ATC speakers / Monitors

[Atc4ever]

Learning to read speaker measurements takes years, not just the curves, but the limits of the research behind them, and how the numbers map onto what you actually hear in a room. What it buys you is prediction. Over time you get better at hearing a speaker's measurements and knowing how it'll sound, both on its own and in a given room. The predictions are never perfect but they land within 80-90% of how the speaker actually sounds, and that's enough to work with. If the measurements predict well and a real listen confirms it, that's enough to buy.

This is why I trust it over 'just listening.' The same speaker can sound more different in two rooms than two speakers do in one, so 'what I liked' and 'what the room did' have to be pulled apart and without audio science you can't. A wide dispersion speaker in a narrow room sounds muddy and echoey, but that's the room piling on early reflections, not the speaker distorting(IMD), even though the two color the sound almost the same way. The science teaches you those signatures: a low ceiling, a deep room, a reflective front wall each color sound differently, and all of them differ from IMD or distortion or just "bad drivers". Once you can hear the difference, you can subtract the room and judge the speaker on its own which is exactly what makes the prediction possible.

Being able to use predictions is probably a powerful tool in the situations you described.
But let me explain why prediction does not work for me.
Last time I went to dealer and bought brand new component was some 20 years ago. Since then I am focused on second hand market. And from many reasons, mostly financial but also because of inability of local dealers to offer some more serious stuff.
When you buy second hand, you have possibility to see and hear component at seller's place but also often at your own home, and that would be the best way to evaluate a component, if you agree.
So, I do not have to predict, I am already there, with component at my disposal.

 

[Atc4ever]

In a proffesional control room, you often have an exceptionally well treated room which is measured with the speakers, and engineers are not only listening to music but work with various elements of music production through the monitors. This goes beyond just listening and reading speaker measurements.

Once I was at a music school waiting for my daughter to finish a lesson. The music school also had a studio where music production was taught and I sat and waited in front of that studio. The professor who taught that course also came by, he had a break, so we got into a casual conversation. I told him that I had never been to a music studio and he kindly offered to show me around. We entered the control room. All the walls were irregularly shaped, the ceiling was made up of multiple sections, at different angles, everything was matte black. I felt like I was in some futuristic movie.
The speakers caught my attention. They were krk rokit 8 active, a fairly inexpensive studio monitors. They were placed horizontally on a very high (about 1,2m) and extremely massive metal stands.
But what completely shocked me was the sound that came out of them. The professor played some funky music.
Never before I heard a music reproduction that was so alive and dynamic, utterly like a real, live music. Dynamics was staggering. Never heard drums so realistic. The sound was incredibly clear, powerful and REAL.
On my comment that monitors are excellent, professor said : they are ok, just the tweeters frequently go dead, so I have to change them regulary, I have a full box of spare tweeters...(!)
The bottom line was that my expensive audiophile system sounded like a toy compared to this.
This, and some other experiences, was the turning point in my hifi hobby.
Over time, I increasingly abandoned the hard core audiophile approach to sound and equipment in favour of pro amps and speakers and the sound alike.

 

[RedVikingHood]

Once I was at a music school waiting for my daughter to finish a lesson. The music school also had a studio where music production was taught and I sat and waited in front of that studio. The professor who taught that course also came by, he had a break, so we got into a casual conversation. I told him that I had never been to a music studio and he kindly offered to show me around. We entered the control room. All the walls were irregularly shaped, the ceiling was made up of multiple sections, at different angles, everything was matte black. I felt like I was in some futuristic movie.
The speakers caught my attention. They were krk rokit 8 active, a fairly inexpensive studio monitors. They were placed horizontally on a very high (about 1,2m) and extremely massive metal stands.
But what completely shocked me was the sound that came out of them. The professor played some funky music.
Never before I heard a music reproduction that was so alive and dynamic, utterly like a real, live music. Dynamics was staggering. Never heard drums so realistic. The sound was incredibly clear, powerful and REAL.
On my comment that monitors are excellent, professor said : they are ok, just the tweeters frequently go dead, so I have to change them regulary, I have a full box of spare tweeters...(!)
The bottom line was that my expensive audiophile system sounded like a toy compared to this.
This, and some other experiences, was the turning point in my hifi hobby.
Over time, I increasingly abandoned the hard core audiophile approach to sound and equipment in favour of pro amps and speakers and the sound alike.

I will take budget near-field monitors in a treated room over a $10 000 system in an untreated room set up in the mid-far field.

