CJD / Canaiolo / RS28a

[thejash]

Good day,

I build these http://www.divine-audio.com/canaiolo/ several years ago and use them almost daily, that being said...

Does anyone know if CJD is still active in the community? I would be curious to know if he, or someone else for that matter would be interested in revisiting those speakers and modifying the crossover to fit the new RST28A now that the original RS28a is no longer available. I unfortunately, have had bad luck with those original RS28a tweeters and just recently had one fail (glue joint on the diaphragm failed), might be salvageable. I thankfully had a spare but I went to order a replacement and that's when I realized it's no longer available. So if anyone has an extra RS28A or the replacement diaphragm's kicking about, i'm interested.

Thanks!

-Josh

[buggers]

There is No replacement for the RS28a tweeters, which means that a completely new crossover would have to be designed and that is very unlikely. Chris has not been active for some time.

[thejash]

Darn that is rather unfortunate. I have all the gear to take the proper measurements etc but I will be perfectly honest, it's been probably 10 years since I had all the gear setup and I find the task rather daunting at this point. Thankfully I'm okay for now but I guess I will really need to get lucky and source some RS28a's second hand.

[davidB]

If you built the design with separate boards for each driver, as did CJD, it does not have to be all that traumatic.

Put the board on top, put in a good RS, measure in place in your room, then try an RST. Some of the impedance corrections for the RS will not be needed, but should not hurt much for a first try.

Then try the RST with just a cap, say 10uf, to protect it.
Look at the level in the top two octaves. If it's reasonable, good. If not, try padding with a series resistor.
Measure again.

Now look at the crossover region- if there's a hump, move the point up, or go steeper.
If there's a dip move down. You are aiming for -6db at about 1500hz, but do not obsess about a number.


What you want is to duplicate the overall look of the measurement you got with the RS, with whatever oddities your room and measurement methods created.

If this goes well for you, great! If not, create the frd & zma files for a sim for both tweeters in the same physical setup, and either you or one of our resident sim wizards can design a filter just for you and your room. Doesn't get better than that!



Good luck, and, of course, if you are captured, the secretary etc., etc., etc.,.........

[thejash]

Thankfully everything is split into different boards and should hopefully be accessible. If it comes down to it, I guess I will have to do what I have to do, like I mentioned, after 10 years of not measuring or designing at all, the task is just daunting. Plus locating all the equipment at this point.. ugh lol. I have moved a few times between then and now so finding everything will be rather.. interesting. I do have time on my side though as i'm still up and running but considering how often they get used, I would rather be prepared then have to scramble.

[Chris Roemer]

i PM'd you - yesterday