Ribbons are usually not suitable for use with 1st order (6dB/oct) crossovers.
Raal themselves recommend 2.8kHz 4th order (24dB/oct) for the 70-10.
To get the similar protection from a 6dB xover one octave below crossover point (1.4k) you'd have to cross at 22kHz, which seems a bit pointless.
It appears it is not possible to use a 6dB xover with the 70-20 since Raal says a single cap will produce a 24dB slope. Guess they fiddled with the transformer ribbons use to get the impedance up to a level amps can digest.
I use Founteks as supertweeters, they are crossed in at 15kHz 24dB/oct with some heavy protection an octave below (18dB hi pass). Fountek recommends the use of at least 18dB slope filters in any case.
Also ribbons distort quite a bit low down (see Zaphs measurements on his site). I wouldn't use them below 5kHz.
Raal themselves recommend 2.8kHz 4th order (24dB/oct) for the 70-10.
To get the similar protection from a 6dB xover one octave below crossover point (1.4k) you'd have to cross at 22kHz, which seems a bit pointless.
It appears it is not possible to use a 6dB xover with the 70-20 since Raal says a single cap will produce a 24dB slope. Guess they fiddled with the transformer ribbons use to get the impedance up to a level amps can digest.
I use Founteks as supertweeters, they are crossed in at 15kHz 24dB/oct with some heavy protection an octave below (18dB hi pass). Fountek recommends the use of at least 18dB slope filters in any case.
Also ribbons distort quite a bit low down (see Zaphs measurements on his site). I wouldn't use them below 5kHz.
thanks , guys
no ribbon for me IMHO :-( !!!!!
cheers
inertial
Phaseless paolo pontello
Well that would be your massive loss…
I own a set of RAAL 140-15D AM monopoles and a set of RAAL 140-15D AM dipoles, and IMHO they are the greatest thing since sliced bread. You just need to use something around a 4th order crossover, that’s not such a big ask.
Chares Darwin summed that up in this bit...
"Raal themselves recommend 2.8kHz 4th order (24dB/oct) for the 70-10.
To get the similar protection from a 6dB xover one octave below crossover point (1.4k) you'd have to cross at 22kHz, which seems a bit pointless."
Besides they sound sweet crossed over around 3k, so why waste all that lower goodness for the sake of a few more components.
Or go digital... I'm currently running mine at 36dB L-R.
"Raal themselves recommend 2.8kHz 4th order (24dB/oct) for the 70-10.
To get the similar protection from a 6dB xover one octave below crossover point (1.4k) you'd have to cross at 22kHz, which seems a bit pointless."
Besides they sound sweet crossed over around 3k, so why waste all that lower goodness for the sake of a few more components.
Or go digital... I'm currently running mine at 36dB L-R.
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