ATC SM75-150S Dome Mid Measurement Data

Bub, ATC don't use dsp generated brick wall filters.

 

Please stop trying to appear clever, google is everyone's friend these days.

Paul's graph shows a pretty flat response AFAICT, and certainly very flat in the region which you are claiming is bad. He has measured a genuwine ATC monitor rather than something lashed up in a shed.

 

Interesting graph, Paul. Do you think the level difference between the bass and midrange is real or a measurement artifact? Also, if the native response look anywhere close to the measurements from Ralph and Shin (and I wouldn't know why they should be dramatically different), there must definitely be some eq#ing in the xo. The response for the tweeter looks eq-free.

 

Nowt wrong with mounting ATCs high whatsoever. What would be interesting to see is if they are angled down towards the listener in those studio shots, it's hard to make out.

Listening to an ATC 3way (or any other non-coincident-driver 3way) from 31-33" away is very wrong, however. When I had the 50s, 45-50" was the minimum listening distance I was comfortable with.

 

I sit corrected.

 

fox's ATCs are spookily the same height as mine. We've done the monkey dance together an' all.

 

Unless you listen in an Anechoic Chamber, once you get 3-4 metres away from a speaker, room reflections start to take effect, so having the 100a's so high wouldn't matter as much, and listening 20 feet away would blur the vertical dispersion IMO.

Feel free to flame me Bub if you want to, but sitting so far away from your speakers may give one reason why differences in equipment some of us hear and bother about are less of a problem to you, as I, for iinstance, have only had smaller rooms in which to listen... Just an opinion.

 

This is kind of the point, if there's an audible problem it must manifest itself in the composite.

But I wouldn't expect to see it on a 1/3 octave smoothed curve.

I really don't know. Perhaps an expert can help. I'll be doing more poking about now I've got a vaguely sensible first pass. I might even pay for ARTA... I think part of the top end lift/droop is a consequence of the Behringer measurement mic response.

On the monkey front the sound is very different between sitting and standing with the speakers on the low stands. So lifting them might make more use of the zone.

Paul

 

I have a generic correction file for ARTA and the ECM8000, drop me an email and I'll send it to you.

 

yes we have - using our ears to access the subjective impact of a measured design compromise. we hear a hardness in the upper mid. in my case across ten years of listening to atc in multiple systems in which the atc was the only common factor.

bubs contention that anyone else is an inexperienced listener is ludicrous given he buys on the basis of brochures reviews and industry recommendations. The unspecified others were specified as my brother and best mate - who once worked in the hifi industry. Saying the sme is not as good as the sp10 is not anywhere close to showing that mike made an sme sound worse than an lp12. pure conjecture on bubs part and nothing more than wishful thinking to keep his cosy world from crashing down

 

bb

i suspect Bub is winding you up. I also suspect he cares less about HIFI than you think.


edited to add - and everybody else, apparently.

any chance you get a life as well?

 

BBV you've missed the point. You hear 'hardness in the upper mid'. Shin/Ralph post a graph showing a resonance and the motley crew leap to a conclusion. But unless you can show that resonance in an actual ATC speaker implementation you haven't taken a step towards cause-effect. It's just assumption.

FWIW why do the measurements at http://ldsg.snippets.org/vendors/atc.php not show the resonance?

Paul

 

I bet they even out the problems in the crossover.

I've heard they do that, and all the smoothing caps are a reason for the speakers low sensitivity (in passive format)

All 3rd party information btw, not knowledge.

 

Paul, could you attach the measurements you reference? I can't open them.

 

Please fellas, forget three way passive ATC's (excepting the 45, which is very cheap by comparison). The manufacturers don't recommend them for reasons explained earlier.

 

You can't "even out" a resonance or break up mode. You can attenuate it by placing it way outside of the pass band and using steep slopes. ATC do the latter but not the former.

 

Paul, firstly there's no time domain information there such as a MLSSA plot. Secondly, the impedence plot stops at 1khz. Thirdly, there's something odd about taking measurements seemingly at 80db on a 94db/w drive unit don't you think?

 

eg. attached.

Paul

 

2k, but I take your point.

Absolutely. But then taking the numbers at face value I seldom listen louder. Out of interest at what level were the measurements at the top of the thread taken?

Paul

 

Perhaps my eyes are playing tricks, but that resonance looks pretty unimportant to me, given the scaling on the graph of 2db per division.

Firstly, it occurs at a point where the response is already rolling away naturally and secondly it's on the right side of a steep 4th order crossover.
Thirdly, the notch is narrow in nature which is subjectively less audible than one of lower amplitude over a broader frequency range.

Lastly, depending where you measure we are looking at a best case deviation of 2db and a worst case of 4db which is hardly severe.

250 posts to get absolutely nowhere!