A166 reflector (with holes in it?)

[LostForWords]

I am currently assembling the parts for two Pass F5 amplifiers to drive a pair of A166 speakers, but am struggling to find suitable a chassis. The natural alternative would be to place the amps in the reflectors for the speakers with heatsinks placed on the rear walls. There are two concerns: overheating and sonic effects of ventilating the reflectors

While the amplifier boards could be enclosed in small diecast Hammond cases mounted outside, components such as transformers would need additional ventilation and I am a little worried that any attempts at providing ventilation in the base/rear wall of the reflectors might harm the performance of the reflectors.

Has anybody done anything similar or have thoughts on this suggestion?

[chrisb]

Originally Posted by LostForWords

I am currently assembling the parts for two Pass F5 amplifiers to drive a pair of A166 speakers, but am struggling to find suitable a chassis. The natural alternative would be to place the amps in the reflectors for the speakers with heatsinks placed on the rear walls. There are two concerns: overheating and sonic effects of ventilating the reflectors

While the amplifier boards could be enclosed in small diecast Hammond cases mounted outside, components such as transformers would need additional ventilation and I am a little worried that any attempts at providing ventilation in the base/rear wall of the reflectors might harm the performance of the reflectors.

Has anybody done anything similar or have thoughts on this suggestion?

One of numerous ideas we'd had during the genesis of the Frugel-Horn project was to include a small "helper woofer" in the rear panel of the deflector prism (there are several from which to chose in dimensions that can be shoehorned to fit).

As long as the deflector panels facing the horn mouth are solid, you should have no problem. This is one of the few areas where I heartily endorse liberal use of MDF - a couple of layers of 3/4 or even 5/8" with a bottom and top plate would be structurally sturdy enough to not require a back panel at all. Of course, an open backed prism of welded 1/4" steel plate could be used to augment the heat sinking area - treat the remaining steel surface with adhesive or spray on damping materials ( Dynamat, truck bed liner, etc.) if there are any audible resonances.

[LostForWords]

Many thanks for your response Chris. This was my intuitive response too, but on checking the volume of all the actual components used in the F5, it would seem that I would need more than a shoe-horn! Nevermind, it occupies the mind and I do theoretically have the same space again behind the triangular prism reflector, which can also be used. Now all I have to do is find a way of arranging all the components without the need for calculus or fairy dust.