ATC active vs. passive

Perhaps poster @lonemountain can chime in. He has extensive knowledge of and experience with ATC speakers. 

I love tube amplification and worried that if I get an active model I may not achieve the tube sound. I read that active amplification is superior for multiple reasons but would that trump the benefits of tubes? Would I regret actives in the long run? 
would it be possible to easily convert active to passive ?

hi @ei001h

There are some dealers in the north east with 50s, so you need to call the main Lone Mountain office in Las Vegas for more specific info or look up the website.

Now to answer your question, comparing 40 to 50, the big picture idea is ATC focuses on low distortion drivers across all models as bandwidth gets larger. Then ATC explores the entire active vs passive issue with passive and active versions of nearly all models (like the 40 you mention and the models below in price and size and models above).

Most ATC models sounds quite similar and are classed by dynamic range capability and resolution as well as bandwidth. This means you can select a model based on what’s best for the budget, room size, SPL requirements, low end requirements, dynamic requirements, etc. So ATC doesn’t do the "larger/more expensive is always better" thing like most companies do.

Active gains you more resolution, better imaging and lower total system cost (you get 3 amps in each speaker as part of the active package that are all big linear power supply and low distortion Class AB designs). This enables phase adjustments and other things internally that you cannot do in passive system- no matter how good the amp is in said passive system (even ATC passive). In active, colors of the amplifiers and sources shine through more than in passive system due to the lower distortion nature of the design and removal of the masking distortion left behind by a passive crossover and cabling. If you are a tube lover, I recommend you get a great tube preamp-it will definitely sound like a tube system. Active reveals more about cabling, phono stages, cartridges, CD players- everything in front of the amplifiers/speakers. All of these values are really choices for you to make and not all of these values appeal to everyone. For example, if you are in a 10x12 room, this extra bass may not be worth it (a 10x12 room cannot support much below 55Hz or so). The "clearer below 720" value might be worth it to you if you listen to a lot of orchestra or a lot of vocals or piano and could be more important to you and this would mean you don't need a larger speaker. If you are an acoustic guitar fan and like that type of music, spending money on getting lots of deep low end by going larger may not pay off for you.  Then something like the 20 might be better, small , lower cost, but still supere resolution.

So if those values of more low end, clearer lower midrange and bass and better dynamics attract you, then investigating the larger ATC models like the 50 would be a good idea. If not, the 40 is a great speaker in both passive and active forms. The sound would definitely be very similar between them.

Brad

Lone Mountain

ATC Importer to the US 

Looks like ATC will be on display at the Capital Audio Fest. Not sure what models.

https://www.capitalaudiofest.com/exhibitors2024

@lonemountain 

appreciate the detailed response

1. I have a big room, 45 x 15 ft

2. listen to classical, piano and large scale orchestra at high volume 

3. absolutely love tube sound and have the ability to bi amp a passive system if needed. I enjoy the harmonics that tubes bring 

4. I value accurate tone and timbre of musical instruments, especially cello piano and violin. 
 

5. I have an all analog system with TT and tube everything in the chain 

knowing all this, would you still recommend an active over passive ? 
in what situations would passive be recommended? 
 

Thanks 

As stated often here, it's best to audition, both if possible. I understand that can be difficult to do but we all perceive things differently. My experience as an active speaker designer / manufacturer is that, all else being equal, an active version and a passive version of the same speaker can sound very different. Even when using the same amps. I won't go into the many benefits of active speakers here (there are volumes written about the subject by people much smarter than me) but my experiences strongly suggest that active systems usually perform better if properly designed.

I understand your concern about the amplification used. Like yourself, I prefer tube gear and use tube amps and preamp in my personal systems. Our active speaker systems are different than the ATC active systems in that you can use any amplification you choose, be it solid state or tube gear. Some of our customers use 300B SET tube amps and other use 200 watt solid state amps. They both sound different and both can sound great. The customer makes the choice.

I have not heard active ATCs only passive so my comments speak only to active vs passive system. 

At the shows I have heard both the active and passive ATCs. The passive speakers were being driven by a S.S. amp. I thought the actives sounded much better. In fact, I really liked the actives and thought the passives were pedestrian sounding. Could have been any number of factors.

we have both the 40 actives and passives on display

so if you want to demo both we can do it for you.

Dave and Troy

audio intellect NJ

Atc dealers

I'm interested in 50 and above. Where can I demo those in NY/NJ/MA/CT area? 

