I tried a larger throat as you've said. Walt reccomended 100cm^2. But anything above 10cm^2 is no longer flat to 1.6KHz! It is more near 1KHz or lower. I plan on running them at high levels, 120db in some cases (like when I'm showing off my system). I also enjoy high levels of output. According to Hornresp I'll need about 60Wrms to do this. Do you think this will present any huffing sound or any other unwanted noises with the very small throat? What freq would you reccomend I crossover at? 250Hz? or is that still too low for this horn?

> in practice you will need a volume in front of the speaker to
> couple the speaker to the horn.

I am not exactly sure what you mean?!

> For ATC you should enter the cone area and the volume should be at > least cone area X maximum excursion, this to prevent the cone from > hitting the panel which is in front of it.

I've tried using the ATC figure the same as Sd (344.9cm^2). And for throat chamber volume, I used 550cc which is Sd*Xmax (Voice Coil Overhang) Since the program needs it in cc for some reason, does 1000cc equal 1 litre?. However using the two figures above (344.9cm^2 and 550cc) significantly restricts my high frequency response (have also tried a larger mouth). The same also goes for the throat area when I increase it. Can any of you suggest ways around this?

Thanks!
Adrian