Dear members,

I have almost decided to buy ATC SCM150ASLT. But before investing big ammount, I still need to answer few questions. I will be very thankfull if you can answer some or all of them. There is no possibility to audition in my country, so I will need to take some risks and order anyway. Also local dealers usually know less and just care about selling more gear for more money. I would really appreciate that.

I am still a beginner in hi-fi world and this will be my first big system. I own near field monitors Genelec 8351, which I like. But I already want an improvement and I am looking for the big sound.

I mainly listen to electronic music, also ambient, down-tempo, nu-disco and etc. My music often inludes some instruments and vocals. I do not listen cheap mainstream EDM. I only occasionally listen to other genres like rock/jazz/blues/pop/rap and etc.

Few tracks to get an idea:



Question 1 - Models.

Do I correctly understand, that all these models sound totally the same? SCM150ASL Pro, SCM150ASL and SCM150ASLT. Difference is only in cabinet finishes and added accessories (grills, stands)?


Question 2. Room.

Speakers will be in a summer wooden frame-house. Made from 15 cm. glasswool inside and some drywall. Room has two big windows from floor to ceilings. Room dimensions is around 5-6 m. x 8 meters. Ceiling height moving from 2.4 to 2.8 m. I will ask for professional acoustician to treat my room after we install speakers. At least primary reflections and solve biggest room issues if we find any.

  • Is my room large enough for ATC SCM150ASLT? What is the smallest room recommended?
  • I have attached my room plan. How far from side walls and rear wall I shoul place the speakers? Is my plan good?
  • Speakers will stand in front of glass wall. I know it is not good. But still usable? What problems I may face and if it will be possible to solve them?

I understand , that nobody can guarantee the sound quality in a specific room. But I just need your guidelines if you have any.


Question 3. Pre-amp and DAC.

I will be listening only to digital files through my computer. Maybe I will add vinyls/cd and streamer after few years, when I will have extra budget.

My goal now is to get maximum out of my speakers, with buying least needed boxes, but best quality, so they match my speaker quality and price range. I do not understand if I need pre-amp and if it affects sound quality.

Please help me to get right strategy what to buy now, and what I can upgrade later. And how big adding better dac or pre-amp affects overall sound quality.

So questions are:

  • Can I just buy best I can afford pure DAC (with analogue sound level control) and go straight to my active speakers (so there is no pre-amp in my system at all)?
  • Or I need DAC, not pure, with some kind pre-amp funkcionality?
  • Or I need to buy pre-amp and Dac (separate boxes)? Would that improve sound quality a lot, because of pre-amp in the system?
  • Or I should better buy best DAC I can and add pre-amp later? Or otherwise - I should buy now best pre-amp and simple DAC, which I can upgrade later?

If I am getting it right, I do not need a pre-amp now, if I play only digital files from my computer. I should now buy best pure DAC I can and which matches my system’s quality and price range, am I correct? Later on I could add pre-amp (I would choose ATC SCA2 pre-amp for brand synergy), which would improve sound quality just a little bit, but I could add vinyls also. Is that correct?

If yes, could you give reccommendations for pure DAC, that are known for good synergy with ATC? Which model could be good match for my system in terms of quality and price range? Should I invest in DAC like 5-10k.€ to get most of my speakers?


Question 4. Updates.

ATC models have been updated quite long ago. And ATC 50 year aniversary is coming next year. Would it be wise from my side to wait till let’s say Munich Hi-Fi Show to see if there are any big news from ATC? 

I would be very sad to buy my first big system and find out that it was updated just few months later…


Question 5. Audition SCM150ASLT.

Do you know any place in upper part of Europe like Poland, Germany, Scandinavian countries, where I could go and audition ATC SCM150 model? I would fly there to listen before buying.


I will be very very very thankful for all your answers 🙏





1) Yes they sound the same but there are differences in how a ASL monitor and ASLtower sound due to stands used on the ASL. If its sound anchors, the sound would be the same or better on the monitors. If its wooden stands, the towers would be better.

2). Is this room you will have some challenges in that the surfaces on the first reflection points (side walls) are different. There are many solutions but be aware that it’s the differences in surfaces that are the biggest challenge to creating a strong image off axis response (off axis is an ATC strength). Different surfaces reflect different frequencies and reflect them differently in response. In other words, getting off axis reflections to be "the same" as on axis is the way to ideal imaging.

