Turbosound; The relics

The HF horns are arranged in the centre of the stack to provide a single point source.
They also experimented with various combiners and manifolds for HF, including one with 4 x JBL 2420 on a small horn.

They had a few bat-shit ideas, not least of which the TFM-3 which was a tri-amp beast, apparently even BRP wouldn't touch them (3-amp channels and an FDS360 per send) most them were stripped down and the woodwork skipped at Star Road.

Here is the original flyer, dated 1986, introducing the TFM-2:
http://www.spamabyss.net/pictures/tfm2flyer.jpg

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I can't remember much about the TFM-2 except that very few were sold, so it was a major failure as a product.

UK List Price in 1991 was GBP 1722, Export Price was GBP 861. Even allowing for a substantial discount off list,  I suspect they were too expensive for the market.
Also perhaps too radical a departure from the existing designs of the day. Monitor engineers are very conservative - you don't risk your job with a new product if your client is happy and confident with what they've used for the last few tours.

It was another 15 years before d&b came up with coaxial wedges that redefined stage monitor speaker quality, and of course advances in radio technology have ensured that in-ears have now replaced wedges for many applications.

And I'm sure somebody once told me a sad story of plastic horns melting in the heat after a day on a festival stage in the Southern European sunshine...

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TFM-2 Information from Component Map (Issue 3, December 1994):
Up to S.N. 152259
Bass LS-1506 (RC-1506)
Mid LS-1509 (RC-1508) but I think RC-1508 is a misprint
HF CD-202/16 (RD-020)
Network PX-2M

S.N. 512263 onwards
Bass LS-1506 (RC-1506)
Mid LS-1509 (RC-1509)
HF CD-203 (RD-203)
Network PX-F2

(RC and RD are the recone and re-diaphragm kits)
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From a Product Range Catalogue, undated but Edgetech period, so around 1990:

TFM Series:
The TFM series embodies the results of two years of extensive research This programme has led to the development of the TurboConcentric principle (patents pending).
Turbosound have created the new technique to provide the floor monitor user with a standard of performance which emulates that of the TurboMid device, yet in a shallower cabinet profile.
The TurboConcentric device also acts as a waveguide for the HF driver, mounted in the centre of the unit.
THe TFM series is unique in providing finely detailed full-range information at very high power levels from compact floor monitor enclosures.

TFM-2
The TFM-2 High Power Floor Monitor is a bi-amped 3-way enclosure. It contains a front mounted 15" midrange driver and a concentrically mounted 2" compression driver, using the TurboConcentric principle. A downward-facing 15" bass driver is loaded by a development of the TurboBass device and outputs through an aperure on the front lower face of the unit.

TFM-2 Specification
Biamp, 2-way, EP-6 connector
Weight 56kg (123.5 lbs)
LF 1 x 15", MF 1x 15", HF 1x 2"
Frequency response 60 - 18k Hz, +/-4dB
Dispersion 60 degrees conical @ 6dB down
Power handling total 550W RMS, 1100W programme
Sensitivity 104dB 1W 1m
Max SPL 123dB (135dB peak)
Crossover point 250 Hz
LF 8 ohms, MF/HF 8 ohms

A later (Winter 1992, AKG era) version of the catalogue added the TFM-250 and 350, but these didn't make use of the "TurboConcentric device" and were of conventional design. They were still listed in the
Winter 1994, (Harman era) catalogue but by then the TFM-2 had been dropped from the range.





Edited by madboffin - 25 October 2015 at 12:23am

Any information on that 15" coaxial from the tfm-2?
I tried fitting a b&c like the d&b max monitor driver.
But the distance from the high horn to the cone seems to big, more than enough space for my fingers.

I wonder if the original driver had a horn in the middle fitting the outer horn?
Otherwise the cone must've been very flat, but often turbodrivers are curvilinear (not flat)

I wanted to do a measurement with / without the horn on the b&c yesterday, but didn't get around to it.

Any info?

Yeah, they're turbo, they're LOUD!
I made a thread on the box...

No original drivers, fitted fane studio 15b, even though it's not that powerfull watt-wise it plays loud.
Then I fit a b&c neo coax much like the one in the d&b, but I can't decide wether I like it with the horn or not, the directivity of the horn is very nice, I'd have to measure it, the horn is almost 2 cm from the cone, so the original driver must've had a very flat cone I assume, but where would i get that turbopd?

madboffin wrote: The drumfills look like TMS4, and the sidefills stacked pairs of TMS3.

Edited by L8 ECU - 11 November 2015 at 6:32pm