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Puzzling results with ATC SCM50ASLT loudspeakers vs. previous system

Look up SBIR (Speaker Boundary Interference Response) it describe how the proximity of a hard boundary (wall/ceiling/floor) will change the response, mainly low end.
-Distance to front wall <1M: Reduced SBIR
-Distance to front wall between 1M-2.2M: Deep SBIR notches mainly in the range 40-80hz
-Distance to front wall >2.2M: practically eliminate SBIR down to quite low frequencies
 
AndyU said:
For the 50s, 100s and 150s you just use an amp pack rack kit with the standard amp packs. You can either retrofit your existing amps, or get them supplied with amps from the factory:

https://atc.audio/wp-content/uploads/2017/12/Amp_Pack_Rack_Kit_TDS_web.pdf

The 200s and 300s get a completely separate amp, the P4:

P4 | ATC Loudspeakers

atc.audio atc.audio

As to adjusting for soffit mounting, I think I’ve read somewhere on Gearspace that pro installers like Northward do this.
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that’s interesting. Can you buy amp packs for pro audio, and put in place yourself ?
 
FN19 said:
that’s interesting. Can you buy amp packs for pro audio, and put in place yourself ?
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I dare say you can, but I think the crossovers are set at the factory for your particular drive units, so you really would need to know what you are doing to fit them yourself. I know when my midrange unit developed a fault many years ago, ATC wanted the whole speaker back.
 
AndyU said:
I dare say you can, but I think the crossovers are set at the factory for your particular drive units, so you really would need to know what you are doing to fit them yourself. I know when my midrange unit developed a fault many years ago, ATC wanted the whole speaker back.
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Yeah, I couldn’t retrofit anything myself, had to send whole speaker if so
 
S-Man said:
Since I don’t consider SCM50As to provide great sound, it’s not really an issue for me.

I get great sound from my system with my speakers 55cm from the front wall. They are domestically acceptable and sound wonderful.
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Your wonderful may be another man’s shite, as it would seem mine is to you. Haven’t heard the 50 actives but given they were the founder’s firm favourite and I find the 100ASLT ‘wonderful’…
 
TheFlash said:
You seem to be confusing studio heritage with studio deployment, and seeking to constrain/guide domestic deployment based on this. ATC now has decades of domestic HiFi experience.

It’s ok not to have enjoyed your own experience of the SCM50As without seeking to rationalise it! Mind you , I hope you didn’t have the SCM50As soffit-mounted when you heard them.:)
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The last time I heard ATC 50s was the anniversary edition at the Munich show a few years back. I somehow got in a lock-in after the show had closed, for the trade people, and spent a long time listening to the speakers with different sources and different music.

The mid range and trouble was superb. The bass alignment is not to my liking.
 
I don’t see how anyone with a normal sized room could accommodate 2m from front wall. My speakers are about 30-40 cm out.
 
S-Man said:
The last time I heard ATC 50s was the anniversary edition at the Munich show few years back. I somehow got in a lock-in after the show had closed, for the trade people, and spent a long time listening to the speakers with different sources and different music.

The mid range and trouble was superb. The bass alignment is not to my liking.
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Cool story.

Can I just check these were the actives? Apologies, but I don't know whether the Anniversary came only as actives or there was also a passive version.

I had the passive SCM40's for a few weeks here before deciding to stick with my ProAc D30RS; the passives had lovely highs and mids as you describe, but just didn't have the bass depth/shape/slam I sought. Fast forward and the active SCM40A's displaced ProAcs for the first time in 30 years. The treble and mids were a good step up from the passives but the bass was transformed; finally I'd found my does-it-all speaker.
 
TheFlash said:
Cool story.

Can I just check these were the actives? Apologies, but I don't know whether the Anniversary came only as actives or there was also a passive version.

I had the passive SCM40's for a few weeks here before deciding to stick with my ProAc D30RS; the passives had lovely highs and mids as you describe, but just didn't have the bass depth/shape/slam I sought. Fast forward and the active SCM40A's displaced ProAcs for the first time in 30 years. The treble and mids were a good step up from the passives but the bass was transformed; finally I'd found my does-it-all speaker.
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Yes active.

Actually I was probably sporting a trade badge, even though my links with the industry are tenuous.

Funnily enough, on the first evening there, we realised that the chap on the trestle table next to me at dinner was Alan Shaw. Super chap, nicer than he appears on YouTube. He was most interested in our bass extenders (if KEF decided not to go with it). The second evening we had dinner with John Dawson. As a keen amplifier amateur, I really enjoyed that!
 
cooky1257 said:
Apparently the amp packs to have are either the mk2 or the SE.
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Oh first time I've heard that. Do you have a source? I think the latest is mk4 which hasn't changed design since around mid noughties - I think Ben or Rich said they reviewed mk4 and decided not to change anything, around the time they did the SE.
 
S-Man said:
2m from the front wall is really inconvenient and obtrusive IMO.

Also, how does this reconcile with ATC’s recommendation to soffit mount in studios 🤔?
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Not sure about ATC specifically, but every speaker I’ve owned, including PMC, Meridian, Kef etc has sounded better at least 1m, usually more into the room. By better I mean giving the most realistic illusion of having muscians playing. Unfortunately that isn’t necessarily the best position for even frequency response and perhaps analysing the sound of the recording, so I suppose it depends on one’s tastes and priorities. Of course, as you say, having speakers way out into the room is very obtrusive. Once one gets to dipoles and omnis all bets are off; with my German Physics the best position for music was over 2 m into the room and about 1 m from the side walls which sounded very convincing but didn’t do much for the bass between 28Hz and 40Hz.

As for ATC speakers generally, they are about the only make I’ve heard that I would put up against the latest Quad stats or MBL/German Physiks offerings. I found the mid range of the 40s beguiling and very convincing.
 
PS: I think listener position is vital, getting at least 1 meter into the room helps everything. Also for listener and speakers, rule of odd fractions can help.
 
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darrenyeats said:
Oh first time I've heard that. Do you have a source? I think the latest is mk4 which hasn't changed design since around mid noughties - I think Ben or Rich said they reviewed mk4 and decided not to change anything, around the time they did the SE.
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The source was an ATC tech- Ive no idea why that would be the case other than perhaps the mk2s may be using more discrete components /fewer Ic's......
 
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