ATC SCM 50 SL reviewed

[Purité Audio]

http://atcloudspeakers.co.uk/wp-content/uploads/2018/01/Hi-Fi_Critic_SCM50PSL_WEB.pdf

Keith

 

[Cosmik]

... the sound was impressive, dynamic and powerful, with a desirably fast and crisp bass, but also with a mild and somewhat detached ‘chromium’ sheen to the upper treble. Deleting the supplied metal terminal jumpers and substituting bare wires fixed the sheen

When someone writes something like that, IMO their credibility reduces to zero. Everything that follows is probably in their imagination. If metal jumpers affect the sound audibly (in a way that resembles the aesthetic qualities of the component!), then all the other blather about coils, motors, frames, chassis, etc. is pointless. Clearly in this person's mind, a component's specification and design is meaningless if something as simple as an electrical link can impart an audible change, so why even state factual information about these things?

(I was once granted an audience with said person!)

 

[fas42]

When someone writes something like that, IMO their credibility reduces to zero. Everything that follows is probably in their imagination. If metal jumpers affect the sound audibly (in a way that resembles the aesthetic qualities of the component!), then all the other blather about coils, motors, frames, chassis, etc. is pointless. Clearly in this person's mind, a component's specification and design is meaningless if something as simple as an electrical link can impart an audible change, so why even state factual information about these things?

(I was once granted an audience with said person!)

OTOH, my interest in what they have to say about the sound picks up ... an inconvenient truth about audio is that a chain is only as strong as the weakest link, and if a piece of cheap metal happens to be the latter, then the most incredible magnet structure in the world is not going to make it better ..

Poor quality electrical links do add a "detached ‘chromium’ sheen" to the sound, and the better the rest of everything, the more pronounced that weakness will be, subjectively - would you drive a Ferrari using the cheapest wheel nuts one could buy from a bargain store?

 

[Wayne]

Poor quality electrical links do add a "detached ‘chromium’ sheen" to the sound

Are there any published reports that address this "detached chromium sheen"?

 

[RayDunzl]

Are there any published reports that address this "detached chromium sheen"?

This is all I could find at the moment...

 

[fas42]

Are there any published reports that address this "detached chromium sheen"?

There's a whole industry that deals with the behaviour of electrical contacts in the real world - the guru here is Ragnar Holm, the bible is "Electrical Contacts - Theory and Application" ... unfortunately, bare metal to metal contacts are rather unpleasant things, if you want to guarantee integrity of that interface - it gets very complex, very fast.

Yes, it's all low level stuff, and it shouldn't make a difference to audio ... but the more "transparent" the system, the easier it is to hear the impact of this area. Typically, the treble will develop an unpleasant edge to it - yes, call it "metallic" if you like - the call is, "turn the volume down!", or, "hit it with some EQ!" - the usual aspirin.

Specifically, a paper in the audio world? Maybe there is, maybe not - I've come across many accounts where the particular individual realises there's a problem, and does something about it.

 

[fas42]

My most recent experience was a NAD integrated amp , the one in the current experimental setup. When I got it the treble was bloody awful - it was "throw the thing out the window!" quality - OK, sigh, sigh, here we go again ... steadily went through the unit, and got rid of every junk metal to metal contact in the beast - there were dozens of these - finally, the treble emerged into clear air ... very nice, without having done anything else to the unit.

 

[Wombat]

OTOH, my interest in what they have to say about the sound picks up ... an inconvenient truth about audio is that a chain is only as strong as the weakest link, and if a piece of cheap metal happens to be the latter, then the most incredible magnet structure in the world is not going to make it better ..

Poor quality electrical links do add a "detached ‘chromium’ sheen" to the sound, and the better the rest of everything, the more pronounced that weakness will be, subjectively - would you drive a Ferrari using the cheapest wheel nuts one could buy from a bargain store?

How do you know that your perception of 'detached chromium sheen' is like the reviewers?

 

[Wayne]

This is all I could find at the moment...

Sounds like a poor choice of sound effects, not poor electrical connections.....

 

[Wombat]

A bad habit of 'audiophiles' is to draw on other areas of science and engineering(and metaphysic?) to justify their beliefs. The reality of these suppositions is that they are usually made in ignorance of audio science, the referenced field and its relativity to audio, and are meaningless - but they satisfy their flawed thinking processes - even after the error is explained.

Use of false analogies and meaningless terms is rife in 'audiophile' comment because of lack of knowledge of the subject and a need to be seen as 'credible'.

 

[Jakob1863]

The obessesion with real or imagined "audiophile" reasoning flaws always surprizes me. As if anything wrt biased or flawed resoning would be exclusive to "audiophiles".....

