On Tue, 21 Nov 2006 19:13:11 +0000, Eeyore
wrote:



Andy Evans wrote:

For years I've been using a single driver now (Monacor 130AL, aluminium
cone like a Jordan). Of course it's not perfect - bass is only just
there and treble could be better. That's the deal. But nevertheless I
add ribbon tweeters (Decca) and take them away. Yes, the ribbon sounds
better but the crossover doesn't.

So, what do you guys feel rocks your boat? Are you in the camp of full
frequency response or that of total integrity (or whatever words you
feel describes a single driver)?

As a reference, the best speakers I know are panels like Magneplanar or
even better Apogee - yes they have crossovers but the sound remains the
same top to bottom in terms of delicacy, so you have the "feel" of a
single driver.

If your drivers are up to the task, just use a first order crossover ( 6dB /
octave).

By its very nature it can't screw up. It will always give constant power and
pressure and eliminate any phase 'nasties'.

No, a singe order crossover can't be linear phase - you need at least
second order to achieve that.


To do it right you also need to compensate the drivers to amke their impedance
flat too btw.


That is part of the art of speaker design. You start with the
theoretically correct values, then juggle them to make them work with
the real world impedances. Then you do a sensitivity analysis - that
is sensitivity of the design to variations in speaker and component
tolerance. Then you do a yield analysis to see how many will arrive
within spec, then you centre the design so that even if it isn't
perfect at nominal impedances, as a many as possible will pass spec.

That is why it is only the professionals who can afford to make many
models and even more measurements will ever be good at producing
decent speakers.

d

--
Pearce Consulting
http://www.pearce.uk.com