Active crossover on Mission 752

[davidsrsb]

I am thinking about going active on my old Mission 752s, as decent speakers are so expensive in Malaysia.

The original crossover is a simple series inductor on the mid/bass and 2nd order with notch on the metal dome tweeter. Crossover frequency is about 2 KHz.

From Lynn Olsons postings in the "sparkling treble" thread recently, I suspect that 2nd order on the low pass and 3rd or 4th on the tweeter would be better. The Audax Aerogel mid seems to get into trouble at 3 KHz.

Any opinions on the tweeter amplifier? I had a look at some of my "brighter" recordings via Audacity and was suprised to see that David Bowies Heathen was hitting digital full scale after 2 KHz high pass and was only 6dB down on average power - a real tweeter killer

[AllenB]

Since the a treble amp will be dealing with lower level signals, it stands to reason to use a class A amp, but just a suggestion. Any reason you wouldn't just modify your passive crossover?

[_henry_]

hi david,

i believe by going active will enable u to strategically EQ into ur room, which is very very important these days.

for shaping of freq response, it may or may not be an upgrade.

cheers
henry

[juz400]

For inexpensive experimentation I HIGHLY recomend the MiniDSP 2x4

[_henry_]

definitely!

[davidsrsb]

I will have to find out more about the MiniDSP and if I can get one out here. It would be nice to be able to high pass at about 100Hz as I have a decent subwoofer. I see the midbasses moving quite far on some music.

I used to think a class A on the treble amp was a good idea until I checked the peak levels on some CDs and saw digital full scale after high pass filtering. This means the amplifier has to swing nearly as far as the mid/bass amp, just a few dB less equivalent to any padding resistor. The treble amp does see a relatively high load as most tweeters are 8 Ohm loads. The Audax mid/bass is a 6 Ohm load.