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Turntable rumble

M

MilesGopal

Active member
Joined
Jul 10, 2023
Messages
64
Location
South Africa
Need some help please
Noticed excessive rumble on my sub when playing my turntable at high volumes
Its not always audible and I only noticed it recently
Not sure how long its been there
Tried multiple amps, different subs, external phono-stages - same story
If I put the arm down on a still record and tap the plinth I can replicate the issue

TT- Stock standard Clearaudio Concept
There is a ground connection
MMV2 cart
The stylus was replaced by our dear friend G some years ago
Rega TT Wall mount

I tried some vibrapod isolators too with no effect




https://imgur.com/a/8mR4hkh
 
Years ago I cured TT rumble on a 301 by placing a normal Staedtler (sp?) eraser (±30x15x20mm) under each corner of the TT plinth. At that time the TT was mounted 10cm from a very efficient wall stander speaker. This "mod" isolation worked perfectly, total cost about 60c each.


-F_D
 
Family_Dog said:
Years ago I cured TT rumble on a 301 by placing a normal Staedtler (sp?) eraser (±30x15x20mm) under each corner of the TT plinth. At that time the TT was mounted 10cm from a very efficient wall stander speaker. This "mod" isolation worked perfectly, total cost about 60c each.


-F_D
Click to expand...
Thanks
I gave that a try now but no luck
 
Generally rumble when playing records on a turntable are strucural borne noise from the turntable motor, what You describe is mechanical feedback,
the problem is the subwoofer, put isolating feet under that instead of under the TT.

Ingvar
 
Ingvar Ahlberg said:
Generally rumble when playing records on a turntable are strucural borne noise from the turntable motor, what You describe is mechanical feedback,
the problem is the subwoofer, put isolating feet under that instead of under the TT.

Ingvar
Click to expand...
Thanks
I thought so too but its happened with two different subs and another set of speakers
 
Turntable is on a wall mount, resonance frequency seems to be well in the audible range. Hmm. Something is lose on the TT. Check how well seated the stylus is, is the cartridge mounted tight. If your turntable has that magnet stabilised abomination of a tonearm, good luck.
If you cannot find the cause of resonance and diminish it, subsonic filter *may* help.
 
Tonearm has the magnetic bearing
I’ve had it for years- maybe 7 or so
Not had an issue since recently- but only recently added a sub
Hopefully something loose- I’ll check in the morning
Thanks
 
MilesGopal said:
Everything seems pretty tight
You think changing the cart will help?
Else I could try something like this:-

FMOD 30Hz sub-sonic filter (pair) high pass - HARRISON LABS

HARRISON LAB FMOD 30Hz sub-sonic filter (pair) high pass active crossover simulator
www.decibelhifi.com.au www.decibelhifi.com.au
Click to expand...
Can't offer a solution but if you do want to try these I can possibly assist with getting it to SA for you. We have staff travelling between Oz and SA on occasion.
 
The problem is still feedback and to minimze/get rid of that should be the first step before resorting to a high pass filter.

Looks like wood floor, on concrete or on wood sub structure?

What kind of wall is the Rega shelf mounted on?

Most likely isolating feet is required both for TT and speakers/sub, if load specified Sorbothane types are available, go for those.
 
MilesGopal said:
Tonearm has the magnetic bearing
I’ve had it for years- maybe 7 or so
Not had an issue since recently- but only recently added a sub
Hopefully something loose- I’ll check in the morning
Thanks
Click to expand...
I think you might have answer it - the resonance was probably always there, you just didn't notice it before the sub came in.
 
MilesGopal said:
Everything seems pretty tight
You think changing the cart will help?
Else I could try something like this:-

FMOD 30Hz sub-sonic filter (pair) high pass - HARRISON LABS

HARRISON LAB FMOD 30Hz sub-sonic filter (pair) high pass active crossover simulator
www.decibelhifi.com.au www.decibelhifi.com.au
Click to expand...
Personally, I stay away from subsonic / rumble filters. I'd hunt the origin.
Anyway, low cut filter from 30hz diwn is cutting it too high. Sub 18-20hz was typically the norm. I think I have a Nakamichi subsonic filter actually. I'll check and let you know.
 
Ingvar Ahlberg said:
The problem is still feedback and to minimze/get rid of that should be the first step before resorting to a high pass filter.