Brad gave a great description of the ATC 50. I'll add a big reason why active is better. Amplifier tests are done with resistors of a given value. Real speakers are not resistors to the amp, the are also capacitors and inductors and their affects vary with frequency. Amps like resistors, not capacitors and inductors. That's why great amps spec often like ordinary amps but sound better. They are built(big part is the power supply which is costly) to handle capacitive and inductive loads. Active speakers are much less reactive. The crossover comes before the amps. And that is a big deal.

I'll ad one historical note. My friend, Gordon Holt, the founder of Stereophile purchased a set of active ATC 50 speakers. Gordon had a great ear. And he did a lot of live recordings. He told me the ATC 50 active speaker was one of a very few speakers that made his recordings sound real like they sounded when he was recording.

@arion wrote:

... my experiences strongly suggest that active systems usually perform better if properly designed.

+1

Our active speaker systems are different than the ATC active systems in that you can use any amplification you choose ...

Which simply implies that your speaker systems are outboard actively configured, whereas the ATC’s are bundled active speakers (with the exception of the SCM300’s). I find it’s commendable that you’re working from an outboard active platform (like I do myself, and which any DIY’er/audio entrepreneur can pursue) that grants the user the freedom of choice with regard to amplification, and essentially any other aspect (and I’m aware much more than outboard active config. alone is part of your product concept).

Moreover: this way the dichotomy between active and passively configured speakers systems can be diminished, as most see it as - in effect - a bundled vs. separate component distinction and solution, and not as something that per definition comes down to where and how the crossover function is applied, and that both of these approaches can be attempted as separate component solutions.

Active vs passive-- keep in mind that the amp inside the speaker will probably not last that long.  If you want to potentially keep your speakers for decades, then I would go with passive.  I'm not saying that the internal amp will die in a decade, but why take the chance?  How long is the warranty on the ATC actives?  This is not a comment on the sound of the ATC's.  This is just a comment from someone who owned a sub-- a $2,500 sub-- that died after a decade due to the internal amp dying.  Class D amps are notoriously difficult to repair.  I'm guessing that most active speakers have Class D amps inside them.  Anyway, just my 2 cents.  If anyone can counter what I'm saying here, I'm all ears.   BTW the manufacturer quoted me a price to fix the sub that was about 75% of what I paid for it.  So I passed on that.

I don’t want to derail this conversation, but the whole solution really matters. I have not heard ATC’s nor am I privy to their internals. The correct approach, IMHO is to listen and judge for yourself.

Having said that, I want to point out that just because ATC makes 2 versions of the same speaker box with the same drivers doesn’t mean the choices in the crossover are the same, so a lot of these points about one or the other version being naturally superior are hard to prove. For myself, I would find it nearly impossible to make the same passive and active speaker. The biggest difference between active and passive is that I have to make fewer design compromises in an active speaker.

For instance, I just made an active 3-way center channel with 4th order LR filters between every driver, all drivers in positive polarity. I’d never attempt this as a passive, and would be relegated to 2nd and 3rd order filters and highly unlikely they’d maintain the same polarity. Active, especially with DSP, just makes everything so easy. If I were at ATC, and they asked me to "activate" an existing passive speaker it would be just incredibly tempting to enhance it’s performance when transitioning.

So, point is, no idea of the ATC speakers attempt the same driver crossovers, polarity, etc. so hard to use them as a judge. In fact, it’s just super hard to do a real apples to apples comparison of any active vs. passive speaker. Judge the whole package and do so on a case by case basis.

My tube amp is Auris fortissimo, 100W Push pull. 
I’m concerned it wouldn’t be enough to power SCM150 that I’m considering. 
I have a big room, I like to listen at high volume. I am in the position to buy anything ranging from 50 to 150 both passive and active. I’m trying to make the right decision 

@erik_squires wrote:

If I were at ATC, and they asked me to "activate" an existing passive speaker it would be just incredibly tempting to enhance it’s performance when transitioning.

Exactly, because that’s what active config. offers. Which is to say: it’s not about "fairness" of comparison vs. passive, but what active qua active can offer.

So, point is, no idea of the ATC speakers attempt the same driver crossovers, polarity, etc. so hard to use them as a judge. In fact, it’s just super hard to do a real apples to apples comparison of any active vs. passive speaker.

ATC isn’t going for an altogether different "voicing" passively, but rather will aim for the crossover option that best accommodates the design passively. Conversely the active iteration will take advantage of the design options given here, like amp-to-driver direct connections, shorter cable runs, precise phase settings for each driver, amp-load independent driver sections, (line level) crossover values being impervious to load (read: heat), different i.e.: steeper slopes, etc.

