NHT Super One monitor distortion

Tim Sprout

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Jul 17, 2022, 7:19:32 PM7/17/22

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One of my NHT Super One near field monitors is distorting through the
range of 20 Hz - 1000 Hz. It fell about 12 inches recently off it's
shelf onto my desk. There is no apparent damage to the speakers and I
only just noticed the distortion now. Could a loud volume spike have
fried the woofer? Any ideas how to troubleshoot and repair?

Any recommendations for a replacement set of passive monitors? I am
driving them with an Adcom GFA 535II amp. Are the NHT SuperOne 2.1's
comparable?

Thanks.

- Tim Sprout

palli...@gmail.com

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Jul 17, 2022, 8:11:17 PM7/17/22

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Tim Sprout wrote:
=================

> One of my NHT Super One near field monitors is distorting through the
> range of 20 Hz - 1000 Hz. It fell about 12 inches recently off it's
> shelf onto my desk. There is no apparent damage to the speakers and I
> only just noticed the distortion now. Could a loud volume spike have
> fried the woofer? Any ideas how to troubleshoot and repair?
>

** Remove the woofer and take a look inside.
There may be a loose object in the box or caught in the back of the woofer.
Also check the feed wires are free to move and not touching the frame or each other.
I've seen one example where they touched under drive at a particular low frequency.

..... Phil

Don Pearce

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Jul 18, 2022, 3:23:19 AM7/18/22

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On Sun, 17 Jul 2022 15:19:25 -0800, Tim Sprout <tims...@yahoo.com>
wrote:

It is possible that as a result of the fall the coil is now rubbing
against the magnet. Push the coil gently in and out. Any grating sound
and that is the problem. The fix may be as simple as tapping the
magnet assembly with a soft mallet. You will have to remove the cone's
dust cover to see which side is touching.

d

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Scott Dorsey

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Jul 18, 2022, 4:26:34 PM7/18/22

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Tim Sprout <tims...@yahoo.com> wrote:
>One of my NHT Super One near field monitors is distorting through the
>range of 20 Hz - 1000 Hz. It fell about 12 inches recently off it's
>shelf onto my desk. There is no apparent damage to the speakers and I
>only just noticed the distortion now. Could a loud volume spike have
>fried the woofer? Any ideas how to troubleshoot and repair?

Pull the woofer out and see. Is the magnet still firmly attached to the rear?
Does the cone move in and out evenly with pressure straight down from your
fingers or does it scrape? If you carefully cut open the dust cap (cut
around the outer edge so it can be reglued) you can see if there is damage
to the voice coil or if the voice coil has come off.

If the driver is damaged, send it to a speaker reconing place and have
them fix it. Speaker Factory in Gaithersburg, MD or the Circuit Shop in
Kentwood, MI both do good work on consumer drivers.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

palli...@gmail.com

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Jul 19, 2022, 1:23:53 AM7/19/22

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Dope Pearce wrote:
=================

>
> >One of my NHT Super One near field monitors is distorting through the
> >range of 20 Hz - 1000 Hz. It fell about 12 inches recently off it's
> >shelf onto my desk. There is no apparent damage to the speakers and I
> >only just noticed the distortion now. Could a loud volume spike have
> >fried the woofer? Any ideas how to troubleshoot and repair?
> >

> >

> >Thanks.
> >
> >- Tim Sprout
> It is possible that as a result of the fall the coil is now rubbing
> against the magnet.

** FFS - it only fell "12 inches ".

> Push the coil gently in and out. Any grating sound
> and that is the problem. The fix may be as simple as tapping the
> magnet assembly with a soft mallet.

** ROTFL !

... Phil

geoff

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Jul 19, 2022, 6:03:37 AM7/19/22

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On 19/07/2022 5:23 pm, palli...@gmail.com wrote:
> Dope Pearce wrote:
> =================
>>
>>> One of my NHT Super One near field monitors is distorting through the
>>> range of 20 Hz - 1000 Hz. It fell about 12 inches recently off it's
>>> shelf onto my desk. There is no apparent damage to the speakers and I
>>> only just noticed the distortion now. Could a loud volume spike have
>>> fried the woofer? Any ideas how to troubleshoot and repair?
>>>
>
>>>
>>> Thanks.
>>>
>>> - Tim Sprout
>> It is possible that as a result of the fall the coil is now rubbing
>> against the magnet.
>
> ** FFS - it only fell "12 inches ".