 

[goat76]

I couldn’t resist a good deal on these beauties. A pair of ATC SCM20 Classic.

@DSJR. No, they are not the active model.
@dfuller. No, they are not the studio version with curved edges for reduced edge diffraction.
@Gregg Hermetech. Yes, I had my eyes on these, which is why I asked you earlier this week why you prefer the SCM20 over the SCM25 and SCM40.


My first subjective impression when setting them up yesterday wasn't very good; they sounded thin and nasal, and the center-panned vocal tracks sounded too distant and unnatural. I immediately thought I had made a big mistake buying these speakers.
But it didn't take me long to realize that the SCM20s don't work with the same toe-in setup as the SCM40s. While I have found that the 40s work best with a toe-in that crosses the axis around 20-30 centimeters behind the listening position, the 20s work better with way less toe-in, and at the current position (work in process), the axis crosses somewhere around 130-140 centimeters behind the listening position. This change makes these speakers sound really good. Puh!

I will continue fine-tuning the positioning of these loudspeakers and the integration with my subwoofers before I say too much. Still, my initial first impression after just a few hours listening is that they might have the edge over my beloved SCM40s.
Let's see when I find the time to make some measurements of them.

 

[dfuller]

I couldn’t resist a good deal on these beauties. A pair of ATC SCM20 Classic.

@DSJR. No, they are not the active model.
@dfuller. No, they are not the studio version with curved edges for reduced edge diffraction.
@Gregg Hermetech. Yes, I had my eyes on these, which is why I asked you earlier this week why you prefer the SCM20 over the SCM25 and SCM40.


My first subjective impression when setting them up yesterday wasn't very good; they sounded thin and nasal, and the center-panned vocal tracks sounded too distant and unnatural. I immediately thought I had made a big mistake buying these speakers.
But it didn't take me long to realize that the SCM20s don't work with the same toe-in setup as the SCM40s. While I have found that the 40s work best with a toe-in that crosses the axis around 20-30 centimeters behind the listening position, the 20s work better with way less toe-in, and at the current position (work in process), the axis crosses somewhere around 130-140 centimeters behind the listening position. This change makes these speakers sound really good. Puh!

I will continue fine-tuning the positioning of these loudspeakers and the integration with my subwoofers before I say too much. Still, my initial first impression after just a few hours listening is that they might have the edge over my beloved SCM40s.
Let's see when I find the time to make some measurements of them.


View attachment 538817

I'm curious to see if these show the same mid-rise as the SCM19s.

(Also wonder if this is something they'd "fix" with NFS data... might not be fixable via XO, might just be a driver quirk)

 

[goat76]

I'm curious to see if these show the same mid-rise as the SCM19s.

(Also wonder if this is something they'd "fix" with NFS data... might not be fixable via XO, might just be a driver quirk)

Except the different cabinets between the SCM19v2 and the latest version of SCM20 Classic, ATC uses their S-spec tweeter in the 20s with the crossover point at 2.2 kHz, while they have the crossover point at 2.5 kHz for their none-S-spec tweeter in the 19s.

Another small difference is that the SCM19v2 is specified to reach down to 54 Hz, while the 20s are specified to 55 Hz.

When I get to measure my SCM20s, I will make sure I place the microphone right at the height of the loudspeakers acoustic center, which is exactly 277.3 millimeters from the bottom of the cabinet for the passive version of this speaker. (The acoustic axis is 287 millimeters from the bottom for the active version.)

 

[thewas]

When I get to measure my SCM20s, I will make sure I place the microphone right at the height of the loudspeakers acoustic center, which is exactly 277.3 millimeters from the bottom of the cabinet

Could you maybe also make a couple of vertical measurements, like plus minus 10 and 20 degrees?

 

[goat76]

Could you maybe also make a couple of vertical measurements, like plus minus 10 and 20 degrees?

Do you have any suggestions how I could do a vertical measurement in a reliable way, without introducing too many new variables caused by moving the microphone?

Horizontal measurement are much easier to do, as I don’t have to move the position of the microphone at all. I use markings on the floor and just turn the loudspeaker 10° at a time.

EDIT: I can probably lay the speaker on its side on the stand.

 

[Soniclife]

Do you have any suggestions how I could do a vertical measurement in a reliable way, without introducing too many new variables caused by moving the microphone?

Horizontal measurement are much easier to do, as I don’t have to move the position of the microphone at all. I use markings on the floor and just turn the loudspeaker 10° at a time.

EDIT: I can probably lay the speaker on its side on the stand.

