Some years ago I built a simple near field cube with a 4" full range I
bought from MCM and I must have lucked out on these drivers, because
everytime I hear these speakers they blow me away.

A: Can anyone recommend a currently available 4" full range they like?

B: I'm thinking of building a 4 - 6 speaker series/parallel column using
full range drivers as I always wanted to hear what this no crossover, in
phase approach can sound like.
(I'll use the 2 columns with a subwoofer).

What are opinions on this configuration (a line array?).....pros and
cons......like I say, I've always held these little cubes as my favorites.

Theoretically, the full range can make alot of sense and sound damn good.

I've tossed around a few designs using the Foster C100K03 and similar drivers.
But these days there are lots better (I've seen some smaller Bose drivers
available cheaply that might bear some experimentation, but any of the
speaker-centric groups would be worth visiting).

I mounted 10 drivers on the pentagonal faces of a dodecahedron, with the top and
bottom faces each feeding a pipe (originally I thought the pipes would provide
transmission line loading, but I think their cross-sectional area was too small,
so they ended up sealed). I don't like the directional effects of coplanar
drivers producing the same signal, and I thought that the angular offset between
drivers would allow each to cover a similar solid angle, and the natural
directivity at higher frequencies would reduce mutual interference. But when I
did the figures, it turned out to be quite a compromise - I would need to mount
4" drivers at about 1" pitch for this angle to work properly. Nevertheless they
actually sounded quite good with little evidence of the interference that must
be there (warm but otherwise relatively neutral, no doubt helped by the lack of
diffraction problems).

The theory said I could improve the interference by using just 4 drivers
close-spaced at 90 degree increments, which I then did. As the magnets prevented
close packing, I stacked two back-to-back 180 degree pairs vertically as close
as possible (added bonus - all the rear leakage flux is clocked, so slight
increase in gap flux and sensitivity, and virtually no purity problems in
adjacent CTR monitors). This design was also very compact and easy to make, but
didn't seem to hit the spot as well (symmetric mounting caused bad
diffraction?).

If you stick with the cube, make sure the driver is offset by different amounts
vertically and horizontally, to spread the diffraction resonances.

On Tue, 18 Nov 2003 10:20:01 -0500, "EBG" wrote:

Some years ago I built a simple near field cube with a 4" full range I
bought from MCM and I must have lucked out on these drivers, because
everytime I hear these speakers they blow me away.

A: Can anyone recommend a currently available 4" full range they like?

B: I'm thinking of building a 4 - 6 speaker series/parallel column using
full range drivers as I always wanted to hear what this no crossover, in
phase approach can sound like.
(I'll use the 2 columns with a subwoofer).

What are opinions on this configuration (a line array?).....pros and
cons......like I say, I've always held these little cubes as my favorites.

Theoretically, the full range can make alot of sense and sound damn good.


Tony (remove the "_" to reply by email)

I've tossed around a few designs using the Foster C100K03 and similar drivers.
But these days there are lots better (I've seen some smaller Bose drivers
available cheaply that might bear some experimentation, but any of the
speaker-centric groups would be worth visiting).

I mounted 10 drivers on the pentagonal faces of a dodecahedron, with the top and
bottom faces each feeding a pipe (originally I thought the pipes would provide
transmission line loading, but I think their cross-sectional area was too small,
so they ended up sealed). I don't like the directional effects of coplanar
drivers producing the same signal, and I thought that the angular offset between
drivers would allow each to cover a similar solid angle, and the natural
directivity at higher frequencies would reduce mutual interference. But when I
did the figures, it turned out to be quite a compromise - I would need to mount
4" drivers at about 1" pitch for this angle to work properly. Nevertheless they
actually sounded quite good with little evidence of the interference that must
be there (warm but otherwise relatively neutral, no doubt helped by the lack of
diffraction problems).

The theory said I could improve the interference by using just 4 drivers
close-spaced at 90 degree increments, which I then did. As the magnets prevented
close packing, I stacked two back-to-back 180 degree pairs vertically as close
as possible (added bonus - all the rear leakage flux is clocked, so slight
increase in gap flux and sensitivity, and virtually no purity problems in
adjacent CTR monitors). This design was also very compact and easy to make, but
didn't seem to hit the spot as well (symmetric mounting caused bad
diffraction?).

If you stick with the cube, make sure the driver is offset by different amounts
vertically and horizontally, to spread the diffraction resonances.

On Tue, 18 Nov 2003 10:20:01 -0500, "EBG" wrote:

Some years ago I built a simple near field cube with a 4" full range I
bought from MCM and I must have lucked out on these drivers, because
everytime I hear these speakers they blow me away.

A: Can anyone recommend a currently available 4" full range they like?

B: I'm thinking of building a 4 - 6 speaker series/parallel column using
full range drivers as I always wanted to hear what this no crossover, in
phase approach can sound like.
(I'll use the 2 columns with a subwoofer).

What are opinions on this configuration (a line array?).....pros and
cons......like I say, I've always held these little cubes as my favorites.

Theoretically, the full range can make alot of sense and sound damn good.


Tony (remove the "_" to reply by email)