Intro
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At Alpha-Audio, we have already reviewed a number of ATC products, but somehow the SCM20A slipped through the Alpha-Audio net. Finally, we have had this popular studio monitor in the studio for a while, and here are the results.
In 1974, pianist and jazz lover Billy Woodman started ATC as a manufacturer of loudspeaker drivers. First in the PA market (live concerts), gradually moving more and more into studios. The 3-inch mid-range driver SM75-150 saw the light of day in 1976, a so-called ‘soft dome mid driver’. Its great success led to the first loudspeaker in 1979, the S50, and about 10 years later the active version of this was released, the SCM-50A. As with so many ATC products, the SCM50A is still in production, as is the preamplifier SCA2 that we previously reviewed. In many areas of studio monitoring, ATC offers reference products in the top of the market.
ATC SCM20A
The SCM20A was introduced in 1990. The abbreviations with which the model was subsequently labelled tell us something about its iterations. SL refers to the upgrade of the bass driver in 1996, the mk2 marked the new high driver in 2014. In terms of technology and casing, the SCM20A is comparable to the passive SCM19 V2, the consumer model that colleague Geoffrey reviewed. The SCM20A is ATC’s ‘entry-level’ model. With active speakers, it is always good to remember that it is an ‘all-inclusive’ package. Amplifier, drivers, filters, speaker cables; it’s all there. Just connect a good source with a volume control and you’re ready to listen to the music.
The SCM20A is a 2-way active speaker with a 6.5 inch/150mm mid/low driver and a 1 inch/2.5mm high driver, developed by ATC itself, of course. The crossover frequency is 2,100 Hz. A bi-amp amplifier delivers 200W to the mid/bass driver and 50W to the high frequency driver. Sound pressure level (SPL) is 108 dB at a distance of 1 metre.
It is a closed system and the cabinet is very solid, rigid and heavy, weighing 23.5kg. We have rarely had to lift a monitor of a relatively modest size (45x25x29cm) with such a high ‘specific gravity’ into place! On the back we see a bass boost control, an input sensitivity adjustment and an XLR input. Above that are the amplifier’s cooling fins. The back is also equipped with two metal brackets that protect the electronics and connections and also serve as handles.
Hi Yung,
I have been following you guys for some time and I would just like to say, thank you for your work here and sharing your reviews and comparisons. You are just about the only group who actually compares like products in a systematic manner. As a former HiFi dealer, we used to take great care in not only comparing products in the evaluation for what to carry in the store but we went to great lengths to find proper combinations of components etc. It is a sad situation that this is just simply not done for the most part in the majority of the market. Publications, be it in print or on-line nor dealers take the time for the most part. So, thank you for that effort. It takes time and dedicated effort and it is very much appreciated.
I am curious how you would compare the ATC SCM 20A to that of the equivalent monitor in the PSI line? Also, in the ATC passive line up, how would you characterize the differences between the SCM 12 Pro and SCM 20 Pro?
Thanks, again….Best regards….John
Hi John,
Thanks so much for your kind words! We strive to do just as you mention; to be as transparent as possible in sharing what we hear and experience. And yes, to compare it with like products (which is not always what all manufacturers want). Let’s just say that the brands we are reviewing here are confident to be compared with other models, and have confidence in our methods.
On your question: I have only listened to PSI monitors on a factory visit and at PSI/Weiss booths during hifi shows. The PSU A21-M is also a 2-way active speaker, the crossover frequency is at 2.4 kHz. I was really impressed by the larger model, the PSI A25-M. A three-way system, midfield. You should compare therse two if you want a serious shoot out. I would say, based on my memory, that PSI sounds a little more ‘hifi’ than ATC. This is also due to the bass reflex topology of PSI whereas ATC is a closed speaker. The ATC SCM20A is almost twice the weight of the PSI A21-M, which says something about the inertia of the speaker casing. But both brands are a pleasure to listen to. No listening fatigue, very accurate and fast.
On the passive ATC monitors: I have not listened closely to these yet. In general, you will need very good amplification for these speakers and since this has already been done by ATC in the active models, we think the price/quality ratio is in favour of the latter category. Unless you already have very beefy and precise amps, look for the active models.
Yung,
Thanks for the prompt response and your perspective. In these days of pay to play by the manufacturers and distributers, it is a breath of fresh air to read and hear via your YouTube group reviews. You guys are doing a great job and approach things from a clean slate. That is commendable. Thank you, once again.
Best regards….John
ATC SCM 20A Pro. You wrote under Cons:
“Everything is audible
Poorly mixed tracks are mercilessly exposed”
Aren’t those the point for a Pro studio speaker?
Yes, you are right that this is the point to pro monitor speakers.
Nevertheless, you would be surprised how many of these speakers perform differently compared to the ATC SCM20A.
We have reviewed quite some professional monitors, please read these and this review. The list of pros and cons does not cover the full story.
Happy reading!