8 inch RCF coax

[holger honda]

Hello does anyone know the s/t of the RCF L8CX200 coaxial driver or where to get them? I found them for 70 bux at

http://www.savinglots.com/djequipmen...akers&RPC=1000

and I think these are the drivers inside the Mackie cx81.
But I dont know..
Cheers!

[Brett]

They looked interesting, until I saw the published FR. Seems like the HF unit isn't particularly well integrated, but at least it has a mylar diaphram, which is a big plus for me. Haven't used them, so might sound OK in practice. My interest was piqued to see if I could use them in my bass guitar rig.

I also found a few places in the US that were a couple of $ cheaper.

[holger honda]

Originally posted by Brett
They looked interesting, until I saw the published FR

hey there did you see something i did not?
where?
thanks

[Brett]

Originally posted by holger honda
hey there did you see something i did not?
where?
thanks

http://www.rcf-precision.de/pdf/L8CX200.pdf

[Variac]

Mackie does use RCF stuff in their products, and they also own RCF or they merged or something- they are part of one group.

A lot of pro stuff seems to have some pretty screwy response curves. Maybe this one is just a bit more honest. The fact that its pretty sharp spikes rather than rounded reinforces this.

I wonder how this sounds vis a vis the Radian 8" coax at $340
Or the 10" Eminence coax Adire uses in their monster PA box w/ an 18" woofewr

[Tim Moorman]

Seems like any time the HF unit fires through the cone, as in the typical coax, you see a truly bizarre response plot, though I must admit this one looks like a malfuntioning HF. Jeez, what a mess.

Way better off with a two way. The 8" portion looks pretty good, actually.

I've heard the big Altec 604, 605, and some Tannoy, so I know coax can be done well.

Tim

[Tim Moorman]

I did find another 8" coax that looks better. Probably cost more, too.

Click on the pdf file.

http://profesional.beyma.com/ENGLISH/producto.php

Never heard it, but certainly better response(smoothed?).

Tim

[Coolin]

Originally posted by Tim Moorman
Seems like any time the HF unit fires through the cone, as in the typical coax, you see a truly bizarre response plot, though I must admit this one looks like a malfuntioning HF. Jeez, what a mess.


Tim

How about the coaxes that use a small horn instead of using the bass driver as an extention of the horn. Anyone heard these?

This is what i mean. i think these are pretty cheap too.

http://www.paudio-europe.com/products/db_1_6.htm

about half way down. Altec i beleave did this as well.

[Variac]

Hey guys, you have to scroll down on the link , but there they are!

I think Tannoys and some Altecs did this in the past. Some highly regarded drivers.

The rap against them I believe is that you get resonances from the areas between the back of the horn and the woofer cone.

How about something like these but with a conical type horn?
Maybe we could make our own from these models, but unscrew the rectangular horn and substitute the conical?

I guess this probably doesn't help... If the horn diameter could be
smaller , maybe, but I was thinking it could be mounted in a cylinder/ phase plug type thing the diameter of the voice coil.

So the opening of the horn could be about 4" . Anyone know the cut off frequency for a 4" horn?

Paudio makes some good stuff I think....

[GM]

>I think Tannoys and some Altecs did this in the past. Some highly regarded drivers.
====
Altec did. AFAIK, all Tannoys just use the cone as the 'horn'.
====
>The rap against them I believe is that you get resonances from the areas between the back of the horn and the woofer cone.
====
Yes, that was one of their problems, but their later designs got around this by making a large enough horn to lower the XO point enough that it is not an issue and horn load the main cone to get the best blend in the XO BW: http://www.lansingheritage.org/html/...akers/9864.htm
====
>So the opening of the horn could be about 4" . Anyone know the cut off frequency for a 4" horn?
====
~13560"/pi/4" = ~1079 Hz, though its pathlength will determine the LF corner/roll off rate, with a 1/4WL considered to be the acceptable minimum.

GM