[sdiy] Dynamics and speakers, was:Advice

[Czech Martin]

all true.
and even more:
usually the RMS power os speced, if you are lucky the maximum
power it can handle dealing with sine waves.
And the "anechioic" magnitude rersponse.
Phase is always omitted.

I have never seen a speaker or chassis spec sheet with 
nonlinear distortion graphs, of even spectra.

Because the results are horrible.


And: all this arguing anbout 1dB ripple here, and another 0.5dB
here makes me really laugh.

Just set up an ideal point source into an ideal room.
You can do this by several mirror image sources.
Then look at the total response:
the magnitude and phase will wiggle up and down almost in
chaotic fashion, and it will change if the "mic" is moved only
a few cm.

Of course it is good to have the anechoic data, but in reall
life there will be a floor, ceiling and walls, and thus
the "ultra linear characteristic" the advertising tells us
will be totally distorted, no matter how you shape the room,
no matter how many damping pads you add.
It will still wiggle up and down, you can hope to prevent only
the extreme peaks.

m.c.


> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Thomas Dunker
> Sent: Donnerstag, 5. Februar 2004 13:34
> To: Mike Peake
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Dynamics and speakers, was:Advice
> 
> 
> 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
> 
> 
> 
>