There is no ATC SCM150ASL Pro review or frequency response curve.

[Sacha]

Yeah, you can educate people without acting like a haughty know-it-all prick. I've posted my actual real-world experience here, from going outside, touching grass and listening to / working on speakers. Speakers that don't have comprehensive measurements published on the internet, admittedly. If that holds no value for you then wonderful, use whatever speaker you like and measures best, I truly dgaf I'm not trying to sell you or convince you of anything.

PS directivity is not the only metric that matters when evaluating a speaker. Even if we had directivity measurements for the speakers I use, which we don't.

 

[Ktacos]

4.5-5.5 kHz at least. Also, doubtful the 4kHz dip of that magnitude is edge diffraction.

If it is, just as much an indictment of the speaker and the brand when people have figured this out for the last 20+ years.

So yeah my intuition was correct, you're confusing edge diffraction with a DI mismatch. The crossover point of this speaker is 2.2khz, well below the issues you speak of. That region appears to be very clean in terms of dispersion.

If you think those issues are of too great of magnitude to be from the edge, well all I can say is you've possibly not tested much in the way of edge terminations on baffles. That is like textbook edge diffraction artifacts.

 

[kma100]

I didn't notice you in the rooms...

I believe the skepticism comes from the fact that the speaker measures really well and has many subjective positive reactions to it. Your "worse speaker" comment is a bit surprising and doesn't match with what people are hearing. Of course it might have been a room/speaker issue for you, but even then knowing its properties, it seems highly unlikely it was *that* bad!

 

[Jimbob54]

Yeah, you can educate people without acting like a haughty know-it-all prick. I've posted my actual real-world experience here, from going outside, touching grass and listening to / working on speakers. Speakers that don't have comprehensive measurements published on the internet, admittedly. If that holds no value for you then wonderful, use whatever speaker you like and measures best, I truly dgaf I'm not trying to sell you or convince you of anything.

PS directivity is not the only metric that matters when evaluating a speaker. Even if we had directivity measurements for the speakers I use, which we don't.

We don't talk to each other like this here.
Next time will be a formal warning. Thanks

 

[dfuller]

We don't talk to each other like this here.
Next time will be a formal warning. Thanks

Hey man, I appreciate the desire to keep it cool - but I do recommend you look at Ilkless's posts in this topic. Very inflammatory.

 

[dfuller]

Quite, a trip to the measurers would sort all this out, as if that is ever going to happen.
Keith

Well, we're in luck, because we actually had this exact thing posted earlier in the thread. Look what it does at tweeter axis - Exactly what shows up on S&R's graph, a big HF boost and a very narrow suckout. I'm chalking this up to measurement error.

 

[Jimbob54]

Hey man, I appreciate the desire to keep it cool - but I do recommend you look at Ilkless's posts in this topic. Very inflammatory.

There is an awful lot of posts from many folks in this thread with a less than ideal tone.

But I only saw one equating a member to a ***** or not giving a fuck about someone's opinion .

But yes, a polite but firm request to all members to chill out a little or I will lock the thread down as I'm not sure what is left to be said that is constructive .

 

[goat76]

I really don't understand where that high boost is coming from because it sure as shit isn't audible. My guess is measurement error - ATC's measurement axis is 5 degrees below the center of the midrange, and people miss that part. It doesn't show up in other measurements of the 25 either.

That doesn't look like SCM25s at all to me. I had them next to KH310s and they were a little softer up high if anything.

My understanding in science is poor/incorrect data is worse than no data at all.

Yes, the measurements for the SCM25 are most likely done at the height of the tweeter, but that is not the correct height as all ATC's 3-way loudspeakers have their acoustic center at the height of the mid-dome driver. The measurements on the SCM40 done by AVMentor are also likely done at the incorrect height.

Here are two measurements of my SCM40s. The orange one is measured at the correct height which is the height of the mid-dome driver, and the blue one is done at the height of the tweeter which is the incorrect way of measuring ATC's 3-way speakers.

 

[MAB]

I love the responses when the suggestion of measurements and ATC are used in the same sentence.

I do think measuring speakers should be a priority in the industry. It’s one of the reasons this site exists. And the point of this thread, as provocative as the suggestion may seem. Would prevent some of the arguments, or at least provide something to argue about.

 

[Purité Audio]

Well, we're in luck, because we actually had this exact thing posted earlier in the thread. Look what it does at tweeter axis - Exactly what shows up on S&R's graph, a big HF boost and a very narrow suckout. I'm chalking this up to measurement error.

View attachment 410035

I can quite believe it Martin lives just up the road from me and his measuring room is not much more than a cupboard.
Standardised Klippel measurement is imo clearly the way ahead.
Keith

 

[Sokel]

Height of measurement (and listening of course) is absolutely a thing for highs.
Here's how mine (non-ATC's) measure (in room-non gated,1m) at tweeter/mid/ and between (labels down the chart) :

and at 1/24 for detail:

 

[AudioJester]

So yeah my intuition was correct, you're confusing edge diffraction with a DI mismatch. The crossover point of this speaker is 2.2khz, well below the issues you speak of. That region appears to be very clean in terms of dispersion.

If you think those issues are of too great of magnitude to be from the edge, well all I can say is you've possibly not tested much in the way of edge terminations on baffles. That is like textbook edge diffraction artifacts.