Enough to do damage depending on what it landed on.

>
>
>> Push the coil gently in and out. Any grating sound
>> and that is the problem. The fix may be as simple as tapping the
>> magnet assembly with a soft mallet.
>
> ** ROTFL !

Yes for sure.

But more likely to be the pole-piece moved anyway.

geoff

palli...@gmail.com

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Jul 19, 2022, 6:32:22 PM7/19/22

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geoff wrote:
>> > Dope Pearce wrote:
> > =================
>

> >> It is possible that as a result of the fall the coil is now rubbing
> >> against the magnet.
> >
> > ** FFS - it only fell "12 inches ".

> Enough to do damage depending on what it landed on.

** That is total BS and we are told how it landed.

> >> Push the coil gently in and out. Any grating sound
> >> and that is the problem. The fix may be as simple as tapping the
> >> magnet assembly with a soft mallet.
> >
> > ** ROTFL !
>
> Yes for sure.

** Yawwnnnnnn....

> But more likely to be the pole-piece moved anyway.

** Very unlikely in fact.

The OP needs to DO what I posted.

..... Phil

geoff

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Jul 19, 2022, 8:21:07 PM7/19/22

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Yes , do what you posted and if not that then what I suggested is the
next most likely possibility. Especially if a particularly solid desk.

Similar with dynamic mics. Actual experience with both types of gear.

Time to take yer meds again phalluson.

geoff

palli...@gmail.com

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Jul 19, 2022, 8:33:24 PM7/19/22

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geoff wrote:
==========

>>>>> Dope Pearce wrote:
> >>> =================
> >>
> >>>> It is possible that as a result of the fall the coil is now rubbing
> >>>> against the magnet.
> >>>
> >>> ** FFS - it only fell "12 inches ".
> >
> >> Enough to do damage depending on what it landed on.
> >
> > ** That is total BS and we are told how it landed.
> >
> >>>> Push the coil gently in and out. Any grating sound
> >>>> and that is the problem. The fix may be as simple as tapping the
> >>>> magnet assembly with a soft mallet.
> >>>
> >>> ** ROTFL !
> >>
> >> Yes for sure.
> >
> > ** Yawwnnnnnn....
> >
> >> But more likely to be the pole-piece moved anyway.
> >
> > ** Very unlikely in fact.
>
> > The OP needs to DO what I posted.
>
> Yes , do what you posted and if not that then what I suggested is the
> next most likely possibility. Especially if a particularly solid desk.

** Horse manure.

> Similar with dynamic mics.

** Complete bullshit.

..... Phil

Don Pearce

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Jul 20, 2022, 3:30:57 AM7/20/22

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A 12 inch drop onto a solid surface is plenty enough to shift a
speaker magnet. A movement of less than 1mm is sufficient to cause the
symptoms described here.

palli...@gmail.com

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Jul 20, 2022, 6:36:25 PM7/20/22

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Dope Pearce wrote:
=================
>>
> >> >One of my NHT Super One near field monitors is distorting through the
> >> >range of 20 Hz - 1000 Hz. It fell about 12 inches recently off it's
> >> >shelf onto my desk. There is no apparent damage to the speakers and I
> >> >only just noticed the distortion now. Could a loud volume spike have
> >> >fried the woofer? Any ideas how to troubleshoot and repair?
> >> >
> >
> >> >
> >> >Thanks.
> >> >
> >> >- Tim Sprout
> >> It is possible that as a result of the fall the coil is now rubbing
> >> against the magnet.
> >
> >** FFS - it only fell "12 inches ".
> >
> >
> >> Push the coil gently in and out. Any grating sound
> >> and that is the problem. The fix may be as simple as tapping the
> >> magnet assembly with a soft mallet.
> >
> >** ROTFL !
> >
> >

> A 12 inch drop onto a solid surface is plenty enough to shift a
> speaker magnet.

** Yawnnnnn..........

But not at all likely in the case actually described.

...... Phil