Looks like wood floor, on concrete or on wood sub structure?

What kind of wall is the Rega shelf mounted on?

Most likely isolating feet is required both for TT and speakers/sub, if load specified Sorbothane types are available, go for those.
Click to expand...
Its a brick wall
Wood floor on concrete
 
fdlsys said:
Personally, I stay away from subsonic / rumble filters. I'd hunt the origin.
Anyway, low cut filter from 30hz diwn is cutting it too high. Sub 18-20hz was typically the norm. I think I have a Nakamichi subsonic filter actually. I'll check and let you know.
Click to expand...
Thanks
Please check on the filter and let me know
I'll try to get to isolate it more in the meantime and see if that helpd
 
I just remembered this from my past which may or may not be relevant.

Many years ago I bought a bunch of studio stuff. Amongst these were 2 SABC mk3 "Doc Viljoen" turntables. They came in SABC stands. This was basically a huge floor standing frame, made of welded square tubing. It had a Formica top in which the table laid. It also had clip on press wood and formica sides. Right a rumble box if you ever heard one. I discarded the side panels and had the top replaced with a wood top 2 inches thick. This was made from wood strips glued together -like a chopping block. Another top fitted on top of this in which the turntable was. Separating the 2 were very high tech,very expensive,German made feet. These were basically two pieces of metal separated by a ceramic ball.

The old table sounded phenomenal in the main system. The bass portion there are huge horns with ten 15 inch bass drivers and are flat to 27Hz. However, being horns they then fall quickly and are 6db down by 26 Hz , ten or fifteen down by 25 and gone thereafter.

But the Doc Viljoen is big and full of you know what, so I moved it to the TV room. That is the usual: Big L/R speakers and sub. And it rumbled . Jeez it was bad. So I replaced the high tech Finite Elemente feet with tennis balls and the rumble was almost gone. During that time a young, knowledgable Forumite visited and laughed at the high tech tennis balls.

Years late I got from Ghost an EMT 930 Broadcast table. I had a frame built from Siberian ply. But it rumbled. I fitted those same Finite Elemente feet and the rumble was gone.

Tennis balls are cheap and if you don't mind people laughing, try it. If that doesn't work, a high pass filter at 30Hz. When pre amps still were proper pre amps most had those. I think even the Audio Research SP3 had one. Ingvar? No prisoners last solution: Do what I did and move all equipment to a separate room.
 
Agaton Sax said:
I just remembered this from my past which may or may not be relevant.

Many years ago I bought a bunch of studio stuff. Amongst these were 2 SABC mk3 "Doc Viljoen" turntables. They came in SABC stands. This was basically a huge floor standing frame, made of welded square tubing. It had a Formica top in which the table laid. It also had clip on press wood and formica sides. Right a rumble box if you ever heard one. I discarded the side panels and had the top replaced with a wood top 2 inches thick. This was made from wood strips glued together -like a chopping block. Another top fitted on top of this in which the turntable was. Separating the 2 were very high tech,very expensive,German made feet. These were basically two pieces of metal separated by a ceramic ball.

The old table sounded phenomenal in the main system. The bass portion there are huge horns with ten 15 inch bass drivers and are flat to 27Hz. However, being horns they then fall quickly and are 6db down by 26 Hz , ten or fifteen down by 25 and gone thereafter.

But the Doc Viljoen is big and full of you know what, so I moved it to the TV room. That is the usual: Big L/R speakers and sub. And it rumbled . Jeez it was bad. So I replaced the high tech Finite Elemente feet with tennis balls and the rumble was almost gone. During that time a young, knowledgable Forumite visited and laughed at the high tech tennis balls.

Years late I got from Ghost an EMT 930 Broadcast table. I had a frame built from Siberian ply. But it rumbled. I fitted those same Finite Elemente feet and the rumble was gone.

Tennis balls are cheap and if you don't mind people laughing, try it. If that doesn't work, a high pass filter at 30Hz. When pre amps still were proper pre amps most had those. I think even the Audio Research SP3 had one. Ingvar? No prisoners last solution: Do what I did and move all equipment to a separate room.
Click to expand...
I actually tried squash balls this afternoon
I'm not really known for my patience with this kinda thing
How I regret hooking up that subwoofer- would have been blissfully unaware
Apparently this will work too - silicone bikini fillers

BvtJfHV.jpg
 
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