Seems at least a couple of people disagree with mass being that much of an issue.
www.adireaudio.com/Files/WooferSpeed.pdf
http://web.archive.org/web/20010810141852/lambdacoustics.com/library/whitepapers/bl_mms.htm
I've not seen you mention inductance, or linearity of inductance yet.
Like a zobel is going to make any difference to the driver performance or inductance variation with position in the gap. It will only make a net Z curve change to the network as seen by the source.
I've got the 3 disk Arkology dub mixes on the pad for launch...
I heard they used 18's for headphones down at Black Ark !
Difficult question I know, but, when I meet a Clash fan I always have to ask what their desert island Clash LP would be (one only I'm afraid).
Me..? Just gotta be Sandinista (3 times as much of one of the best bands ever).
The Jesus & Mary Chain are gettin' a few spins round here at the moment.
So's every thing by Spector inc. Do Ron, Ramones, Lennon + George.
Also McCartneys grudge remix of the 'Let It Be' LP
and also believe it or not Laibach's cover of the 'Let It Be' LP
Everything by The Cabs & Richard H Kirk.
Kerosene by Big Black
The Mondays
Straight Outta Compton
etc. etc. too much music...
Simon
Sandinista of course.
Recorded quick like it should be. They recorded and mixed the entire thing in 3 weeks!
On the other hand London Calling has got that Guy Stevens production going for it.
But in the end Sandinista is also the first album I ever bought (3 weeks before I bought my first TT) so that swings it!
Ramones fan since I heard 53rd & 3rd. Still theirs was the loudest gig I've ever been to.
Not a great Beatles fan, my favourite renditions of their songs were performed by The Residents.
For some year I bought everything remixed and/or produced by Adrian Sherwood which is quite wide ranging from dub via Depeche Mode, PWEI, Simply Red to Ministry, Einsturzende Neubauten and KMFDM.
The other day I went on a memory trip down youtube lane and Kerosene was one of the first, then some New Model Army, That Petrol Emotion and indeed Laibach (they make me laugh) finishing with Shinehead, Anthony RedRose and a couple of sleng tengs.
'twas fun!
Seen some old footage of jamaican recording studios and they too seemed to favour Tannoys augmented by huge bass bins. An unbeatable combination especially for dub.
Recorded quick like it should be. They recorded and mixed the entire thing in 3 weeks!
On the other hand London Calling has got that Guy Stevens production going for it.
But in the end Sandinista is also the first album I ever bought (3 weeks before I bought my first TT) so that swings it!
Ramones fan since I heard 53rd & 3rd. Still theirs was the loudest gig I've ever been to.
Not a great Beatles fan, my favourite renditions of their songs were performed by The Residents.
For some year I bought everything remixed and/or produced by Adrian Sherwood which is quite wide ranging from dub via Depeche Mode, PWEI, Simply Red to Ministry, Einsturzende Neubauten and KMFDM.
The other day I went on a memory trip down youtube lane and Kerosene was one of the first, then some New Model Army, That Petrol Emotion and indeed Laibach (they make me laugh) finishing with Shinehead, Anthony RedRose and a couple of sleng tengs.
'twas fun!
Seen some old footage of jamaican recording studios and they too seemed to favour Tannoys augmented by huge bass bins. An unbeatable combination especially for dub.
Hi CD
I think my voice coil got a bit overheated in that driver shootout yesterday !
Personaly I don't know why I ever get drawn in, passion I guess.
When I was at college, I definately ate brown rice & beans to finance the best audio gear & my vinyl addiction.
The Stage-Line did 'look' OK in the picture (like it was made proper like init.).
How that plastic chassis Audax ever got to to be considered, well ?
It looked like the brochure was a slick airbrush job marketing game to me.
I actualy bought a Stage-Line product the other day.
It was a 2u high swing out headphone support arm for a 19" rack.
Just what I needed, could have made something I guess but this was quick and easy.
Or so I thought.
The mounting bracket which is supposed to be square ie. 90 deg was a trapezium shape !
They had welded it together and shipped it anyhow.
It cost me £5, which is not the earth.
In fact it was so cheap I could not be bothered to send it back, and I needed it.
The upshot is, to be usable I need to get it in the workshop and file the trapezium to a square, and probably re-paint it to stop rust.
