You may find they need the grills on which is what they are designed for as the extra baffle step introduces diffraction anomalies. Also those sl drivers take a few hrs so they may become less direct in the coming days . Be interested in your long term appraisal as these have always been in my radar. Did you compare to the 19a? Same mid bass sl drive unit but slightly lower spec tweeter.
1 Like
This is a term I read from time to time and never understand. When ever are bass notes heard when not in the music? (Too many speakers on the other hand curtail bass that is in the music!)
1 Like
Sure.
That was a clumsy expression. Maybe I should try explain that better…
Some speakers, seem to make bass notes almost continuous. These not so, just where it’s in the music. Even then, these notes start and stop with precision. And the really really low notes only occur when it’s appropriate. How’s that?
I’ve used this description before. Owning DBL’s with a bass unit this size of a small planet (ATC by the way) one expects the bass to be almost constant in level and extension. However, it isn’t. I’ll play tracks where the bass is hardly noticeable and it would remind me of listening to Linn Kans. Then, the next track I play has some extended bass and it will rattle the window or be so low it’s almost subsonic and starts the dogs barking. The counter to this, and probably a result of poor design, is speakers where the drone or overhang from the bass is constant and ends up just being fatiguing. I’ve heard plenty of speakers with this trait!
2 Likes
Very eloquently put. 
Much better than my own clumsy effort.
Tried to say something similar, ( as you), in my second effort just above. Yours is so much better expressed.
Nicely done…
BW
R
1 Like
You got it right, ATC actives are all about that.
I’ve reasoned it this way that I want the speakers to be extremely accurate, powerful, fast and in control. If I want to make the sound easier and more “romantic” I can use the front end to tune the sound to my liking, with something like a NOS DAC or maybe a tube preamp. But the speakers should be as accurate, neutral and powerful as possible.
Also 20ASL’s sound more in control/snappier than 40’s because their bass doesn’t hit quite as deep as with 40’s, which have a bigger and dedicated bass element in the three-way design. This effect was the same with 19A vs 40A. I’ve auditioned 19A extensively back in the day, when I made the move from passive 40’s to active 40’s. My plan originally was to upgrade from passive 40’s to 19A (because I had small budget back then), but I ended up going all-in with the 40A’s. Two years with them and move to a bigger apartment and I went even more all-in with 50ASL’s.
1 Like
Interesting 
I assume you mean the stand mounts?
I’m learning that speakers are such a personal thing, on this bit of our journey.
But, I’ve yet to fathom why - an objective technical reason - why I prefer the ( SCM20ASLT ) different floorstander active 20 Towers, to 40’s in the bass department. That’s what my ears tell me.
On paper, the tech’ spec’s show the 40’s being superior, with LF extension and cut off. Having heard them both, the active 20 Towers go way lower than their printed tech’ spec’s. And seem to have buckets of control - my perception - more than the 40’s. Unless someone suggests otherwise, I’m assuming it’s the better ATC driver technology employed in the 20 Tower albeit two way design. Plus, more powerful amp packs ? Maybe better integration. Some of the parts and all that ?
1 Like
No I meant the towers, so 20ASLT. 19A which I auditioned back in the day, is also a floorstander.
ATC specs are very conservative when it comes to the bass extension. 50ASL’s are specced to 38hz (-6dB) but they play to ~24hz in my room (-0dB), I’ve measured this with UMIK-1 + REW.
Smaller speakers with less bass extension tend to always sound faster and snappier than bigger speakers with deep hitting low end. Obviously things like more powerful amp pack and higher specced elements will have an effect also.
20ASLT is a great speaker and there’s nothing weird liking it more than 40A. Many people prefer even the 19’s to 40’s. It comes to room acoustics, electronics used, preferences etc. 40’s sound balance is smoother and the midrange is slightly more prominent than with 19’s, which then again can sound more crystal clear and snappier. They’re also easier to fit in the room since the bass doesn’t hit so deep. I assume this is the case with 20ASLT’s also.
