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Old 15th October 2014, 11:43 AM   #11
Bill poster is offline Bill poster  Thailand
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Old 15th October 2014, 12:05 PM   #12
markaudio is offline markaudio  Hong Kong
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Hello Sarathssca, (guys)

To confirm: All the regular members know Markaudio drivers are measured in a fully anechoic chamber on industry standard baffles at standard measured distance of 1 metre. I've posted and commented numerous times on the equipment our company uses. A simple search should reveal the many posts I've made on this subject. Indeed, I made several posts advising members how to make environments more anechoic. This includes room damping advise and baffle sizing information.

Spekr recently revealed that he didn't know what RAW was/is. So why he's making these comments is surprising as without necessary knowledge, its impossible to correctly understand the differences in data presentation.

The bulk of the driver industry provides smoothed data. Should they provide RAW data, most drivers will have a response similar to, or in many cases, worse than Markaudio units, regardless of then being full-range or limited bandwidth.

I responded some time ago to members requests to publish raw data. Sadly the danger is situations like that being generated by Spekr as makers presenting smoothed data have a presentation advantage.

Spekr's errors are further compounded by his liberal application of equalisation, with no understanding of the on-off axis function of most full-range and wide-band drivers and their dispersion characteristics; particularly noticeable with his error on "beaming", an partly variable audible phenomenon the preserve of larger units > 8" depending on application.

Spekr remains highly dismissive of experienced members who have good verifiable "track records" of the design and application of full-range, wide band and FAST systems. Ironic as spekr is, in effect, undermining the spirit of Diyaudio. Yet he could learn much if he were to become genuinely willing to inhale the experiences of others with actual knowledge. He seems to be keen to take a topic wrecking ball to a number of threads.

Far as I can see, Spekr hasn't published any comprehensive project work, so we have no knowledge of his methods for box design(s), box build quality, driver installation, measurement, testing and room set-up. How open and honest he is will be is a matter of judgment in the context of the lack of knowledge.

I'm all for fair minded comment and at the end of the day, not everyone will like Markaudio drivers. But its is increasingly depressing to see comment being dressed up as "expert fact" when the author has little actual knowledge.

For those who are fair minded, I welcome comment on these drivers. Its your opportunity to let me know what you'd like to see being advanced in the design stage of these units.

http://www.diyaudio.com/forums/marka...lpair-8-a.html
http://www.diyaudio.com/forums/marka...5-gen-2-a.html

Currently their responses are near flat, so issues to do with on-off-axis placement come into play. Much depends on what members favour in relation to in-room positioning of their projects. Both drivers are in their early phase.

Apologies Sarathssca as your thread is some respect is being pushed off-topic. The Markaudio section is open to those who may wish to have the subject of their thread being more regularly maintained.

Thanks
Mark.

Last edited by markaudio; 15th October 2014 at 12:27 PM. Reason: typo fixes
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Old 15th October 2014, 12:34 PM   #13
spekr is offline spekr  United States
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Mark, please comment on content, not on the contributor.

Quote:
Originally Posted by markaudio View Post
Hello Sarathssca, (guys)

To confirm: All the regular members know Markaudio drivers are measured in a fully anechoic chamber on industry standard baffles at standard measured distance of 1 metre. I've posted and commented numerous times on the equipment our company uses. A simple search should reveal the many posts I've made on this subject. Indeed, I made several posts advising members how to make environments more anechoic. This includes room damping advise and baffle sizing information.
Could you provide more information about your "fully anechoic chamber"? You show data down to 20Hz and I've never heard of an anechoic chamber that is anechoic down that low.

Quote:
Originally Posted by markaudio View Post
Spekr recently revealed that he didn't know what RAW was/is. So why he's making these comments is surprising as without necessary knowledge, its impossible to correctly understand the differences in data presentation.

The bulk of the driver industry provides smoothed data. Should they provide RAW data, most drivers will have a response similar to, or in many cases, worse than Markaudio units, regardless of then being full-range or limited bandwidth.
Well, I know the term RAW from photography Never heard it is some kind of standard within the industry. It also doesn't matter. Why? Because it deflects from the important stuff: How good is the frequency resolution of the data and is any smoothing applied. A frequency response like the one you've shown can't be true unless the driver is really that bad. The response looks more like the snapshot of a steady-state measurement with noise as the test signal.

