ATC speakers / Monitors

[andreasmaaan]

Found these measurements for the mid driver:
http://studio-hifi.com/images/ATC75-150S_JeffBagby.pdf
The distortion is indeed very low - on par with the best mid frequency drivers.

The vexing thing is that the measurement SPL is not stated there.

 

[Moonhead]

Makes we wonder why they're so popular in the pro audio world

marketing, just like apple.
I do like my smartphone, not sure I would like the speakers though.

 

[Thomas savage]

Makes we wonder why they're so popular in the pro audio world

Reliable and established.

 

[Vintage57]

Reliable and established.

They are both of those

 

[Purité Audio]

I don’t understand why they don’t introduce a more contemporary design?
I would enjoy supporting a UK company.
Keith

 

[Deleted member 4708]

The vexing thing is that the measurement SPL is not stated there.

I think it is 95db. There is a black line around 95db in the pictures - that seems to be the signal. The difference between the original signal and the 2nd/3rd is around 60db for the 400Hz-4khz. I think that's impressive.

 

[andreasmaaan]

I think it is 95db. There is a black line around 95db in the pictures - that seems to be the signal. The difference between the original signal and the 2nd/3rd is around 60db for the 400Hz-4khz. I think that's impressive.

I think that's highly unlikely. The second distortion measurement, taken with the XO network in place, actually shows similar or even lower disortion at "100dB"/1kHz. That doesn't make any sense. Also, other distortion measurements of the non "S" version show it to have far higher nonlinear distortion at lower (than 95/100dB) SPLs. According to Jeff Bagby, the main difference is in the size of the magnets, which could not possibly account for such huge discrepancies.

 

[Deleted member 4708]

I think that's highly unlikely. The second distortion measurement, taken with the XO network in place, actually shows similar or even lower disortion at "100dB"/1kHz. That doesn't make any sense. Also, other distortion measurements of the non "S" version show it to have far higher nonlinear distortion at lower (than 95/100dB) SPLs. According to Jeff Bagby, the main difference is in the size of the magnets, which could not possibly account for such huge discrepancies.

From the doc I linked, as per guy who did the measurements (Jeff Bagby):
"Yes, in my opinion, on an absolute basis, this is an exceptional driver and one of the finest midrange transducersI have ever listened to or measured."
These are unequivocal statements from someone who measured the driver first hand. Look at his measurements at 95db - that is why he uses the word exceptional.

 

[andreasmaaan]

From the doc I linked, as per guy who did the measurements (Jeff Bagby):
"Yes, in my opinion, on an absolute basis, this is an exceptional driver and one of the finest midrange transducersI have ever listened to or measured."
These are unequivocal statements from someone who measured the driver first hand. Look at his measurements at 95db - that is why he uses the word exceptional.

I don't disagree that it's an excellent driver.

I do disagree that your assumption that it was measured at 95dB/1m is justified, and I strongly suspect that it is false.

Apart from the reasons I already mentioned, 1m is a suboptimal distance from which to take a nonlinear distortion measurement in non-anechoic conditions, and Jeff Bagby was no fool when it came to measuring loudspeakers.

Finally, if the measurement really were conducted at 1m, you would expect to see the effects of in-room reflections at low frequencies. But these are apparently not present/significant, which is further evidence that Bagby did the sensible thing and measured from a distance of 20cm or 30cm, which would give the best possible picture of nonlinear distortion in the absence of an anechoic chamber, but which would exaggerate the apparent SPL - which is almost certainly what has happened here.

 

[Chrise36]

Quote from hifi choice ATC scm 100se review:
ATC uses an underhung (short coil, long gap) motor geometry in both the bass driver and midrange driver. so it's no surprise that they both achieve low distortion at 90dB SPL, recording 0.2% at 100Hz and <0.1% at 1kHz, respectively.

The exact figure for the midrange unit was 0.048% with second, third and fifth harmonics predominating.

THD 100Hz/1kHz/10kHz (for 90dB SPL/1m):
0.2% / <0.1% / 0.1%

 

[Deleted member 4708]

Quote from hifi choice ATC scm 100se review:
ATC uses an underhung (short coil, long gap) motor geometry in both the bass driver and midrange driver. so it's no surprise that they both achieve low distortion at 90dB SPL, recording 0.2% at 100Hz and <0.1% at 1kHz, respectively.

The exact figure for the midrange unit was 0.048% with second, third and fifth harmonics predominating.

THD 100Hz/1kHz/10kHz (for 90dB SPL/1m):
0.2% / <0.1% / 0.1%

If this is not ultra low I am not sure what this is. Link: https://www.hifinews.com/content/atc-scm100se-loudspeaker-lab-report

 

[Dialectic]

I've seen more broken passive speakers in my life than broken amp sections in active speakers.

Same. I have been able to break passive speakers with aggressive amplifier choice and volume levels, and I've owned passive speakers, amplifiers and preamps that have failed on me, sometimes after less than two years of use.

But I've not experienced (or even seen firsthand) any failures with active speakers.

 

[Scholl]

There was a test of the ATC-SCM25a by Resolution. HD measurements with 90dB SPL at 1m. The woofer is not that good as far as HD is concerned, around -40db below 400Hz. The midrange and tweeter are better. Below -60db overall.

ATC SCM25a review

 

[Purité Audio]

I don’t believe anyone is questioning the quality of the driver, although again I believe in terms of mid-range domes the Neumann is the top performer, but one driver does not a loudspeaker make,


Keith

 

[Chrise36]

I don’t believe anyone is questioning the quality of the driver, although again I believe in terms of mid-range domes the Neumann is the top performer, but one driver does not a loudspeaker make,


Keith

What do you think of Jeff Bagbys project with this midrange and the rest SOTA drivers? Would it surpass anything else out there?

 

[Deleted member 4708]

I don’t believe anyone is questioning the quality of the driver, although again I believe in terms of mid-range domes the Neumann is the top performer, but one driver does not a loudspeaker make,


Keith

A driver doesn't make a speaker but it's a good start
All the ATC drivers are great imo and corroborated with A/B amps and a good crossover...

 

[Senior NEET Engineer]

Makes we wonder why they're so popular in the pro audio world

My dealer said they have the best resolution in mids.

 

[Deleted member 4708]

Does anyone here think that crossing over to the ATC mid at 380Hz (like it is done in the ATC line) is a bit too low and creates distortion / compression at high SPL levels?

 

[q3cpma]

A driver doesn't make a speaker but it's a good start
All the ATC drivers are great imo and corroborated with A/B amps and a good crossover...

They are certainly very good drivers but these very Stereoplay reviews really show the dispersion problems. I know I can be insistent, but the KH420A has exactly all of these advantages without the inconvenients. Look isn't too bad, even if I do prefer ATC too on that point.

 

[Deleted member 4708]

They are certainly very good drivers but these very Stereoplay reviews really show the dispersion problems. I know I can be insistent, but the KH420A has exactly all of these advantages without the inconvenients. Look isn't too bad, even if I do prefer ATC too on that point.

I have no problem with your persistence. While looking at the Stereoplay pictures above, on the right side (active ATC), I can see 60 degrees loss is less than 10db at 10khz and 15db at 20khz. To me that looks rather good.