ATC SCM 40 question


I recently bought a pair of ATC SCM40 speakers. I have them placed in a room approx 12ft sq. They are on the back wall, seating on opposite side. I can't move the speakers into the room or move the chairs into the room as I barely got away with buying these and can't encrouch any further, the missus was not happy at the size of them!

Anyway, they sound pretty incredible a lot of the time, but I've noticed on some recordings, not necessarily bad ones, just they can come across a little shrill and sharp, like the highs are overheated somehow.

I'm driving them with a PS Audio S300 Poweramp, that is being controlled by an RME ADI 2 DAC. 

I've tried messing with the dsp settings on the RME but I just can't seem to ease the issue.

My question is, does this seem like an equipment issue? Or maybe a cable issue?

I don't want to end up spending serious cash upgrading the amp or dac if that is not the problem. But I know the SCM40's need a lot of juice and the S300 only has 140w per channel, and the recommended is 150w. Or is that just a top end volume concern? I'm already looking at the Hegel H20, I can't get the ATC poweramp as I don't have the space for it.

Also I was looking at the Anthem STR Preamp. Something that might calibrate the sound better for the room. Maybe a cable upgrade?

Anyway, these are just my rambling thoughts on an ongoing issue, any advice at all would be much appreciated. I really want to solve this as when these speakers sing, they really sing!



Are these new or the original version?  I don’t think driving your amp with the RME DAC is doing you any favors here so you might entertain adding a good preamp, and it’d be good to know what cables/interconnects you’re using.  Do you have a carpet on the floor?  Also, you could try to tame first reflections on side walls and maybe try putting some felt around the tweeters.  Just some thoughts FWIW. 


I know the feeling. Bought the SCM19v2, as that was all that was allowed.

You're right, they do like a bit of power to really let loose.

Were the SCM40s new? How long have you broken them in for?

Thanks for the replies everyone!

@jerrybj Yeah I was in the doghouse for a while. I went with the forgiveness over permission tactic, just about worked!

To answer the questions:

Brand new SCM40's. I've had them for about four weeks now. I listen everyday but have not done any specific 'burn in' process.

Chord Shawline X Speaker Cable

Chord Shawline Analogue XLR Cable 

Supra USB Cable

I'm sorry to hear the RME might be inadequate, I had thought it a perfect solution and would leave the PS Audio S300 to do all the work. So the preamp is still important even with a power amp in the chain? That leaves me in a quandry as I've got space constraints. The preamp can not be taller than 12 cm, and must also incorporate a high end DAC. Any recommends would be appreciated. I thought about the Anthem STR but I'm a bit put off by the dac chip apparently not being the best. 

As I say, this system is almost perfection, with the right recording that doesn't tickle the high end too much, the speakers sound unbelievable. Stick on a bit of Gordon Lightfoot, beautiful.


I'm steering towards the Sablon 2020 usb cable but fear it mightt be overkill.




I love my ATCs. End game speakers for me.

I ran mine in for 150 hours when I got them. Had them on loop when I went to work, dodging people at home.

I used to have QED Silver Anniversary speakers cables. Very bright. Have you considered the silver plated Shawline could be adding that sharpness?

I've built my system based on limited space. A cupboard 600x550x420mm with four shelves, including Blu-Ray player. System has to be hidden from sight, with no 'ugly' cables.

I use the Mad Scientist Black Magic USB cable. Very good.