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ATC speakers / Monitors
- Thread starter Pearljam5000
- Start date
I would order a MiniDSP Flex 8 for the tuning part. It would allow almost perfect tuning for my room and situation.
For amplification i would use my existing Yamaha integrated in the beginning, then, as my DSP configuration matures, i would probably get two Hypex NC122MP module amps for mid and tweeter, bass would stay with the Yamaha.
Eventually i would bypass the internal cross-over networks and drive the chassis directly (except maybe a capacitor for tweeter protection, you never know).
That would possibly make a far, far, far better speaker than the regular SCM40a v2 for my specific room, for a lot less dough. Also, if i am able to get a pair for about 3500€, the resale value in a few years, even if a SCM40 v3 is released, should be about 2500€ or higher, as can be seen with the SCM40 v1 and SCM40a v1.
I doubt that part though, a well factory tuned and calibrated speaker (provided ATC did so to make unit variation as low as possible as those beloved monitor brands here, which I believe they will do so given their name) plus a DSP will likely be way easier to tune than individual drivers driven by external amps. in room minor differences would affect even gated measurement results, with driver varation being present and individual amp power difference in place, in room EQing them to look the same likely create some different tonal balance speakers and making the pair sounded off in different channels.
Of cour,se if you use a well treated room, put the individual speaker and the exact amp using to drive the driver in the final config, and then use the samse channel of minidsp to do initial driver integration it could be done, but for a home user, for floor standing speakers of that heft, I doubt that would be a good idea to do so... of course, for geeks like quite some of us, the DIY part might be the fun part, that's another story
I bet a proper way in active version is to measure the driver variance and the amp and then have a bit of pot inside to do minor level+ response matching, kinda like put the driver into a measuring box or something with the screw mount and do a sweep with standard current, and then at the amp do a power sweep so they know the exact power output of the plate amp used, and dial in minor variances to make the tonal balance within spec and reduce unit to unit variation, IIRC similar procedures were seen in factory tour videos in Neumann and Genelec and it seems with batch rating of drivers it's a reasonable approach to make the speaker varies as little as possible for actives.
for passive speakers I think the most they can do is to measure and classify the drivers and crossover components as good as they can, say, 0.1% tolerance batches, so a pair of speaker sent out from factory would perform as similar as it can (still more than any factory actives undergone simple factory calibration) and would be (muc) better than user tinker around at home for complete speakers in their set up position in room. but all is guess work tbh and maybe someone will step in and say that I am totally wrong that you can do better than ATC factory (or any vendor IMO) guys do in their facilicity before assembly of the speaker
The crossovers have trimpots to adjust levels.
DSJR
Major Contributor
The 50A's and 100A's had level and phase adjustments to best blend the bass and mid drivers together. Level for the tweeter as well but not sure on the phase blending though. Somewhere in the depths of audio papers I kept, I have the 'service instructions' as it then was, describing how to set these things up for phase. A long time has passed now, but I'd expect the 40A's surely to have this as well.
For general domestic use in a medium sized room and sort-of mid field listening (so less then 4m?), I'd still say the 50ASL is the one to aim for (sadly it's way expensive now) as the enclosure is better, the properly designed grilles act as dust protectors on the ever-sticky domes and can protect from little proddy fingers and the stand mounted 'classic' versions have nice enough veneers and can be slid around (no spikes necessary).
I don't uderstand the value in the SCM40a considering that i have to DSP correct it anyway to my room. Basically, i get a vibe that you are saying a SCM40a with DSP is somehow by default better than a SCM40 with DSP and amps. So much better in fact, that it beats the second options value?
Unless the speaker enclosures or drivers are fundamentally different, there is no good case that can be made for the SCM40a in 2023, as i can fix level and phase in DSP, and i get better amplification for much less than the premium i pay for SCM40a over the SCM40.
I guess ATC owners don't run DSPs, in which case their opinion should be discarded anyway. Why would i not make use of the largest advancement in speakers in the last 30 years?
Unless the speaker enclosures or drivers are fundamentally different, there is no good case that can be made for the SCM40a in 2023, as i can fix level and phase in DSP, and i get better amplification for much less than the premium i pay for SCM40a over the SCM40.
I guess ATC owners don't run DSPs, in which case their opinion should be discarded anyway. Why would i not make use of the largest advancement in speakers in the last 30 years?
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I know a lot who do.
No, it's more that there is not a single scenario where I'd want a passive crossover rather than an active.
Their opinion has value obviously.
With a Flex 8 you would bypass the passive crossover (as i wrote earlier, you probably want a capacitor in there to protect the tweeter against stupidity).
Straight from the amp into the driver.
You're effectively making it an active speaker, then.
With higher flexibilty and less cost, yes.
It all depends on getting a pair of SCM40 used for a fair price and in my area of course, that part is as of yet unsolved.
However, in my mind they sound really great
That goes into the mental satisfaction category then. No right or wrong up that point, as long as you convinced they sounded betterWith higher flexibilty and less cost, yes.
It all depends on getting a pair of SCM40 used for a fair price and in my area of course, that part is as of yet unsolved.
However, in my mind they sound really great
Talks a bit of nonsense, takes apart a ATC SCM16a (an older active monitor with aluminium cast enclosure), and builds a passive cross over for it.
Not much to see for us, except some sweet SCM16a guts.
The spectral decay looks fantastic!
DSJR
Major Contributor
Do you not realise (I did try to explain) that the mid dome is run basically wide open so absolutely minimal driver overlap unlike more traditional bass and mid setups, the doping is done by hand and is thereby variable, albeit as tightly controlled as they can do it and the transition from bass driver (non SL) to the mid dome simply can't be done satisfactorily in the passive configuration. This scenario is EXACTLY the same in the other three way passives they do!!! Too little doping and the dome works too high and too much doping and it doesn't go high enough. This is one advantage that other makers of top quality three ways may not have, as modern mid drivers appear to have a wider bandwidth and can be crossed over more easily in a passive system while giving little away at domestic volume levels perhaps?
If you've heard the passive 40's and are happy with what you hear, then that's wonderful for you, but I've now heard rather better at the same price (you may disagree) and I rather liked the actives which work great in a small to middling UK room with no DSP to play with (it's not a cure *all* you know
) and which offered a greater sense to me of the reverb tails (ghastly term) in many contemporary recordings. I'd love for some of you intending domestic use to try some current issue Harbeth C7-XD (MUST be the XD version as earlier incarnations sounded bloated all too often) to see if their more modern sonic qualities can bypass the old fashioned looks and 'old fogey' connotations ATC work(ed) on the following principle - you want bigger, you get a bigger pair!!! Worked for me for many years, but now, subs are the fashion (all these extra boxes) and DSP can only really work at the listening position unless the room is perfectly optimised (not many domestic rooms are anywhere near that, judging by the terrible system setups I've seen online and DSP certainly WON'T sort them out).
Come back KH420's, all is forgiven!!!
(Lord, I hope that's a good thing to say ) - they're only £8300pr or so in the UK...
@DSJR, i hear you, buy the bigger, pricier stuff. But i'll continue to search for a good priced and local pair of SCM40v2, not SCM40a, not SCM100a, not SCM150, if you don't mind.
You quoted my post without reading my possible solution to this (if it needs one, that is still not decided by me), it's a MiniDSP Flex 8, 6 channels of amplification and bypassing the passive network.
Beats having no DSP.
Fair enough and agreed.
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