1 Like
Maybe they just tick more boxes for you in your setup and room.
When I did some research some time ago the 20’s looked ideal but I was put off by the price, I know it supposed to have a better cabinet and the tweeter is from the higher range of ATC speakers but maybe you are paying for a superior performance it can deliver as well otherwise I guess people would opt for the more cost effective 40a, just my theory, I know some people will say just because it’s more expensive doesn’t make it better but from what I have experienced it usually does exspecially similar items from the same manufacturer.
2 Likes
Lastest update, from Saturday 8th June.
Some Answers…
Came back to Basically Sound - a week later - to return loan speakers.
Was so impressed with the active 20 Towers - last week - took them home for a longer listen and get used to, in our own music room. Really enjoyed having them at home.
Back with Tony @BasicallySound , with an afternoon ahead, requested we do one more thing…
As we ran out of time last week, respectfully enquired if we could listen to passive and active speakers again. To compare. This time, adding a decent power amp, with a passive system. It’s been in my mind for some time, how this affects things, an open question, from the start. How this alternative passive approach might compare to active options.
We set up our home system again…
Demo’ system as follows…
ND5 XS2 → DC1 →
nDAC → HiLine →
SN3 + HCDR →
A Naim NC250 was used later, as a proxy, for a “decent power amplifier”.
Image : Our home system - with PMC Twenty5 23i - used as active, then passive incorporating Naim NC250, (as proxy for a “decent power amplifier”).
First step, was listening to PMC Twenty5 23i as active again.
Strangely, found this needed an hour or so to tune into the system, room and speakers again.
Honestly, think I missed the ATC mids, in this moment.
(Sometimes, it is only when something is taken away, you notice it)
So, took time to readjust to the different presentation offered by the PMC 23i’s.
In these situations, it’s almost like one has to “reimagine” all the music you’re familiar with.
A piece of acoustic guitar, which was forward with ATC, is now less present.
But, an electric bass has more life and easier to follow.
The whole musical sound stage sounds more balanced, maybe even handed, with PMC.
Image : PMC 23i, as active.
Active and Agile
Starting to get used to the sound signature of an active system.
Or at least an active speaker system, integrated, in the way that ATC and PMC design and manufacture.
Have now listened extensively to three different executions of active speakers, PMC and ATC, albeit at different price points.
Including living with probably the best active execution - ATC SCM20ASLT Tower - at home for a week.
They all share some common characteristics, compared to equivalent passive speakers.
It’s punchy, energetic, across the whole spectrum. Sound stages open up more too. The aspects I like about this sound is the speed, agility, accuracy of things. You also hear more control (of notes and instruments). The music comes alive more.
Accuracy, agility, speed, more open soundstage.
Power is Control
The PMC’s were configured back passive again. It’s takes less than 5mins each speaker to swap the crossover modules on the rear.
Then, Naim NC250 ( on hand, as proxy), was connected to SN3 to add a better power amplifier into the system.
Image : PMC 23i, as passive. NC250 providing the power.
The reason this is interesting ( to me) is the maths involved.
Apart from any sonic benefits from active, there is the necessary higher cost, as a consideration. Where as, adding a better power amp, might be more cost effective. Maybe ?
Listening, first impression was positive. Differences were obvious. More power, control. Music was so effortless and refined.
But the music had also lost something too? It sounded more laid back, relaxed, easy, even tame, with some of the detail lost. The system had became maybe a bit lazy, with all the speed and agility that active provides, now lost. Nuances of articulation and separation was less apparent.
Tony was in the room, ( maybe he was curious too). After 2 or 3 tracks, we chatted about our thoughts. We went over a couple of tracks we knew and pointed out things that were both better, but also not so.
Using the PMC active modules ( @ MRRP £1,795) and their respective amp pack, was maybe unfair to compare with a £6k power amplifier. We felt it was sufficient for this crude experiment and produced an outcome we could identify.
Played another 30 minutes of familiar music, to confirm a few things.
