Help/advice from ATC SCM40 owners past and present,please

From what I have read and researched these speakers sound like they could be just what I have been looking for, but up to the moment I have not heard them in the flesh. I just wanted to know from owners present/past how tolerant they are on room size and placement?
Our lounge is 3.5mx5.5m with lots of soft furnishing, solid floor and walls so a pretty well damped room, they would be used across the room with at least 1m clear of the corners but I would like to keep them as close as possible to the back wall, about 2.5-3.0m apart, seating distance being about the same, that’s my first question.

Second question is about my partnering equipment, is what I have now suitable as there seems to be a lot of talk of the power they require to get the best from them. I do like to listen at medium to high levels, I have wide musical tastes but no classical, choral or jazz anything else goes.

Thanks for taking the time to read this post, thanks in advance.

I had the SCM 40s in the same room dimensions but firing along the room rather than across. Absolutely beautiful, the speakers are also very tolerant to being close to the wall. Regarding the equipment, perhaps the 200 is a tad underpowered for the 40s ? I have the NAP 250 DR and sometimes I have the feeling that the speakers could be even better with a more powerful amp…

I have ATC SCM40s, but mine are active, so effectively they have over 240 wpc driving them. ATC’s minimal recommendation is 75 wpc and the NAP 200 power amp is 70 wpc. On specs alone, you’re on the margin, but some folk use them with a SuperNait, so a 202/200 setup might work, but ideally, you’d add a HiCap. When I heard them driven by a 250DR (and compared with a 300DR), I did think that for my musical tastes, I’d want at least a 250DR but a 300 would be preferable. My strong recommendation would be to audition at home if you possibly can and consider SCM 19s as well.

On room size, I think they’d work for you. My room is only a little larger than yours and I love them. They are closed box speakers, so less sensitive to room positioning than ported models. But they can still benefit from experimenting with placement. I started with mine firing across the room and ended up with them firing down the long dimension. But that’s partly driven by the way my lounge is furnished and where doors are located.

If there’s any chance of a home audition, that’s what I would do.



Like @PeakMan I also have the active versions of the SCM40s. I home demo’d the active and passive versions at the same time, with the passive versions driven by a SN2. I would have been perfectly happy with the passive setup, but preferred the active version which just gave a little more in terms of drive and grip on the music. The difference was there, but much less pronounced than I sometimes read from other people’s experiences. I’m sure a HiCap or a separate pre/power amp would close the gap to the passives and you also have a future upgrade path open to you. Stories about them being a difficult speaker to drive and needing huge amounts of power seem to be overdone from my experience.

On room size, I currently have them in a temporary room (4m x 3.5m) without much other furniture in there. I thought this might be a bit too much speaker for the space, but actually they work terrifically well. I’ve played around with their location and found them pretty accommodating, which I put down to the closed box design. Certainly less fussy then many other speakers I’ve tried.

The SCM40s excel with vocals, thanks to the famed mid driver. Overall, they just have a very balanced sound signature which I can only describe as just sounding right. When auditioning speakers from other brands I really struggled to get on with many of them. I felt like many of them were trying too hard (accentuated treble, shouty bass etc.) and whilst they perhaps sounded good when you first listened to them I found them wearing for longer listening sessions.

As @Peakman says, best thing is to try and get a home audition. Speakers are so personal and the room can make a big difference. Good luck with it.

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Many thanks for your response, hopefully the room will not be a no go area, positive feedback from other also seems to confirm this.
Seems the 200DR may not get the best from the 40’s but it sounds promising from a starting point, at least not totally out of the question.

Thanks Roger for your in depth reply, actives would not be totally out of the question, if you factor in the cost of upgrading the power amp against the straight cost of the actives compared to the passives the difference starts to look more acceptable, well relatively anyway.

The SCM 19’s where not really on my radar as they do not have that legendary mid range unit and from most accounts this is the making of the 40’s.That is the one area that is let down in my current PMC’s,as good as they are there are times when vocals are definitely compromised a little and as it is an area the ears are particularly sensitive too I would like to avoid that and vocals seem to be a strong point of the 40’s .

I understand the closed box design will help with room placement which is one advantage of the PMC transmission line, they are not as sensitive to room boundaries as many other designs.

Thing are starting to sound positive,thanks.

I moved from the PMC 25.23’s to ATC SCM40A’s in a 5.5 x 3.5 room, at first I thought the ATC’s would be too much, extensive home demo, but have worked out well, fantastic speakers, would recommend trying the actives.

Thanks Oxbow for your input much of which confirms PeakMan’s thoughts ,a HiCap is definitely on my list of upgrades but the actives could be an option but it would mean selling the 200DR and adding the trade in value of the PMC’s to help offset the additional cost of the actives, would I be right in thinking the 202 would work well with the actives?

