[sdiy] Dynamics and speakers, was:Advice

[Thomas Dunker]

On Tue, 3 Feb 2004, Mike Peake wrote:

> At 12:52 AM +0100 2/4/04, Thomas Dunker wrote:
> >
> >  How cool is it to have 24 bit resolution and 120dB S/N ratio when the
> >recorded signal ends up being compressed to the dynamic range of worn
> >cassette tape - or worse. Why are we supposed to get all excited about
> >THAT? What a joke!
>
> Lower self-noise and better low-level linearity
> for those of us who enjoy other than the new
> mastering results and make our own music?

 It's not that I don't welcome improved media, and I totally understand
how added resolution and dynamic range helps in the studio work, I just
think it's a shame that we never get to hear what digital has to offer in
terms of dynamics because we have no speakers that can handle it.

 This guy named Drew Daniels once sent me this article describing a vey
big speaker system he'd designed. He had some kind of affiliation with JBL
at the time I think, or else just a "Lansing fan" (like myself) and used
pro series JBL stuff from top to bottom. His claim was that "JBL speakers
were digital ready before digital was ready". Of course, it wouldn't have
to be JBLs - but they represent a kind of industry standard. It is correct
to say that most people's speakers can't handle real life dynamics, but
it's not true that NO speakers come a lot closer than others.

 It goes without saying that efficient and dynamically capable speakers
need to be reasonably large, it's a consequence of the physics involved
the way I see it. Nobody expects a natural "bass instrument" like an
acoustic bass, sub-octave organ pipes or bass drums to be the size of a
shoebox. Moving lots of air WITH PRECISION is not a simple thing to do,
and it's not cheap either.
 I think that instead of actual "hi-fi" reproduction we've grown
accustomed to a complex of different forms of distortion that are typical
of conventionally amp-driven, undersized and inefficient speakers and tend
not to expect anyhting else when listening to reproduced music. So we try
to make the recordings sound good on the average speaker. Fair enough.

 Someone commentted on the size of bass horns. Yes, they need to be big.
As far as I'm concerned they'd be too big for my living quarters. The main
point isn't that you have to use horns, but that the driver's job is made
easier by the acoustic impedance matching provided by the horn. A massive
increase of cone area in the bass region will help much in the same way in
terms of easing the load on the driver(s) and reducing dynamic
nonlinearity. I myself actually use an open baffle design, with sixteen 8"
woofers per side. They were designed for dynamic performance and low
distortion rather than the ultimate sub-bass, and the need for a well
considered tradeoff was obvious.

 Anyway, the most basic problem is that people don't want big speakers,
and small speakers are less efficient and less dynamically linear than
what the best speaker technology has to offer. Look at how a loss of
dynamics is never thought of as actual DISTORTION though if you look at
the signal before or after compression (of before and after being
reproduced by a speaker) then quantitatively what LOST INFORMATION could
be any more obvious than the dynamic aspect? And qualitatively - well,
depending on the music, of course - isn't it true that dynamics is one of
the things every musician uses to express him/herself and that this
matters more to the musical performance than say the noise floor or
harmonic distortion? It could just be me, but in my experience more intact
dynamics simply sounds more LIFE-like, and I thought that's some
of what recording and playback was supposed to achieve...

 It's symptomatic of the audio industry not to discuss the things that
their gear doesn't do well, and measure only the stuff that gives nice numbers
and nice looking graphs, and this attempts to conceal the many ignored
problems and lack of actual progress in some fields. It's also ironic that the
digital media that were expected to push the envelope for sound/music
reproduction  in the home have failed to motivate the industry to identify and
solve the problems in the analog gear and particularly the speakers. In fact the
opposite us true, speakers keep getting smaller and smaller, thanks to the
surround hype.

 If the recording media and the speaker technology is going to keep
pushing in opposite directions in terms of dynamics, I can not see how
this situation can be expected to change. I know some DVD players allow
you to select dynamic range ("theater"/"home") according to your system's
quality, now that's an unusually GOOD idea from the industry folks. If
only something similar would happen to audio recordings...

 Finally, I think the use of compressors involves some sonic "aesthetics".
Recordings typically differ as much - or more - than different playback
systems and speakers - also in terms of dynamics, and the discussed
"punch", which may or may not be something a little bit different. In some
places hard compression may sound just right, in other places ridiculously
out of place - depending on the music, the musician's instrument and
technique etc.

 OK, this has little to do with synths - except that it may be useful to
remember that you probably never heard your synth sounds as good and
complete as they COULD because it's always going to be filtered through
the myriad imperfections of speakers. (In some respects maybe headphones
come closer?)

 Well, back to business I guess...

 On the modular synth, me and my co-builder completed just the power
supply and the 24dB/oct. filter (RJ Wilson's design). The filter is
working really good and we've made some music with it already, so it's
been very encouraging so far.

Thomas