Intermittent Problem With My Depth i subwoofer

[Robert D]

I bought a great Depth i sub back in 2012. It had a couple of minor problems when I first bought it and the dealer I purchased it at fixed those up for me. For awhile everything worked great. Then back around 2018 or so the sub would put out a weird static/crackling sound. It sounds like it is coming from all three woofers. It goes on for maybe a minute, kinda faint, and then goes away. About 2 weeks ago for the first time it made a big thump that was loud enough that we thought someone had knocked at the door. My daughter actually got up to check the door! LOL

For the most part the sub works fine, but we can be watching tv and then the static sounds kicks in. It only happen maybe 2 times a month. I found that unplugging the power and then plugging back in seems to make it stop. Another thing I noticed is that the sound can persist even when everything else is turned off, like when I turn off the tv and stereo/amp. It takes a few minutes for the power on the subwoofer to go into standby, and during that time you may hear the sound.

I called in to ML but now with coronavirus there isnt anyone there to take calls for service. I emailed but even that is stretched thin. We communicated back and forth some but was told that he cant really get me any answers now and will get back later. Id like to fix the issue. My guess is a problem with the amp board, and replace that. I dont want to replace it though if its not bad. There are other parts like the power supply, toroid, and control panel. Havent been able to get too far with ML now. Hopefully things look up there.

 

[roberto]

Hola Robert,

Usually that's coming from the power supply. I do not understand yet the why the sub is doing that. It is a heavy transient. Usually this heavy transients could come from the mains AC. The AC from your house energy goes away for a fraction of a second and comes back.

This could produce that heavy odd heave bass energy sound. It is produced while the capacitors of the power supply are discharging their energy and suddenly they get charged again.

A very strange situation. Also, could be a failure at the subwoofer mains AC transformer too. What bugs me, is that it starts to work with no problem. Please keep us posted with your findings.
Happy listening!

 

[Robert D]

Hola Robert,

Usually that's coming from the power supply. I do not understand yet the why the sub is doing that. It is a heavy transient. Usually this heavy transients could come from the mains AC. The AC from your house energy goes away for a fraction of a second and comes back.

This could produce that heavy odd heave bass energy sound. It is produced while the capacitors of the power supply are discharging their energy and suddenly they get charged again.

A very strange situation. Also, could be a failure at the subwoofer mains AC transformer too. What bugs me, is that it starts to work with no problem. Please keep us posted with your findings.
Happy listening!

Yes, it is very strange. The heavy sound only happened one time. The faint static sound, almost like something scratching the woofers, is the one we get the most. Again it is quite rare and only happens a few times a month. It always seems to happen right in the middle of a good movie!

Im considering just buying the balanced force 210 but dont really want to spend $3500 right now in the middle of this pandemic, our family income is down. For now it works great most of the time, its mostly just annoying.

 

[roberto]

yup, I am with you here. Sometimes, digital streaming or digital DVD can produce severe odd noises. I have some files on my storage hard drives, that have been corrupted. Those are bad and horrible noises. I'm just thinking loud...if you have an electronic problem, usually is not intermittent. The failure remains. Even visual when you have a fried resistor. Smoke with lovely colours arise...

With tube gear, this is a frequent possibility. Specially with the Audio Research Company. The bias output tube resistors, when a power tube fails, this resistor is fried. The resistor value is 1 ohm/3 watts.
Please, tell us your findings.
Happy listening

 

[Robert D]

yup, I am with you here. Sometimes, digital streaming or digital DVD can produce severe odd noises. I have some files on my storage hard drives, that have been corrupted. Those are bad and horrible noises. I'm just thinking loud...if you have an electronic problem, usually is not intermittent. The failure remains. Even visual when you have a fried resistor. Smoke with lovely colours arise...

With tube gear, this is a frequent possibility. Specially with the Audio Research Company. The bias output tube resistors, when a power tube fails, this resistor is fried. The resistor value is 1 ohm/3 watts.
Please, tell us your findings.
Happy listening

Its definitely not the source because it makes the sound even when the receiver and amp are turned off, its done it after I turned everything off and the sub is just sitting there waiting to turn off by auto. The scratchy sound is emitted. At first I thought it was just the front speaker but after getting down it sounds like its coming from all 3. I took out two of the woofers and made sure the connections were all tight and they were. That was the recommendation I got from ML in my email. I asked them for advice hoping they could tell me which component may be at fault but he didnt know and said it would be awhile before he could get back to me. Covid-19 has staff way down I guess.