The NC250 is a fine amplifier. Refined and easy to listen to. It has power and control. Some grunt too.
It was a fascinating experiment.
Left me thinking I understand active better.
And what power amplifier contribute more generally. Power and control.
It seems adding a “better” power amplifier is a positive way forward, (with system building). Yes, it improves things, with SQ. The NC250 offers something better, compared the SN3 (power section) and also the PMC active modules (their amp’ packs). Specifically, with power and control.
(Note : Speculating… Maybe the ATC amp packs, which I feel are a better active execution, would fare better, just focussing on amplifiers alone ).
However, separating out what active provides too, it’s more nuanced.
Assuming you like what active sounds like, ( as this might not be everyone’s “cup of tea”), a well executed active integration, complete with equal and adequate amp pack is maybe better.
Accuracy, speed, agility, sound stage, as well as power and control too.
In the moment, Tony remembered from our first session, the general aim for the customer was to eventually combine active speakers, with a further step to a “better and separate pre-amplifier”.
So, without much of a fuss, the conversation was brought back to that step and we naturally chatted about our findings, at that time and a few weeks back. ( See original OP above).
Full Circle, to the Start.
Having chatted about what a pre-amplifier does, this idea niggled away in my mind, for maybe 20 minutes. Long enough to build the courage to ask another question. “Please can we put the 332 back in, just to see how that compares again”?
I’m always reluctant to ask for things.
But, often it then seems so easy when all the items are on hand and quick to insert into a demo system. It took minutes to do.
(Maybe another advantage of working with a local dealer and building that trust).
Having returned the PMC’s to active again, the SN3 + HCDR was removed and NAC332 added instead, as a proxy for a “better pre-amplifier”.
Image : PMC 23i, as active again. This time, with NAC332 adding details and nuance.
With the first few bars of music, smiling, as reminded how this works.
All the detail, nuance and refinement from good source and separate Naim pre-amplifier working with active speakers. This time, the active PMC speakers were so much better for the pre-amplifier. This sound SQ trumps the passive alternative of adding better power amplifiers instead. Having listened to all these alternatives, would put my money into a decent pre-amplifier, ( with active speakers). Different approach to system building, but no less for the difference, maybe better?
Accuracy, speed, agility - detail, timbre, nuance, refinement - as well as power and control.
Now thinking this is the sweet spot. ( To my ears ).
- A decent source (for us, that’s ND5 XS2 → nDAC)
- A decent pre-amplifier, ( such as NAC332 or NAC282, or whatever).
- A decent active speaker solution. Insert your PMC or ATC preference here ?
So, audio system building isn’t straight forward
It’s a balance of inter-related things, combined for best effect.
No one path is a perfect and prescribed route. This allows for several routes.
Add a better power amplifier, as this is a positive step.
Or add an active speaker system. If you like the active sound, maybe this is better?
(The sum of such audio system parts maybe addling up to more)?
Take you pick ???
The Music is the Real Star
In all of this, it is the music that shines. With active, it maybe gets better.
Here are the test tracks used for this latest session. In no particular order…
(Note : Picked out some HiRes pieces, this time).
Lou Reed : “Walk on the Wild Side” + “Perfect Day”, from Transformer, (1972). @ 96Khz / 24bit
Bonobo : “Shadows”, ( feat. Jordan Rakei), from Fragments, (2022).
Coldplay: “Midnight”, from Ghost Stories, (2014)
Miles Davies : “So What”, from Kind of Blue, (1959) @ 192Khz / 24bit
Maribou State : “Wallflower”, from Portraits, (2015).
David Sylvian : “Orpheus”, from Secrets of the Beehive, (1987).
Massive Attack : “Angels”, from Mezzanine, (1998).
Massive Attack : “Unfinished Symphony”, (1991). @ 96Khz / 24bit.
Beth Orton : “Stolen Car”, from Central Reservation”, (1999).
EBTG : “Another Bridge”, from Eden, (1984).
