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In the Forum: Horn-Loaded Speakers
In the Thread: Vitavox S2 with Electromagnets
Post Subject: The HF field-coil and temperature.Posted by Romy the Cat on: 4/26/2006

I do not know how my S2 driver will sound but I defiantly know that it will have the problem with temperature. Looking prematurely at the driver’s sound it looks like it produce the necessary magnetic force at 2A-2.3A, that heats a lot of this driver.

This brings an interesting dilemma about a conceptual design of HF field coil drivers. With the LF driver it is easy and with the lower current a LF driver works very nice. However, to get HF and transits from the HF driver it looks like it is necessary to drive a driver harder with the poles locate as close to gap as possible. However, the drivers witch work “inside”, and particularly if we want to reduce the inner driver tape rate have, no space to locate a sufficient amount of core. So, a solution would be to put coils in the back path but since we do not want to locate coils too far from the gap we still face the temperature dilemma. Is water cooling, low take rate, “inside firing” drive would be too crazy to consider?

So, how to make the “inside firing” drivers shorter, dump inside a sufficient amount of electromagnetic core at high current and still do not heat it up? At this point I do not know. Probably the “outside firing” diaphragm is the only solution for a high current, low temperature filed coil driver but it would not be the Vitavox’s cones and plug anymore, and only God knows how it might sound.

Well, at this point, without known if an electromagnet is worth to pursue, I would not worry about it but purple conceptually I feel that there is no solution for  “inside firing”, HF, low tape rate, filed-coil compression driver, unless you pump a liquid helium through the driver…

Rgs,
Romy

PS: Taking about the Cogent drivers with “soft” fifer cones… it woiuld be fun to listen it at triple of qudruple current driving that coil (if they have enoght core matera in there)....

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