ATC Monitors - 2x2-way plus sub or 2 larger?

I've heard the SCM25's, mids were awesome, highs were nice as well, as for bass... the KH310's would smoke them in regard to extension. How loud do you like to listen? There's a good chance that ATC's will go louder as their dome mid has crazy high SPL capability. And they tune their low end more for SPL, rather than extension.

My main reservation in recommending the SCM50'ies is the low end. For 15k I'd like to have a full range response from my speakers. SCM50'ies might leave you yearning for a sub just as much as KH310ies might. If you want to skip subs, I'd recommend the KH420 instead.

 

I'm a quiet listener - every now and then I'll crank it, but I'd be surprised if I'm seeing peaks above 75 usually. I recognize that I'd be acquiring a crapton of SPL that I won't use to get those mids.

And your concern re extension is valid - even the ATC 150s seem like they'd benefit from a sub. My 7050 goes down to 25Hz so I'm used to that capability. In fact I will just put in a high-pass on the Gennies at 60Hz and see what that sounds like, how much it detracts.

I must say the relative pricing of the ATCs vs Neumanns is sobering. If money were not a consideration I'd add a couple of subs to the 50's and call it a day...but for 15k you could do a lot of interesting stuff. Hell you could biamp a set of those intriguing PAP Trio Voxativs with an Aficionado and a Vidar for way less than that. Which is a whole different kettle of fish of course.

 

I used to have the SCM20s, passive, non-SL version, driven by Bryston 4BST, 250 W/ch. They would only come to life above 90db. If you listen far-field they still might be OK, near-field I would demo them first. The midrange is an acquired taste. Boosted presence region and up to 10K made them sometimes harsh and strident for no reason. A good tool for professionals to find flaws. For critical listening, it depends on your preferences. FWIW.

 

SPL levels is my biggest concern with ATC. Seems they really only shine at higher volumes which is a place I'm rarely at.

It's kind of baffling to me honestly. For a studio monitor company building a speaker that seems to hit it's best performance at higher volumes, who is listening to that day-in, day-out as a mixer? What is the rationale there?

 

Some use them to impress clients, some mix at high levels daily. I haven't found a speaker that could do loud and quiet equally well. My Harbeths are brilliant at low levels but fall apart above 100db.

 

Flatter frequency response, fast transients, high power handling and lower distortion are advantages I’ve read around lower-efficiency sealed-box designs. I’m definitely not an expert in this space however like some others are. Ease of placement due to sealed box as well is a factor.

I would agree with @yvv’s assessment as well that the passives I wouldn’t recommend for low volume listening because of this. Higher efficiency designs are better suited - or active designs, since crossovers can be better optimized. I don’t know that I would say my SCM19s need to hit 90dB to open up, but certainly something closer to 85dB at least.

 

They mix at a set, calibrated volume, which is normally 80-95 db or so. Much of the time, a mix will be done at 85db and then cranked up briefly just to check how it gels at higher volumes or if it falls apart. Nobody is mixing on an NS10 style speaker or an NS10 replacement like the ATC SCM20 at 100 db.

Studio monitors have to go loud due to equal loudness contours. They're not going to approach flatness until crank them past 80 db or so. All the overcompensating small woofer, "full range" monitors faking low end extension with eq and a massive limiter turn to distorting or wool hell as soon as you crank them, i.e. iLoud Micro, JBL LSR 305, KH 80, Kii3.

The danger with something like the ATC 20 is that it has no bass but a long slow rolloff due to it's sealed design so you may be tempted to crank it way louder to get the bass up to normal levels. You absolutely should not buy it for just listening to music. You'd be better off even with a pair of Yamaha HS8 (or Adam A7X) from Guitar Center for example, as they have bass, sounds more normal (HS8 only one of the HS line that actually sounds normal. A7X most normal sounding Adam 2 way), and you won't be tempted to crank them to 100 db to even out the tonality with their dryness. Neumann KH120 is more rounded off, warmed over version of something similar.

Tracking monitors also need headroom past the normal listening level to accommodate percussive transients, guitar amps, string screeches, etc.

 

Maybe a bit of a derail, but just want to confirm - will higher sensitivity speakers generally work better at lower spl?

 

I don't think there is a direct correlation.

The stiffness of the driver's surround: IMO, ATCs are not good at low volume because the rubber or whatever they use should be stiff enough not to add too much distortion or bottom out at high levels. That's why the listening distance might be also important. If you listen to the SCM20 at 6-7m they would have to work much harder to reach the same SPL and over come the sourround's stiffness or whatever keeps them from opening up. Relevant to the 2-way designs only.

