Little is known about the Tonträff Loudspeaker from Elektrofon AB. The name Tonträff indicates that it is intended to hit the notes spot on.
The speaker was introduced in 1957 as a new revolutionary Hi-fi speaker.
The ideas behind the design are same as the ones used in the Coal-shuttle.
Stig Carlssons idea was to sacrifice some of the efficiency of the speaker unit in order to gain a better bass-response from a small bass reflex speaker. The box was cast from a specially selected material resulting in a box free from box resonances. The box has no parallel surfaces.
We will give our impressions as soon as possible.
Most items are probably according to Restoration and upgrading.
Stig Carlsson used relatively few different units at the time in his speaker designs so the information given is likely to be relevant.
It is likely that a change of tweeters to the new Peerless CT62 would give lower distortion and better response in the top frequencies, although accessing the tweeters in their molded cavity is a big problem.
Little is actually known about this speaker so this information might be somewhat inaccurate.
Box volume: 24 litres*
Principle: Omnidirectional, bass reflex type. Midbass placed on slanting baffle, unit firing diagonally into the roof. The tweeters are placed on the sides near the front corner of the speaker. No parallel walls in the box.
Frequency range: 30-18.000 Hz*
Frequency response: 50-16.000 Hz*
Crossover frequency: Unknown
Impedance: Probably 8 ohms**
Mid-bass: 1pc 210mm. Philips 9710**.
Tweeters: 2 pc, placed in separate cavity, oval shaped tweeters, type not known, probably Jensen (or Isophon)
* Data from brochure
** Deductions and educated guesses based on the available information, Stig Carlssons contemporary designs and preferences for drive units.
No known information
Should you find any additional info regarding this speaker please contact us.