EBTG : “Missing”, from Amplified Heart, (1994).
John Martyn : “Sweet Little Mystery”, from Grace & Danger, (1980).
Going Forward…
We now have PMC Twenty5 23i at home, for next home trial.
Happy Sunday listening.
R
16 Likes
I don’t think so, as the bass-mid driver is a (relative) compromise compared to separate bass and mid drivers. IIUC the mid dome of the driver in 20 was ‘pinched’ from the very same SM75-150 used in the 40 and upwards, and grafted onto the bass cone, to assist in giving it as close a performance to the dedicated mid as they could achieve. But, as one example of compromise, in the mid unit the dual suspension only has to cope with the miniscule movement required for reproduction of frequencies down to 350 Hz or whatever, whereas the mid-bass unit has to cope with considerably greater fore-aft movement.
1 Like
Afternoon ratrat another fine account of your last demo, I had a few questions from your last post but these have been pretty much covered in the last account of a visit to your dealer, who seems to be a very accommodating gent.
I liked the sound of the combination of the newer preamp with the 23i’s , would you say you are any closer regarding the route you would like to take?
When I recently added the 282 to my system for me it made a very appreciable benefit so I can understand the positive gains of using the new 300 pre.
The only reservation I would have reading your very informative posts are your descriptions of the active sound maybe a little bit too real for my tastes, I like smooth but with drive and control plus detail but not too much of smack you round the face but this can be very track dependent perhaps one of the most frustrating things with a system.
I have noticed recently after a few changes that certain albums are more listenable to if that makes sense, so l’m tempted to keep on the path of improvements to the front end before deciding which way to go with my next speaker choice.
Many thanks for taking the time and effort to share your journey, always a most enlightening and enjoyable read👍
3 Likes
Thanks for a great write up and insight into Tower series of ATCs.
In the auld days, a lot of Naimees would advocate a ‘pre-amp first’ approach to building the best VFM system. I understand your line about the extra detail/nuance the 332 brings having recently bought one and I think I would characterise it as ‘phrasing’ or as sometimes described like a bigger window for the music to come through.
2 Likes
Thx for sharing your experiences. Very interesting. Looking the 3 system set-ups you talking about, I think the Nova PE with passive PMC’s or ATC’s would also be a nice road of comparing.
I’m waiting a nearby dealer having a Nova PE to do the test with PMC’s.
2 Likes
Thanks for sharing.
In context, the whole statement…
The SCM20ASLT has a better tweeter.
The SCM40’s use the SH25-76 HF unit whereas the SCM20’s use the higher spec’ Super SH25-76S.
The active 20 towers also have better quality cabinet build (stiffer, heavier too) and larger amplifiers.
The super linear SL specification mid / bass driver is no slouch. It does an excellent job.
A hypothesis, maybe the sum of these parts comes together and works really well, as a whole?
Technical specifications and other physics things aside, always rely on what my old cloth ears tell me. The active 20 towers are actually pretty good.
It would be great to hear from others - with first hand experience - and explain why the active 20 Tower sounds a better speaker, (compared to 40A’s ). @Patu makes a decent effort. Thank you
It would be ideal to hear an opinion from anyone that has actually done this comparison.
Using “search”, only one forum member @Jukemark has recent experience of owning a pair of active 20 towers.
Always been an advocate for finding out, allowing ears to listen and decide after careful thought, based on actual experience.
Best wishes
R
2 Likes
Hi @silverback
Thanks again for the encouragement.
As mentioned previously , intention is always to share something useful and give something back to the forum. Hopefully, others might benefit from the accounts.
One of the themes of this thread is the symbiotic relationship between a great dealer and customers on a longer term journey, building a system. As always, trust ( and benefits) works both ways.
Yes, now looking at active options.
Currently have the PMC Twenty5 23i in our house, for home loan, etc. Will likely pick one of the active options.
Considering our source, with a decent preamp and active speakers, feel that’s a more desirable sound, compared to other passive options.
