BillFitzmaurice.info

I am building Western Electric 66a horns for my new house. They can play down to 120hz. I can build two THTLP's and put them in corners. The we66's will be next to them about 20 inches away. I am sure tuba's can take care of the lower frequencies but how does it sound over 100hz? As they are low distortion, even though I pass them at a higher frequency I think they would still be hard to localize so they can work.

I do not want to go tapped horn route as I do not find them sounding good over 80hz (actually my preference is 60hz). I have built 20hz full size tapped horns before. As the Tuba's are front loaded horns, I am more hopeful about 80hz-120hz area sounding good.

I am using dsp for time aligning and correcting all the responses, so not much problem there.

They'll work well to at least 150 Hz.

What happens above 150? Do the folds act like a low pass filter?

The folds act as a low pass filter yes, but that's a good thing. It's one reason why THD is far lower than any direct radiator. However, when the distance between the panels and the bends gets longer relative to the wavelengths being passed response gets more ragged. Localization isn't an issue unless you run them to at least 300Hz. Tapped horns have higher THD, the result of one side of the cone being exposed to the air, and higher excursion for the same output level. That is the price paid for their smaller size compared to a front loaded horn. They still have lower THD than direct radiators, but not as low as front loaded horns.