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

FWIW, My SHL5plus and Graham ls59 went as loud as I wanted. they can play up to 95db at the listening position without breaking up.

I wonder if the unsatisfactory bass from BBC design is simply due to the 8 inch mid being used in both the graham, spendor or harbeth, most of their medium desing are centenred around a 8 inch midbass. No matter how good the cabinet is, a 8 inch doing bass will never be the most satisfying bass possible

Im pretty sure harbeth 40.1, Graham ls58 or sp100 which all use a 12 inch woofer can give good bass.

 

The unsatisfying bass is due to poor design, not driver selection. Harbeths and other BBC style speakers are defective by design. Yamaha HS8 manhandles all Harbeth with an 8 inch woofer, MDF cabinet, underpowered plate amp, and much cheaper drivers as it's much better designed as a whole

All of the BBC style speakers are bad. Something like the Yamaha HS8 is just mass produced, decent, and lacks old fart audiophile cache due to being everywhere, having dry treble, and not being very detailed.

 

To me it looks pretty clear - boundary loading increases gain in omnidirectionally radiated acoustic energy. As it's mostly bass, then larger speakers will have more increased low end and small ones less so. No speaker can completely avoid this.

This is a great paper you've shared, but I'd have to say that in 42 years since its publication we've learned a thing or two. Both in material science and in computer simulation. Mass loading thin walls is good compared thin unloaded walls, but thick MDF and HDF is abundant these days, so is FEA simulation and intricate bracing techniques (often overdone, sadly).

Here's what KEF has to show.







It is debatable whether the KEF LS50 is really the second coming, but the cabinet was rock solid and there was no trace of cab coloring. What's more - rigid cabinetry is the leading paradigm in speaker design, which is a good indicator of its superiority.

 

Yep the cabs on the LS50 are rock solid for sure. Too bad they’re etched and metallicy sounding and don’t do anything else particularity spectacular IMO.

The Dynaudio Special Forty is another small speaker that sounds pretty great and gets rave reviews, but that I always felt had just a slight amount of fuzziness/buzziness or congestion on certain tracks and certain passages.

This is a thick walled and braced design, but Stereophile found cabinet resonances that were high enough in level or hear:



https://www.stereophile.com/content/dynaudio-special-forty-loudspeaker-measurements

 

So you are giving the KEF LS50, The Speaker for The Dead, as I call it, as an example of what the industry has achieved in 42 years? You can't be serious, you are just pulling my leg, right? You forgot to include one more graph, the frequency response of the KEF:



So much for FEA simulation and intricate internal bracing indeed.

I think I'm incredibly lucky here. For years, since The KEF LS50 was introduced and watching all the hype around it, I've been asking myself and people in the industry a simple question. And you, as someone who , if I understand correctly, does the frequency response correction for living, are possibly one the best persons to answer: What is this speaker good for? Obviously you think it's a good speaker if you are still debating whether it's the second coming and giving it as an example of the industry achievements. But what is it good for?

 

it baffles me. People use speakers in untreated rooms, where bass reflections are actually what you hear

how the hell can the cabinet be heard when you have bass reflection almost as loud (about 5db less then the direct signal) as the direct signal

so really, if you listen to your speakers in a untreated room, talking about the "cabinet" hearability seems ridiculous

the highest cabinet modes that I see in measurements of BBC speakers are 40db. well this is not something you can hear when you listen at 80db at the listening position. can someone enlightened me?

 

It's not the cabinet radiation as much as the influence to the transient behavior.
Wild guess, but I bet the group delay might be horrific up to high bass,
whereas from traditional stiff speaker it sucks low down only.
What ever the explanation it would be even wilder to say a Harbeth making tight bass. No matter the room.

 

JA of Stereophile has included them both in Class A (restricted LE), LS50 pulled it off with costing 4 times less. With roughly 4.5" of woofer it gets the same low end response as the M30.2 with 7.5". I really hope that the Harbeth has way better SPL due to extra moving area.

I don't know how exactly JA measures speakers, but my LS50 measurements looked like this -



70Hz is a room mode, 140Hz seems like a table bounce. The curve was plotted from 70 measurements in my living, measurements have been weighed according to their proximity to listening spot. The 1.6kHz dips looks subpar and tweeter response seems to follow some Hi-fi tuning.

What in my opinion doesn't look too good in the JA measurements of the M30.2 is the waterfall plot -



Compare that to the LS50 -



Paying 4x the money should get me at least a cleaner decay plot?

I'm a marketing person who sells frequency response correction for a living. We don't let the scientists roam free on the forums!