You put the speaker on it's side and move it horizontally, angle between the speaker and the mic is the same as moving the mic up and down. Easy to do with a nice box shaped small speaker.

 

[goat76]

You put the speaker on it's side and move it horizontally, angle between the speaker and the mic is the same as moving the mic up and down. Easy to do with a nice box shaped small speaker.

Yes, I realized that after writing my post. You probably missed my edit.

I couldn’t do that with the SCM11 because of the curved cabinet.

 

[Soniclife]

You probably missed my edit.

Yep. I Will be interested in the results.

 

[DSJR]

I couldn’t resist a good deal on these beauties. A pair of ATC SCM20 Classic.

@DSJR. No, they are not the active model.
@dfuller. No, they are not the studio version with curved edges for reduced edge diffraction.
@Gregg Hermetech. Yes, I had my eyes on these, which is why I asked you earlier this week why you prefer the SCM20 over the SCM25 and SCM40.


My first subjective impression when setting them up yesterday wasn't very good; they sounded thin and nasal, and the center-panned vocal tracks sounded too distant and unnatural. I immediately thought I had made a big mistake buying these speakers.
But it didn't take me long to realize that the SCM20s don't work with the same toe-in setup as the SCM40s. While I have found that the 40s work best with a toe-in that crosses the axis around 20-30 centimeters behind the listening position, the 20s work better with way less toe-in, and at the current position (work in process), the axis crosses somewhere around 130-140 centimeters behind the listening position. This change makes these speakers sound really good. Puh!

I will continue fine-tuning the positioning of these loudspeakers and the integration with my subwoofers before I say too much. Still, my initial first impression after just a few hours listening is that they might have the edge over my beloved SCM40s.
Let's see when I find the time to make some measurements of them.


View attachment 538817

My first ATCs were original 20 passives with Vifa based tweeters (the solid tweeter front plate was an ATC addition I believe) and finished in red lacquer (cough). They NEED power to get going - 100WPC was barely enough for me and double is preferred, just to get over the inertia of the very tautly suspended bass-mid driver. I used them on original-model Epos ES14 stands initially, which they perfectly fitted and later, the single pillar stand they made for a while. The only thing I found difficult in my then room was the lack of deep bass. I've no doubt the SL drivers have a slightly clearer perceived tone, but these NEVER shouted in passive form and on jazz and acoustic instruments, they excelled (I should have borrowed a NAD 2200 power amp as this may well have been ideal...)

My last ATCs were the original dark blue 20ASL pros and these weren't as pleasant in a domestic setting. The Vifa tweeters spat, the admittedly clear mids dominated (as measured) and despite the bass-lift adjustment, subjectively it became a one-note thump I don't remember from my 1992 era passive ones. What's more, one of the drivers went slightly off-centre and started rubbing at seven years old, so a potentially expensive repair as I was no longer part of an ATC dealership. I inverted said driver which fixed it at least temporarily and sold them at profit back in 2009. The lack of grilles was a dust trap on the once sticky doping.

Nah, you enjoy the 20 Classics you have and see how the low bass to mid balance differs and allows closer to wall siting domestically. You really do need a powerful amp however (I never did get to see how say, one of the later Crown XLS or similar big cheap amps behave here). ATC used to distribute Sumo amps many years back, but I have no user-knowledge of these. the larger Rotels were good as is the Quad 606 family.

 

[thewas]

EDIT: I can probably lay the speaker on its side on the stand.

Also if you lay the mic or both on the floor you could do ground plane measurements which usually increase the gating window significantly.

 

[AlmaAtaKZ]

I will try to measure my scm7 v2 when I get some free time, hor and vert

 

[goat76]

My first ATCs were original 20 passives with Vifa based tweeters (the solid tweeter front plate was an ATC addition I believe) and finished in red lacquer (cough). They NEED power to get going - 100WPC was barely enough for me and double is preferred, just to get over the inertia of the very tautly suspended bass-mid driver. I used them on original-model Epos ES14 stands initially, which they perfectly fitted and later, the single pillar stand they made for a while. The only thing I found difficult in my then room was the lack of deep bass. I've no doubt the SL drivers have a slightly clearer perceived tone, but these NEVER shouted in passive form and on jazz and acoustic instruments, they excelled (I should have borrowed a NAD 2200 power amp as this may well have been ideal...)

