Gemme Audio VFlex magic

Status
Not open for further replies.
Jump to Latest
#83
Robertburchell said:
Sealed behind the driver, and along the line. Takes a hairpin turn at the bottom. There is a verticle holy brace in the rear section.
Click to expand...

Here are some pictures on the inside, you can see the wire come out the long tapered channel. The view is without the back panel on. The pictures are sideways also. The panel with the cutouts is stiffen up the walls, otherwise it's a large chamber.

URL]


URL]
 
#86
xrk971 said:
I still can't understand this drawing/plan. Is it sealed all the way down to the hairpin turn or are there leaks along the way from the driver chamber? Is there a better plan somewhere - I would like to model this.
Click to expand...

Take a look at the following pictures of Arteluthe inside ( click to watch them all ):
https://www.facebook.com/Arteluthe/...446768602./380738752046804/?type=3&permPage=1

chrisb said:
KrammeAcoustics- thanks for the update
Click to expand...

You're welcome
 
Last edited:
#94
xrk971 said:
Ok with back panel on - what is dimension of the port? Looks like a MLTL with a skinny first leg. Don't see how this is going to be any good. It will have deep bass but be peaky one note bass.
Click to expand...



Those pictures with the back panel off, I got off the internet, I could not find any pictures of the back panel. The skinny first leg is tapered. It's like a tapered port charging a large chamber that is mass loaded.
 
#98
Thanks for the Arteluthe Facebook link. Lots of good photos there - I understand it now. One thing that gives me a lot of pause on the designer's attention to sonic detail is the fact that the tweeter bezel (a round circle) is not rebated flush with the baffle as shown here. It is a substantial step, and a round step is the worst thing you can do for mounting a dome tweeter. We are talking 6 to 10dB sawooth peaks/dips in the upper register. It will sound very rough. Adding a chrome accent bezel does nothing for this.

An externally hosted image should be here but it was not working when we last tested it.
 
#99
chrisb said:
the FE108Sigma is a delicious performer in the midrange band, but no effin way you'll get usable 20Hz from them in an enclosure that size - or possibly any, including a Kleinhorn.
Click to expand...

Actually, based on published specs it has a usable ~8.8-727.3 Hz loading BW, so given a large enough horn with a tiny filter chamber tuned to load down to ~8.8 Hz, then it will theoretically be nominally flat to ~12.4 Hz at ~108.5 dB/W/m according to Prof. Leach's math. This will of course also be its peak power response over much of its LF BW due to having so little low distortion excursion.

Having built a couple of this type BLH alignment with much higher BW drivers to be of reasonable size for proof of concept, this is a reasonable prediction, though with the trade-off that this will be all of its usable BW since the massive acoustic loading combined with the long distance delay will ~completely damp its mids/HF BW.

As Bell Labs/W.E. proved back in the '20s though, similar alignments loaded with high Qt compression drivers with a phase plug in lieu of a sealed rear cover can make for an impressive performing wide BW horn.

GM
 
Status
Not open for further replies.
Top Bottom