Hi, Cowanaudio
I'll do some measurement in couple days (lack of measurement gear) when I see how does Audiotools works on my smartphone (Yeah.. smart!) that I just installed. Waiting for iMM-6 mic in a day or two.
BTW, what signal would be more realistic for measurement: White or Pink noise?
Measuring will be done in my room...
I'll do some measurement in couple days (lack of measurement gear) when I see how does Audiotools works on my smartphone (Yeah.. smart!) that I just installed. Waiting for iMM-6 mic in a day or two.
BTW, what signal would be more realistic for measurement: White or Pink noise?
Measuring will be done in my room...
Maty, it was off axis I was most interested in. The MA plots show very poor on axis behavior, they don't even fit in a +/-10dB window from 100Hz to 10,000Hz. Unless zmajz is doing something very special in his implementation his speakers would show up very poorly in a direct comparison with any KEF loudspeakers, especially the superb LS50.
I'm curious what could be causing that huge resonance at 400Hz. That's got to sound bad.
I'm curious what could be causing that huge resonance at 400Hz. That's got to sound bad.
G'day zmajz
If you can't gate your measurements you need to get your speakers away from any boundaries, which probably means outdoors on a still day. Measured indoors you'll get a huge influence from the room which doesn't represent what the human ear hears terribly well. Hopefully what you see is better than what MA show in their advertising.
Maty, it was off axis I was most interested in. The MA plots show very poor on axis behavior, they don't even fit in a +/-10dB window from 100Hz to 10,000Hz. Unless zmajz is doing something very special in his implementation his speakers would show up very poorly in a direct comparison with any KEF loudspeakers, especially the superb LS50.
I'm curious what could be causing that huge resonance at 400Hz. That's got to sound bad.
Below Maty's shared A-11MS datasheet graphs (blue) on a same vertical 60dB scale as KEF LS50 (red) on axis graph shared in post 71, had it been 01st of April one could have said are you joking about LS50 is better
Understand for some out of box A-11MS can be a great project, what is not understandable is we told below blue traces that is real live visuals mean mostly nothing and we shall start use our ears because MA drivers have superior perfect reference low level details 30-60dB down and will run over that LS50
Could be wrong about A-11MS but for many other MA transducers that resonance used to be the abrupt cone transition cause the rubber surround is underhung, in ergo's nice informative objective post 50 for A-7 transducer resonance for underhung surround go again but less huge as for A-11MS and remind me in the past MA CHN-70 showed same objective huge data tendency as A-11MS and based that experience then expect also HD will go little crazy there at that resonance.
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Thanks for the data sheet graphs. Any of us could look those up in a second. What we're after here is measurements of zmajz's speakers. Surely, the enclosure affects how the speaker will perform. No?
Tom
Below Maty's shared A-11MS datasheet graphs (blue) on a same vertical 60dB scale as KEF LS50 (red) on axis graph shared in post 71, had it been 01st of April one could have said are you joking about LS50 is better
±10-15 dB variation within the audio band. It makes me wonder if the MA driver is measured in a live room. At least that would explain the deep notch at 400ish Hz (although it's high for a room mode). It wouldn't explain the peaking in the HF end, though.
I generally like the MA drivers. I have a pair of A-6p in front-ported boxes. They're great office/computer speakers.
Tom
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Also, the MA driver factory data are claimed to be measured in an anechoic chamber with a premium Earthworks microphone and LMS measurement system/software. This has been discussed at length in previous threads where user measurements vs factory measurements were presented.
If you look at the factory Alpair 11MS data, you will see the LMS logo at the bottom. The problem is the use of a 0dB to 100dB with 10dB major divisions. It smooths things out.
My measurement of a CHN-70 a while back using a nice trapezoid baffle yielded a similar dip behavior and overall rough response. A measurement in a large open baffle which should not have baffle edge effects gave a similar result. It is the suspension and driver mechanical design that causes this. But, small width dips like this are very hard to discern to the ear. Peaks are much more noticeable - our ears fill in the missing content psychoacoustically, but we cannot suppress peaks as well. Sort of like we do not notice blind spot in our retina's fovea, but we cannot ignore a bright flash of light no matter how faint upon a dark background. So I would not say that this driver doesn't sound good or play music in a way that is unappealing to many. It just cannot be used for a studio mastering or mixing monitor.
