View Full Version : Horn based speaker design

01-22-2007, 04:16 PM
Here's branwells latest creation.

Thread here;

snip ..

For those of you that need a push to try wave-guides…..

For reference, in the past two years I’ve had active and active/passive systems configured in WWMTM, WWMT, WMTM, WMT and had them in ported, sealed, and in dipole configurations. Also had some ported line arrays….

Drivers used included Peerless 12” XLS, Eminence Kappa Pro 15lf-2, Seas W22, W18ex, SS18W/8540, 15M, PHL 1340, 1120, SS9900, Seas Millennium, Morel 110, North D28, G2, Newform 45” Ribbons, OW1, and a few I’ve probably forgotten.

Last summer I got a pair of BMS-4540ND compression tweeters with DDS I-90 Pro wave-guides. Also picked up a pair of 10” PHL extended midrange drivers.

I intended to set them up with the 15” bass drivers using a DEQX crossover, but being a compression tweeter and 10” mid, I had big time second doubts. Anyway, got them setup in temporary boxes and listened for a while. This was enough to convince me that I really should be getting some better boxes built…

The system came apart.…

….and for the last couple months, I rolled through all my “normal” configurations while figuring the box thing out for the pro drivers

Yesterday, got the new boxes stuffed with the BMS and PHL drivers and spent a few hours on the crossover. Points ended up at 200hz and 1600hz. Slopes are 96db per octave.

I suppose the most controversial component in the speakers are the compression tweeters and wave guides.
So, how do they compare to the other tweeters mentioned?
There simply is no realistic comparison. The BMS not only has an order of magnitude more headroom, but it just plain sounds a lot more real. Cymbals, Triangles and instruments with a lot of air and shimmer are the best I’ve heard. Fantastic definition. They also excel with complex sounds such as brass and large orchestras.

The 10” midrange? Again, like the BMS, it just feels unlimited in headroom and never sounds strained. Female vocals never sound thin and male vocals project with great weight.

Anyway, for those of you that are tempted to try a wave-guide: I’d say go for it. The more even dispersion and extra headroom they provide at the bottom end do pay off.

For those of you thinking of trying a compression tweeter, some of them are pretty nasty, but I’d take a BMS with Digital EQ over any ribbon or 1” dome I’ve ever heard.

If there is one thing this system has enforced in me, it’s that the more I think I know, the smaller and less interesting my world becomes.

Heres a photo of one of the speakers. Just need to round the edges and paint them....


On crossover points:
I looked at the measurements and used the tail of the BMS response as a low marker and then a few hundred hz prior to the cone break up of the PHL at the upper end. I then had the DEQX create a series of calibrations between those two points and listened while switching back and forth from the listening position via a laptop. Oh the luxury of technology ?. Ended up picking 1600hz because it sounded most real on a verity of material.

On the PHL:
It’s the 3431…

Here is a graph of a smoothed measurement the DEQX used to create the correction / crossover for the system. I took out the bass to make it clearer.
There are some diffraction artifacts visible, and what else is interesting, the mid needed no baffle step correction, just some general EQ….

A couple of the PHL driver….


DDS Contact Info : DDS moved at some point in the not too distant past. Incase your contact info is not current, here is their website which has some info.

On distributors : I got a pair of the DDS I-90s from here:
Would be worth asking if they will ship to Europe.

On mounting : The I-90 can be ordered with Screw or Bolt mounting.

01-22-2007, 04:29 PM
I talked to branwell recently and in the past about drivers and speaker design.
His line array comments had me interested because I haven't tried the newform
ribbons because the specs on them didn't indicate they are a good candidate
for higher SPL line array designs. He seemed to agree and said the output is weak.
I think he also made a one tweeter line array before. I encouraged him
to explore the line array in more detail using much better tweeters to get more
output as the line array will beat out the horn design with ease, but it *may* cost more
to implement. People using horns usually use them because it's the lowest cost
method to get SPL and it's easy to build.

The good news, he really seems to like the sound from
that horn setup so I posted his design here because it might be in the reach
of people interested in the bigger sound without spending a bazzilion dollars.
PHL Audio right now is on the top of my list for best midrange drivers.

01-22-2007, 06:38 PM
I take it you are a member over on HTG... What's your username?

01-22-2007, 06:43 PM
Oh, and I forgot to add...

Looks like a pretty happening little horn setup... Should sound real big...

01-22-2007, 07:42 PM
I take it you are a member over on HTG... What's your username?

I visit many forums mostly lurking and only a few that I post alot on. That one ain't one of them :laugh:

I posted the design here because I like that type of waveguide and midrange
driver used, plus branwell has racked up some good experience points in the
past few years building all kinds of different systems so his comments have
a reference attached which makes the comments more valuable.