The cabinet construction plays its role. Dead and inert cabinets are not very good at low level (used to have the whole B&W Nautilus line and still have the older Matrix 805 model). Thin-walled BBC designs are very good at low levels without exception but they are not as good when played loudly (with few exceptions)

The driver's and cabinet size. Large driver surface area and wide baffles. B&W Nautlius 801 was very good at low volume despite being low sensitivity and incredibly power hungry. At the same time small monitors like Harbeth P3ESR or Spendor S3/5 can be very good if listened very close. Both are closed boxes, by the way.

IMO broadcast, not studio monitors are more suitable for home listening unless you are into heavy and loud music. My son is listening to some heavy trash death metal or whatever they call it in the next room right now on his active Focal CSM40s pro speakers with a corresponding Focal sub and it's a good combination. Considering.

 

I say there is correlation. The higher eff hi-fi bass and mid drivers have high mech Q and soft spiders.
Bass drivers for pro use have good mech Q but strong spider, thus perhaps need some waking up.

 

BBC style cabinets like LS3/5A and Harbeths fall apart at high volumes as they are poorly constructed, being essentially defective by design. More perceived bass content coming through means greater resonance, more bloom, and more time smearing. They’re total crap from the 70s meant for monitoring male speaking voices in vans with the very limiting manufacturing and tech available in the UK at the time. Outside of that use? They’re excrement.

If you’re not listening at anything close to reference levels (around 85 dB), then you’re not hearing the material. A speaker that is bad at normal, 75-95 dB volumes at the recommended listening position is a bad speaker.

There is no difference between broadcast and studio monitors except for awful f'ing shit like the Fostex 6301 meant for news vans. I had that as I got it for nothing. If you pay for anything like that for listening to music and expect it to be high fidelity, then you’re delusional. Broadcasters monitoring dialog only and stuff will just typically use cheaper powered active monitors or headphones. The BBC uses typical Genelec type stuff now, which are way better speakers than Harbeths.

Focal sucks. Nobody considering stuff like big ATCs should touch Focal’s wool and etch with a ten foot pole. Focal are for B&W masochists and Harbeth humpers types only.

 

I recently obtained my first set of BBC style monitors (larger than the LS3/5A) and I’m loving them. They are just way less forward and in your face like the ATCs and most of the other speakers I’ve listened to. I’ve owned Focals as well and didn’t like them (way too tipped up metallic treble and wooly bass) but I’m loving these, which was a surprise even to me.

They are a nice contrast to the ATCs. They do staging, imaging and timbre in a way that kicks the ATCs. And they definitely don’t break a sweat anywhere near the volumes I listen to in my fairly small room. However they’re still pretty inefficient and don’t seem to play great at low volumes either, especially since I don’t listen nearfield (more midfield).

 

High efficiency hi-fi speakers tend to have a rather small headroom. Especially so if single driver is asked to play in a very extended bandwidth. An exception is PA drivers, but very few of them are truly high fidelity. Some are decent, but the focus is on dependability and SPL.

When you run a speaker loud a few things happen. Firstly, the tonal perception changes along the lines of Fletcher-Munson curves. Studio monitoring environments run at 83-85dB which is decently loud, I don't think that many listen this loud at home. Second thing that happens is the harmonic and intermodulation distortion rises as the system is driven harder. Some speakers can sound better this way, if one prefers distorted sound. Also some drivers at higher SPL's change their distortion profile and 2nd order becomes dominant at high volumes. Then there's another psychoacoustic rule - louder ALWAYS sounds better when compared to a lower volume.

As for thin walled cab school of thought... There's a reason why it's all but abandoned, save for some designs where it's marketed as a benefit. I can't stand people idolizing the BBC monitors. They were decent speakers from a time when decent speakers were hard to find. What makes me laugh the most is when some say that these designs were specially made to excel at human voice reproduction. Harbeth even says that they tune their speakers with human voice. Well guess what, the speakers were made to work in production vans and their so-called vocal focus was so that the engineer could pick out swear words when they were out in the field.

With this said - sub-par speaker design is rarely lethal to their performance. Ella Fitzgerald will sing nicely on most of them, especially if the listener thinks that the speakers were specially made for vocals.

P.S. You can find a superb array of graphs here regarding studio speakers. Most of the designs are from yesteryear, but some show exemplary performance. For example, it's evident why ATC SCM20ies sound mid-centric.

 

Dumb question: when y'all talk about SPL in this way, are you talking about peaks or about steady state material? Like if I wanted to know what "ran at 83-85dB" sounds like, would I send pink noise through my system, crank to 83-85dB measured from listening position, and then plan music at the same setting?

 

You run pink noise at -20dBFS, which should read 83dB c-weighed on an SPL meter. So in a studio your system should be 103dB capable.

