jcmusic Posted March 8, 2007 Share Posted March 8, 2007 Ok guys I have a question about these wall mount shelves. If the shelf is mounted to the wall to try and isolate vibrations from the TT, what happens when you have khorns? I can sometime feel the vibrations on the walls on the other side of the room. So if this shelf is connected to the wall, how does it isolate the vibrations that my speakers are creating? Jay Quote Link to comment Share on other sites More sharing options...
LarryC Posted March 8, 2007 Share Posted March 8, 2007 My wall-mount Target was installed to keep floor vibrations away from the 'table, since those were my major problem -- before then, even light footfalls made the stylus jump. One side of my mount is screwed directly into a stud (I'd be reluctant to put much weight on it if it wasn't). It was suggested in another thread on this subject that the wall used for mounting should rest on the foundation for maximum stability -- I'd never thought about it, but do have it mounted on an exterior wall. My offhand feeling is that attaching it to at least one stud will minimize vibrations through the floor and walls. Other isolation under the table might be needed if airborne vibration is a problem. lc Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted March 8, 2007 Moderators Share Posted March 8, 2007 Larry, I think you are exactly right, as usual when it comes to TT's. I have the two shelf target, it is now on an exterior wall. The mounting holes are 16" apart so if you have standard spacing on your wall studs you can can bolt it safely to the wall. The screws that came with the Target were a bit thin for my tastes and i would recommend getting some beefier ones from the hardware store. In my case, the media room is located upstairs. Vibration in that room is a major problem. You can feel vibrations all across the floor when people are walking anywhere in the room. Needle skips were a major problem until I went with the wall mount. After mounting on the wall there were none of those problems, you can literely jump on the floor and it will not cause any jumping on the tonearm. So in answer to your question, the TT wall rack is to isolate the turntable from the floor. If you have slab construction and the TT is going on the first floor there should not be a need to have a wall rack, except for maybe space, height concerns. The Target is under 200 and works great. Finite elemente, the high dollar rack company makes a single shelf unit for a grand, yes, $1,000, it is real pretty wood, and has a grid/baffel system in the actual wood shelf. No way in hell it can be worth that much money. You can buy a lot of extra isolation platforms, air bladders (which LarryC uses), ball bearings, Carbon fiber pucks, and a bunch of other snake oil with that $800.00 diference. Travis Quote Link to comment Share on other sites More sharing options...
LarryC Posted March 8, 2007 Share Posted March 8, 2007 Travis, Absolutely right, I forgot to mention using beefier screws. I used as large a one as I could fit through the Target's hole, and 2.5" long as I recall, to go well into the stud. I did just one that way as my studs are only 13" apart. Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted March 8, 2007 Moderators Share Posted March 8, 2007 Larry, How old is your home, was 13" the std. at one time, or are they 13" apart at that section of the wall because of a door or wall? I know this has nothing to do with TT wall racks but I have always been curious about that. My parents had a home in California, built in the 40's, that had studs on 12" centers, but have never seen anything like it since. Travis Quote Link to comment Share on other sites More sharing options...
jcmusic Posted March 8, 2007 Author Share Posted March 8, 2007 Ok let me ask another question, If I can feel the vibrations is it safe to say that they are effecting my TT? Jay Quote Link to comment Share on other sites More sharing options...