I bought my LS50ies, funnily enough, after a listening session at a local dealer. That was before Sonarworks headhunted me and stuck a measurement mic in my hand for the first time. I liked the looks of the speaker, after reading the whitepaper the science behind it made sense and I loved how it sounded. So, it might've done something right!

As with most popular things, it's probably overrated in some aspects, but I never found it to be especially harsh or dead sounding. And the coax driver threw a very wide sweetspot with almost no tonal shift if you'd move around.

I'd say the audibility of cabinet radiation will most probably be very listening material dependent. For stuff with very little going on it might actually make individual sounds richer and add extra space/body. Not unlike harmonic distortion. I do fear, however that the benefits of this might invert with busier stuff, where it would smear details. -40dB is considered audible, when talking about distortion. I agree that the actual audibility will be room dependent, but I can't see the benefit that comes from this compromise.

 

You know what is the most interesting thing about the JA waterfalls? He takes the highest peak and goes 24db down. So a speaker with the more uneven response will be looking cleaner that a neutral one . It's very obvious even on the graphs you've just quoted. For the graphs to be comparable we would need 36db or 48db waterfalls, but that wouldn't go well with the manufacturers, would it? I'm sure JA knows exactly what he is doing and he is doing it on purpose.

If you personally own and like the LS50 than you are probably one of the people who are not sensitive to the timbre of metallic drivers. Good. Have you listened to the Harbeth P3ESR?

 

4.5 inch of the ls50 exhibit 10% THD at 100hz at 90db.
who cares how low a 5 inch woofer can go when the midbass souds like a toy. btw, the kef ls50 bass sounds objectively coloured

Ive owned the ls50. they dont play even remotely close to the shl5+/30.1.

 

Harbeths objectively suck more. Totally smeared and incoherent. FR doesn’t matter as stuff with worse FR is less smeared and more coherent. The waterfall plots are going to be totally messed up as well as the impulse response. Even the bigger ATC impulse response is far, far from normal and Harbeths are far far, worse sounding in the same low end problem spot of ATC. They’re indefensible, expensive toys that sound like crap.

Harbeths are for deaf people who eat Metamucil for breakfast and listen to Diana Krall. More deaf old farts would probably prefer non LS50 KEF anyway as they can’t hear the highs and the bigger KEFs giant v shaped rock out speakers like Porta Pros made huge and expensive as HitmanFluffy put it better than I can and there’s no reason for another analogy.

LS50 is thin laser beam and is worse sounding than some cheaper KEFs. All are murderous on axis. Sure KEF kills Harbeths but how LS50 became so hyped, I do not know. LS50 isn’t a very fun speaker. I think it’s the car paint.

 

Im pretty sure you have no personal experience with BBC speakers; they are not perfect but ive never heard anyone who have owned them describe them as "awful". You seem to enjoy expressing disgust of many audio products that you have never owned or even had in your system .

im not convinced in typical rooms that the cabinet resonance can be heard. theoretically, when it comes to room acoustic, cabinet resonance ala bbc cannot be heard since the bbc cabs coloration is in the bass region where room modes totally dominates the LF.

 

They’re f'ing awful. I would never, ever buy a BBC speaker or Harbeth as I think, okay so don’t just think I know as I have perceived, that they’re dogshit. If you think that I should buy something that I know is truly dogshit compared to speakers I have liked and the ones I have owned in the past then you’re sadly delusional.

Just because you were impulsive and naive enough to actually buy Harbeths (aka dogshit) yourself, doesn’t make you a universal determiner of the validity of whether dogshit is dogshit. You do not need to be Divine in Pink Flamingos munching on dogshit to know what is dogshit. Harbeths sound like shit in comparison to most everything else in untreated rooms too. Just because you can’t tell the difference doesn’t mean that there isn’t a difference. LS3/5a are shit too. The BBC switched from them and the bigger ones as Genelecs are better in pretty much every single way, even the old 1030a and 1031a. Their superiority doesn’t take a terribly attentive person to realize either.

 

KEF measurements show main resonance at 170Hz and 350Hz. Not sure if thats what I'd call bass.

 

The waterfall of the Harbeth M30 shown in this thread is very very clean to my eyes. It closely follows the frequency response with almost no hush. One of the best I've seen from the Stereophile. All those high mountains and ridges can only scare people who don't have a clue, especially bearing in mind that we are dealing with one the best FRs ever measured by the Stereophile so it should look high and deep and ominous. Waterfalls have very little value in terms of telling us how a loudspeaker would sound like without looking at other measurements. The only thing that particular waterfall tells me that this speaker is a good candidate for EQ without any adverse (phase shifts, added distortion etc) effects and if it's done properly can sound true to the records. Which it does. The KEF's waterfall doesn't tell anything. Too shallow. And with a frequency response like it has, who cares about waterfalls anyway?