On 19 Nov 2006 03:59:47 -0800, "Andy Evans"
wrote:

You should also know that the full-range driver is in fact a myth. They
are all dual cone devices with some sort of mechanical crossover

Hi Don - yes, the majority are as above, but I'm talking single cone
here.

http://www.bmm-electronics.com/Produ...roduct_ID=2731

Here's the frequency response:
http://www.bmm-electronics.com/docum...SPH-130ALc.pdf


Well, that one goes really nasty above about 4kHz, so you would want
to be crossing over into a tweeter at no more than 2kHz to keep that
lump from making this one screech. I wouldn't want to try for a single
driver speaker using this driver - and nor would the manufacturers,
reading their web site.

I am also curious as to why the response starts falling below 150Hz. I
can't see any reason for it in the impedance curve or T-S parameters.

This will also really need helping out at the bottom end with a
subwoofer if you want deep bass. Its Xmax isn't up to shifting a great
deal of air.


The Jordan is similar.
http://www.ejjordan.co.uk/drivers/jx92.html

As you can see, you can just about coax enough bass from these
aluminium units and the highs are there. The Monacor isn't as peaky as
the fr suggests. I have a friend with the Jordans and in my opinion
they sound better with no tweeter. He's endlessly working on the
crossover - I think it's better without. Maybe it's a cop-out to not
use a crossover, but crossovers do alter the sound, and I'm not sure
it's worth it in the end.

If you are adding a tweeter, you absolutely must have a crossover -
there is no way tweeters can handle bass frequencies. But this
certainly isn't a "just do it" sort of thing. You do need to put in
the work to integrate their responses together, otherwise you will
have a bad-sounding setup.

d

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