the subwoofer cabinet were all the vibrations will shake them apart in a few years.

I'll second that. For a song and a piece of aluminum plate to cover the hole, I replaced a plate amp in a big money subwoofer with a second hand external. My advantage was that it's attached to a modern home theater receiver that controls all aspects of it's subwoofer output, so I wasn't in need of the controls that come with the original amp.
This may be all moot in the case of the Depth i with the 3 drivers. That amp may be something unique.
 
If they give an overly expensive estimate, I'd considering ripping the amp out and replacing it with an appropriate sized BASH or Dayton plate amp.

Ironically I have a 15 year old cheapo KLH sub that I bought on Craigslist for $25. It was sold at Costco in the late 90's Early 00's. It sounds WAY better than it deserves to and I beat on it hard nearly daily. At one point the magnet seperated from the frame because it drives harder than its construction can handle. I had to gorilla glue it back together and it still pushes along.

It's funny how some cheap stuff can handle time and abuse, and some of the well built expensive stuff goes belly up so quickly. I can say most of the stuff in my "repair" pile is from the 90s-2000's.
 
the problem as i see it is that most all subwoofers are built with cheap plate amps (even high end sometimes) that and the amps should never be built into the subwoofer cabinet were all the vibrations will shake them apart in a few years.

A well built sub doesn't vibrate or shake. It's just the woofer that does anything. If air pressure messes up a plate amp then it's cheap garbage.

To be fair though it could be vibrating depending on how it's being used and cold solder joints could go open. Pretty sure a manufacturer of high end plate amps would account for the possible vibrations
 
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A well built sub doesn't vibrate or shake. It's just the woofer that does anything. If air pressure messes up a plate amp then it's cheap garbage.

To be fair though it could be vibrating depending on how it's being used and cold solder joints could go open. Pretty sure a manufacturer of high end plate amps would account for the possible vibrations

Don't forget the heat....

You can easily design for heat and vibration....just put the amp in separate box.
 
Most subs use amps that I doubt throw off excessive heat, vibrations I dunno.....seems if it was a huge issue it would have been addressed long ago, there are plenty of "cost no object" subs.....they would seperate amps if needed.
 
Most subs use amps that I doubt throw off excessive heat, vibrations I dunno.....seems if it was a huge issue it would have been addressed long ago, there are plenty of "cost no object" subs.....they would seperate amps if needed.

It doesn't take terribly keen eyesight to notice the difference between a $300 plate amp and a $50 second hand power amp. Even the best of subwoofer manufacturers seem to use some pretty lightweight looking stuff, shoved into an unventilated enclosure, knowing you'll never see it until the warranty is a year and a half gone. I know the evidence to support my claim is light-weight anecdotal, but I've had to replace plate amps on every subwoofer I've ever had, and I drive them like an old man. The last one got replaced with a $50 used Kenwood that has lasted ever since.
 
I have a lot of experience with different subs, and i can tell you ALL of them fail after a few years... I have had Polk, Sunfire, Definitive technology, JBL. The amps will only last about three years and they fail. The worst one is Carver's True Subwoofer. The amp failed every 12-18 months. The service guys say the parts and design was very low ball and they will fail. Another factor is that the rail design on the Carver was not reliable.

Polk offered to sell me replacement subs for 1/2 price but I honestly was not that impressed with their sound so i opted for different brands. In the end, i went DIY and designed the sub with a separate sub-enclosure for the amp. I also made the mounting panel removable so if the amp fails, I can replace it with a different amp by replacing the mounting panel as well...
 
Most subs use amps that I doubt throw off excessive heat, vibrations I dunno.....seems if it was a huge issue it would have been addressed long ago, there are plenty of "cost no object" subs.....they would seperate amps if needed.

The driver generates heat and it is dumping it into the space shared by the amp. This is particularly true for sealed subwoofers.

Virtually all of the "cost is no object" DIY builds use external pro amps. Reliability is one of the reasons though bang for buck performance makes them the obvious choice.
 
I have ML reQuest speakers and I have found that forward firing subs don't seem to blend well. I finally settled on an Acoustic Research/Sunfire ARS-300 that worked for about 15 years. It got retired last year because of automatic on/off feature not working the best (fine if done manually), and I replaced it with a REL T5 down firing sub with even less power and a smaller woofer and a smaller price. End result is happiness.

'ner
 
I have a lot of experience with different subs, and i can tell you ALL of them fail after a few years... I have had Polk, Sunfire, Definitive technology, JBL. The amps will only last about three years and they fail. The worst one is Carver's True Subwoofer. The amp failed every 12-18 months. The service guys say the parts and design was very low ball and they will fail. Another factor is that the rail design on the Carver was not reliable.

Polk offered to sell me replacement subs for 1/2 price but I honestly was not that impressed with their sound so i opted for different brands. In the end, i went DIY and designed the sub with a separate sub-enclosure for the amp. I also made the mounting panel removable so if the amp fails, I can replace it with a different amp by replacing the mounting panel as well...

How can you say "all", cause I have a Def Tech sub from 2000 still works like a charm, 2 M&K sealed subs even older still going strong, my dad has 2 Vandersteen units 7 yrs and no issues, friends have Martin Logan, Zu, Velodyne, JL.....and that's just off top of my head. Nobody ever had to dick around with anything other than placement and integration.
Either you are unluckiest guy ever or exaggerated a bit.
 
A 3 year warranty on any audio gear is unheard of, on speakers never, on a sub is just crazy.

Martin Logan gave you all the protection they could for any reasonable buyers expectatios.

Powered subs tend to have a high failer rate and your 4 1/2 years is good prior to service, any service.

When you buy a car do you bring it in for service while it's under warrany? Do you drive it into the ground never servicing it and then wouder why it broke down after the warrany ended.
 
It doesn't take terribly keen eyesight to notice the difference between a $300 plate amp and a $50 second hand power amp. Even the best of subwoofer manufacturers seem to use some pretty lightweight looking stuff, shoved into an unventilated enclosure, knowing you'll never see it until the warranty is a year and a half gone. I know the evidence to support my claim is light-weight anecdotal, but I've had to replace plate amps on every subwoofer I've ever had, and I drive them like an old man. The last one got replaced with a $50 used Kenwood that has lasted ever since.

My experience and travels simply don't support these claims of failure in "every sub"....I'm meeting some really unlucky folks here. Maybe me my family and friends are all super lucky..... Yea thats it lol.
 
A 3 year warranty on any audio gear is unheard of, on speakers never, on a sub is just crazy.

Martin Logan gave you all the protection they could for any reasonable buyers expectatios.

Powered subs tend to have a high failer rate and your 4 1/2 years is good prior to service, any service.

When you buy a car do you bring it in for service while it's under warrany? Do you drive it into the ground never servicing it and then wouder why it broke down after the warrany ended.

All the speakers that I have bought recently have a 5 year warranty.

'ner
 
Plate Amplifiers

Where's the 100,000 uF of storage capacitance? The big heat syncs? The transformers that one hurts their backs lifting into place? It wasn't until my umpteenth failure that I thought to myself, "Hmmmmm....there seems to be some sort of pattern here," and started paying attention to the construction of plate amplifiers -vs- external amplifiers and wondered why this relatively modern phenomena (plate amps) didn't seem to follow the template established by older technology (external amps). The only thing I could think of was the modern market - cost and convenience. A quick Amazon search will support my belief in that external subwoofer amps generally come with their own butler and a quick Google search will find plate amps more commonly beefed about than other components.
 
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