Many thanks for all the very useful advice, I think I need to work out where my budget could be what with the sale of some equipment and the trade in value of others, then arrange to get a demo.

It is good to know the 40’s respond well to improvements at the front end which is a big benefit.

I think after reading all the advice I may indeed demo the passive and actives and see how I feel afterwards, again many thanks for taking the time to reply.

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It is a legendary midrange unit, yes. However, their new tweeter is a legend in the making, and you get it across the range. I wouldn’t discount the 19s, which should be easier to drive than the 40s. Additionally,
the 19s have an SL spec main driver. Neither the midrange or bass driver on the 40s are SL spec - you have to climb to the much more expensive 50s to obtain that treat.

I’m biased as I have 19s, but fronted with a 52/250 combo, my ears give out well before any signs of stress start to appear as the volume pot is turned up. In fact, I find quite the opposite, the Fidelity and realism of the music is just flat more palpable as you ask more from the 19s.

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I have my 40’s 0.7m from the corners, 2m apart and 11 cm from back wall. I only have a humble nova but it works well for me at the volume level I listen to. I would suggest trying it with the amp you already have first. This speakers are easier to drive than some folk realise, impedance remains level across the range making them an easier load.

I tried the 50’s and they were too much for my room. I tried both 40 passive and active and the actives were much better - sold a 300 & super lumina which pretty much covered the cost of the 40’s.

As others have said there is huge value in engaging a dealer and doing a home demo but based on your description I see no obvious reason why they wouldn’t work in your room.


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Hi Silverback
I’ve got similar room dimensions a Nap 200 and purchased ATC 40’s a couple of months ago.
I had the 19’s on loan for a few months before that, which sounded great - but the 40’s are noticeably better.
The Nap 200 is easily capable of driving the 40’s - however I’ve had a 250 dr on order since January - without auditioning, as I’ve always aspired to own one !
I wouldn’t hesitate to recommended you get the 40’s , you really wont regret it !

A price equation.

ATC SCM40 passive + NAP250DR =£8199.00

ATC SCM40A (active) =£7400.00 (plus necessary cabling/unbal-bal) transformers etc)

If you are happy with the 202/200 passive combination, job’s a good’un.

If not, I would suggest that the actives are the route to take, assuming you like their presentation.

Don’t forget the cost of speaker cable too that would be required if goi g passive.

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I assume the OP has already got NACA5 or equivalent, but sure, if you go for some more exotic cables the price could rocket.

Opinion suggests fancy XLRs are not needed I have read.

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I’ve owned 40, 40A and currently 50ASL. Active versions need more space to breath since they hit so much harder and bass reaches deeper. I used 40 passives with midrange Naim-setup (SN2 + HCDR) and while it sounded good back then, after moving to actives I realized how underpowered that setup was for the 40’s. 40A sounded like a different speaker compared to passive version. With passives I had zero problems with too mucb bass but with the actives the bass got slightly too much in my room back then. I think your room size should be ok for 40 + NAP200DR. If you decide to go for actives, the bass hits much deeper and with more power though.

Hi there ,

I’'m another happy member of the Active 40 club , they are wonderful speakers for sure and I have them in a room slightly larger than yours with no issues . I actually think I listen at lower volumes than before such is the grip of the Actives .

For a couple of years I had Passive ATC 19’s powered by a 250 DR amp which worked really well , I originally had a supernait 2 but the 250 made a substantial difference . It was then crystal clear to me that ATC respond well to more power . I sold most of that system when I moved out for renovations so it was easy for me to start afresh down the Active route which I haven’t once regretted .

In the perfect room I would always choose Active but with the Passives could potentially be tuned to your room with different amps . As others mention I’d start with a home demo of the Passives if possible . Of all the speaker brands (PMC , Neat ) I’ve owned ATC sealed box are the most room friendly here .

Incidentally I’m contemplating buying some Active 50s and went for a demo last week at the dealer I bought my 40s from . 4 years ago they offered a direct Active / passive 40s demonstration , they have since stopped doing this and sold the passive’s on as the vast majority chose Active .

Good luck with your search .

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I was surprised to find that I preferred both SCM40 and 50 passive over active. That was with a 300DR though, I can’t imagine reaching the same conclusion with a 200 or a Supernait.

Do not forget to take into account the 3rd dimension I.e. how high is your ceiling. The higher ceiling will enable more tolerance to a degree, with the speaker in a smaller room.

That was at the Acoustica show right ? ATC had 2 rooms IIRC , one with passive 50s on the end of a very nice high end Naim system playing Dark Side of the Moon very nicely while I was there .

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