So, the point isn’t really an apples to apples comparison between the passive and active iteration - in fact it’s not necessarily desirable nor possible - but rather what each design route facilitates and is inherently limited by or has an advantage through.

That being the case - with the same drivers, speaker housing and product sound philosophy - you don’t get much closer to a bearing on the overall capabilities and characteristics offered by active vs. passive here. Even with different amps over the passive iteration you will get the general idea vs. active.

As I’ve mentioned in another thread long ago, I have done a very close active vs passive comparison at a trade show - same speakers, ATC amps for passive system run passively biamped, active using the internal amps with the same output devices and design in both active and passive.. The power available in both systems was roughly equal. The active system exhibited much bette imaging and better high resolution of fine details like room sound, reverb tails, harmonics on piano, acoustic guitar, violins. I offered visitors to the room a choice to pick and not everyone picked the active - although I couldn’t understand how they couldn’t hear those improvements.

One note - the comment about amps not lasting a long time inside the speaker is simply not true - unless it’s crap amp. They are in their own separate enclosure even inside the speaker and there is no shared space. Also all ATC is class A/B, not class D. That being said, we regular service active speakers that are still working after 30+years! Many studios use them 24/7 for 10-20 years. With 6year warranty we see very little failure.

brad

Op 100watts of tube power drives the 40s beautifully 

We have driven our 40s with a 100 watt Synthesis a100 sounds fantastic 

DAVE AND troy

Audio Intellect Nj

ATC DEALERS 

@lonemountain 

Thanks for your input. 
“The active system exhibited much bette imaging and better high resolution of fine details like room sound, reverb tails, harmonics on piano, acoustic guitar, violins. ”

I understand what you said above. I recently auditioned Wilson XVX and I was blown away with every metric that audiophiles find valuable. It was the most powerful, transparent, detailed with perfect accuracy and imaging that I’ve ever encountered. However, it was not enjoyable engaging or musical. It was analytical and clinical. That isn’t what I want. That’s why I’m entranced by tubes. The beautiful sweet sound with rich harmonics is that I’m after. I’m used to high powered SET sound  

would you still recommend actives for my taste ? 

@lonemountain

I have the smaller SCM 19’s bi-amped using the connectors on the speakers. Does bi-amping bring some part of the improvements of the active version?

I find the accuracy and imaging to be excellent. The speakers ’disappear’

Solo piano sounds like it is the room. I have extra speakers for HT and sometimes I feel sure the surround speakers are being used when listening to regular 2-channel.

@lonemountain 

1. is it possible to self modify Active into passive down the line if get tired of active and would like to try other amps ?  Is it possible to purchase passive crossover and swap them at home? 

2. 150 is considerably wider baffle than 50. How does this affect the imaging and the ability to disappear. Logically, 150s should be much harder to disappear 

The OP needs to make an appointment to listen to whatever speakers he decides upon because he has very particular tastes about the flavour of what he hopes to hear.

By all means discuss and consider what others have to say, then leave home and listen, to anything really. Go to the nearest big city and make a trek from dealer to dealer. Tell them your budget and ask if they have anything they think you should hear. Listen. You might find something entirely different to what you envisaged which blows your mind. Or not. Get out and listen.

I have passive ATC SCM40 v.2 speakers in a 22 by 24 foot room, which replaced similar ATC SCM35 speakers. I replaced the speakers after 18 years of ownership primarily because the production of the tweeters was moved in house, and the treble became significantly smoother and less hard with poor recordings. Otherwise, they sound and behave similarly.

I initially ran the SCM 35’s using an Audio Research SP6B preamp driving a Conrad-Johnson MV75-A1. The C-J amp was not able to control the woofers well enough for my liking, and I brought a heavily rebuilt GAS Ampzilla out of retirement, which did a significantly better job of driving the speakers dynamically.

After replacing my preamp with a Cary SLP05 with ultimate upgrade and my Ampzilla with a new production SST Son of Ampzilla II amp, I upgraded my speakers. This combination drives this speaker really well and is what I would recommend. I have also driven the system with Schiit Freya+ and original Saga preamps, and would think amps like the Schiit Tyr or PS Audio BHK series would be great.

 have also heard the active ATC SCM40’s numerous times and to my ear they have a sense of tremendous dynamic control and really excellent imaging and sense of inner air and space, as Lone Mountain (the US distributor) suggests. I think my setup approaches the active ones, just a bit less effectively. I wholeheartedly recommend both setups, but definitely with solid state amplification and tube pre amplification.

