[sdiy] semi ot: loud speaker for synths

[Czech Martin]

Harry,

-a sub in the corner was not intended.
 I think this simply doesn't work. I can hear, if
 low frequency pressure is on one ear or the other,
 I do not believe into this "sub bas has no
 direction" nonsense. The intensity on the ear
 towards the speaker is always higher then on the other
 ear, the closer you are the more pronounced.
 Also, correlation has to be watched 
 for a single subwoofer, otherwise it might
 cancel in the summing amp already
-I can not see what the membrane diameter has to do
 with the useable displacement. (This is not the maximum displ.).
 But I can see that a large membrane (remember the 80cm
 Fostex chassis?) has problems with stability and
 partial resonances. Given that the coils, magnets
 and crimping have the same quality, a 4*10
 can work better as a 1x18, because the seperate membranes
 are better controlled
-a bandpass or other vented construction can make sense
 if the LPF cutoff frequency is pretty low, say 50Hz.
 Other frequencies must not be transmitted (electronic
 filter). In that area you have the first resonant modes
 of the room, so the characteristic has nothing to do
 with the anechoic theoretical response.
 A good bandpass design can prevent too much distortion,
 which is a main problem for deep bass sinoids.
 Only if it works with frequencies it can not handle
 or is deliberately tuned too high you get this boomey
 "annoy the neighbour" sound you mentioned.
 Of course this does imply a 4 way system.


m.c.

> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Harry 
> Bissell Jr
> Sent: Montag, 24. November 2003 21:46
> To: Peter Grenader; john mahoney; synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] semi ot: loud speaker for synths
> 
> 
> Y'all got your flamesuits on ? :^P
> 
> Like the movie "Godzilla"... bigger IS better.
> 
> One good 18" can outrun almost any of the so-called
> powered subs.
> 
> Making a system with "bandpass" boxes in a mistake
> IMHO... good for earthquake rumble and hip-hop
> annoyance
> of pedestrians and other motorists... but not for
> HiFi.
> 
> The 18" does not require special (active) EQ and servo
> amps etc...  They are extrememly efficient by
> comparison.
> 
> OK now that I've whacked Peter (hmmm that sounds
> different than I meant it.... ;^)
> 
> lets discuss why the modern "small" subwoofer might be
> better.
> 
> 1) It fits in your studio
> 2) You CAN spare the extra power
> 3) you have no problem with the active crossovers
> 4) did I mention its small ???
> 
> These are good things, which you pay for in loss of
> efficiency, and ultimately in overall SPL.  NOT a
> studio
> problem.
> 
> I was assuming that the use (since we were talking
> about like 4 x 12" speakers) would be for live sound
> reinforcement... in which case the bigger box is going
> to win every time.
> 
> In my studio I'm using JBL4410 and I agree that there
> is plenty of bass from a 10" driver and you don't need
> bigger than that. But if I tried them live... Id turn
> those 10" cones into confetti in no time. There is a
> limit to the excursion possible in a 10" speaker.
> 
> Given a choice... I'll take the 18" for live (and YOU
> get to be my roadie).  For home, I don't feel the need
> for subwoofer at all.  I like a good full range system
> better than one sub in the corner...
> 
> ...your mileage may vary :^P
> 
> H^) harry
> 
> 
> 
> --- Peter Grenader <peter at buzzclick-music.com> wrote:
> > Czech, listen, I have Bob Diamond's email address
> > (founder of Diamond Audio.
> > later with M&K, now with Cervin Vega). He can tell
> > you the optimum cabinet
> > design if you want to do it yourself.  Contact me
> > off list for that address.
> > 
> > in regard to this:
> > 
> > john mahoney wrote:
> > 
> > > my point is that good low end does not require 18"
> > drivers.
> > 
> > Absolutely correct -18's are total overkill.  I
> > think you've guys have seen
> > that I worked at M&K for three or so years.  Now
> > remember - they invented
> > the dedicated powered sub (1973), so I assume they
> > know something about how
> > they work.
> > 
> > They don't make anything larger than dual 12s, and
> > the second one is in
> > push-pull formation - meaning you don't hear it,
> > it's mounted FACING INTO
> > THE CABINET and is purposely out of phase with the
> > other (this serves to
> > push and pull the audible driver from the inside.  A
> > more efficient method
> > of what a port attempts to do).
> > 
> > You should be fine with 12s, even 10s if the amp
> > isn't one of those $26
> > dollar Sanyo jobs that Genelec uses for their low
> > end subs.  Those things
> > suck.
> > 
> > 
> > 
> > Peter
> > 
> 
>