The irony here being that the ATC advocates suggest ATC dont provide measurements because people interpret them incorrectly. Maybe ATC got it right lol

I need to back to Amir's great videos on spinorama interpretation

 

[goat76]

I'm amazed someone can so confidently proclaim ATC's engineering superiority from intuition and anecdotal experience when they can't even see a directivity mismatch stare them in the face of the measurements they make

4.5-5.5 kHz at least. Also, doubtful the 4kHz dip of that magnitude is edge diffraction.

If it is, just as much an indictment of the speaker and the brand when people have figured this out for the last 20+ years.

So yeah my intuition was correct, you're confusing edge diffraction with a DI mismatch. The crossover point of this speaker is 2.2khz, well below the issues you speak of. That region appears to be very clean in terms of dispersion.

If you think those issues are of too great of magnitude to be from the edge, well all I can say is you've possibly not tested much in the way of edge terminations on baffles. That is like textbook edge diffraction artifacts.

Yes, there is a lot of irony here.

 

[AudioJester]

Yes, there is a lot of irony here.

They are all still correct that in this day and age its inexcusible to not provide detailed measurements for expensive speakers, particularly when they can even get it done for free!

 

[Ilkless]

So yeah my intuition was correct, you're confusing edge diffraction with a DI mismatch. The crossover point of this speaker is 2.2khz, well below the issues you speak of. That region appears to be very clean in terms of dispersion.

If you think those issues are of too great of magnitude to be from the edge, well all I can say is you've possibly not tested much in the way of edge terminations on baffles. That is like textbook edge diffraction artifacts.

I know XO is 2.2kHz. This doesn't mean the mismatch has to be centred there. CtC, cone and dome profile, XO slope are all confounding variables.

I didn't totally discount edge diffraction. What I'm saying is there are diffraction artefacts, that are layered upon XO issues.

The window across which the dips occur is not indicative of an isolated diffraction artefact. That looks at least a 15-20° window -- way to wide to be predominantly diffraction.

Your assertion that it is predominantly diffraction does not corroborate with John Atkinson's measurements over the years of normalised off-axis behaviour that all show a flare.

But go on, go and legitimise and platform the woo woo purveyors.

 

[Ktacos]

But go on, go and legitimise and platform the woo woo purveyors.

It's like your goal was to be set to ignore, which is a request I will happily grant. Not sure what's up but people have been unusually nasty on the site as of late.

 

[DRNNOO]

PS directivity is not the only metric that matters when evaluating a speaker. Even if we had directivity measurements for the speakers I use, which we don't.

In real life, measurements is how loudspeakers are developed and used extensively in the engineering of loudspeakers by serious people. Directivity, an aspect of Dispersion, is the most potent factor in loudspeaker Accuracy. Dispersion is the sole dividing factor of loudspeakers being played within their linear/power range. Directivity can increase the Accuracy of a loudspeaker to a level that cannot be achieved by any other means, given we are talking strictly the loudspeakers ability to perform in a room.

I've posted my actual real-world experience here, from going outside, touching grass and listening to / working on speakers.

Ears lie measurement's don't.... I'd trust a set of comprehensive measurements over your personal word of mouth any day of the week and that is also the position of professionals in this industry =)

 

[richard12511]

Interesting, I sold my SCMA150 after 14 years and replaced them with KH420. That was 5 years ago. I consider it an upgrade.

I preferred the KH420 as well in the test we did.

 

[DRNNOO]

I preferred the KH420 as well in the test we did.

Interesting, I sold my SCMA150 after 14 years and replaced them with KH420. That was 5 years ago. I consider it an upgrade.

At face value, The front baffle of the KH420 looks more like what any front baffle should, nice curves, smooth, no sharp transitions. Is it the end of the world if a cabinet has 90 degree corners? How could it be ATC and others do it anyway. Does it impact performance? 100% and it makes a difference in the final result. Take the ATC drivers and upgrade the baffle and yes the performance will increase. Its not even a big deal and its loudspeaker design 101. Is it the reason why the guys above liked the Nuemann better? No idea lol but do I trust their opinions over the next guy, nope. Show me the measurements and I'll decide for myself. Its nothing personal but audio can be complicated and getting into the subjective is slippery slope. Just show me the measurements I want to see, cause I know what I want to see there. Both models have 3" dome midranges in a waveguide, and the ATC-SM75150S is kind of a holygrail midrange. The CSD graph of the ATC mid below is impressive and the only CSD measurements I've seen as good come from large top shelf compression drivers on large waveguides. Of course theres other top performers out there. I don't think any one is losing with either model of speaker, tbh. I'd take the ATC for the mid and larger lF driver.

The Horizontal polars of the KH420 are pretty good.

The stand out driver from ATC is its mid

 

[574stereo]

I had SCM25s next to my KH310s and aside from some extra sub extension from the KH310, the SCM25s sounded better. Smoother, more revealing of small changes in tone/distortion when loading up plugins (changes in oversampling were extremely audible on the ATCs but not so much on the KH310s). Dynamics more audible too, hearing exactly what a limiter was doing on the ATCs vs the 310s was very revealing.

I ended up buying a pair of SCM50 actives and kept the Neumanns to form an Atmos rig (thinking of selling now as the Atmos market for music is dying thankfully).