My last ATCs were the original dark blue 20ASL pros and these weren't as pleasant in a domestic setting. The Vifa tweeters spat, the admittedly clear mids dominated (as measured) and despite the bass-lift adjustment, subjectively it became a one-note thump I don't remember from my 1992 era passive ones. What's more, one of the drivers went slightly off-centre and started rubbing at seven years old, so a potentially expensive repair as I was no longer part of an ATC dealership. I inverted said driver which fixed it at least temporarily and sold them at profit back in 2009. The lack of grilles was a dust trap on the once sticky doping.

View attachment 538919

Nah, you enjoy the 20 Classics you have and see how the low bass to mid balance differs and allows closer to wall siting domestically. You really do need a powerful amp however (I never did get to see how say, one of the later Crown XLS or similar big cheap amps behave here). ATC used to distribute Sumo amps many years back, but I have no user-knowledge of these. the larger Rotels were good as is the Quad 606 family.

The ATC SCM20s definitely need subwoofers if someone strives for a full-range sound, as I do. But that is also the case with the SCM40s, so I have already used two subwoofers to complement those speakers to reach the full range for many years before I bought the SCM20s. With subwoofers besides each SCM20s, I don’t have to use the wall for bass enforcement and can instead focus on finding the best possible positioning for optimizing the stereo image. I think that is usually best achieved with the speakers placed some distance from any boundaries.

I use a fairly powerful amp that drives these speakers with ease, a 200W Musical Fidelity M6i. It’s an integrated amp, but I use it with the HT-passthrough, and either a Linn Akurate DSM is used for streaming or as a phono preamp, or a Marantz receiver is used for multichannel sound.

My idea with the purchase is to decide whether the SCM20s or the SCM40s take the crown of being the front speakers for both the 2-channel music and surround sound, and which ones will be the back surround speakers. And I will also see if I can find a solution to use the SCM11s as side surround speakers. The only problem is that I wouldn't be able to position them perfectly per Dolby's recommendation, since there's a doorway to the left and a window to the right. An ATC C3C is the center speaker in the system.

The loudspeaker stands I use for the SCM20s are the ones I previously used for the SCM11s, a pair of matte white NorStone Stylum 2 stands that I think look great with the new speakers. The height of the stands is 60 centimeters, and with spikes, Linn Skeet feet, and isolation feet between the stand and the speakers, the acoustic axis of the SCM20s ends up exactly at the same height as my ears at the listening position.

 

[Ultrasonic]

But it didn't take me long to realize that the SCM20s don't work with the same toe-in setup as the SCM40s. While I have found that the 40s work best with a toe-in that crosses the axis around 20-30 centimeters behind the listening position, the 20s work better with way less toe-in, and at the current position (work in process), the axis crosses somewhere around 130-140 centimeters behind the listening position. This change makes these speakers sound really good. Puh!

Interesting. ATC would advise both are pointed directly at the listener of course. I'll be honest I've only ever tried mine on-axis.

 

[Atc4ever]

The ATC SCM20s definitely need subwoofers if someone strives for a full-range sound, as I do. But that is also the case with the SCM40s, so I have already used two subwoofers to complement those speakers to reach the full range for many years before I bought the SCM20s. With subwoofers besides each SCM20s, I don’t have to use the wall for bass enforcement and can instead focus on finding the best possible positioning for optimizing the stereo image. I think that is usually best achieved with the speakers placed some distance from any boundaries.

I use a fairly powerful amp that drives these speakers with ease, a 200W Musical Fidelity M6i. It’s an integrated amp, but I use it with the HT-passthrough, and either a Linn Akurate DSM is used for streaming or as a phono preamp, or a Marantz receiver is used for multichannel sound.

My idea with the purchase is to decide whether the SCM20s or the SCM40s take the crown of being the front speakers for both the 2-channel music and surround sound, and which ones will be the back surround speakers. And I will also see if I can find a solution to use the SCM11s as side surround speakers. The only problem is that I wouldn't be able to position them perfectly per Dolby's recommendation, since there's a doorway to the left and a window to the right. An ATC C3C is the center speaker in the system.

The loudspeaker stands I use for the SCM20s are the ones I previously used for the SCM11s, a pair of matte white NorStone Stylum 2 stands that I think look great with the new speakers. The height of the stands is 60 centimeters, and with spikes, Linn Skeet feet, and isolation feet between the stand and the speakers, the acoustic axis of the SCM20s ends up exactly at the same height as my ears at the listening position.

