A Copernican View of the Turntable System


Once again this site rejects my long posting so I need to post it via this link to my 'Systems' page
HERE
128x128halcro
Addendum. Dear Chris, you made an important discovery without knowing what you discovered. Otherwise you would at least pronunce: Heureka. There is no way to value anything without comparison. Even 'better' assumes some, not to mention 'the best'. Alas your method is to expensive: two or more 'locations' are not attainable for the most of us. So I have a proposition which is even cheaper than Halcro's concrete arm pod. Buy the cheapest MM cart you can find ( I have some from East Germany) and
use it by every listing session for one hour and then switch to whatever other cart you own. You will be suprised with the result. BTW such results seems to be the 'basics' in psychology.

Regards,
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.
Pryso,

Jim Smith went around my listening room with a mic measuring bass energy and concluded that my rack was in a good location on a side wall behind the first reflection point and not near a corner. I believe his recommendation that the rack not be placed between the speakers has more to do with the mass of the equipment and rack effecting the imaging and soundstaging of the system. Soundstage depth and center-image density and clarity are improved when there is open space between and behind the speakers. At least this is the case in my system and I would think in most others.
Hi Pryso

I agree with what Jim Smith and yourself say. I also keep my TT’s on racks 6” from the side long wall wall in the 12 x 24 ft room.


Speaker Angle


This picture is the regular placement. The only positioning change I needed to do for this experiment was to rotate the midrange/tweeter module and angle the woofer box a few inches inches to point at the TT’s directly.

The front of the woofer is 9 feet from the front wall. The SP10 TT at the rear is actually 7 feet from the back wall – looks deceiving. The Lenco is only 5 feet from the speaker woofer not 6.

Armpod Recommendation

For those of you that use a metal (brass, SS, bronze, other ) armpod have you tried a few drops of oil in the tonearm mount screw holes before you mount your tonearm ?

I’d really like to get your impressions on what this does to the sound for you. I am using some oil in the armpod and the SP10 SS legs.

Cheers
Interesting thread. Reading comments about resonant energy in stands/shelving etc. I was reminded of this "seismic" stand product from Townshend I just read about and which looks very intriguing to me (I love the TT too but that's another topic). Check it out (below the Rock 7 TT) http://ear-usa.com/townshendsinks.htm