 

[Robert D]

Oh, another problem. I thought I would take out all 3 woofers but one appears to be glued in! I took out all the screws and the woofer wouldnt budge. I had some issues with the sub right out of the box and took it back to the dealer to fix. That was many years ago. Im wondering if they might have glued in the woofer. Not sure why they would do that, maybe it was rattling after they took it out? So now that woofer is stuck fast in there. No way thats coming out. Luckily its not on the amp board side, but it is next to the power supply and I think it would be near impossible to replace the power supply if I cant get that woofer out.

 

[roberto]

Sometimes rattling sound is because one cable is touching the cone. This cause the rattle. You have to take off the back plate, and address the cables. Because your Depth I is servo controlled, there are two different kinds of coils on each woofer. One is for the servo control and the other is for the sound. Just address the cables in a such manner that they do not contact the cone of any of the three woofers.

Regarding the odd noise, I really do not have a clue. If you say that being the system off, and you got it, I can't think of what could cause that ugly sound. Your description make me wonder about digital garbage. But from where it is coming? I have an idea, just disconnect the audio cable, the RCA from the sub, leave it on during night or through the day and if the noise appears, definitively it is the power section of the sub.

Happy listening.

Happy listening.

 

[spkrdctr]

Hmmm.. it sounds like a bad whatchamacallit. Commonly referred to as a bad thingamajig. Seriously, it sounds like you have a couple of things it could easily be. First and foremost, I would guess a bad solder joint somewhere as they are intermittent, heat sensitive, and vibration sensitive. A real pain in the butt to find if you are not a repair technician. If it is that then you will have to take it somewhere to get fixed and pay some money. At this point I would recommend jumping to your next purchase in a new sub rather than sink money into this older one. The second issue it could be is a breakdown in an electrical component. Again, this needs a thorough going over to find it which is hard as it is intermittent. So, I recommend that your follow your own advice and keep working with this one for another 6 months or so and then buy the new one. If I was still in repair I could spend a few hours finding the problem with the associated test gear, but being intermittent it can be very tough to find, even for a good repair guy. Good Luck in whatever you decide to do. Another last possibility is to take it in for repair but tell them if it's over say $500 you don't want it fixed, or something like that. Let us know what you decide and what happens.

 

[Robert D]

Hmmm.. it sounds like a bad whatchamacallit. Commonly referred to as a bad thingamajig. Seriously, it sounds like you have a couple of things it could easily be. First and foremost, I would guess a bad solder joint somewhere as they are intermittent, heat sensitive, and vibration sensitive. A real pain in the butt to find if you are not a repair technician. If it is that then you will have to take it somewhere to get fixed and pay some money. At this point I would recommend jumping to your next purchase in a new sub rather than sink money into this older one. The second issue it could be is a breakdown in an electrical component. Again, this needs a thorough going over to find it which is hard as it is intermittent. So, I recommend that your follow your own advice and keep working with this one for another 6 months or so and then buy the new one. If I was still in repair I could spend a few hours finding the problem with the associated test gear, but being intermittent it can be very tough to find, even for a good repair guy. Good Luck in whatever you decide to do. Another last possibility is to take it in for repair but tell them if it's over say $500 you don't want it fixed, or something like that. Let us know what you decide and what happens.

Yeah, im thinking you are right. It would be ignorant for me to just go in and replace the amp circuit board not knowing for sure where it is. I think you are probably right about the lose connection somewhere in a solder joint. The sub is 8 years old. Thats a bit longer than my Paradigm lasted I think. Im only on my 2nd nice sub. I will most probably just end up replacing it and put it down in the basement with my old stereo, since it still works most of the time. Really waiting now for this virus to pass because right now it looks like our family might lose all income since my wife is nervous about losing her job. It would be foolish for me to spend a lot of cash on luxury items now.

Another problem is that I have a good feeling that the panels on the Prodigies I bought are going out too. I have another thread on here on that. Those are 20 years old, i bought them used about 5 years ago. If I spend money it will probably be on replacing those first, since the sub works most of the time.

 

[Peter Hogan]

I've had issues with a Velodyne sub that was servo controlled. It would give occasional noises even when disconnected from any sources. It seems the servo sensor was getting noisy, and the servo system would faithfully reproduce that noise. The only cure was a new driver (speaker) as the servo sensor was part of the speaker and not replaceable, that was cost prohibitive, so I bypassed the built in servo-controlled amp, and used an external amp to drive the speaker without servo-correction. The distortion might be a tad higher, but it still sounds great, and no more background noises.

 

[Robert D]

I've had issues with a Velodyne sub that was servo controlled. It would give occasional noises even when disconnected from any sources. It seems the servo sensor was getting noisy, and the servo system would faithfully reproduce that noise. The only cure was a new driver (speaker) as the servo sensor was part of the speaker and not replaceable, that was cost prohibitive, so I bypassed the built in servo-controlled amp, and used an external amp to drive the speaker without servo-correction. The distortion might be a tad higher, but it still sounds great, and no more background noises.

