original crossover schematics for clone ATC SCM 100

I have got the XO from internet but I can't remember the site.
 

Attachments

  • atc scm50 scm100 crossover.gif
    atc scm50 scm100 crossover.gif
    9.2 KB · Views: 5,418
  • Like
Reactions: 1 user
TwangBar said:
Thanks for posting the xover. Would you happen to know if the mid is the 16 or 8 ohm version? I have an old pair of Proac Studio Towers which was their SCM50 take off - and they used the 16 ohm version of the mid.

Thanks.

Given the values of the components in the zobel and for the series inductor I would guess that it is the 8 Ohm version of the mid.
 
To my understanding the scm50 uses 8 ohm mid sm75 (s version). They are very expensive. Other than sensitivity, both are very high quality, have the same midrange purity and details. Very pleasing to ears.

I have had a pair of brand new 16 ohm of ( non s version of sm75-150 ). I wish to clone scm50 passive xo with different woofer & tweeter.

After being provoked reading the following old thread:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=27135&highlight=

i tempted to go with b2500. With massive magnets they look very high quality at least on par with sb75 or maybe better. Report mentioned it has well integrated with sm75 with slamm bass and very relealing on bad recording.

For tweeter i will use the famous ss revelator r2904/7000 because they are avalable in local shop, very expensive but still in a favourable with their discounted pricing.

I use lspcad for designing the xo (3 way passive).
 
Twangbar. Sorry for the slow respond. The project is still on developing stage - so it needs some time to run.

For woofer, finally i bought a pair of volt B2500 from solen. It costed around $800 a pair plus $250 shipping and $200 customs etc. Well quite expensive but i think its worth.

For tweeter, i realize R29.7000 here locally is still expensive at approx $800 a pair (discounted price), so for the budget sake i would change my mind on going with Seas Millenium T25CF002 or probably SS 9900. Can you advise which one is better?

So the configuration will be B2500 + SM75-150 (non s version 16 ohm) + T25CF002 (or SS 9900).

Cabinet will be tuned at 70L or so. Do you have such autocad design drawing with internal bracing (to follow to SCM50 model) ?> Thanks
 
Tamariska - Sounds like you are well on your way. I used the Seas T25C003 - which is what I think ATC uses. It is the the non-ferrofluid version so it is a bit more efficient (91 db).... and not too expensive! Harbeth also uses this model so it must be good eh?

As for the SCM50 box - as stated elsewhere, the "50" denotes it's volume in liters. Also, I think I have read the their box is not internally braced... but I could be wrong. I think also that it is stuffed with insulation... so it may act more like a larger box. Anyway, bracing in my mind is always good..... maybe use the golden ratio for determining position?

My (modified Proac Studio Tower) box using the ATC woofer is 65L and is braced. I modified it by building a new front baffle out of 3 layers of 3/4" MDF and put in one brace between the mid and the woofer. I'll try and post a picture.

Cheers,
Twangbar