Turntable woes

[Spirit84]

My son has a Project turntable.
He lives in a 3 story old house on a busy city street. He lives on the 3rd floor in a converted attic.
Even though he is on the highest floor, everytime a city bus or truck drives by his window the torearm skips! The floor is hardwood.
The table has been setup and aligned properly. The table sits on top of one of those Ikea wall units - horizontal configuration with 2 rows. He uses the 2 rows to store his vinyl and his gear sits on top.
I am trying to think of some cheap DIY vibration absorber that we can place under the table that will absorb the rumble.
Any ideas?

 

[Soniclife]

Bicycle tyre with wooden shelf on top? Inflate till bouncy and not much more, balance / level the shelf with weights.

 

[Pavioni]

What cartridge? Have you run the arm/cartridge numbers thru Vinyl Engines evaluater to pinpoint its resonance frequency? This will give you a head start on what frequency you need to filter.

Many years ago I lived in a similar structure and went thru hell trying to cure footsteps on a wooden floor and traffic vibrations with my The AR Turntable and V15 IV combo. None of my surface mount contraptions (tennis balls under a granite slab, homemade sandbox,etc) worked,no internet back then so it was all trial and error.

What did work marvelously well was a trip to the shelving department at the local hardware store where I cheaply put together an adjustable wall mount shelf. Not the best looking thing but I never had any vibration problems again. Don't know if anybody still makes wall shelves for TTs but they were beyond my means back then.

 

[Spirit84]

Bicycle tyre with wooden shelf on top? Inflate till bouncy and not much more, balance / level the shelf with weights.

I actually thought of that! Thanks

 

[DonH56]

I had the same problem many years ago; if I moved in my chair the thing would skip. I used old mattress springs to suspend the TT. No skips even when Grandmother stomped across the room with my laundry (that I left in the dryer). I was also able to tune the suspension by adjusting the number of springs.

 

[Spirit84]

What cartridge? Have you run the arm/cartridge numbers thru Vinyl Engines evaluater to pinpoint its resonance frequency? This will give you a head start on what frequency you need to filter.

Sumiko Blackbird - tracking at about 2.1 grams.
I have never heard of the evaluater. I will check it out.

Many years ago I lived in a similar structure and went thru hell trying to cure footsteps on a wooden floor and traffic vibrations with my The AR Turntable and V15 IV combo. None of my surface mount contraptions (tennis balls under a granite slab, homemade sandbox,etc) worked,no internet back then so it was all trial and error.

What did work marvelously well was a trip to the shelving department at the local hardware store where I cheaply put together an adjustable wall mount shelf. Not the best looking thing but I never had any vibration problems again. Don't know if anybody still makes wall shelves for TTs but they were beyond my means back then.

Great idea except that he is renting and I don't think the landlord would approve!

 

[Pavioni]

That's why the good Lord invented spackle

 

[TBone]

Those Ikea wall units can shake rattle and roll with the best of em ... and any attempt at isolating the turntable from such - might be fruitless. Past concentrating on isolating the table, perhaps try minimizing the Ikea's tendency to get excited during bus stops by securing it more firmly to a near wall.

 

[TBone]

What cartridge? Have you run the arm/cartridge numbers thru Vinyl Engines evaluater to pinpoint its resonance frequency? This will give you a head start on what frequency you need to filter.

This is not the frequency he will need to filter, filtering the cart resonance freq. will have no bearing fixing this particular issue which is based on the structure of the mount.

Apps (some better than others) have long been available - providing more detailed resonance freq characteristics.

What did work marvelously well was a trip to the shelving department at the local hardware store where I cheaply put together an adjustable wall mount shelf. Not the best looking thing but I never had any vibration problems again. Don't know if anybody still makes wall shelves for TTs but they were beyond my means back then.

TT Wall shelves can often be found on the second hand market ... and you are correct ... it would go a long way in solving the problem.

 

[Fitzcaraldo215]

All my TT isolation problems were solved by wall mounting, way way back. Footfalls on a hardwood floor had been the biggest. I never varied from wall mounting, and never had another problem attributable to induced vibrations.

 

[Pavioni]

Truck and bus ground induced vibrations occur at 10-15hz which is why I inquired about his arms resonant frequency. Traffic noise audible to us occurs between 700-1500hz and is thus outside of the scope of this problem.

 

[Frank Dernie]

All non-suspended TTs are very sensitive to traffic rumble though I have never known of one so mounted that the arm skipped.
Making a mount with a natural frequency around 5 Hz will fix the transfer of frequencies over about 10 Hz but leads to potential irritation with use.
Mounting the TT on the wall will reduce the amplitude to a level where the arm won't skip and the TT will still be easy to use.
When I worked for Garrard traffic vibration from the road 4 floors down the other side of the factory car park was clearly picked up during rumble measurement on a non-suspended TT sitting on a solid oak work-bench, so anything to be measured accurately had to be mounted on a spring mounted block with a Fn around 3 Hz, but that requires a lot of static deflection.

 

[Wombat]

All non-suspended TTs are very sensitive to traffic rumble though I have never known of one so mounted that the arm skipped.
Making a mount with a natural frequency around 5 Hz will fix the transfer of frequencies over about 10 Hz but leads to potential irritation with use.
Mounting the TT on the wall will reduce the amplitude to a level where the arm won't skip and the TT will still be easy to use.
When I worked for Garrard traffic vibration from the road 4 floors down the other side of the factory car park was clearly picked up during rumble measurement on a non-suspended TT sitting on a solid oak work-bench, so anything to be measured accurately had to be mounted on a spring mounted block with a Fn around 3 Hz, but that requires a lot of static deflection.

Wall mounting: Walls(clad framed) vibrate too. T/T platter/discs near speakers do. So do those Perspex lids. CDs are an obvious answer in some cases.

 

[Frank Dernie]

Wall mounting: Walls(clad framed) vibrate too. T/T platter/discs near speakers do. So do those Perspex lids. CDs are an obvious answer in some cases.

Well yes, "solid" brick walls will transmit structural vibration too, but not enough to cause the stylus to jump out of the groove!
No non-suspended turntable isolates from this, and most isolated TTs do not isolate in all 6 degrees of freedom. Pretty well only the AR and its progeny do, outrigger suspension towers are too far apart to isolate rocking modes over the full audio bandwidth.

 

[TBone]

Wall mounting: Walls(clad framed) vibrate too. T/T platter/discs near speakers do. So do those Perspex lids. CDs are an obvious answer in some cases.

(sigh) Everything vibrates ... inc. my funny bone after reading obvious & silly replies.

 

[Wombat]

(sigh) Everything vibrates ... inc. my funny bone after reading obvious & silly replies.

Your insight is welcome. Start with the silliness first. Your reply above is supercilious without clarification.

https://dictionary.cambridge.org/dictionary/english/supercilious