LarryC Posted March 8, 2007 Share Posted March 8, 2007 Travis, My lil' Cape Cod was built in the mid-1930's, so I have 13" everywhere except the upstairs dormer. Plaster (plaster board, I think) walls, too, so fortunately I can support a 100-lb. Townshend-Wadia CD transport combo with wall anchors alone since there I wasn't lucky on stud placement. I know it's plaster because I had to buy a masonry bit to drill the holes. But I hold my breath every time I put the transport back. Incidentally, my CD transport and DAC are supported with smaller Rega TT wall mounts for which the store (SoundWorks) made custom 17" X 17" platforms. Very handy for me. Larry Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted March 8, 2007 Moderators Share Posted March 8, 2007 Ok let me ask another question, If I can feel the vibrations is it safe to say that they are effecting my TT? Jay Short answer is no. The type of suspension system, if any, will have an impact as to how much vibration is actually reaching the turntable and how that vibration causes an interaction bewteen the stylus and the record/platter. Just because you can feel vibrations on the floor does not mean that it is reaching your TT, but it is a good sign that you need to look at the issue. As I mentioned above, like Larry, when folks lightly walked across the room my needle would jump all around. The factors that are going to have a direct impact on how much vibration is going to reach the turntable is what type of stand is it sitting on, the suspension system (springs, like on Linn, can be more suseptable to vibration), the tone arm, and any isolation device(s) between the TT and the stand. What type of construction is the home? First floor? Wood or carpet? If it is pier and beam, wood floors, you will probably notice a big difference with a wall mount. If it is on a slab, it should make little or no difference except maybe wood floors with an unsualy tie end system. I know just the very basics about construction methods, and what little I know is simply from what I have experienced in homes I have lived in. Your part of the world they have such beautiful homes, construction, etc. There is very little slab construction, I mean you even bury people above ground, so I would say you are going to have pier and beam construction, meaning there is space between the first floor and the actual ground. The first floor is supported by wood stilts that sit on the ground (usually on cement blocks on the ground) and the stilts support beams that run the lenght of the floor. These beams are what the subfloor is attached to. The wood stilts (piers) in a lot of places are 4x4's, however, in your part of the country it is very common to see cedar or cypress logs used for this purpose because of subteranian termites. If you are on pier and beam, but have never notice a skip or a bump with people walking on the floor, you could probably correct any vibration issue without going to a wall rack. However, if you do get skips or jumps, with even light walking, or people sitting down in chairs, you will save yourself a lot of time and expense by going to a wall rack and going from there. Travis Travis Quote Link to comment Share on other sites More sharing options...
jcmusic Posted March 8, 2007 Author Share Posted March 8, 2007 Travis my house is on a concrete slab, and my floor is a cermaic tile. I have no issues that I know of, I am just trying to find out what I can about vibrations so I can use this info to further my music enjoyment. I just assumed that if I could feel the vibrations from across the room, they were in some way affecting my TT. Jay Quote Link to comment Share on other sites More sharing options...
mas Posted March 9, 2007 Share Posted March 9, 2007 Jay, the correct answer is 'very possibly'. Quite simply you are dealing with the conduction of energy throughout a mechanical system. Energyis transmitted both via transmission via the air and via conductionthrough rigidly coupled structure (e.g. floor, walls, etc.). Typically,any situation features a combination of sources, as well as theturntable itself which will tend to exhibit various resonancecharacteristics as any 'thing' will. Additionally, generally (but notalways), conduction is a dominant form of energy transmission simplybecause it tends to be more efficient. If you are located ona slab, the odds are that the floor will not be a major source ofconduction, but depending upon if such a structure floats, is anchored,post and beam, etc., it can still conduct energy that can betransmitted to objects in contact with it. Wall mounted systems cancertainly be affected by both energy transmitted via the air as well asthrough the wall and any adjoining structure. In other words, anysetting is a complex system with potential sources and sinks for thetransmitted energy. Walls are usually less of a problem than floors,but they can certainly result in vibration being transmitted toanything mounted to them. The best answer/solution to such aproblem is to identify the structure least affected by the energy andto mount the TT there - utilizing a mount that tends to be looselycoupled to the surface, and thus which will best dissipate what energyis available to be transmitted. Once you identify this 'spot', one can better evaluate the available options. PSIf you can feel the acoustic energy, so can the mechanical components, bethey the wall, turntable, shelves, etc. So yes, they are affected too. The real issue becomes, is the transmitted energy having a significantdetrimental affect on the performance of the TT. Quote Link to comment Share on other sites More sharing options...
