My island speakers

[vgeorge]

My island speakers


After two years of collecting the parts, building a new listening space and finally adjusting the speaker and crossover, I hope that this project came to a near end.
My initial aim was to create something with as much sensitivity, at least above 100Hz, in order to be able to use low wattage tube amplifiers, and at the same time preserving the dynamics of a live orchestra.
The drivers used are GPA 288H 16Ohm with Azura 425 horn, Fostex T925 tweeter and 2x Eminence Deltalite 2512 in a BFM omnitop enclosure. For the lows there is a 290 litter bass reflex tuned to 22Hz with Lambda TD15X 4ohm, crossed actively with CX4300. The 288H are -9dB down with a 3636 Autoformer.
Amplifiers used are a McCormick DNA-1 for the Lambda and an F5 for the all the rest. (OK, there is a plan for a tube amp in the near future)
This project was inspired and influenced by Lynn Olson of course and his thread here in DIYAUDIO.
All the crossover development was done by SALAS, who was very generous with his help. As I live in an island, I was mostly taking measurements and given feedback from him. In fact his help made all the difference. Thanks again Nick.
Below you can see some pictures, the final crossover and a measurement (in room) of the system at 2 meters.

[adason]

nice

[GoranB]

WOW!!!
Im jealous
Are you satisfied with sound? Tell us more.

[vgeorge]

I think I like the sound very much now!
There is presence and dynamics to the music, along with naturalness.
FYI you have to time-align the drivers, especially the tweter were a few milimiters are very important to the final response.
Also, I wouldn't make the bass box so big, but I had them and I have the space.
Also I need to make a proper stand for the horns and the tweeter sometime!

[studiotech]

Looking sweet! Love the white with the yellow curtains behind.

Greg

[Truetone]

Hi George, Great to see the sytem - looks spectacular - wish I could hear it. And have a swim off that beach. Nice to see the beautiful looking response on the 425 horns - typical Le Cleac'h :-) Rgds lower mids - do you think there is any possibility of getting a Lambda 15M driver to go up high enough to integrate with teh 425 horns? I am also leaning towards 4 way for this reason.

martin

[POOH]

I think you should ditch the midbass cabinets (not sure what a BFM omnitop is but it sure looks like it's aborting the center of the midrange from your measurements) and use the drivers a non-resonant open baffle. Those cabinets look to be wanna be horns, either use a proper straight horn or ditch the funky top and flares.

[Salas]

The mid-bass slots and flares are rugged neighbours to the Le Cleac'h indeed. Here is a 3rd octave that Vgeorge had sent sometime, not sure if its at the 4.5m away sofa but its full room RTA. I hope I will visit to listen to his system myself too sometime in late spring.

[vgeorge]

Originally Posted by Truetone

Rgds lower mids - do you think there is any possibility of getting a Lambda 15M driver to go up high enough to integrate with teh 425 horns? I am also leaning towards 4 way for this reason.

martin

I think that TD15M can easilly integrate with the 425 horns, but you are going to drop the horn around 13 dB. I considered this, but i wanted something more sensitive.
My system efficiency is an estimated 100dB and has an impedance of more than 14Ohm, only droping to 8Ohm on the last octave. This is one reason why I put the 2512 drivers in series. I was getting too low impedance with the drivers parallel. The other was to integrate the level with the tweeter.

[vgeorge]

Also just found this from Lynn regarding TD15M and 425:

Quote
Both of us wish the efficiency was a bit higher; the horn is being padded down by 13~15 dB, which seems more than a bit wasteful. Three different ways to get the efficiency of the bass module higher would be a short horn, which has uneven response; some kind of folded backhorn on a Lowther-type driver (which also has uneven response); or a quartet of prosound-style 12" drivers in a closed or resistive-vented box. That would get the efficiency in the 70~700 Hz range up beyond 100 dB/metre/watt, and provide better match to the large-format horn.