Plinths? Much of this discussion has me wondering.
Plinths are constructed in so many different ways that I believe it is impossible to generalize about their sonic contribution. Many earlier designs were a simple box (open inside). More recently most seem to be made with solid materials. And the variety of materials is almost endless -- particle board, MDF, ply, Birch ply, solid hardwoods, glued strips of hardwood (like cutting boards), Corian, Obsidian, slate, marble, granite, composite (like some Kenwoods), glass, acrylic, aluminum, stainless steel, lead, etc. Then there are composites or combinations of these materials, as with constrained layer damping. Setting aside dimensions, each material has its own resonant frequency. So how can the "sound" of plinths be lumped into a single category?
Even a "plinth-less" table must have some means of support for the motor, bearing, spindle, platter, and arm (be it separate or attached). And those support materials also have their own resonant frequencies.
So what I really wonder about is if those who now find favor with plinth-less designs have simply eliminated the sound of unmusical resonances in whatever plinth material they experienced with a plinthed table? If so, does that mean ALL plinth designs are inferior? Or simply that the plinth they did hear was not the best material choice? And further, would a better material choice result in favoring that over their plinth-less example?
I certainly respect comments by Raul, Halcro, etc. but I also respect those of Albert Porter, mikel, J. Weiss, etc. I remain confused! ;^( |
The galleon captain says to his slave crew, "I have good news and I have bad news."
"What's the good news?" they cried.
He said, "We're going to Jamaica." The response was wild cheering.
Then one of the crew ask, "So what's the bad news?"
The captain replied, "We'll have Buddy Rich beating time."
Hey, German or not, a little humor shouldn't hurt. |
Re: laser levels.
For anyone interested I have an inexpensive solution. I own a Lazerpro (CL2060) which is a 16" (38 CM) aluminum level with a built-in dot or line laser light. Place it on a nearby surface (check for horizontal with the built in bubble level) adjusted for the height of your motor unit and use the laser line option to project the exact elevation for your arm mount.
I purchased the Lazerpro to facilitate speaker toe-in. That was several years ago but I'm certain it was less than $20. |
Raul, and others interested in low cost laser levels -
This site offers a model that looks like mine with a slightly different model #, CL6062. Price is $19.95 There may be other sellers.
http://www2.dealtime.com/lazerpro-cl2062/products |
Ralph, I believe there is one more factor in the perception of three-dimensionality or spaciousness -- how close one sits for a live performance. One season as an experiment I chose different seating locations for each of a half-dozen concerts by our local symphony. The variations in sonic effect were sobering. Unless I was front-center, I din't hear the live spatiality I hear in some recordings.
I think a major influence in the awareness/desirability of soundstage and spaciousness was Harry Pearson at TAS. Those descriptions could be counted upon with every review he wrote. Then I learned that his preferred seat at Carnegie Hall (and I must suppose other venues) was row 2 or 3, dead center. Well, that explained a lot.
Now, how ironic that most older recordings were made with 1-3 primary mics which were better able to capture the natural sonic space of the program, even when home audio equipment did not product it so well. But currently with (some) improvements in the equipment which better allow spatiality to be reproduced, everything is multi-multi mic'ed and channel mixed so that artificial reverb must be added to provide any sense of three-dimensionality. |
Chris, I can offer an experience to help answer your question.
My turntable is placed on a 60" shelf, fitted within an alcove on a side wall of the listening room. The shelf is 18" deep and the walls forming the sides of the alcove extend a few inches beyond the shelf. For some time I had the tt at the far right end of the shelf. This placed the arm/cartridge close to the corner of the alcove. One day I was dusting the table/arm (using a camel hair brush) while I had a CD playing. I happened to lean over the platter while some fairly strong bass was being played. I was amazed with the amount of bass energy heard with my head close to that corner.
Realizing the probable harm from my cartridge working in that environment, I relocated the tt to the left end of the shelf. This resulted in the arm/cartridge being slightly left of center along the shelf and away from the corners. When I then played an LP with only average bass content (probably a jazz quartet) I heard improved overall clarity.
This shelf is 3/4" ply and attached to the walls on three sides and has an added brace along the fourth side. It appears to be rigid but if I place my fingers lightly on the surface while playing music with much bass energy I can feel some structure-borne vibrations. For this reason, I use a 2" deep sand box between my tt and the shelf.
So, for whatever degree of structure-borne vibrations that reach my arm/cartridge, and they would logically be greater at the mid-point of the shelf than the corner (less bracing), the change to reduce air-borne vibrations resulted in an overall sonic improvement. |
Chris, maybe it is just me but this seems to be a bit confusing. You said you tried two tts on the side wall, "directly opposite the firing of one of my speakers". Does this mean one speaker is toed-in to such a degree that it is aimed at one of your tts?
Now perhaps a few points were suggested in my earlier comments that were not made clearly.
First, it is not always easy to differentiate between airborne and structure borne vibrations. After I moved my tt, it was then located in a position with less structural bracing (likely bad), yet it sounded cleaner. So in my case I must infer the minimizing of airborne interference was a net gain over the increase in structure vibrations.
Second, I think a lot can be understood about equipment location from the study of speaker interface with the room. It seems to be understood that where three planes intersect (any corner) you will find the greatest build up of bass nodes. (Insert assumption that bass frequencies have more energy, thus are more detrimental than higher frequencies.) While the corner of my alcove may not have been as severe as a room corner with longer walls, my experience (two shorter walls and a large shelf = three planes) still supports this point. Less of a problem with bass node build up may be realized where two planes meet -- two walls, a wall and floor or ceiling. Further reduction occurs with only one plane (along a wall and up from the floor) while the least airborne interference may be away from all walls and the floor, while admitting this may be the least practical.
I believe this also relates to Jim Smith's recommendations in "Get Better Sound" when he promotes side wall equipment locations over front wall between the speakers.
Conclusion: try locating your tt/arm/cartridge where there will be the least bass node build up. |
If I understand Raul's position here then I fully agree with him. The role of the turntable and tonearm is to be as neutral and accurate (adding or subtracting no colorations of their own). Then each person can pick the cartridge that presents the characteristics that suits their experiences and tastes the best. When the turntable and/or tonearm introduce strong colorations of their own, the cartridge matching question becomes far more complex.
As similar condition might extend to the choice of amp and speakers. If so, the amp should be as neutral (perhaps within it's power range) as possible so the speaker choice can be made to suit the preferences of the owner. But in this example I believe the listening room acoustics must be considered equally and along with the speaker choice. |
Correct Lew, my father's name was Henry and everyone called him Hank. |
Lew, you just described what I have evolved to with my own design. Hopefully now my local woodworker can turn it out for me. |
I'll jump in to comment only on an experience with air-borne interference with my turntable.
My listening room has a 5' wide alcove along one sidewall. Within that I constructed two full width shelves to place source components. This accommodates freestanding record storage boxes underneath.
Initially I placed my turntable at the far right end of the top shelf. Unconsidered at first was the result of the arm/cartridge being very near a corner as it's arc traced a record. One day I had reason to lean over the platter area while music was playing. I was startled to hear the amount of low frequency build-up in that corner.
Considering those air-borne vibrations were affecting my vinyl performance, I moved the turntable toward the left hand end of the shelf. Of course the table was still the same distance from the sidewall, but being close to the mid-point of the 5' shelf, the arm/cartridge now operated some distance from either corner.
The result was obvious with any music played at moderate to moderately high levels. It was overall much "cleaner", with greatly improved definition and reduce sonic smearing.
Just as we want to avoid corner placement for nearly all loudspeakers, I believe all component placements should follow the same guideline for best performance. And hey, it was free!
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