I've always been a huge fan of ATC monitors, and every time I get to work on a pair it's an absolute pleasure. As a listener, I always notice new sounds in my favorite songs, often unheard on other monitors or headphones. As an engineer, my mixes translate great on the first pass to any listening environment, and the client is always extremely happy.
While demoing the ATC SCM45a, I got goosebumps multiple times from how amazing the songs were sounding through these speakers. There is a magic that happens in the higher frequencies of ATCs that no other speaker in its class can quite compete with. Without any DSP, they are very airy, crystal clear and pleasant sounding even at extreme monitoring levels, resulting in very little fatigue after long listening or mix sessions. The low end is always very tight and focused, even in the sub frequencies, and the speakers can be extremely loud with barely any noticeable distortion.
The SCM45a has taken ATC's old three-way speaker design to the next level. They are designed with a Tri-AmpPack, allowing each frequency driver to have its own amplifier. All frequency ranges have continuous power loads, with 150 Watts going to the low drivers, 60 Watts going to the mid driver, and 25 Watts going to the high-frequency driver. The SCM45a is perfectly symmetrical layout design, not mirror imaged, so an extra speaker makes for easy LCR set ups. Due to “unique to ATC” 3" midrange dome design, you get a much wider sweet spot for the listener, making for a wider working area.
Compared to the ATC SCM25A, the new design of the 45 makes room for a second 6.5" low-frequency driver. By splitting the low-frequency load to two speakers, less stress is put on a single driver, and greatly reduces the non-linear distortion from 20Hz - 380Hz. This also lowers low-frequency response down to 42Hz increases total output of the single woofer brother ATC 25 by 3dB. This helps the 45 play louder longer, and keep the entire frequency spectrum sounding crystal clear, even on a song with a lot of power in the low end, which is usually what begins to overload your speakers.
The SCM45a is the second ATC speaker to include the new in-house built high-performance SH25-76S dual-suspension tweeter. As I mentioned earlier, I've always considered ATCs to have incredible top end, but I was completely blown away by the improvement on the SCM45a using this new tweeter. The stereo image was very wide, but also had a tight focused center.
When listening to tracks by Adele or Sam Smith, I could really hear the finest details of their voice, the reverbs and delays were wide and airy, and the high-frequencies never felt like they were attacking my ears. All complimented by a powerful, focused, low end, and mid-range that kept the SCM45a sounding powerful even at low listening levels.
The low end response was also absolutely amazing. I went through multiple genres of music to put this to the test. I started with some classic rock style music, which typically doesn't have that much low end information. Tracks like "Every Breath You Take" by The Police" or "Thriller" by Michael Jackson always seemed to be a little thin in the kick drum frequencies, but that's not the case with the SCM45a. Right off the bat, I was impressed by how tight and punchy the kick drum was, but also had more depth in the sub frequencies then I'm used to hearing.
With SCM45a, you have some low-frequency compensation to adjust for half or full space operation. This compensation adds up to 3dB around 40Hz. When I dialed in more boost, it brought whole new life to the tracks I was never able to hear, and didn't diminish the original integrity of the mix. The Bass Boost is accessible through an access hole on the rear panel of the SCM45a, adjustable with a small flat plastic trimmer tool. Do not use a metal screwdriver, for the pressure of the metal blade can damage the circuit board trimmer. User note: Returning the bass boost to flat restores the factory speaker calibration.
Other comparably priced options that are equally worth considering are the Barefoot Sound MM26, Kii Three Pro, and PMC IB1S-AIII. Amongst these options, the ATC's strengths are its very well defined and accurate midrange presentation, which is largely due to their wonderful proprietary in-house built midrange dome driver. On the flip side, ATC favors midrange accuracy over low-frequency elements of a mix that are more present with the Barefoot or PMC options, which both have massive low-frequency extension.
The footprint of the ATCs is rather large for a nearfield speaker, so they may not integrate well into a small room. Look at the ATC SCM25A for a smaller footprint or the Kii Threes, an option for small rooms since they pack a lot of high-quality bang in an exceptionally compact package. Priced at $11,500 a pair, they are worth every penny. They exceeded expectations on everything I put through them, from classical, rap, Motown, pop, rock, folk to country.
To hear the ATC SCM45a in person, Vintage King has demo sets of these speakers in both our Nashville and Los Angeles showrooms. If you'd like to learn more about the monitors but aren't close to either of our showrooms, please contact your Vintage King Audio Consultant by email or phone at 888.653.1184.