There isn’t a single dealer in the northeast that has ATC SCM50 or higher.
I’ve auditioned most other brands ranging from 10-300k, none of them had the dynamics, timbre and accuracy of ATC except Avalon acoustics Saga. Those are the very best I’ve heard but the price is out of reach. 

I auditioned SCM40 active and passive. The active demo was controlled by ATC preamp. The passive was driven by North Moon 641/681 DAC ( this DAC was also the source for the active setup)

I preferred the passive setup; I ended up purchasing the passive SCM40 v2 to use with moon 761/791. Super happy. These speakers have taught me a lot regarding natural sound and high performance. I understand why there is so much praise for ATC.

@ei001h 1. is it possible to self modify Active into passive down the line if get tired of active and would like to try other amps ?  Is it possible to purchase passive crossover and swap them at home? 

NO this is not possible due to the calibration necessary to set individual driver loves to build cohesive anaphase linear system.  Theoretically you could purchase an ATC passive crossover (for the model you have). Installing it would not be something to do at home.  You'd have to remove most of the drivers to get inside the box. 

2. 150 is considerably wider baffle than 50. How does this affect the imaging and the ability to disappear. Logically, 150s should be much harder to disappear.  The wider baffle is of course to fit an 15 instead of a 9 inch woofer.   The waveguide on the midrange and tweeter do not allow the drivers to depend on the baffle for pattern control;  the dispersion pattern from these drivers is less than 180 degrees.   I have heard the 150s sound as good as 50s but with more low end due to the larger woofer.  Doug Sax, mastering engineer extraordinaire, (now passed) used 150s installed in a soffit to get the ideal, bass is now working into half space instead of full space. So no I don't think this baffle width is a major factor in comparing these two models (although I will ask engineering about it).  In 20_ years I have never had anyone note this or say they can hear this difference.  Rooms are such a major factor influencing imaging and the ability of the  speaker to disappear.  1st reflection problems can dramatically affect this aspect of speaker performance.         

@theophile 

+1 and excellent post.

I have passive 40s V2, driven by an older solid state Musical Fidelity amp. When I got a streamer and a DAC with warmth—in both cases—everything became a little bit tubier. I’m very happy with my system now. You can definitely warm up solid state power with your source and your DAC.

ATC 40A was my first active speaker, 3 years ownership.  Dynamic, fast attack, nice imaging.  Could be an end game transducer.  It's that good.  Moved to ATC 50A.  It is a very different animal.  More of all that's great about the 40A.  It's quite simply in a different league, as it should be.  My end game transducer.

These benefit greatly from Townshend platforms, Furutech DPS 4.1 power cables  and of course everything done properly upstream.

Have fun

I'm leaning toward 150 passives. Part of this hobby is constantly playing and tweaking with components. 

What tube amp would pair well with ATC?  I'm open to integrated as well. I doubt my current 50 and 100W tube amps will do justice on 150. 

I heard the Mcintosh hybrid amps are too slow for ATC. 

I’ve no experience driving ATC speakers with tube amplification.  However, I abandoned tube preamplifiers as they were simply too slow for the speed of the 40As and 50As.  This happened with my Manley Jumbo Shrimp, Manley 300B and highly modified de Havilland.  I moved to Sugden and Luxman C900u.

Also run passive ATC 20s with SS and 7s.

The 150 is a physical monster.  I hired piano movers for a second story location of my 50s.  Best of luck with the quest.

I have a pair of ATC SCM50 passives running through a c900 and m10x pre/power combo.  For me this setup is all I will ever need.  Silky smooth at low volume and that's retained at much higher DB.  They match very well.  

Another variable to consider is in the active option, is it using DSP or using analog xovers?  You can have active but without DSP.

If using DSP, I am assuming the speakers take the digital signal directly from the cd player, perform DSP, then using an internal DAC to convert it back to analog before feeding it to the internal amp.  

For example, if you have a 3way speakers, you will need 6 DAC, three for each channel, which won't be cheap.

I bought ATC scm40 and powering them with luxman 595, MASTERSOUND 845 and Grandinote Shainai integrated amp. 
I like the tonality and happy with low end. However, the tweeter is inferior to my Triangle Magellans. I’m still interested in ATC 50 and 150, hoping the tweeter is a big upgrade from the 40. 
if I get the 150, I probably won’t have enough to upgrade my amp for a while. Hopefully luxman 595 is enough. 

