building speakers Thielle/Small Parameters?
Ben
and resonant
frequency of my speakers. of course i don't have any info on them myself. If
anyone knows anything they are16 Ohms Celestion G12T-75 and celestion g12h,
are these the same as Thielle/Small Parameters?
BillHart,KarenPierce
1. Yes, Vas, Qts, and Fs are the most important of the T-S
parameters. There are others.
2. Speaker building isn't a favorite topic of this discussion group.
The consensus here is that if you don't know what you are doing it is a
waste of time and money except for the education you will get, because
the results won't be very good. If you do know what you are doing and
have the proper equipment you will spend a LOT of time and almost as
much money as if you went and bought some decent quality ones on the
used market. Do a deja news search for previous discussion on this
topic.
3. If you want to try box design, do plenty of reading on the web and
maybe your local library. Most of the writing has been about audiophile
systems. Closed-back (sealed) boxes are not the most common type so you
will have to look harder for that information.
4. Celestion doesn't seem to promote the design of boxes using T-S
parameters. If you haven't read it yet, be sure to check out the
discussion at
http://www.celestion.com/pro/text/ttext.htm
Note particularly the fact that T-S parameters are measured at low
signal levels and guitar speakers tend to be rather nonlinear so the
calculations don't predict high power operation very well. You could
try the speaker lists found on the aforementioned speaker builder sites
and the libraries of data that come with some of the shareware speaker
design programs. They have NOMINAL small-signal values for a lot of
drivers.
5. If you figure out why they promote open-back cabinets but say that
ported boxes are likely to cause damage, let me know. It would seem to
me that there would be at least as much air resistance below resonance
in the ported box as in the open-back cabinet.
Bill
Charlie Escher
Not worth worrying about for this usage. Just measure a Marshall (or whatever)
cab you like. Seriously, those Celestions work fine there, why fight success?
BTW, no those numbers aren't T-S parameters. Try http://www.webervst.com for
the specs on those speakers, and some tips on building cabs.
bm...@yahoo.com
> Not worth worrying about for this usage. Just measure a Marshall (or
whatever)
> cab you like. Seriously, those Celestions work fine there, why fight
success?
The celestions(greenbacks) have neither the frequency response or the
power handling to be use as a PA speaker--they are barely adequate for
a guitar cabinet a single 1x12 e120 has tone to spare over the same
cabinet fitted with celestions and even the e120 is not a PA speaker.
George Gleason
Sent via Deja.com
http://www.deja.com/
Ben
building.
Charlie Escher
Right of course, George. I assumed from the poster's mention of a closed
back (not ported) cabinet, that his intent was to build a guitar speaker
cabinet.
--CE
bm...@yahoo.com
us was right:-) BTW for the newbies the reason guitar cabs are
usually open is for the bass rolloff caused by phase cancellation
(partial or complete) of any freq longer than the distance from the
back of the speaker to the front dumps alot of mud out of the guitar
sound. you will note most bass cabs are closed and ported
Denny Strauser
> Charlie Escher <charl...@gorge.net> wrote:
>> Right of course, George. I assumed from the poster's mention of a
>closed
>> back (not ported) cabinet, that his intent was to build a guitar
>speaker
>> cabinet.
>>
>Yes as a pro live sound I assumed it was a PA box and that means one
of
>us was right:-) BTW for the newbies the reason guitar cabs are
>usually open is for the bass rolloff caused by phase cancellation
>(partial or complete) of any freq longer than the distance from the
>back of the speaker to the front dumps alot of mud out of the guitar
>sound. you will note most bass cabs are closed and ported
>George Gleason
Boogie makes (or, at least, used to make) a 2x12 cab with one open
back 12 and one ported 12.
A ported 12 will put out more low end.
A sealed cabinet (enclosed & unported) will have a flatter response.
I'd prefer either of these to an open back cabinet.
Denny