Hobby-Hifi
This one from Germany (via AudioCircle), nice! Wonder how it sounds?
Jaz
This one from Germany (via AudioCircle), nice! Wonder how it sounds?
An externally hosted image should be here but it was not working when we last tested it.
Jaz
Has anybody seen this speaker? It is JMB Acoustique La Chose. I read a small blurb about it in a British Hifi magazine, there is very little info elswhere. Their web site is a bit akward. The price seems to be steep over 20,000 EUR. One of the driver is eminently recognizable as Fostex, sitting on the top, the other two not so sure. The bass arangment, it looks as if two drivers are facing each other? How does that work?
Somehow it looks appealing.
"The bass arrangement, it looks as if two drivers are facing each other? How does that work?"
those woofers are like clam together to form isobaric, in opposite phase, push-pull, google it or search here, there is lots of info on isobaric subwoofers
it has advantage of lower box volume is required for the same low frequency extension
on the other hand you have to sacrifice the efficiency a little
its only good if you need small box, but for open baffle, I am not sure...
I would expect on open baffle its the cone area and xmax what counts, I am not sure if isobaric has any advantages here
those woofers are like clam together to form isobaric, in opposite phase, push-pull, google it or search here, there is lots of info on isobaric subwoofers
it has advantage of lower box volume is required for the same low frequency extension
on the other hand you have to sacrifice the efficiency a little
its only good if you need small box, but for open baffle, I am not sure...
I would expect on open baffle its the cone area and xmax what counts, I am not sure if isobaric has any advantages here
If the two drivers had weak motors, then there's be the obvious benefit but not unlike you, i'm not sure what gives here either. I'd be interested to see the developers comments on why the isobaric clam.
push pull, face to face, should result in more linear motion, in theory
that is if there really are two woofers
I only see one in the picture, the way its shown
or am I looking at the wrong picture, the one with plexi baffle
that is if there really are two woofers
I only see one in the picture, the way its shown
or am I looking at the wrong picture, the one with plexi baffle
Looks like a single driver mounted on a perspex baffle... sort of like the Gradient Helsinki
dave
An externally hosted image should be here but it was not working when we last tested it.
dave
I'm also only seeing one woofer, but if there are two, then you'd have less distortion (as you've pointed out) and depending on the wiring increased output. Two time the area and half the impedance (???) equals 6dB added output....maybe😀
Best Regards,
TerryO
It looks like a push and pull, two of them. So the sensitivity would stay the same and the only advantage would be the distortion issue, as mentioned before? Thanks.
An externally hosted image should be here but it was not working when we last tested it.
If it's actually push-pull, then what you have is basically a dipole with hardly any benefits and the expense of an added driver?
Best Regards,
TerryO
Best Regards,
TerryO
ah, but look at the symmetry
might be the optimal way to use clamshell woofers
considering the usual weak magnet/motor of inexpencive OB woofers
it might improve linear motion much more than we imagine
its tempting
great pictures
If it's actually push-pull, then I think your answer is correct as it's just about the only sensible choice. 😀
However, I can see possible benefits if it's push-push.
Best Regards,
TerryO
The 2nd picture is oriented so as not to hide the 2nd driver 🙂
To be usefulul it would have to be push-pull. This will reduce even order harmonics, possibly increasing odd-order, It also gives double the extra noise you get from the backside of the driver. You get twice the motor (that the Vas halves is immaterial). Whenever i see push-pull i remember something Nick McKinney said. Any drivers with adequate motor design (including his) would get little or no benefit from push-pull.
You could get almost all the same benefits, and the ability to move 2x the air with half the rear of the driver noise, by offsetting the drivers such that they both moved air separately.
dave
(they are push-pull)
There are woofers designed to have very low third harmonic, I would use one such or a custom one for such task.
I wonder how low they go...
It says 25.000 € per pair without delivery. And it says edition limited to 50, numbered and signed.
maybe the frame is hollow and it has a vent at the back....
kind of ri-pole but not really
might want to try this
yeah, it does
but I think it might solve some of the problems having a dipole with large woofers close to a back wall
I said might 😉