Summits humming even when not connected

[David100]

Hello,
My summits (3 weeks old) are humming, both of them.
The noise is very low and can only be heard very close to the speakers when they are not playing. The sound is more like a little kitty purring. It comes from the woofer, not the stator.

They keep humming/purring even when they are plugged to the AC and not connected to the system.

Is the problem in the speakers or in my line ?
Is this a ground loop problem or not ?
Can this harm the speakers ?
Can powerfilters solve this, like the devices from ps audio (noise harvester ? power plant premier ?)

Any help welcome
Thank you very much

David

 

[User211]

I had a Descent humming problem recently - but it turned out to be a step-up transformer, which was too close to it. In other words, make sure you have nothing like this close to the sub-woofers...

All sorts of things can cause hums - another porblem can be MC/MM phono stages too close to the power amp etc. Experiment with moving components around as a first step.

Fridges and other household appliances can also get into the loop, so try turning those off briefly, to see if they have any effect.

Does it only happen when certain sources or a particular source is switched in? If its only the phono, you may need to earth your deck. You may also find that you can NEVER totally eradicate hum on a phono input, but you should be able to get it to reasonable levels.

Your power amp may have developed a fault etc... just keep trying changing things and give feedback to this forum and we'll nail it.

 

[benleeys]

Hello,
My summits (3 weeks old) are humming, both of them.
The noise is very low and can only be heard very close to the speakers when they are not playing. The sound is more like a little kitty purring. It comes from the woofer, not the stator.

They keep humming/purring even when they are plugged to the AC and not connected to the system.

Is the problem in the speakers or in my line ?
Is this a ground loop problem or not ?
Can this harm the speakers ?
Can powerfilters solve this, like the devices from ps audio (noise harvester ? power plant premier ?)

Any help welcome
Thank you very much

David

The sub in all the 3 pairs of Summits I've come across, including mine, 'hummed', whether connected to system or not. The sound can be heard the moment it is connected to power line. It's actually more like a soft low frequency 'shhhhhh' sound. I believe it's inherent in the design.

 

[David100]

To User211: Thanks for your answer, but there is nothing located close to the speakers and I have no phono. Fridge and so on are quite far away, but indeed I may try to turn them off to check... But this can take ages.

To Benleeys: I am happy to hear I am not alone. You are right, it is a kind of low frequence "ssshhhhhh" (combined with a very low hum). Indeed it is stronger in the first moments after connecting to the power line. When I listen to music and then stop listenning, it is much lower, but still it is there and I can hear it when the room is very quite.


I would like to know if eveybody has the same problem (and if so I can accept it for myself), or if there is a way to get rid of it.

 

[User211]

Hm, those Summit power amps are class Ds... like the Descent... can you switch them out of circuit, so an external amp is used? If so, does the noise go away? My Descent makes no noise whatsoever... so why should the Summit?

 

[benleeys]

......I can hear it when the room is very quite.

I would like to know if eveybody has the same problem (and if so I can accept it for myself), or if there is a way to get rid of it.

It's probably the noisy Class D amp used to drive the sub. You have to put your ear almost against the grill to notice it. Don't forget though, that the Summit goes quite low (24Hz), otherwise you probably won't get to hear the noise.

Let's see if the new update will cure it. Meanwhile, enjoy the music. :music:

 

[User211]

It's probably the noisy Class D amp used to drive the sub. You have to put your ear almost against the grill to notice it. Don't forget though, that the Summit goes quite low (24Hz), otherwise you probably won't get to hear the noise.

Let's see if the new update will cure it. Meanwhile, enjoy the music. :music:

http://www.martinloganowners.com/~tdacquis/forum/showthread.php?t=90

The Descent goes a bit lower. Just this minute put my ear right against one of the woofers, with no source or preamp on. There is a slight "sssssssh" noise that increases a tiny fraction with the gain at max. It is NOTHING MUCH, and you can't hear it from a foot or so away... in my books that rates as a very quiet component.

Hope this helps. Also David100 - it maybe what you are hearing IS mains noise and one of those PS Audio regenerators could well improve it... there's no way a bit of noise will damage those Summit woofers, though.

Just curious anyone - can you switch the internal Summits woofer amps out-of-circuit and use an external power amp? Why would you want to is NOT a sufficient answer... I just want to know if it can be done easily.

 

[Neil H]

Does the hum vary with the time of day. I ask this because I had Quest's in which I could hear a hum at night but not during the day. It turned out to be caused the line voltage getting too high at night ie. In Australian it is supposed to be at 240 but got to over 260 at night. Eventually the power company changed some settings in the street and dropped the voltage.

My Summits don't hum at all but I have a power conditioner that keeps the voltage exactly at 240

 

[robertawillisjr]

Are the speakers in an HT setup or is there a cable connected to any of the equipment. Your Summits may be the most sensitive equipment in your rig and are telling you that there is a connecter somewhere that is creating a ground loop and therefore the hum. Which will be heard even if your equipment is off (this is most common when a TV or Satellite cable is connected to your equipment) but can be caused by some other faulty interconnect.