In my case I think the servo is on the amp? It seems to output the sound through all 3 speakers. I'm not sure what a servo does or where it usually is.

At first I thought it was only the front speaker,so I swapped 2 and the sound stayed on the front. When I listened really carefully it sounds like the popping noise is emitted from all 3.

 

[Peter Hogan]

The servo measures the actual speaker cone motion vs what the drive signal is. It then derives an error signal that it uses to modify the drive signal so the cone motion more accurately tracks the signal input. The servo sensor is necessarily attached to or part of the speaker cone, to measure it's movement. The servo signal is fed to the amplifier circuitry to do the signal comparison, error generation and feedback correction.

 

[Robert D]

The servo measures the actual speaker cone motion vs what the drive signal is. It then derives an error signal that it uses to modify the drive signal so the cone motion more accurately tracks the signal input. The servo sensor is necessarily attached to or part of the speaker cone, to measure it's movement. The servo signal is fed to the amplifier circuitry to do the signal comparison, error generation and feedback correction.

Thanks for the explanation. So its probably not servo since the sound is coming from all 3 speakers. I think the amp board is probably the culprit, but cant be sure. Anyone else have an idea?

 

[spkrdctr]

No one can diagnose your sub over the internet. You will get a bunch of ideas but no one knows what it is. I can use all of my experience to come up with a diagnosis that is very close and pretty much right on target. You then can narrow it down from there. Here goes.
Upon examination through the internet, I have determined that your sub has a problem that is really quite common and easily fixed.
I of course, am not charging any money for this technical explanation. I will give it out for free.
Your sub has an intermittent problem that is classified as broken. So your sub is broken. There I feel so much better giving you my technical answer. I'm sure others will back this diagnosis up.

I think my basically quarantined life is driving me a little nuts. So, I come to this site and try to be funny. I I have fallen pretty low with the COVID mess. How low can I go? That is a good question. So far, I'm not talking to my cat and having him answer me. If he all of a sudden starts talking to me, I will then cease all activity and just watch tv!

He has been looking at me like he wants to tell me something..........

 

[Robert D]

No one can diagnose your sub over the internet. You will get a bunch of ideas but no one knows what it is. I can use all of my experience to come up with a diagnosis that is very close and pretty much right on target. You then can narrow it down from there. Here goes.
Upon examination through the internet, I have determined that your sub has a problem that is really quite common and easily fixed.
I of course, am not charging any money for this technical explanation. I will give it out for free.
Your sub has an intermittent problem that is classified as broken. So your sub is broken. There I feel so much better giving you my technical answer. I'm sure others will back this diagnosis up.

I think my basically quarantined life is driving me a little nuts. So, I come to this site and try to be funny. I I have fallen pretty low with the COVID mess. How low can I go? That is a good question. So far, I'm not talking to my cat and having him answer me. If he all of a sudden starts talking to me, I will then cease all activity and just watch tv!

He has been looking at me like he wants to tell me something..........

Yeah, it officially has a problem with it! I'll probably just end up using it until the problem starts happening quite often, and at that point take it to the store where I bought it and have them diagnose it or just toss it and buy new. Right now it can't really be diagnosed because the popping sound is so rare. It happens maybe once a month now.

 

[Robert D]

Kinda hard for me mentally to just throw away a nice piece of stereo equipment. Suppose I could bring it in to the store and just give it to someone that wants to tinker with it.

Right now the balanced force 210 looks like what I'd get to replace my depth i.

https://www.martinlogan.com/en/product/balancedforce-210

 

[roberto]

Hola Robert,
The BF-210 is totally different than the Depth I. Instead three speakers of 8", you have two 10" subwoofers. I was a Depth I user, but when the BF-210 came out, and having the special USB port for a firmware made specifically for any ML speaker's model, I bought one.

I can say that the bass notes are deeper and the blend with my CLXs is fantastic. It looks like there is not a sub, until a very low frequency note is present. The bass intensity notes and the phase is very easy to adjust.

Happy listening!

 

[Robert D]

Hola Robert,
The BF-210 is totally different than the Depth I. Instead three speakers of 8", you have two 10" subwoofers. I was a Depth I user, but when the BF-210 came out, and having the special USB port for a firmware made specifically for any ML speaker's model, I bought one.

I can say that the bass notes are deeper and the blend with my CLXs is fantastic. It looks like there is not sub, until a very low frequency note is present. The bass intensity notes and the phase is very easy to adjust.

Happy listening!

Just wish it weren't $3500. I'll get one eventually. Probably wait for mine to die.