Dear Macrojack: I think that because there are several subjects on it it is almost imposible to tell which one is better: DD or BD.
If we take two of the TT primary functions: speed accuracy and speed stability, we can conclude that the DD beats the BD system: example, the Walker one has 0.002% on this spec against 0.001% on an SP 10 or Exclusive.
If we take the wow and flutter, the Sp 10 beats ( easily ) my Micro Seiki RX 5000: 0.015% against 0.025%.
We can take too the Rumble and here in the case of Walker or Avid it is around 90 db against 92 db on the SP 10 or 95 db of the Exlusive one
Btw, I own SP 10s, Denons, Micro Seiki, Luxman and Acoustic Signature.
From the point of view of how it performs on their designs the DD ones beats the BD: you can " see " at the measurements and this is a fact, period.
It is curious the BD manufacturers almost don't give almost any specs about: I wonder why?.
All those specs are extremely important to know about the quality build design if not which were or which ones are the TT targets on the TT design and how the designer compare the result ( build ) against those targets ?. Of course that the TT designer can had other kind of targets but it does not sense to me if he do not take in count those ones like speed accuracy and speed stability between others.
The TT specs can't tell me " per se " how good is the music reproduction performance but tell me how good care take the designer on the build of that unit and at least on the speed spec can tell me what " to wait " for.
Now, the " best voted " today TT is the Rockport that is a DD design and in the other side the Walker is the best example of what we can have in the BD designs.
Both designs go to an extreme design, here we can't say ( real ) which is better because in both trhey take in count almost all the issues for a perfect TT performance design: speed accuracy/stability, kind of motor, platter resonance/vibrations, energy disipation, plataform, air bearing, tonearm, quality on execution, " beauty on that execution ", etc, etc.
Which one do you like and which one performs better? ? , this is a subjective answer and we can have different answers about like different persons we are.
Which one is better?, here we have to go for facts: measurements, something objective and for this point of view the DD is a better one.
I send to build my plynths of my SP 10 and Denon TTs with a solid beautiful marble and Onyx one piece stones ( 40 kg ), as a fact this plynths function like the tonearm boards. I use the Audio Technica pneumatic suspension footers and tip toes like between TT and the plynths.
These DD TTs are very precise and have better music sound reproduction quality performance at both frequency extremes than my BD TTs: this is very easy to find out, play a piano work in either design. Why am I not using them?: because I need to mount, at least, three tonearms in each TT ( that I can change in any moment ) and the Micro and AS ones comes ready to work on it.
One of my future targets is to build a system plynth/arm board for I can use my DD TTs in the same way that my BD TTs, in the mid time I have to accept a 95-98% ? quality performance of what I can achieve with my DD TTs, not big deal.
Regards and enjoy the music.
Raul.
