Frugal Super-Tweeter

[Toppsy]

OK so what can you do with a 3” dia. Postal tube a couple of 5W resistors, a 2.2uF Solen Cap and a Mark Audio Tweeter #3 OR CSS ERT26?

Answer; Make a Frugal SuperTweeter like this:



Frugal by the fact they are dirt cheap to make and with the tweeters costing as little as £18.50UKP +VAT a pair (CSS ERT26 @ $13,00 each) and having a relative usable flat FR up to 30KHz makes it a candidate for a cheap SuperTweeter.
Yes the tube tweeter housing is simply a cardboard postal tube with a 12mm MDF disc cut with a hole-cutter to mount the driver on and albeit covered in some black SolarTex and the plastic end stopper spray painted matt black. Not showing in the second photo are the Red and Black 2mm sockets mounted on the rear that were installed after a rummage in my spares drawer for suitable hook-up connections. But they are these:

105-0802-001 WIMA | 10A test socket 2mm, red | 102-9276 | Welcome to RS Online

The above photos show the ST’s on the cradles that came with my (expensive) Fostex T90A’s and in keeping with the ‘Frugal’ theme I thought how can I make these cheaply? Answer; Buy a £1.35 broom handle from my local hardware store along with a couple of 6” nails! Yes nails. These just happen to be 6mm dia. And perfect for the job and more important cheap! The end result of the new cradle looks like this:



And the final finished ST’s sat atop a pair of Frugal Horn Mark3 with MA CHP70 main drivers looks like this:



For those that love the mellow and natural sound of this driver in these cabinets but bemoan a slight lack of top end sparkle then this is the perfect solution.

[badman]

Nice little setup. Some felt on the faceplate would improve it- that hard edge is not a good thing acoustically.

Building A Budget (Super?) Tweeter Reaching the stratosphere! Article By Jeff Poth This would take more crossover work but would give you a better matched directivity profile.

[Toppsy]

Thanks for the link Badman. Interesting read.

Not sure what you mean by adding some felt on the faceplate?

These ST's are still in the experimental stage and though using a simple L-Pad to give a -7dB attenuation on the Tweeter #6 and a inline cap the results are quite impressive. I might make up another pair of tubes with the face plate cut to a 5-deg slope to match that of the front baffle the FH3's. But from initial listening it was found the position of the units had far greater affect on the sound rather than sloping the face by 5-deg. I think a smaller cap say 1.8uF may be evaluated next and perhaps add some roofing lead inside the cardboard tube to help stability and add some mass to the unit, as long as this doen't affect sonics.

But the guy that these were made for is very pleased with the results and I will pass on your comments and link to the web pages you posted.

[badman]

A little ring of felt surrounding the dome (not obstructing it) would absorb energy from the tweeter before it 'illuminates" the hard edge of the mounting flange. This tends to smooth response, off-axis in particular. It also has the benefit of absorbing some of the radial energy, making a better directivity (only slightly, this is a small effect in such an install) match to the fullrange.

[Toppsy]

OK. Sounds good to me.
I'll check with the missus to see if she has any spare offcuts of felt in her sewing box.

Thanks for the tip.

[troopa]

I just ripped apart my very first speakers today
A cheap set of "Tuscany series 2" HT speakers
well apart from the great quality 10ohm bass and mid drivers as well as little 3" 3 ohm mids in the center channel i ended up with 5 x 1" 6ohm tweeters of non existant data and was curious for fun if i can use these in this set up if my speakers are different ohm without doing damage to my reciever?
even pulled out the "Quality" cross overs too :P

[DYNABLASTERTUNERS]

but isn't that tube the worst shape for difraction?!

"The absolute worst enclosure is a circular tube (cylinder), with the driver mounted in the exact centre of an end-cap."
Baffle Step Compensation

[Wavebourn]

Originally Posted by DYNABLASTERTUNERS

but isn't that tube the worst shape for difraction?!

Depends on wavelength.

[Toppsy]

DYNABLASTERTUNERS wrote:

but isn't that tube the worst shape for difraction?!

I'm not sure why you refer to "worst shape" diffraction. Tweet No. 3 is a rear hermetically sealed design and the tube is also sealed and houses the L-Pad resitors and inline polyprop cap.

The simple 'Frugal' ST design was inspired by the likes of the Fostex T90A etc. as a cheap alternative add on top mount tweeter. So are you saying these are also flawed?

[Pano]

I like the stands. Gotta make a pair of those for my tweeters.