Active coaxial 3-way speaker with linkwitz transform woofer

[alexclaber]

Am pondering a set of floorstanders with the SEAS H1333 coaxial driver with passive crossover in sealed cab plus a 120Hz 24dB active crossover to a Peerless 830452 in a sealed cab with linkwitz transform.

Will the output of the Peerless be completely omnidirectional and thus side-mounting be feasible?

Which amp modules should I be considering? My calculations suggest that 70W will take the H1333 to Xmax and 200W will take the 830452 to Xmax. I suspect that's more power than I need for fairly high SPL at home.

Anything else?

Alex

[AndrewT]

@ frequencies below 120Hz the bass driver will be omnidirectional.
You can fit the bass anywhere in the box, but you may get best from it, if it's very near the floor.

What are the sensitivities and impedances of the drivers?

[alexclaber]

Originally posted by AndrewT
@ frequencies below 120Hz the bass driver will be omnidirectional.
You can fit the bass anywhere in the box, but you may get best from it, if it's very near the floor.

That seems logical. That'll also reduce the risk of the cab shaking with a heavy cone moving back and forth. I did some googling after posting this and found a few commercial cabs like this but I'm always sceptical that commercial designs are done for marketing reasons and not sound reasons!

Originally posted by AndrewT
What are the sensitivities and impedances of the drivers?

Calculated sensitivity of the coax mid-woofer is 86.8 dB and of the subwoofer 87.5dB.

Am initially thinking of an 8.5 litre enclosure for the coax so Q=0.707 and a 30 litre enclosure for the subwoofer so Fs=42Hz and Q=0.372, which is then transformed to Fp=25Hz and Q=0.707, which requires about 12dB of boost at 20Hz (i.e. 16x power).

Alex

[AndrewT]

Hi,
with that level of transform boost, the upper bass and mid will have about 9dB of extra SPL available.
Be careful you don't overdrive the bass speaker.