Quote:
Originally Posted by markaudio View Post
Spekr's errors are further compounded by his liberal application of equalisation, with no understanding of the on-off axis function of most full-range and wide-band drivers and their dispersion characteristics; particularly noticeable with his error on "beaming", an partly variable audible phenomenon the preserve of larger units > 8" depending on application.
Measure any driver on- and off-axis and it will reveal lobing, beaming, resonances, etc. This can easily be done by anyone (at least for higher frequencies) even without an anechoic chamber at hand. Measuring equipment like CALIBRATED microphones are cheap and readily available. Measuring software is available for free (e.g. REW).

By the way, Earl Geddes has published a nice tool that allows examination of speaker off-axis responses:
http://gedlee.azurewebsites.net/Appl...nPolarMap.aspx

Last edited by spekr; 15th October 2014 at 12:48 PM.
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Old 15th October 2014, 12:40 PM   #14
Mooly is offline Mooly  United Kingdom
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Mark audio alpair 7p vs alpair 7.3


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Old 15th October 2014, 12:58 PM   #15
spekr is offline spekr  United States
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Quote:
Originally Posted by Scottmoose View Post
MA drivers are measured under anechoic conditions on appropriate IEC compliant baffles, 1m distance, normalised to 1w (rather like most reputable manufacturers), sans software smoothing, using Earthworks measurement microphones in a full LMS setup using slow sweeps which tend to be more revealing of mechanical behaviour than, say, logarithmic chirps etc. (useful though the latter can be of course).
The data shows variations as large as 10dB, would a measurement with the swept sine technique show anything different?
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Old 15th October 2014, 01:27 PM   #16
Scottmoose is offline Scottmoose  United Kingdom
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A slow (as in 'slow') sweep is typically less forgiving than, for example, a log-chirp since there is greater potential for mechanical resonances to build up. Since most musical signals change rather more swiftly, it tends to provide conservative rather than flattering results. This is useful in suspension etc. design & development.

I hope spekr will allow us to return back on topic now, for the benefit of the OP. Because this is getting ridiculous.
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Last edited by Scottmoose; 15th October 2014 at 01:31 PM.
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Old 15th October 2014, 01:29 PM   #17
spekr is offline spekr  United States
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Quote:
Originally Posted by Scottmoose View Post
You are taking the OP's thread off topic again. I will answer this, but please stop afterward. It is not fair on him.

A slow (as in 'slow') sweep is typically less forgiving than, for example, a log-chirp since there is greater potential for mechanical resonances to build up. Since most musical signals change rather more swiftly, it tends to provide conservative rather than flattering results. This is useful in suspension etc. design & development.
This doesn't answer my question, "The data shows variations as large as 10dB, would a measurement with the swept sine technique show anything different?"

I'll open a new thread.

Last edited by spekr; 15th October 2014 at 01:35 PM.
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Old 15th October 2014, 01:36 PM   #18
markaudio is offline markaudio  Hong Kong
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Quote:
Originally Posted by spekr View Post
This doesn't answer my question, "The data shows variations as large as 10dB, would a measurement with the swept sine technique show anything different?"
You don't understand the data. If you did, you wouldn't be asking this question.

What you need to do is go-away and research. Then seek advice from member's who've done allot more than you (PM's is one way); Instead of you constantly re-railing threads! Or use the "lounge" section of Diyaudio. There's several long running threads that get into the sort of stuff that might entertain you.

I genuinely tried helping you on the Markaudio section, a disaster, you just won't meet others at least half way, especially those who a experienced regular members.

Last edited by markaudio; 15th October 2014 at 01:46 PM. Reason: typo fix
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Old 15th October 2014, 01:39 PM   #19
Scottmoose is offline Scottmoose  United Kingdom
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I'm not sure how I can be much clearer. A lengthy sweep typically provides more conservative / less flattering results than some other methods. QED.
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Last edited by Scottmoose; 15th October 2014 at 01:47 PM.
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Old 15th October 2014, 01:55 PM   #20
markaudio is offline markaudio  Hong Kong
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Quote:
Originally Posted by spekr View Post
Instead of constantly attacking me you guys could provide useful explanations. Instead you pile up off-topic posts that are farther away from the topic than anything I've ever said.
You've gotta eventually wake up. You're de-railing threads when there are places on Diyaudio where you can go to have the audio-philosphical discourse. Here's the thread you need:

http://www.diyaudio.com/forums/loung...surements.html

How far you'll get is questionable because you're so busy "telling" everyone how drivers work and your biblical take on testing and data analysis.

For goodness sake....let threads operate to their original purpose.

Last edited by markaudio; 15th October 2014 at 01:59 PM.
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