OP,

Your thoughts on the larger ATCs are justified. I can still recollect the boogie factor on the large ATCs. They were playing Daft Punk’s Loose Yourself to Dance. It was late evening and I was tired. But still felt like dancing! Stayed back in the room till the song finished. Go for it, if you can. You can get a powerful amp later. I believe they were using some Audionet amplifiers, if I am not mistaken. But a memorable experience.

@ei001h 

Do your SCM 40s have tweeters that sat "ATC" engaged right in the metal flange around them?  If it doesn't, these are the older SEAS tweeters used in the SCM40 Mk1's , while the newer SCM 40 Mk2's use the ATC hand made tweeter introduced in 2017-2018 or so. Now ATC is using only their own tweeter in everything

Brad.       

I have the scm40 MK2 version. Still lacking to my ears compared to Triangle Magellan. I know ATC SCM50 and above have a superior tweeter just not sure how much of an upgrade it will be. 

@ei001h 

What speaker cables are you using and what power cord for your 595? Had that amp 2x and it’s pretty sensitive to power cords. Top end can can trimmed to your tastes pretty easily. 

On my SCM40 I am using Audience Front Row and a DPS 4.1 power cord. Seems to be excellent synergy between the moon 761 power amp and speakers. I have no issues with treble and think the top end is detailed and refined sounding.

I did notice a difference, for the better, when I used DH labs silver jumpers. I am running the jumpers between the teeter and woofer (using the stock plates for now to mid) and I do the AudioQuest recommended way of connecting the speaker cables across the binding posts. 

Lastly, how many hours are on your SCM40’s?

cheers

Speaker cables : 

1. analysis plus solo crystal oval 8 

2. nordost hemidal 2

power cord 

1. Analysis plus  Ultimate power oval 

2 analysis plus power oval 10 

stock jumpers 

scm40 has 500h

I used to have  Analysis Plus full loom (same speaker cables you have) and found it clouded the soundstage. Eventually moved to Purist audio and Nordost for power which was a step in right direction for opening up. Not a fan of AP for power cords on any component. Totally different system, but I think you have many options of tweaking the top end to your expectations. I have found the ATCs to be a very neutral reference. 

Had Heimdall 2 on my Harbeth shl5+XD and found the sound too warm, almost muffled sounding at times.  Audience Au24 sx was much better.

https://partsconnexion.com/speaker-bulk-cable/
For not much money, I believe you can improve your lot.  Also, dpac996 is correct with the Furutech DSP 4.1 recommendation.  Cheers

@ei001h I was looking at the other amps you used with your SCM40’s; The Mastersound starts clipping (1%) around 10 wpc. The Grandinote is rated at 37 wpc and starts clipping (1%) around 30 wpc. Neither amp produces close to double the power as impedance goes from 8 ohms to 4 ohms. The Luxman 595 (very familiar with this, as I used it for many months with Harbeth SHL5+XD) is rated at 30 wpc into 8. The 595 is the most powerful amp out of the three. However, given the Class A envelope and overall low eff of the SCM40’s I can imagine a sound that is not all that stretched out at the extremes. The SCM40s need a wide power bandwidth amp (minimum 75 wpc, better with more power) to show the listener what they are truly capable of. If you don’t change your amps but get the larger ATC’s ( even more power hungry) I am pretty sure you will not get that sparkle and air you are missing.
I am confident that amps such as Luxman L509X/Z, Ayre VX-5 Twenty, Moon 760/761, Boulder 866, Gryphon Diablo 120, etc., would bring you the added sparkle and improved dynamics that I think you are missing with the low power class A and tube amps.

@dpac996

your statement about my amps matches my observation exactly as you predicted

GrandiNote and MasterSound ran out of steam very quickly, I had to max out GN volume to 100% and it was barely adequate

same with MASTERSOUND, beautiful midrange and highs but absent low end

luxman by far the most powerful and I am using it exclusively. 
 

I also have Auris fortissimo tube amp which is 100W, but 595 sounds better 

Which tube amp do you think would do justice to scm150?

SCM150 are serious business :)

I love tube amps. One of my all time favorite tube amps is a Luxman MQ-88uc, but careful consideration goes a long way, as i'm sure you know: room/speaker/ realistic expectations on scale etc.

With the SCM150 and your big room you will probably need to look at push pull tube amps well over 100 wpc. ARC 160S, Carver M350, Octave monoblocks...

I will tell you that I am getting fabulous results with a Moon 761 north amp; The ATC midrange is super special and I'm hearing liquidity and natural vibrant warmth that makes me thinks there are tubes in the chain. I think with any tube amp you are going to be dealing with compromises on big speakers like the SCM150's, but sometimes you can hit on a synergy that defies the paper predictions.