Single wiring ATC SCM11 v2

Posted by: alanbass1 on 24 September 2017

I have been using my NACA5 jumpers since I got my ATCs and always had in my mind what improvements SL jumpers might bring.  I was thinking of taking the plunge but curiosity got the better of me and I unscrewed the six bolts that attached the speaker terminal plate to the speaker cabinet and to my delight saw that there were spade connectors  on the wires each bolted to the rear of the speaker terminals  - one wire to each.  A simple job of removing the bolts from each terminal and attaching the HF and LF spade connectors to the same speaker terminal.  ATC use thread lock so the bolts are resistive to coming off, and once I bolted everything tight I reapplied some threadlock to keep them secure.

The main thing is the sound and I can state that stereo imaging is more precise and high frequencies sound 'cleaner' if that makes sense. Overall 30 minutes well spent and a potential £600 saved!

Posted on: 24 September 2017 by Perol

Exactly

Biwire are decades of bluff and jumpers can only be worse than nothing

 

 

Posted on: 25 September 2017 by Fergi

Why not remove the spade terminals, a big difference when I removed the spades on my Quad 21l2 and soldered direct. Tighter base, noise floor lowered, cleaner voices better diction.

Cheers. 

Posted on: 25 September 2017 by Fergi

Don't use jumpers to bi-wire, just remove insulation, and push through the first plug +ve and tighten then attach to the second -ve, i.e. no joints, always good for reducing the noise floor.

Cheers

Posted on: 25 September 2017 by alanbass1
Fergi posted:

Don't use jumpers to bi-wire, just remove insulation, and push through the first plug +ve and tighten then attach to the second -ve, i.e. no joints, always good for reducing the noise floor.

Cheers

Not keen on stripping back my SL

Posted on: 25 September 2017 by hungryhalibut

I think Fergi is talking at cross purposes, when you have resolved the issue by changes inside the speaker. What surprises me is that ATC use push-on connectors rather than soldering wires directly to the back of the speaker terminals on the crossover. Maybe I've misread something. Biwire terminals are the work of the devil. 

Posted on: 25 September 2017 by alanbass1
Fergi posted:

Why not remove the spade terminals, a big difference when I removed the spades on my Quad 21l2 and soldered direct. Tighter base, noise floor lowered, cleaner voices better diction.

Cheers. 

Unfortunately there are no suitable solder points to the rear of the speaker terminals. They use a bolt mechanism to attached to the rear plate and the spades are sandwiched between this which the speaker wire is connected to with lugs. I have cut off the lugs and directly soldered to the spade connectors

Posted on: 25 September 2017 by alanbass1
Hungryhalibut posted:

I think Fergi is talking at cross purposes, when you have resolved the issue by changes inside the speaker. What surprises me is that ATC use push-on connectors rather than soldering wires directly to the back of the speaker terminals on the crossover. Maybe I've misread something. Biwire terminals are the work of the devil. 

You haven't misread and that is exactly what ATC did. I'm considering changing the terminals for a set of WBT terminals - are there others I should consider?

Posted on: 25 September 2017 by Huge
Fergi posted:

Don't use jumpers to bi-wire, just remove insulation, and push through the first plug +ve and tighten then attach to the second -ve, i.e. no joints, always good for reducing the noise floor.

Cheers

Connecting the speakers using the bare speaker wire is a BAD idea.  Copper oxidises readily in air and soon you'll have a very poor contact from the wire to the terminal post.

Much better to use 4mm plugs with a similar plating material to the socket.