maxg Posted March 9, 2007 Share Posted March 9, 2007 If you have solid floors then the benefit of a wall mount would be minimal. For wooden floors where problems are encountered like those described by Larry then the benefits would be huge. In effect all you are doing by wall mounting is to swap the source of vibration to the TT from floor to wall. Both will carry some vibration whatever you do - but a decent TT setup should be able to deal with it - and one or other, if not both, should be fairly low level with luck. In the ideal world you should probably place the TT in an adjoining room - well away from system vibration - but it is hardly a practical solution and is obviously dependent on what is in that room. I am lucky enough to have solid floors. A herd of elephants could tap dance in clogs in front of my TT and it wouldn't skip a beat. Quote Link to comment Share on other sites More sharing options...
mas Posted March 9, 2007 Share Posted March 9, 2007 A herd of elephants could tap dance in clogs in front of my TT and it wouldn't skip a beat. Max, if you could arrange for that performance, it would make an excellent instructional video! Quote Link to comment Share on other sites More sharing options...
maxg Posted March 9, 2007 Share Posted March 9, 2007 A herd of elephants could tap dance in clogs in front of my TT and it wouldn't skip a beat. Max, if you could arrange for that performance, it would make an excellent instructional video! Best I could do at short notice. Arriving at Athens airport: Quote Link to comment Share on other sites More sharing options...
LarryC Posted March 9, 2007 Share Posted March 9, 2007 One factor may be TT design that minimizes resonances in the table's plinth, platter and suspension and their transmission to the tonearm and cartridge. Many manufacturers now use acrylic, which seems to be extremely non-resonant. My Basis Ovation has an acrylic plinth, a separate acrylic armboard and an acrylic platter. Still, I found that it sounds better with an air-bladder anti-resonance platform underneath. And Max, my speakers are in the next room. lc Quote Link to comment Share on other sites More sharing options...
maxg Posted March 9, 2007 Share Posted March 9, 2007 One factor may be TT design that minimizes resonances in the table's plinth, platter and suspension and their transmission to the tonearm and cartridge. Many manufacturers now use acrylic, which seems to be extremely non-resonant. My Basis Ovation has an acrylic plinth, a separate acrylic armboard and an acrylic platter. Still, I found that it sounds better with an air-bladder anti-resonance platform underneath. And Max, my speakers are in the next room. lc Cant disagree with any of that. In the next room AND on an air bladder - wow. Just to add another factor into the mix - I think the arm design has a lot to do with isolation too. With my arm the armlet is actually attached only by a ball joint to the main arm and otherwise freely suspended. I imagine that greatly reduces resonances. In fact - I can whack the side of the TT with my palm whilst it is playing and nothing happens - it is quite a cool demo to do. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted March 9, 2007 Author Share Posted March 9, 2007 Larry, mas, and max thanks for your comments and your advice. You have cleared up some things for me, now it's time for me to expirement. Jay Quote Link to comment Share on other sites More sharing options...
Mallette Posted March 9, 2007 Share Posted March 9, 2007 Not entirely off topic and possibly useful to some reading this thread. I did not see another approach to TT isolation mentioned here I've used for years. Simply build a column as a table base and fill it with gravel or some other mass. Get enough mass and you can kick it without affecting playback (though your toes will suffer). I first encountered this at the old (early '30s) KWKH radio studios in Shreveport, LA where the TT supporst where poured as columns directly with the floors. That is also an approach if you are contemplating a new home, are totally anal, and know precisely where your TT will be. Dave Quote Link to comment Share on other sites More sharing options...
jcmusic Posted March 9, 2007 Author Share Posted March 9, 2007 Ok Dave since you brought it up, what if I removed the plastic covers on the front two colums of my rack and filled them up with something. Is this along the same lines, these colums are about 50in. tall and run down to the floor. Jay Quote Link to comment Share on other sites More sharing options...
Mallette Posted March 9, 2007 Share Posted March 9, 2007 Where benefit begins I've never attempted to determine. I consider 150 lbs of added mass to be sufficient. Can you get that much in your rack legs? Dave Quote Link to comment Share on other sites More sharing options...
jcmusic Posted March 9, 2007 Author Share Posted March 9, 2007 Depending on what I use for it there's a good chance. Jay Quote Link to comment Share on other sites More sharing options...
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