Real world experience showed me that multiple terminals on a somewhat rigid connection piece of metal can be a real pita wrt reliable (means pure and low ohmic connections) even when fastend with constant torque tools. Edit: Clarification; means when terminals mounted on rigid plate and an additional connection via a quite rigid piece of metal is made,

Given that Colloms also mentioned his difficulties to get reliable/repeatable resistance numbers on those metallic strips, is it really out of reason that there might exist some compromising impact??

Beside that, is "cromium sheen" soundwise really associated with plating of "matt grey" colour?
At least i undertood your remark as a hint that a "shrill" sonic impression is associated with the "shiny" look of the interconnection, which in this case wasn´t - according to Collom´s description - metallic bright...

Edit: Colloms wrote about "matt grey plating" not about "dark grey"

 

[svart-hvitt]

For purpose of balance, the review has measurements as well. So comments should be balanced as well, right?

 

[dallasjustice]

They are directional above 5khz. That’s what you’d expect from ATC. I bet they are dark sounding in most normal rooms.

 

[svart-hvitt]

They are directional above 5khz. That’s what you’d expect from ATC. I bet they are dark sounding in most normal rooms.

What is «dark sounding»? Exaggeration of lower frequencies (than 5khz)?

 

[Rodney Gold]

I had an older active pair , SCM50a's ... they are good speakers... they really only performed well for me at elevated volumes. Very light on bass, excellent mids , ok treble (they have changed tweeters since mine)
One of the midrange drivers started buzzing...ATC quoted me on a replacement dome and coil but when I read the replacement instructions that said "gently tap with mallet" and that you need a signal generator I went for new complete midrange driver. I sold them on due to their poor bass performance

 

[dallasjustice]

What is «dark sounding»? Exaggeration of lower frequencies (than 5khz)?

Look at the lateral off axis measurements in the Hifi critic. The SPL off axis drops like a rock at all frequencies higher than 5khz compared to on axis. I’m not sure what the best word to describe the sound would be. Be it’s not ideal performance for a modern high end speaker.

 

[Jakob1863]

Look at the lateral off axis measurements in the Hifi critic. The SPL off axis drops like a rock at all frequencies higher than 5khz compared to on axis. I’m not sure what the best word to describe the sound would be. Be it’s not ideal performance for a modern high end speaker.

Isn´t that an overreaching conclusion? As the scale of the graph is quite fine (only 5 dB on the horiontal lines) and the frequency range quite extended til 50 kHz, i´d to the contrary say that the ATCs are quite flat above 5 Khz within 30 degree lateral, means only ~ 2 dB down from the imagined 0 dB line.

Of course i´ve to admit it is partly speculative in thinking that the 20 khz vertikal line is located just left from the "20 kHz" descriptor as it is the case for the lower frequency lines....

Edit: left from the "20kHz " ....

 

[fas42]

"Chromium sheen", dark grey, dark sounding are just words for describing how various types of audible distortion register subjectively .. of course, it's not politically correct to talk about distortion here, we need to pretend it's FR, or directional characteristics, or room behaviour ... oh, well ...

Sounds like the ATCs have suspensions that have to be warmed up, conditioned quite strongly, every time - this is the huge 'flaw' with dynamic drivers as a class of devices, the means of supporting the diaphragm in alignment with the motor is a relatively poor engineering solution, and is nowhere near good enough in terms of flexibility, suppleness of movement. Could call it a poor S/N compromise ...

The only solution is to drive them hard, at switch on. Something I've been doing doing for decades - hammer them with high energy rock, say, for an hour or two to stabilise the mechanical system - then, and only then, listen critically to how the system is performing

 

[Wombat]

The obessesion with real or imagined "audiophile" reasoning flaws always surprizes me. As if anything wrt biased or flawed resoning would be exclusive to "audiophiles".....

Real world experience showed me that multiple terminals on a somewhat rigid connection piece of metal can be a real pita wrt reliable (means pure and low ohmic connections) even when fastend with constant torque tools. Edit: Clarification; means when terminals mounted on rigid plate and an additional connection via a quite rigid piece of metal is made,

Given that Colloms also mentioned his difficulties to get reliable/repeatable resistance numbers on those metallic strips, is it really out of reason that there might exist some compromising impact??

Beside that, is "cromium sheen" soundwise really associated with plating of "dark grey" colour?
At least i undertood your remark as a hint that a "shrill" sonic impression is associated with the "shiny" look of the interconnection, which in this case wasn´t - according to Collom´s description - metallic bright...

Not obsession but frequent observation. There is no mystery in metal to metal connections and their integrity can be measured, as can any compromising affect on signals.

'Too much imagination, not enough knowledge and application'.

 

[fas42]

There is no mystery in metal to metal connections and their integrity can be measured, as can any compromising affect on signals.

How would you suggest that be done?