Rerurn to Romy the Cat's Site

Dresden wrote:

… One very important component I'm leaving out of the cost of the horn is amplification (the horns will be active, using class-D amps).  The reason for my choosing class-D amplification is that the modules and various components for building what I consider very capable amplifiers can be purchased at low cost and assembled by me (again, the mantra is to save money for the purpose of appropriating it toward the casting of the horn mouth, said cost as of this date undetermined).  I have found two manufacturers which offer class-D amplification at reasonable costs, said amplification capable of delivering the target power and sustainable performance (one is located in Germany, the other in England).

I see absolutely no rational to go for class-D amplification on bass horn. Leaving inside all alleged imperfections of class-D amplification’s Sound the only advantage that class-D amplification has is cost, size, heat generation and power. Yes, you can buy for $40 a module that will be cold-running and output 200-400W with 95% efficiency but the bigger question: do you need it?

The JBL driver that you selected is 95dB sensitivity (would like to see more but it is me). Using it as a compression driver will give you extra 2-3dB sensitivity; the horn’s equalization will give you 6-7dB. So, we are will be arriving to ~103dB of sensitivity. A proper horn positioning might give you an extra 6dB, let say 2db from the room’s gain to make the number even. So, we are talking about 105dB. Even if you have a large room of 1500 sq feet then with 10W of amplification you will be able to develop sound pressure enough to make you deaf. So, why would you need a powerful amp in there, particularly the class-D amp? As single ended SS or a chip amp for 10-20W will do fine and might cost very much the same or negligibly more. You might look at the many high-quality amp kits available from some high-end oriented companies; some of them might be good. I think that you shell be able to find a prebuilt kit for under $100-$150 (retail) that would have a good SS single-ended amp, two stages amp of 20W. it is what I would be looking if I go for an “active” bass horn.

Rerurn to Romy the Cat's Site