MarkAudio OM-MF4 (6cm only)

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#61
adason said:
Yes 'should'.
They can disagree, who cares.
Thread is about tiny fullrange.
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Well, I care, since as far as I know, you are not the sole arbitor of how measurements are taken and no such requirement exists for accurate data. In many cases, it actually causes problems. For a few more examples, ask Floyd Toole, John Eargle, Seas (who measure everything at 0.5m, as do several others) etc. And it seems that John and Jeff, with their detailed, carefully set out website & guidelines in the first case, and extended writeups / presentations on quasi-anechoic measurements, phase alignments etc. in the second, may have done more on this aspect for DIYers than you, I & the majority of others have.

'Thread [being] about tiny fullrange' actually makes it more significant, since small drivers are typically more susceptible to unwanted room reflections at 1m in non-anechoic environments, and a closer farfield measurement position will simply reduce the chances of those occuring, making for more accurate data, and an easier life for the designer too. 1m is just a standardised location for SPL / sensitivity, no more. Easily accessible example (see p.3): http://audio.claub.net/software/FRD_Blender/White Paper - Accurate In-Room Frequency Response to 10Hz.pdf
 
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#64
Scottmoose said:
Well, I care, since as far as I know, you are not the sole arbitor of how measurements are taken and no such requirement exists for accurate data. In many cases, it actually causes problems. For a few more examples, ask Floyd Toole, John Eargle, Seas (who measure everything at 0.5m, as do several others) etc. And it seems that John and Jeff, with their detailed, carefully set out website & guidelines in the first case, and extended writeups / presentations on quasi-anechoic measurements, phase alignments etc. in the second, may have done more on this aspect for DIYers than you, I & the majority of others have.

'Thread [being] about tiny fullrange' actually makes it more significant, since small drivers are typically more susceptible to unwanted room reflections at 1m in non-anechoic environments, and a closer farfield measurement position will simply reduce the chances of those occuring, making for more accurate data, and an easier life for the designer too. 1m is just a standardised location for SPL / sensitivity, no more. Easily accessible example (see p.3): http://audio.claub.net/software/FRD_Blender/White Paper - Accurate In-Room Frequency Response to 10Hz.pdf
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No, i am no arbitor. You can measure at any distance, what do i care.
All i pointed out, to someone who posted two fr response graphs in one post side to side, that they do not have the same dB scale.
He was saying that one looks flatter than the other fullrange. But there was different dB scale used.
Y scale should be 50dB. But to make it look flat, they decided to use much wider scale, zero to 100dB and -20dB to 100dB. They even selected -20dB, that is 20dB below threshold of hearing!
 
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#67
I am not english native, i have to admit, but...
I said 'should', which to me means suggestion, not 'must'...
Measure at whatever distance you want. What do i care. I never said you 'must' measure at 1m.
You can measure at 1cm or 1 mile, i do not care. Just stop putting words into my mouth.

You can use -1000dB scale to +1000dB scale, you will get perfectly flat response. I said scale should be 50dB.
 
#69
adason said:
I am not english native, i have to admit, but...
I said 'should', which to me means suggestion, not 'must'...
Measure at whatever distance you want. What do i care. I never said you 'must' measure at 1m.
You can measure at 1cm or 1 mile, i do not care. Just stop putting words into my mouth.

You can use -1000dB scale to +1000dB scale, you will get perfectly flat response. I said scale should be 50dB.
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As an observation (and I stress I'm saying this without any offence implied or meant: I can't speak anything other than English and I hugely admire anybody who can speak or write in several, or multiple language) -in this context, 'should' tends to be read as a dictat. It's one of the dafter aspects of the English language where some things don't seem that way when spoken for e.g., but can when written.

As it happens, personally I tend to prefer 50dB total vertical scale ranges too, though they're not a requirement as there is no industry standard (alas). Zaph for instance, who was renowned for his blunt attitude toward anything other than quality technical design and is still highly thought of for his extensive driver testing used a 90dB scale (10Hz-40KHz), and you'll struggle to find anybody complaining even now, a decade after he retired from the hobby.

As noted, far field actually starts at 3x - 5x the effective radiating diameter away from the drive unit. If measuring on an infinite or a test baffle, that's sufficient & usually offers less in the way of corruption from room reflections etc., so you can get more accurate results with a shorter gating window. It can even be useful in anechoic conditions. Where you have to be a mite careful though is if you're measuring in a box: to account for step loss you also need to be at least 2x the baffle diameter away. Not a problem for small speakers, obviously -a bit more challenging for larger baffles & monkey coffins, but that's the nature of the beast. 😉
 
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#70
I finished to build the OM-MF4, the sound is quite good, with a good sound scenario, especially in the middle, high frequencies, but the bass is not good. Nandappe told it at the beginning.
So I would like to add a little subwoofer, using the same Nobsound amplifier I use to drive the OM-MF4 (https://amzn.eu/d/8Z1phhq). I think to connect the OM-MF4 and the "new" subwoofer in parallel, adding a simple passive crossover. What do you think? Is it possible with a simple, cheap solution? Any suggestions??
 
#73
planet10 said:
You really should be looking at woofers, not a subwoofer. You need some extention at the top to get a good blend.
Click to expand...

While I'd agree to that, there are exceptions to that. the Omnes Audio SW 6.01 will go far enough up and still provide very good bass. It's affordable, doesn't require a big enclosure and is easy to handle. A sealed enclosure will be very small with good bass. It can be even smaller if you insert a high pass capacitor.
 
#79
Thank you. I think that for the moment I will try only to add a subwoofer in parallel with the same amplifier, to the OM-MF4. I will connect an active Wharfedale sub I have, this one: https://images.app.goo.gl/m4GQ2RGiNxP4oG1eA.
I understand that without a proper woofer I will have a lack of frequencies, but I don't see other solutions without increasing the space available on my desk. I will try to set the right cut in the sub integrated crossover (higher is possible is the best solution?) and also the right wiring to manage the loudspeakers parallel connection without the apposite outputs in the amplifier. Let's try....
 
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