An Objective Comparison of 3in - 4in Class Full Range Drivers
If you look at the factory Alpair 11MS data, you will see the LMS logo at the bottom. The problem is the use of a 0dB to 100dB with 10dB major divisions. It smooths things out.
An externally hosted image should be here but it was not working when we last tested it.
My measurement of a CHN-70 a while back using a nice trapezoid baffle yielded a similar dip behavior and overall rough response. A measurement in a large open baffle which should not have baffle edge effects gave a similar result. It is the suspension and driver mechanical design that causes this. But, small width dips like this are very hard to discern to the ear. Peaks are much more noticeable - our ears fill in the missing content psychoacoustically, but we cannot suppress peaks as well. Sort of like we do not notice blind spot in our retina's fovea, but we cannot ignore a bright flash of light no matter how faint upon a dark background. So I would not say that this driver doesn't sound good or play music in a way that is unappealing to many. It just cannot be used for a studio mastering or mixing monitor.
An Objective Comparison of 3in - 4in Class Full Range Drivers
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Speakers look good - well done. If you can use REW (freeware) to measure once you get a mic, then it will be easy to compare as REW has overlay capabilities where people can share and overlay their measurements. Do you have access to a PC or Mac?
Place the mic on axis about 30cm away like this:
If you can follow the REW calibration procedure and use an SPL meter or your phone SLM to measure ~ 83 dB SPL at the measurement mic would be good. Why? It gives a good signal to the mic without activating too much of the room. Here is what I measured for the LS50 using 1/12 octave smoothing:
And here is the anechoic measurement at the Canada's NRC courtesy of Soundstage:
Even in my cluttered room and using a default window of 500ms, it is quite close to the anechoic response. Certainly good enough to characterise the frequency response of the system.
Looking forward to your measurements!
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There's an interesting article on the development of the LS50 in the AES library:
AES E-Library >> The Development of the KEF LS50, a Compact Two Way Loudspeaker System
AES E-Library >> The Development of the KEF LS50, a Compact Two Way Loudspeaker System
Electronic subscription including the very big archive without paper copy is actually only 65USD nowadays. Just paid my dues yesterday for the next year
Can recommend. Lots to learn there and a good value.Hmm, it is a bit odd indeed. When I log in, the only option I see is 63USD....
...a few min later .... aah found it. It depends on the country. USA for example is 125USD per year but if you register as Estonia it will be 63USD. But then again the closest AES "cell" and events for me are in Finland. So I guess that is why it is cheaper for Estonia.
...a few min later .... aah found it. It depends on the country. USA for example is 125USD per year but if you register as Estonia it will be 63USD. But then again the closest AES "cell" and events for me are in Finland. So I guess that is why it is cheaper for Estonia.
I had been (wifey let it expire while i was in Hospital last time) since 1972 and have the journals to show it. (i’ll fix that some day)
Lately (like the last couple decades) the articles of interest have become fewer and fewer, and living below the poverty level with a company that (ignoring IP) has most of its value in tax savings against losses if a profit was ever to be made (i am in it because i enjoy it, not to make money).
dave
Timmie’s coffee sucks (& don’t ask about their donuts). And the last time i was at MacDs was the early 70s.
You know what they say “friends don’t let friends drink Starbucks”.
I am going to try to talk the nurse into letting me go down to lobby and get a coffee… no coffee in me for over a week now.
dave
I'm curious what could be causing that huge resonance at 400Hz. That's got to sound bad.
I discussed that with Mark. It is mostly a side effect of no spider. The A7ms shows a smaller one.
I have showed those measures to a number of people, who said “that must sound bad”, but the results coming in has no-one (that i have seen yet) has. We certainly didn’t/haven’t.
It is dangerous measuring before you listen. It can bias the crap out of you.
dave
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