 

That’s a sweet array of graphs, thanks for that @Hrodulf

Regarding thin wall design, I’ve read the same as you are saying, and was determined not to touch them with a 10’ pole.

But, I tried a pair a couple months ago and they’re a game changer for me. Here’s a review of them in Sound on Sound: https://www.soundonsound.com/reviews/graham-audio-chartwell-ls6

 

All true, but isn't it the same for hi-fi low eff drivers?
Difference is the amount of heat energy wasted.

IMO, only reason to spend time with a Harbeth is the midrange, it is somewhat special in a good way.
The explanations for that are not shown in simple plots.
I do agree, that the religion around these is retarded.
Similar midrange qualities (polyprop mid driver) can be found from speakers with solid bass.

 

Not trying to convert anyone but there is so much confusion and misunderstanding about the BBC monitors in that post.
First of all, Ls3/5a is a terrible speaker and has nothing to do and never has had anything to do with the quality BBC monitors used in studio. It was designed as a speaker for use in broadcast vans and was never meant to be used elsewhere. It's become an object of a strange cult, mainly in Asia but it had nothing to do with the proper BBC monitors used in studios (LS5/8, LS3/6, Spendor BC1 etc).

Typical Ls3/5a response (the graphs are from the Stereophile): Does it look like it would be good or was tuned for human voice?




Now Harbeth M30.2: perfectly flat from 200 to 2K (the mid bass hump comes mainly from the John Atkinson's measuring method). Most of the studio graphs in the previous post, apart from a couple, are not even close :



I wish I could find headphones with the response as bad as above.

Thin-walled designs have their own problems and far from being perfect. To name just one: They are quite sensitive to placement in order to avoid bloated bass. But the same can be said about many ported designs. Bass quality is decent at best. Not very tuneful or tight. I could go on like that for another hour but I'm sure you all know why the thin-walled design was chosen by Dudley Harwood and the BBC Engineering Department in the first place.

I think that to say they are bad because of the strange obsession with the Ls3/5a among certain people is IMO, just wrong . No one who knows anything about the research done by the BBC at the time would even think about the Ls3/5a as a High Fidelity loudspeaker. Hi-Fi speaker my foot.


P.S. Modern BBC designs, represented by Stirling Broadcast and Graham Audio, are , IMO, excellent and moved on especially in terms of driver quality, cabinet and crossover design. They are capable of much higher SPL without compression . The bass quality still suffers IMO. Harbeth speakers are not licensed by the BBC but they are still actively used in post-production. The BBC have done some severe cost cutting and mainly use Genelec and Dynaudio BM5a jobies these days.

 

Why would they be more sensitive to placement than other speakers with omnidirectional bass radiation?

 

First of all it was a rather blanket statement on my part. I just didn't want to pollute the thread about the ATCs with the irrelevant information.

Small BBC or BBC-inspired monitors (Harbeth P3ESR, Spendor s3/5,SA1) are closed boxes and don't exhibit this behavior and very placement friendly.

Medium boxes (Harbeth M30, C7ES3, SHL5, Graham Audio LS5/9, Stirling Broadcast LS3/6) are more problematic and IMO all have this problem to varying degrees.

The short answer to your question is: nobody knows. One would think that it would be connected with the vibrational behavior of a thin-walled cabinet. The measurements show the opposite: thin-walled cabinets produce less audible resonances than thick walled ones albeit with a higher Q. (Source: http://downloads.bbc.co.uk/rd/pubs/reports/1977-03.pdf)

I've had a discussion about this problem with both Alan Shaw (Harbeth designer) and Derek Hughes (Graham Audio and Stirling Broadcast designer) and they both tried to assure me that the problem was room dependent and in my head only. Disagree with both. I'm not the only one among the Harbeth owners who is not particularly thrilled with the bass quality.

My theory ( and it's a pure speculation) that at high spl that vibrational behavior gets out of control, becomes more audible and interacts with the room more because of the sound energy emanating from the top, side and rear panels. You would ask a question why it doesn't affect the rest of the spectrum?
Because the whole idea of the thin-walled design was to push the cabinet resonances down and out of the most important midrange, which is never affected or coloured by the cabinet and is solely dependent on the driver quality etc.

The great news though that this mid-bass bloatiness exhibits minimum phase behavior and when EQed out, the bass lines are crystal clear, tuneful and very easy to follow. Metallica has all the aggressiveness, punch and testosterone. It doesn't make them rock or electronica speakers because even EQed, and with the cabinet out of the equation, the rubber surround of the mid-driver is not, IMO, tuned to produce piston-like behavior needed for proper high SPL speakers. But they are very very good up to 100-105db. Loud enough for me and my tinnitus.

I apologize to the OP, @GoodEnoughGear for these excursions and wish you make the right choice.