You may have to disconnect one interconnect at a time. If it is the cable you can purchase something like the no longer manufactured Mondial Magic Splitter.

 

[FISH_MAN]

those should not hum

I would try pluging them into a quality power cond. I have two panamax 5500ex on my system and it is dead silent they should have no hum at all I have owned vantages and now spires if you bought them from a dealer and this
is some how a problem with the summits which I highly doubt it is I would return them for a set of spires and pocket the difference.call martin logan service and ask for melodie or jim powers. they have a great service department the best of any company I have ever delt with.

 

[DrJRapp]

Hello,
My summits (3 weeks old) are humming

They keep humming/purring even when they are plugged to the AC and not connected to the system.

Is this a ground loop problem or not ?

Can powerfilters solve this, like the devices from ps audio (noise harvester ? power plant premier ?)
David

I had the same issue for the longest time with one of my Summits. Recently I discovered that I was utilizing 2 different circuits for my system. The bulk of the gear was on a dedicated 20 amp circuit that was installed just for the system. The one offending Summit was plugged into a regular wall outlet on a different circuit. That wall outlet had a loose ground wire! Plugging both Summits into a strip socket that is plugged into the aux high output socket on the APC power regenerator I use for the voltage sensitive components which in turn is plugged into the 20 amp circuit did the trick.

Obviously there was a diffrence in ground potential causing a ground loop.

 

[twich54]

Similiar deal with mine and every other pair of Vantages I have ever listen to. One needs to get mighty close to hear what your describing but yes, it's there. I spoke with Jim Powers about this over two years ago, at which time they were having a production run of Vantages and he CONFIRMED what I was hearing. unfortunately he had no reason for it ???

 

[David100]

To User211 : No, on the Summits, i cannot disconnect the amp. At least, not without opening the whole speaker, and i am not ready to do so...

---

But I am happy to hear i am not alone, I know now my speakers seem to be normal. I guess I will have to try some power conditionners if I want to get rid of the noise (which is very low - you have indeed to put your ear close to the speaker... but still... I hear it).

I have an additional question : Since the hum happens even when the speakers are not connected to the amp, can it still be a ground loop problem ?I read somewhere that ground loop happens when two devices have a ground at different potentials (or something like that). Does it mean it makes no sense to talk about ground loop when speakers are not connected to the amp, or I am totally missing the point ?

 

[robertawillisjr]

If you mean that you disconnected the speaker wires, then the problem (if it is a problem) is with your power.

 

[tonepub]

try floating the ground to see if it goes away.....

That might be your problem.

Also, this is way out there, but do you have a cell phone
that has internet access? (Blackberry or iPhone)

My iPhone wreaks havoc with my ML subwoofers...

Good luck.

 

[User211]

To User211 : No, on the Summits, i cannot disconnect the amp. At least, not without opening the whole speaker, and i am not ready to do so...

---

But I am happy to hear i am not alone, I know now my speakers seem to be normal. I guess I will have to try some power conditionners if I want to get rid of the noise (which is very low - you have indeed to put your ear close to the speaker... but still... I hear it).

I have an additional question : Since the hum happens even when the speakers are not connected to the amp, can it still be a ground loop problem ?I read somewhere that ground loop happens when two devices have a ground at different potentials (or something like that). Does it mean it makes no sense to talk about ground loop when speakers are not connected to the amp, or I am totally missing the point ?

Read DrJRapps post again - the mains earthing can cause a problem, and will do so whether the amp is connected or not.

 

[iove]

Similiar deal with mine and every other pair of Vantages I have ever listen to. One needs to get mighty close to hear what your describing but yes, it's there. I spoke with Jim Powers about this over two years ago, at which time they were having a production run of Vantages and he CONFIRMED what I was hearing. unfortunately he had no reason for it ???

did he say this was normal or is there a fix for this? I seem to have a Vantage that was produced around the same time and is exhibiting this low volume noise.

 

[David100]

to Tonepub : It is not the IPhone... Immediately after reading your post, I tried to turn it off, but hum still there... But thanks for the suggestion and for the intense moments of hope. Could have helped indeed.

 

[David100]

to user211 : I understand from the post of DrJRapp (and Neil H) that they managed to solve the problem using a power regenerator.

I will try to do so... The problem is here in continental europe, it is not so easy as in the US to try thinks and then to bring back to the shop the things I don't like... So the problem is I don't know if I have to use expensive things as PS Audio Power Plant Premier ($3000), or if a PS Audio Harvester ($160) can do the job.... or something else.

But again, most of my pain is gone when, reading the answers to my thread, I understood that my summits seem to be normal.

 

[User211]

David - the fact your so bothered by it means it MUST be audible from your listening seat? If it is noisy mains. then unfortunately a cheap mains filter will probably adversely affect sound quality in some way - where as the PS Audio regenerator will actually IMPROVE it (or at least IT SHOULD!!!). Difficult one. I did notice this on ebay UK - search for user "hifi_hero" and check his listings - this guy has 30 day trials on cheap and expensive ISOTEK solutions. Since your in the EU he might offer it to you, too. Best e-mail him first, since he says he posts to the UK.