What a fuss, needless to say I havn't got round to it yet.
Ugh !
Simon
Hi again pos
Thanks again for your plot of the JBL compression driver.
Although it sounds great in the AC26, it is obviously totaly unsuitable for any 'real world' DIY speaker build, a shame, oh well.
There seems to be lots on the net about the PT-B99HF-1 waveguide, but personaly this horizontal, narrow vertical pattern doesn't really interest me.
I am looking for 90x90 Sq or 90 cone radiation.
I have considered the circular Dayton waveguides, but part of the spec. for the project is that components used, should be easily available in both Europe & North America.
A friend of mine is soon emigrating to NYC USA, and wants to make speakers there, using the same components available to me here in Europe.
This has been frustrating, as some brands have distribution only in limited areas.
However the JBL PT-B99HF-1 waveguide seems easy to get anywhere.
I love the sound of the AC26 speaker, and am therefore keen to keep my fingures crossed and hope it works as well in the 18" + waveguide.
Can you tell me pos, you have this waveguide already.
Have you made any experiments with it using other compression drivers.
Or can you link me to anyone who has (I can't find any).
Also what are your own personal subjective feelings toward this guide, do you like it, do you like it with CD's other than the JBL ?
Any personal thoughts would be most welcome.
Hope DIY is going good.
Cheers
Simon
I have this waveguide, but only two drivers that can accommodate it at the moment: 2414H and 2407H. The measurements I took are from these combos.
If you replacte the AC16/AC26 netword (it can easily be found in PDF), then you could use the 2414H, but with the same crossover frequency as in the AC16/26, which is far too high for any 18" (if only for directivity reasons).
With the 2407 it can be used a little lower, but still to high for your use.
I plan to use the 2407+ 6"PT waveguide together with a 8" driver (JBL 708G) in a small 2 ways monitoring speaker, but for now I only have measurements, no real world listening experience.
I have used it as a supertweeter tho, above 8khz, and found it sounded great, but that is a bit of a waste
If you replacte the AC16/AC26 netword (it can easily be found in PDF), then you could use the 2414H, but with the same crossover frequency as in the AC16/26, which is far too high for any 18" (if only for directivity reasons).
With the 2407 it can be used a little lower, but still to high for your use.
I plan to use the 2407+ 6"PT waveguide together with a 8" driver (JBL 708G) in a small 2 ways monitoring speaker, but for now I only have measurements, no real world listening experience.
I have used it as a supertweeter tho, above 8khz, and found it sounded great, but that is a bit of a waste
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Hi pos
Just looked at your plots again.
It looks like at a pinch the PT-B99HF-1 waveguide might well be usable down to 1.2K Hz, or at a push even 1K Hz with a suitable CD that operates OK at that frequency.
What do you think ?
Do you see a bottom limit to the physical use of this waveguide, assuming a perfectly flat CD from 20 Hz - 20K Hz (ha..ha..ha).
What would you like your X-over frequency to be at with the 708G, any idea ?
I have the PDF, but replicating the JBL X-over is not a game I want to play, seems daft when one could use a flatter CD in the first place.
Cheers
Simon
Hi pos
Thanks for your thoughts.
I have been trying to find an example of someone pushing the JBL waveguides lower to 1K Hz and have just found one on this forum.
They are using the wideangle (or narrow angle depending on how you think) version of the JBL waveguide, and have crossed at 1K Hz with what seems like great success.
When I finaly choose a LF driver I will listen to it for a couple of weeks, and then put my bets down on a first X-over frequency to try.
The thread is:- S15 by gainphile in this forum, you might be interested.
Cheers
Simon
Hi again AllenB
Phew !
Formidable freakin' fuss for a fist full of foam...
If you ask me.
Hope the DIY's doon good.
Simon
Hi Brett
I briefly glanced at the information in the link you posted.
Moving mass isn't just about 'speed'.
It's related to frequency response and coil size as well.
Whilst papers such as these can almost prove that a circle is a square,
Moving mass remains a very important consideration for a 'real world' project.
Manufacturers strive to reduce moving mass, while being sure not to compromise rigidity, a holistic balance of driver parameters is whats needed.
Since there aren't many successfull speaker cones made of lead, I feel moving mass is a little more important than these papers make out.
Cheers
Simon
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