DIY scm 200 crossover?

cafe latte

Member
2010-10-30 12:37 am
Hi Everyone,
I have a pair of modded Wilmslow atc scm 100's, with the correct tweeters, port length and I even scored a pair of sl bass units recently. Now I have my old non sl drivers sitting on the floor in the hifi room and the difference in sound is to be honest nothing. I am wondering what to do with these extra drivers, I thought about selling them, but that is boring :).
I was going to make some new cabinets for my Wilmslows the correct size, then I though why not go the whole hog and make new cabinets for the scm 200's :D:D
I just need port dimensions and the hard bit the correct crossover, any help anyone?
Cheers
Chris
 

billshurv

Member
Paid Member
2014-03-01 11:53 pm
You won't hear and difference between the bass units until it gets LOUD.

The 200s are active so you might as well do the same. Pick your poison (say miniDSP) and off you go. The crossover points you can get from the brochure (380Hz and 3.5KHz) I would bet money they are LR4.

Hope you are a long way from the neigbours! When finished that will pump some serious air.
 

cafe latte

Member
2010-10-30 12:37 am
You won't hear and difference between the bass units until it gets LOUD.

The 200s are active so you might as well do the same. Pick your poison (say miniDSP) and off you go. The crossover points you can get from the brochure (380Hz and 3.5KHz) I would bet money they are LR4.

Hope you are a long way from the neigbours! When finished that will pump some serious air.

I live on over 600 acres and my hifi room is purpose built with a soundproof air tight door my missus insisted on it :). I was hoping to use my existing amps I have a 185w mosfet heavly biased into class A ( I built) that I have been using on my scm 100 clones and sadly my very good friend had just died and left mt his CJ premier 4 another serious amp so I dont really want to go active as I have two great amps to use. The scm 100's are active and passive are the hifi versions of the scm200's only active?
Cheers
Chris
 

billshurv

Member
Paid Member
2014-03-01 11:53 pm
I live on over 600 acres and my hifi room is purpose built with a soundproof air tight door my missus insisted on it :).
You should be good to go then :)
I was hoping to use my existing amps I have a 185w mosfet heavly biased into class A ( I built) that I have been using on my scm 100 clones and sadly my very good friend had just died and left mt his CJ premier 4 another serious amp so I dont really want to go active as I have two great amps to use. The scm 100's are active and passive are the hifi versions of the scm200's only active?
Cheers
Chris

the 200s are only available active in either pro or tower designs http://atcloudspeakers.co.uk/hi-fi/loudspeakers/tower-series/scm200aslt/

So you have a challenge ahead, but if you do it as a 2.5 Way to compensate for baffle slope based on the 100 x-overs you have, then shouldn't be too hard to do.
 

cafe latte

Member
2010-10-30 12:37 am
You should be good to go then :)


the 200s are only available active in either pro or tower designs http://atcloudspeakers.co.uk/hi-fi/loudspeakers/tower-series/scm200aslt/

So you have a challenge ahead, but if you do it as a 2.5 Way to compensate for baffle slope based on the 100 x-overs you have, then shouldn't be too hard to do.

Not sure what you mean? Another option I could consider is build two sub woofers with the spare drivers, but if pos I would prefer just two speakers
Chris
 

billshurv

Member
Paid Member
2014-03-01 11:53 pm
Sorry. Often if you have 2 bass drivers then you do what is called a 2.5 way, where you roll in the second driver to compensate for baffle step loss. In your case as it's a 3-way, it would be a 3.5 way. Zaph|Audio - ZDT3.5 gives a good description, although in your case you can handle waaay more power.

To put it another way, the extra bass unit gives you 3dB more bass, so you have to attentuate mid and high by 3db less. which means it'll go louder with your existing amps as well as being able to handle twice the peak power.
 
I can't seem to find the particular thread on gearslutz now but there is one where several people claim that SL drivers are worthwhile upgrading and "so much better".

Is anyone around here aware of what's the technically difference between SL and non-SL ATC woofers?
They are spoken to have a THD drop of -15 to -35dB but whats different?
The membrane? The coating? The magnet?