View attachment 539000

Congratulations!
A few remarks:
As for stands, I strongly recommend very massive and heavy stands. Mine were custom-made by a craftsman, target-type, with 4 massive square pillars filled with sand. Upper and a lower plate were of 1 cm thick iron, and a weight of 41 kg per piece.
Such stands make a significant contribution to sound quality.
Between speaker and stands a few small blue tack balls should be attached.
At one time I also had the original atc stands with a walnut veneer bottom plate and a central pillar, but those stands, apart from aesthetics, really did not provide what the scm20 needed.

I've changed a lot of amps in 20 years of using the scm20. (amplifiers are my favorite hifi component).
I have fond memories of: Yamaha p2200 and pc2002, crown psa2 and com-tech 210, lola audio 2111A, electrovoice p1200, quad 510, pass aleph 0, levinson No.27, atc P2... all powerful, mostly pro amps.

Personally, I never lacked bass on the scm20, perhaps because I always used them in rooms smaller than 20m2. However, once, out of curiosity, I got an active rel subwoofer. And indeed, I got a big, full-range sound. But after about a year and a half of use, I sold the subwoofer, I didn't want it anymore. The problem was that with the subwoofer it was now a quite different system, a system in which three new components were added: speaker, amplifier and cables. And it was no longer the sound of the atc 20 that I loved. The wonderful coherence of the sound, which the scm20 possesses, was lost. Overall, I felt that the sound gained in quantity but lost in quality. Maybe with a higher quality subwoofer, or with better subwoofer settings or room treatment, the subwoofer would work better...maybe, maybe, maybe...I gave up on all that and never thought about the subwoofer again.
A three way atc speaker I was thinking about.

 

[goat76]

Interesting. ATC would advise both are pointed directly at the listener of course. I'll be honest I've only ever tried mine on-axis.

Later on, I will try to go back and see again what I think of the sound with the SCM20s more on-axis. With the SCM40s, there's no doubt that they work best on-axis or close to that. In a "workshop" talk, which Ben Lilly of ATC had with studio people in Italy (link below to the workshop video), he mentioned that most people find that the ATC speakers usually work best with a toe-in setting where the axis crosses a short distance behind the listener's head, just like I had figured out for myself with my SCM40s. That was like a confirmation for me that others had come to the same conclusion, and that made me a little surprised that the SCM20s seem to work better with less toe-in. Let's see if I change my mind about that later on.

I'm just speculating a bit here, but maybe the waveguide of the mid-dome driver in the SCM40 has something to do with it, and maybe the SCM20s have a more open and wider directivity in that part of the frequency area. I don't know, both speakers sound great, they just seem to need different toe-in setups to perform their best.

One thing to notice, I always listen with a quite small equilateral listening triangle, with a listening distance of just around 193 centimeters from the loudspeakers. This gives me a high ratio of direct sound, but this also makes positional changes of the loudspeakers quite critical.
When it comes to the toe-in setup, there is more than one parameter to take into account. Besides stereo imaging, it's also the perceived balance of high frequencies and how the loudspeakers interact with the room at different angles when it comes to all the reflections. So I guess people will probably need to adjust the same model of speakers differently, in accordance with different listening distances and how the loudspeakers interact with their specific room acoustics.

This workshop talk with Ben Lilly from ATC is a good watch. It is over 1 hour long, but there are many good things he talks about, and it's obvious that he knows a thing or two about loudspeaker interaction with room acoustics. Somewhere in there, he talks about toe-in setups.

 

[DSJR]

I was too busy enjoying the music to get too anal about it all, but my 20 passives and 100As were toed in gently to my listening position, the 100As having the mid and tweets set on the inside, the mids on listening axis as the speakers were on slightly taller stands. (I did try the 100's with tweeters on the outside, but the already vague imagery (they were in too small a room) was made worse. The 20s did have - for the period - a good dispersion pattern - and I wouldn't say myself that they were that critical of toe-in. Just sayin' guv'nors

I'd echo the need for massy stands. The ATC pillar stands were fine at the time (the 100As came very quickly and I only had the original 20s for nine months or so). The heavy original 'Something Solid' stands were good for the 20ASL pros (I still have the stands as they're too risky to ship). I use 12mm x 3mm approx, clear adhesive feet (mine from RS) on top of the stands, which offer grip for smaller speakers and just enough decoupling for larger ones.

 

[goat76]

I’m not sure it's that important to use massive or heavy stands, at least not as long as the loudspeakers are decoupled from the stands using effective dampening feet, which isolate them completely by lowering the resonating frequency below what the loudspeaker is capable of reproducing.

I use dampening feet made of Sylomer, which do just that. They come in different weight classes and look like this: