Tang Band / Selenium project. The "FK"

[Pano]

The F.K. project.

Hello speaker nuts,
I haven’t posted in this forum before, but I do read here. You may know me from the Class-D forum.

Just thought I’d share the speaker project I’m starting this week. It is designed to work well with the low power Tripath “T-Amps”. Should also work well with the original “T” amp, the triode.

The drivers: (per side)
2 Tang Band WS-789S in parallel
Selenium D210ti 1” compression driver
Selenium BBC style horn
Dayton ND20FA-6 3/4" neodymium dome tweeter

These will go in a 35.5” (90cm) floor standing ported box. 2.75 cubic feet. (78 liters)

The concept behind this was to build a medium size, efficient speaker with great mid range and strong bass at an affordable price. It is designed to work well with “flea power amps”.
So why not go with a standard Fostex, Coral, Lowther, etc full range driver? Good question. My first serious speaker build was 20 years ago with the well known Revue de l’Audiophile Triangle TQWT 17cm with Technics tweeter. Wonderful mid range, very life like, I still miss them. But very bass shy, they just didn’t have much punch or weight. This project is meant to have the glorious mids of the single driver boxes but be able to play lower and louder. We shall see.

The Tang Bands play right up to 12K, but beam above 5K. That’s where the Selenium 1” Titanium and horn come in. The little tweeter is just there to fill in the very top. The crossover is simple and allows a lot of overlap. The 6.5” drivers can play high, and the 1” horn can play low (at low power). The broad overlap seems to work surprisingly well.

I can post the crossover, if anyone is interested.

This project was designed and tested by my buddy John in California; he did all the tuning there. A number of well liked speakers were used as reference, the main reference being the Altec 605 coaxial. I will need to tune these to my own room, that will be the time consuming part.

Why F.K. project? Because after John and I came up with the concept, I had a peek at the Klipsch website. Hey! I’m building a “Faux Klipsch”!

Comments and questions are welcome. Of course there are more details than I’ve put in this already long post.

[nerd of nerds]

Hmmmmmmmmm...

A while back zaph was planning on doing a simple 2 way with similar drivers but scrapped the project.

It was the 5 1/4 poly tb woofer and the dayton neo tweeter he had in mind.


I was planning on doing this project but i need a new monitor badly. The tb woofer is pretty well behaved and would probobly work well for a super simple to construct waveguide speaker....

[niiico]

Looks like a good project.

Much more difficult than mine.
More than 2 ways is much more difficult to design.

Let us know how it sounds with your Octopus !

[Pano]

Hi Niiico,
It is really just a 2 way with a super-tweeter glued on. I may not use the super at all. I generaly don't like them, but this one should be "polite". So not as hard as it looks.

Below is the crossover schematic: All 1st order, as you will see. The horn has an L-Pad, but that will go away when I figure out the attenuation needed. The cap on the super tweeter may need to be tweaked depending on the placement of the driver (phase).

[Cal Weldon]

That's a lot of tweeter for the project, and you're right, you probably won't need the dome. I think you'll find the rating on the Selenium to be more accurate than the TB's so there'll be lots of padding. I would also consider a 12dB on the tweeter. They get really nasty sounding unless cut off.

[Cal Weldon]

Forgot to mention, these aren't going to sound anything like an Altec coax.

[Pano]

Originally posted by Cal Weldon
these aren't going to sound anything like an Altec coax.

They had better not - or there is going to be big trouble!

But seriously, the Altec coax was used as a reference because I like(d) the sound of the Altex and so does JB, who put this crazy thing together. But it's been 15 years since I heard an Altec Duplex, so I'll be no judge there.

JB thinks the new speakers do some things better than the Altecs, some female voice and stand up bass, for example. But not as refined as the Altecs.

The designer says:
"-in a smaller room the F.K's sound more like VOTT than medium sized home hi fi towers. Surprised at the bass power on the low end in a smaller room. Seemed to be powerful down to around 40 Hz even with the higher 50 Hz tuning. Very Altec-JBL like sound, forward and monitor like with oodles of midrange. May be over the top for most folks, but if you like that kind of sound it is habit forming. The micro dynamic resolution of the horn compression driver combo makes direct radiators sound tame."

Will be interesting, if nothing else.

Yes, that 1" horn is a lot of tweeter, but we went thru several good dome tweeters and they just never could keep up with the dual TBs. The horn will have to be padded down a good bit, but that's OK, means no power worries with a 1st order filter and "flea power "amp.

Your note on the 12dB curve for the Selenium is well taken. The idea here is that this driver will play down flat to about 1K, and the horn starts to unload at about 1500Hz. So at the horn cut off (close to the drive actual FS) it should be down 16-18 db.

Hope to have them up and running this weekend, but maybe not, as the table saw is broken. Will have to build a "saw board."

[Cal Weldon]

There are some that will never buy a table saw provided they have their trusty sawboard by their side.

Looking forward to your results.

[happy.gringo]

Were these ever finished, and if so, did you like the result?

[critofur]

And, did you get any good measurements of the W6s? Care to share so I could plug them into PCD and play around with ideas for a design for my W6s?

I guess I'll have to go ahead and build a measurement baffle at some point...