Alpair MAOP 10.2

Right. And for practical purposes, the majority of modelling software round things off slightly; under those conditions, there is basically no difference worthy of the name. I've just had a very quick gander & under identical box conditions, a sealed Butterworth has less than 0.1 litre and about 1Hz difference in Fb; you'd get about that much variation from a change in climatic conditions, and if you can hear that, you're doing better than I am. ;)
 
Haha, thanks Scott and Dave for the explanation. This is reassuring! I have removed the stuffing (stuffing was included in the CM5) which helped a bit. I knew slamming the driver in the only bookshelf enclosure I had available would most likely not be a perfect fit. Lower and midbass is still off by ear. I will have to set up my measuring gear to confirm what I am hearing.

I will refrain from reviewing the driver until it has a proper and suitable enclosure, which they deserve, but I am really excited still. There is a lot just right wrt. The highs, voices and spatial detail.

So, would these fit the Water Buffalo's or Sea Stack MLTL's?

Thanks,

Robin
 
I found that my A driver needs a box of 12.1 liters. Driver B needs a box of 11.66 liters. 0.44 liters difference.
Is that good ? Difference of 3.8%

Madison:
"After construction, each driver is individually measured in the anechoic chamber at the Markaudio factory and pair matched based on that data to within, 0.5% tolerance."
 
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Madisound ;)

"After construction, each driver is individually measured in the anechoic chamber at the Markaudio factory and pair matched based on that data to within, 0.5% tolerance."

To Fs, which is the tolerance criteria.

Variation in boxes is beyond the remit of a driver manufacturer: that falls into the 'up to the builder' category, since any differences vary with box type and alignment.
 
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Today I shorted the ports to the length that modeled well in WINISD (5 cm shorter :p). I also removed the stuffing. The lower bass cleaned up and midbass has more presence now. I am very happy with the result from such small cabinets.

I admit that this is my first exploration of full range drivers and must say they have a lot going for them. It gives a satisfying listening experience unlike many other bookshelves I tried.

So far I am positively surprised what value they are to me.
The lovely thing about DIY is that I can start my search for proper enclosures while enjoying the sound as is along the way!
 
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In order:

  • Golden Ratio is just a set of proportions applied to a given volume. It isn't a box alignment or tuning frequency.
  • They are normally tuned according to the alignment Dave is targeting (remember, these are largely 'his' box type -while others have used variations in the past, in recent years, he's been the one has worked with it the most). The response is not always accurately shown in lumped-element modelling software either -not without some background knowledge of the physics / history involved, & sufficient measurements to adjust the data input to approximate the load behaviour.
  • No, you 'just' use the number that will provide the desired total vent CSA, aspect ratio and bracing to the side-panels.
 
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I'm looking at the Alpair 10 Mar-Ken10 1v01 drawings.
Interesting to look at how it is matched with the driver. 6 ports. Similar to a lot of what's out there from Dave.
Why is there a partition wall inside the box? Target volume is 14 litre. I need only 11-12 litre.
Maybe this box would fit MAOP10.2?
 
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frugal-phile™
Joined 2001
Paid Member
When modeling a miniOnken you need to do an additional mental step not shown by the modeler to estimate the LF extention (anechoic). The alignment is a shape i am looking for. It takes into account the loses in the high R vents. I am not going to give it away, i have given many clues thou.

6 vents is purely aesthetic. Most have 6, some have 8, but 10 more likely (a prime nuber down each side). In some of the less complex varitions you will find 1 or 2 vents.

dave
 
frugal-phile™
Joined 2001
Paid Member
Tuning of a miniOnken is very driver specific, whilei reuse the boxes all the time, the venting changes depending on the driver in the box. Much more so than the box-dominant horns & TLs comeing from Scott. But teh R in the vents decreases the impact on the response of dynamic changes in the T/S parameters.

dave
 
frugal-phile™
Joined 2001
Paid Member
Did this one already, looking for a beta tester.

MK102MAOPT-extents.png


dave
 
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