Adding a pre-loved NAC282 might suit us fine 
The newer NAC332 is a super product, maybe better and doesn’t need an external power supply. But costs a lot more 
Sure, tried to be fair about this for readers.
Experience of really high end systems, they naturally lean towards accurate, transparent, energetic, forward, anyway. ( As more music / information is revealed. @silverback For example, improvement in SQ when add psu to nDAC ). Maybe you’ve experienced this at dealer demo, or events, hifi shows, friends, etc. Active is same direction. For my part, having lived with things, find it difficult to go backwards now.
Maybe try it.
Working with a great dealer - a key theme of the thread - should allow at least a couple of days with loan speakers, to explore for yourself.
Probably best
In our case, feel we need to add speakers first, as this kinda makes the system complete, (for now). But also plotting next few moves too. Which is likely to be PSU for nDAC. Then maybe swapping SN3 for NAC282, ( or better). Hence careful considerations, to ensure it all works.
VFM is always a key consideration (in our house)…
System building on a shoe string, LOL 
Good luck and keep sharing.
Also curious to follow your own journey too.
R
edit : p.s. Agreed. The PMC Twenty5 23i are great looking compact speakers.
edit 2 : @silverback added an extra thought, the example of adding psu, to nDAC.
2 Likes
I think you listed the reasons in your post
It’s also always about system and room matching. 20ASLT will be easier to fit in the room because of less low bass output, which could excite the room.
Anyway, you can’t go wrong with either one. They’re both extremely good speakers.
1 Like
Morning ratrat many thanks for your response, I do feel we are following similar goals maybe with slightly different paths, as usual your approach is very well thought out.
I will be very interested to hear your thoughts regarding the home loan of the 23i’s, these were my first thoughts, when shown an image to my wife she was more than happy especially when I told her they were much smaller than our 26’s, I would guess they would work pretty well in our room (5.5mx3.5m), so for me probably top of my list so far.
I had planned to add a 250dr in the very near future but thinking that I may hold off for the moment.
I have booked a Sunday ticket for the Northern Hifi show in a couple of weeks so will hopefully get to hear the PMC’s in the flesh, plus probably the ATC’s as well, I know it’s not the same but still looking forward to a day out.
You mention psu for the ndac, after some research it seems the non dr version would be the favoured option, old yes but more cost effective and from a lot of accounts seems to marry with the ndac better than the later dr version but personally I have no experience of either so only going by other members thoughts and opinions.
Great thread await your further updates on your progress, again excellent and informative as usual, cheers.
2 Likes
Great post and thanks for update on your own thoughts.
Have now listened and studied both XPS DR and 555 PS, ( back at Basically Sound). Already shared thoughts on those two options. (I’ll find them and post here).
Thoughts on first psu listen : XPS DR …
Thoughts on second psu listen : 555 PS DR …
Yes, Naim lore suggests 555 PS (non DR) is a better match. More “natural”.
Costs effective we like
But can’t help with any personal experience on that one.
Good luck at the show
Do share anything interesting you see or hear?
BW
R
edit : @silverback there you go - thoughts on psu - for nDAC. Hope that helps?
2 Likes
Many thanks for forwarding your other post, again excellent write up.
Not sure regarding the psu, I’ve had mixed feelings in the past, adding the napsc to the 202 I thought was amazing upgrade for the vfm but adding the much more expensive hicapdr I was less convinced, most people say it makes a huge difference but for me that wasn’t the case, have intended to remove it and let the 200dr power the 282 just haven’t got round to trying it yet, perhaps I would appreciate the difference much more, not sure.
I have been hopeful that my local dealer would get a xps or xpsdr in trade so I could borrow for a listen at home just to get a first hand experience of the benefits but from your comments which are very positive regarding adding a psu to the ndac I may take a punt later and purchase one, so many options, this is when it is so helpful to have advice from yourself and other forum members.
Again many thanks for taking the time to reply very much appreciated.
2 Likes