Alpair12P gen2 standmount speakers - Page 6 - diyAudio
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Old 26th August 2012, 03:35 AM   #51
vaughn is offline vaughn  United States
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Not really sure how to contact Scott

I tried his Woden website but it doesn't actually have an email address that I can use.
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Old 26th August 2012, 08:50 AM   #52
Toppsy is offline Toppsy  United Kingdom
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Vaughn,
If you send a pm or email to DaveD @ Planet10 mentioning you wish to contact Scott about this design, Dave will no doubt either give you contact details or forward your request on to Scott for you.
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Old 26th August 2012, 12:34 PM   #53
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OK, since there's been some interest, I'll put this out.

It's purely a DIY design, so for strictly non-commercial use only. For anything else, please contact me direct.

Nothing novel about it, it's a simple BR standmount, albeit with a slightly damped alignment. Internal dimensions:

345mm x 218mm x 218mm (HxWxD).
Driver centre 115mm down from internal top.
Vent 50mm diameter x 83mm long, assuming a vent with a single flared end. Note that there is a slight fudge-factor here since not everyone can get metric vents, or those with flush ends. If you can't, re-size accordingly: the target Fb is 55Hz. Vent centre is 115mm up from the internal bottom, on the rear baffle.
Top, base, back and sides of the box should be lined with damping material -your choice, could be ultratouch, 1/2in fiberglass, wool felt / carpet underlay or similar. I strongly advise avoiding egg-crate foam. Never had good experiences with it & the A12p will almost certainly sound like it needs a large dose of health salts if you put any of that material in the box.

Bass output is not thunderous (as you would expect -you've the wrong box and wrong driver if this what you need), but in a modest space it's surprisingly solid, especially with some boundary loading, and even more so if you have a high[ish] output impedance amplifier like Colin's custom 300b monoblocks.
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Last edited by Scottmoose; 26th August 2012 at 12:39 PM.
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Old 26th August 2012, 01:10 PM   #54
vaughn is offline vaughn  United States
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Thanks Scott!
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Old 26th August 2012, 05:40 PM   #55
AndrewL is offline AndrewL  United Kingdom
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Quote:
Originally Posted by Scottmoose View Post

Bass output is not thunderous (as you would expect -you've the wrong box and wrong driver if this what you need), but in a modest space it's surprisingly solid, especially with some boundary loading, and even more so if you have a high[ish] output impedance amplifier like Colin's custom 300b monoblocks.
Excellent design Mark, Scott and Colin, I really liked this package!

As Scott says bass isn't thunderous, but having heard them, my take is the bass is very good indeed; they just won't move lots of air. So, if you're coming from a large floorstander or from one of Scott's horns then sure you might find them a little less 'thunderous', but if you view them as a "monitor", which they are, then your expectations will be exceeded on all accounts.

Andrew
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Old 29th August 2012, 01:31 PM   #56
vaughn is offline vaughn  United States
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I've started building mine (which I'm dubbing Moose Monitors) and picked up some nice quilted maple to cover them. I'll be sure to post a picture when finished!
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Old 29th August 2012, 02:50 PM   #57
mp9 is offline mp9  United States
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^nice!

A few questions:
Are you using 15mm ply or 19mm ply?
Any bracing?
Also what are you using for the port/flare? I'm thinking of going with a 2" i.d. pvc pipe and either a 3/4" curve rounding over bit (it's actually a 2" rounding over bit), to flare the rear panel or a 1" curve bit if i decide to splurge on the expensive router bit.
I looked at 2" flare/port kit, could make for a more finished look but the requisite 4.25" cut out hole to insert it into the panel seems large to me and allot of excess plastic.
Madisound Speaker Store

Last edited by mp9; 29th August 2012 at 02:56 PM.
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Old 29th August 2012, 03:31 PM   #58
vaughn is offline vaughn  United States
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Quote:
Originally Posted by mp9 View Post
^nice!

A few questions:
Are you using 15mm ply or 19mm ply?
Any bracing?
Yes!

I'm actually using whatever I have on hand, keeping the internal dimensions the same of course. 1" for the front and back baffles, 3/4" for the top and bottom and 5/8" for the sides. I'll remove some material on the inside edge of the driver hole to promote airflow (or whatever the hell it is called). I may install a single side to side brace but this cabinet is so small I'm not sure it is necessary. I haven't really accounted for the added volume of a brace so I may just use a thin threaded rod (1/4" or so) pulling the two sides together slightly. I would drill a rebate on the outside of the panels for the nut and fill it with epoxy afterwards.

Not sure on the vent. I think I'm just going to use 2" i.d. PVC pipe and just give it a minimal round over, like 1/8". I guess I'll need to figure out how to adjust the size though for the 55hz tuning though. I have a Mac so Win isn't usable for me
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Old 29th August 2012, 06:25 PM   #59
Toppsy is offline Toppsy  United Kingdom
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Guys,
I have found these small cabinets don't require any additional bracing. My boxes are made with 15mm BB Ply with the front baffle doubled. For internal lining I have used " wool felt, basically recycled wool carpet underlay felt. Works a treat.

Though a flared port is the optimum I have used these MBR-50 and providing you can place the speakers either in a corner or close to a rear wall I doubt you'll be disappointed with the bass.

If you are making stands make them high enough that he centreline of the driver is at ear level when seated in your favourite listening chair. Do fix the speakers to the stands and use spikes. I have my stands bolted to the speakers and this helps greatly with improved imaging and tighter bass.

Last edited by Toppsy; 29th August 2012 at 06:31 PM.
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Old 29th August 2012, 06:36 PM   #60
Toppsy is offline Toppsy  United Kingdom
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I should have mentioned I have now covered and finished one the speakers and one the pedestal stands in the Birch burr and my son thought they looked like CORK boxes! Kids what do they know . Just need to re-install the drivers wire it up and start on covering the other speakers and stand. I must say this burr veneer is very nice and easy to work with.

Pictures to follow this weekend. Promise.
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