[tbrooke]

These are speakers that  Nelson Pass uses to test his amps they contain a 15" Eminence woofer  from Parts express and the mid/tweeter can be swapped and can be either Feastrex or Lowther and probably some others. It's an active crossover homebrew b Nelson  They sound great and I think it is due to the open baffle and the 15 inch woofer - Small jazz combos do great

What do you think Rick? Can you do something like this with better cabinetry? Why so few 15" drivers? Is a line array of smaller drivers equal to 1 big one? (BTW the drivers aren't cheap)

[Rick Craig]

These are speakers that  Nelson Pass uses to test his amps they contain a 15" Eminence woofer  from Parts express and the mid/tweeter can be swapped and can be either Feastrex or Lowther and probably some others. It's an active crossover homebrew b Nelson  They sound great and I think it is due to the open baffle and the 15 inch woofer - Small jazz combos do great

What do you think Rick? Can you do something like this with better cabinetry? Why so few 15" drivers? Is a line array of smaller drivers equal to 1 big one? (BTW the drivers aren't cheap)

15" drivers usually need large cabinets (for monopoles) so that's why you don't see them that often in home audio designs. If I were to build something similar I would use a dedicated mid and separate tweeter. Full-range drivers are extremely limited in what they can do and often fall way short in terms of price vs. performance. Several smaller drivers in an array can move as just much (or more) air than a larger driver and have better response (frequency and transient) as well.

[Christof]

I'm a little curious about the same thing...maybe a Feastrex field coil with a couple 12 or 15's below it....along the lines of the new Lotus Group Granada.

[tbrooke]

I haven't heard a good sized line array yet and I need to. I like a "big" sound. You are right the Pass Dipoles are impractical but dipoles I have heard seem to have more of an openness than any box speakers I have heard.

Is there a bargain Julietta on the way?

Tom

[Rick Craig]

I haven't heard a good sized line array yet and I need to. I like a "big" sound. You are right the Pass Dipoles are impractical but dipoles I have heard seem to have more of an openness than any box speakers I have heard.

Is there a bargain Julietta on the way?

Tom

Sure, I can scale it down for a lower cost array. Already thought about that. 

[JakeK]

Is it possible to have a wide range driver handling from ~200Hz to ~6K Hz, and make it a 3 way open baffle speaker with a simple crossover and higher sensitivity(above 90?)?
Thank you.

[Rick Craig]

Is it possible to have a wide range driver handling from ~200Hz to ~6K Hz, and make it a 3 way open baffle speaker with a simple crossover and higher sensitivity(above 90?)?
Thank you.

Can you define "simple" crossover?

[roscoeiii]

And did you come across exactly what driver the Eminence is?

[tbrooke]

And did you come across exactly what driver the Eminence is?

Nelson said it was a beta something   I didn't check Parts Express

The quote from S Linkwitz below seems to agree with Rick's thoughts re: Full range drivers

My interest is, of course, loudspeakers and so I looked forward to hearing two exotic full-range drivers that would be mounted in Nelson Pass's large open baffle loudspeakers right on location. The first was a new Feastrex pair, the only one in existence and build with paper cones by a Japanese master craftsman using centuries old techniques for making archival papers. The drivers had very large diameter field coils. So did the Lowther pair, except these were in long cylinders. Both needed magnet supports since the baskets obviously could not hold the weight. The large 15" woofers had their own amplification and there was no shortage of bass output. The full-range drivers were straining and rather colored, though the Lowthers sounded more neutral. It was like viewing a slightly abstract painting when I wanted to see a photograph of the landscape. I did not hear anything that would have given me an incentive to investigate such drivers or to re-evaluate what I am doing. I was quite surprised to learn the retail prices of around $48,000 for the Feastrex pair and $4,400 for the Lowther pair. 

http://www.linkwitzlab.com/design_of_loudspeakers.htm#J%20-

Tom

[JakeK]

Is it possible to have a wide range driver handling from ~200Hz to ~6K Hz, and make it a 3 way open baffle speaker with a simple crossover and higher sensitivity(above 90?)?
Thank you.

Can you define "simple" crossover?

Allow me to put it this way, is it possible to use the open baffle speaker with a 300B(~8w) SET amp (or a 811A SET ~15W) in a smallish room (10x12) with a normal listening volume at ~85db. I can have a separate amp for the bass.
Thank you.

[Rick Craig]

Is it possible to have a wide range driver handling from ~200Hz to ~6K Hz, and make it a 3 way open baffle speaker with a simple crossover and higher sensitivity(above 90?)?
Thank you.

Can you define "simple" crossover?

Allow me to put it this way, is it possible to use the open baffle speaker with a 300B(~8w) SET amp (or a 811A SET ~15W) in a smallish room (10x12) with a normal listening volume at ~85db. I can have a separate amp for the bass.
Thank you.

Maybe but your choice of drivers will really be limited.

[studiotech]

And did you come across exactly what driver the Eminence is?

Nelson said it was a beta something   I didn't check Parts Express

The quote from S Linkwitz below seems to agree with Rick's thoughts re: Full range drivers

My interest is, of course, loudspeakers and so I looked forward to hearing two exotic full-range drivers that would be mounted in Nelson Pass's large open baffle loudspeakers right on location. The first was a new Feastrex pair, the only one in existence and build with paper cones by a Japanese master craftsman using centuries old techniques for making archival papers. The drivers had very large diameter field coils. So did the Lowther pair, except these were in long cylinders. Both needed magnet supports since the baskets obviously could not hold the weight. The large 15" woofers had their own amplification and there was no shortage of bass output. The full-range drivers were straining and rather colored, though the Lowthers sounded more neutral. It was like viewing a slightly abstract painting when I wanted to see a photograph of the landscape. I did not hear anything that would have given me an incentive to investigate such drivers or to re-evaluate what I am doing. I was quite surprised to learn the retail prices of around $48,000 for the Feastrex pair and $4,400 for the Lowther pair. 

http://www.linkwitzlab.com/design_of_loudspeakers.htm#J%20-

Tom

I couldn't agree more.  I heard a design at RMAF09 with an open baffle Lowther(the same field coil I believe) and helper woofer and the Feastrex system with Lambda woofers.  Strained at high volumes and very colored sounding to my ears.  I do still like the idea of a wide range mid, but a fullrange, totally unfiltered driver is not my cup of tea.

Greg

[Carl V]

.if it helps
at last years VSAC & Last Years RMAF Lowther of America
had a nice OB design geared for SET.  He used a Lowther TiConal
driver paired up with a Hemp Tone-tubby 12".  The Crossover was
"simple".  The secret ingredient was a large sealed (?) 18' subwoofer
in the corner.  This was an nice older white colored driver...with a
 reputation of good sound.  It produced a nice sound.  Not 'Shouty'.
It played loud enough to please most show goers.  I've heard a similar
design using french wide-range drivers PHY.  Tweeter integration can
be tricky.

Just something to consider if you are set on SET.