Mark Audio Alpair 11ms Nostromo build

At first I thought they sounded bright. I found a few issues:
1. The back of my drivers were touching the brace but it kept the drivers from having proper excursion because the brace was actually pushing the drivers above the baffle slightly when I tightened the screws. I moved the brace. This changed the sound quality radically.
2. Damped the cabinet partially with bitumen.

They sound very good now and the highs sound perfect to my ears. They sound really dynamic. I have them crossed over to subs at around 100hz. I have no issues in getting them to moderate volumes either.
 
Before doing anything drastic, either try inserting a (roughly) 1ohm power resistor (minimum 20w rating) in series with the driver, or try replacing your speaker wire on an experimental basis with this, or a near equivalent: Pitacs BELL WIRE White Copper Solid Core Bell Wire Cable - 100m

Yep. Copper bell wire. Should give about 1ohm distributed series R over a 6m loop length. Other sources of 22ga - 24ga copper wire are available of course. Preferably the cheaper the better. Free is good (check for offcuts from network installers, skips etc.).

If you feel you need more, higher value resistor, or a longer piece of bell-wire / equivalent thereof. ;) Just watch the latter; solid core, can be a bit delicate, but not exactly a major issue.
 
Hey folks

After building alpair 11ms on fhxl, now I'm considering to build the same drivers in nostromo series as a setup on my work city abroad.

Some things i couldnt understand is the 3 size nostromo builds. I will be pairing these with allo volt+D amp which produce around 35 to 50 watts per channel.

Which size from the nostromo series would be suitable for me. And what is the approximate F0 and F3 of these in nostromo series.

Thanks
 
frugal-phile™
Joined 2001
Paid Member
A quick simm and sketch shows that the A11ms can fit 5 litres. With 15mm material, 24x24x15 cm, so could be packed face-to-face, 24x24x31 before a protective casing. With 12mm or more exotic material that allows for thinner panel material it could shrink even further (at these box sizes mreterial starts to take up a significanr of the gross volume. With a bit of juggling it could be printed on a Form 3L.

Of course one gives up a bit of bass wrt the optimum 9 litre. A bit better damped response and it gives up 7-8 hz F10 (ony hits 50 Hz)

dave
 
frugal-phile™
Joined 2001
Paid Member
The Allo has a low output impedance, certainly low enuff one does not have to worry (unles s hooking up to somethng lke Fostex FExxx for ehich it would not be suited).

I have a similar (diy) amp, i use it with uMar-Ken 6 and the whole lots into a 3-4” haliburton briefcase — speakers ar ehalf the net volume of the mMar-Ken11ms sketched out above above.

dave
 
frugal-phile™
Joined 2001
Paid Member
This one is going to get introduced to my planset, it looks really useful as a traveler.

Now in 12mm. Vent is not figured out yet.

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dave
 

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This looks amazing.. I would prefer a front firing port aswell. Because the rear wall of my speculated speaker placement is not symmetric.

Also im planning to do it in 2 months. So by the time i believe the entire plan will be out.

Only concern is bass only to 50 hz. My current setup has acoustic energy aegis 2 speaker and they have similar spec and the result is i get not enough bass in my room. Sounds a bit thin
 
frugal-phile™
Joined 2001
Paid Member
One of the kool things about the A11ms is that it ca work in a small BR box, but it doesn’t go all that low. It takes something like an FXHL (25-30 Hz) or Pensil (not quite as low and not as much gain) to get down.

Hoffman’s Iron Law.

A10.2 was the bass champ in a BR, EL70 not far behind. The Pluvia 7 is really close to the EL70. A10.3/p do not go as low, A12p even less so. A12pw produces tremendous bass, but is a bassWide and wants 4x as big a box as the A11ms.

If you want to go low tha usually means a big box or helper woofers.

dave
 
The issue im facing is i cant find skilled carpenters at reasonable rates who can do something like a frugel horn or pensil here in abudabhi.

In india i have a carpenter who made fhxl but then shipping it from india to abudabhi is gonna cost a fortune.

So what im looking for is a simple box design which either i can make as flat pack from india bring it in my luggage and assemble myself in abudabhi or ask a carpenter in abudabhi to make it for me. but it has to reasonably simple for both these options and has to reproduce to lower 40s frequencies.

I will continue my search for options. Meanwhile i appreciation all the feedback from you guys.