Consider the TV wall; you would need to decrease the triangle size, the couch would need to be closer, but it could turn out better if heavily treated. It may be easier to achieve consistency in this position than that large glass surface on one side and the broken wall on the other. Be willing to try this or at least consider it (I have no idea which one will actually turn out to be better, there are so many variables, but it is important to try different approaches and listen. SO my advice is tell your acoustician to treat the room for both positions). General advice is the further from side walls the better (reducing reflections), but there are SO many other factors.

3) Everything affects sound quality. Consider the 150 a platform to work from and you will hear differences in absolutely everything- preamps, cables, cartridges, turntables, etc. It’s what makes active fun I think, as the transparency is so high that differences in things upstream are easily identifiable. What is the "right" place to start is a really big question that may have more to do with your budget. ATC favors analog, so the SCA2 is pure discrete analog. The newer CDA2 preamp/DAC/CD player could be a place to begin knowing you will move this off to a smaller system later. You will have many other issues that occupy your set up phase which could last a while. But to be fair, a zillion other preamps/DACs would also work. To begin, I would avoid a high color preamp or DAC. GO for transparent and neutral to begin. The handling of inputs properly will be something that matters over time, as it affects you in the operation of the system more than the exact listening to it. As you evolve and the industry evolves and you WILL want other devices in the future. Having more than one input, even if it’s analog, would be handy. I would start with a preamp DAC or Preamp + DAC pairing treating the computer is just one input on the system.

4) There are no changes coming to the 150 in the next year or two. Changes come slowly at ATC as between product development in consumer and pro they have a lot going on at any given time. Subwoofers are the current project, as you can see from the C4 introduction.

Have you considered the existing SE150? This uses the ATC discrete amp package and is the best audio (highest resolution) ATC offers at the moment.

5) Why not fly to ATC in England and audition there?


ATC US importer

(Consumer and Pro)


@audioslave1561 Nice writeup.

I have two friends that drive their ASLTs (50s in one case and 100s in another) directly with a Weiss DAC501 (in both cases wired ethernet directly in as I do with my 501). I agree; these clean, minimal systems like yours can sound spectacular.

"These puppies need a little room to really sing IMHO." Well said. That's why I downsized from 100s in my room. Those 100s were sold to the friend mentioned above. She has a very large room and they sound spectacular, much better than they did in my room.

"When listening to strings or vocals this set up can be quite cold and clinical when streaming." IMHO, this sounds like a network and/or AC optimization issue to me. I would optimize these (plenty of good threads on that here on Audiogon) before adding a line stage or any kind.

I had an exchange with a previous ATC importer (Keogh?) and he told me that the 50 was the most accurate.  As woofer size increases the top of the pass band is more directional and results in a less accurate frequency response.  He said this wasn't unpleasant but if you wanted the most accurate speaker go with the 50.  

I've often wondered why ATC doesn't have a consumer 110.  It's the most consumer friendly design to have.  Why have the 200 and 300 towers but not an equivalent 100/110?

Pat Keogh was a US dealer with us for ATC in the NE. He’s inactive now but was a strong supporter for many years. Its not exactly true the 50s are more accurate, but it was the founder’s favorite model and over the years one of ATC’s best sellers. Ive sold them to folks like Tom Petty, James Guthrie (pink floyd) and quite a few mastering engineers. Its our least expensive high dynamic range 3 way.

What Pat was talking about was narowing of dispersion behavior of all cone drivers as frequency increases- this is a true. H. owever, ATC crosses over from a woofer to a midrange driver at 380Hz, extremely low for a 3 way. This is well below the frequency of significant performance degrading HF narrowing. This is a more relevant criticism of a larger cone woofer 2 way, say something like a 8" or larger 2 way. 2 ways typcailly cross much higher, as dome tweeters do poorly below 2K. From 1K to 2K there is significant narrowing of a cone woofer.

In horn loaded systems, the rules are different. Now dispersion is determined by physics, throat size and horn mouth size and design. So the net result is that narrowing at HF is still present in horns/driver combos, and it can be somewhat severe in older horn designs (its why multi cells were invented to try and create lots of small dispersion lobes instead of one big one). Bob Keil did a lot of research on this for multiple audio companies a long time ago and is credited with developing the entire constant directivity design approach (which helped raise the narrowing frequency quite a bit and improve fidelity of horns a lot).



"I think the ATC are way overkill for PC streaming electronic music...." 

Most definitely!  You don't need one of the best speakers available, unless you're wanting to reproduce the real, live sound of the best classical, jazz, blues, piano, strings, brass, vocals.  

I only wish I could justify the investment required for the ATC 150's!