Alpair 7 enclosure suggestions

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Well I just pulled the trigger on a pair of Alpair 7.3s from Bob at Creative Sound. Im looking for a little guidance on cabinets that would best suit my application.

I listen to a pretty broad spectrum of music including but not limited to classical, acoustic, country, soft rock, modern rock, hip-hop, jazz, etc. I currently run a vented Trio12 subwoofer powered by a 300 watt Bash amp. My receiver is a Panasonic SA-XR55.

Im comfortable with making cabinets and am not turned-off by complex designs (although the Mar-kens maybe be pushing it). I would prefer to keep them small if possible but am open to larger designs if they will integrate with my system better.

I was thinking a small sealed or vented bookshelf enclosure but have been reading a lot about the pensil's and frugal horns. My only concern with these designs is the larger size and material costs. My room is about 18x20 feet and opens (via a 8 foot wide opening) into a kitchen of equal size.

I'm most concerned with midrange and top-end clarity and control. I would be crossing to the subwoofer at 100-150hz and enjoy an authoritative mid-bass.

Would anyone have any advice on cabinets that might suit my needs?
 
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grakka

Member
2010-08-22 6:45 pm
I have the Alpair 7.3 grey in a Slim bass reflex design and i really enjoy them. My room is 3x4 meter and I don't really need a sub (even tho I'm building a SDX10 with basamp, just for the low end). Small design and easy to build. Images in my build thread here. I would highly recommend this speaker and design to anyone looking for a excellent small speaker. I'm listening to most kind of music and I have not found anything these speakers cant handle well using my Gainclone from chipamp.
 
If you're not thinking small enclosures for shelf or desk top mounting, keep in mind that any of the "monitor" sized boxes will need a set of stands as well.

You could of course build those, but the net footprint / space consumed generally runs the same or even more than a simple floorstander.

I've heard the 7.3 in a fair range of enclosure types, and for the combination of simplicity of build and extended LF performance, I'd pick the Pensil or the FH3. The latter does take more floor space, and they're a simple build from the flat pack kit - after assembling a dozen or so pairs, I can put them together in a Saturday afternoon - it takes longer to veneer them than to assemble.

Another option would be the center channel enclosure that's part of the dMar-Ken paid plan set.
 
I was just browsing through the box plan library at planet10 and saw the slim golden ratio mar-ken cabinets for the alpair. These look simple enough, definatly on my short list.

My father (a furniture maker) is going to help with the build and has several pieces of some very, very nice woods he's willing to donate. The size of the boards will limit the size of the cabinet. That being said, in the interest of achieving a high WAF Id like to use the exotic woods available in smaller, bookshelf sized cabinets. The plan would be to use solid wood for the sides and veneered MDF (cut from the same panels as the sides) for the front, back, top and bottom.

I guess my dilemma is simply that Im unsure if I need the extension of the FH and Pensil cabinets. Given that I will be using a fairly high quality subwoofer, Im not sure If I need much bass below 100-80hz.

Above 100hz or so, do the FH or pensil cabinets offer anything in the way of midrange that is missing from the vented, sealed or Onken bookshelves?

Thanks again for all the help folks!
 
I'm comfortable with making cabinets and am not turned-off by complex designs (although the Mar-kens maybe be pushing it). I would prefer to keep them small if possible but am open to larger designs if they will integrate with my system better.

I have older A7's in bamboo P10 Mar-Ken boxes that Chrisb build. These are the non trapezoid design, which may be within your comfort zone, build wise. The box design would need to be slightly adjusted for the newer A7.3 drivers thou. They are excellent sounding speakers, and work well with a powered sub. The boxes are roughly 9" x 9" x 14" tall.

jeff
 
Unless you already have stands, building floor standing speakers saves you trouble and really don't take up much more room. Small boxes really need a stand to get them away from a wall and up closer to ear level where the imaging capability of a single driver full range speaker shines. There is some directionality offered by bass frequencies emanating from the back horn of the FH3 or the bass port of the MLTL that seems to contribute to stereo imaging, and the portion of bass below say 70 Hz is where the sub fills in and direction is not important.
 
I have recently built a pair of Pencils A 7.3s. They sound quite good with surprising dynamics and bass. They are a very easy build and once stuffing is tuned (I seemed to make that particularly hard) meet almost all of my needs, just lacking that last octave of lower bass. But for most music I enjoy, these are it.

I listen nearfield in a largish room (14 feet x 24 feet) 7 feet from the drivers, the drivers are 7 feet apart on the midline firing "down the barrel" of the room.

Imaging on the 7.3 Pencils is quite good. Inner musical and venue detail equals or betters speakers I've heard costing magnitudes more.
 
I stopped by the ol' mail box today and found myself a box of Alpair 7s. I hooked them up to my amp and let loose some of my favorites (at low volumes!). I have to say, even without being strapped to a set of boxes, these things impress. I took it a step further and slapped them into a set of far-from-perfect small monitor cabinets and I must say.. I'm speechless.

I'll save my thoughts and impressions until I have the speakers mounted in a set of boxes built specifically for them. I plan to run them boxless for the next 3 or 4 days following Marks burn in procedure. I figure I should have the burn in process complete in time for the new boxes.

My cabinet build begins this weekend. I'll be making a trip to my local specialty lumber store tomorrow to pick up a small board for some lovely baffles and couldn't be more excited. I'll be sure to document the build as I know how much I enjoy seeing and reading the projects of others.

Stay Tuned.
 

Bob Brines

Member
2003-01-31 10:11 pm
I just spend a day demoing a pair of A7.3 TL's and a pair of A12P MLTL's. Both full-range. I didn't make the mistake of bringing a sub. For the most part, the SPL was in the 70's to maybe 80dB. Medium bedroom sized hotel suite.

The A12P's sounded great. Loads of good bass, what you would expect for mids and highs. The 7.3's played the music and got deep enough, but were definitely laboring. They had the typical "fall apart on complex music". FM distortion, and boatloads.

Hint. If you want to use the A7.3's at anything more than background levels, you have to high-pass them and use a woofer at the bottom. I do this in my HT. The A7.3's are high-passed at ~150Hz. They can take loads of power and get crazy loud and no significant FM distortion. The A12P's are enough bigger that FM distortion is not nearly as significant as the A7.3's
 
Bob,

I fully intend to cross these Alpairs to a set of stereo subwoofers in "fast" arrangement in the not to distant future. I would like to build the subs as stands for the Alp 7s. I was looking at your open baffle woofer set-up. I'm sure it sounds very, very nice!

I've been researching open baffle systems and would be interested in attempting something like that, however In my current room I do not believe I can get them far enough away from the rear walls.

I was thinking about perhaps selling the trio12 sub I have now and replacing it with a set of stereo 10's.

I like to get a little friendly with the volume knob from time to time and feel the need for some bass support. My now sold fr125 mtm's were crossed to my current sub at 100hz, and I'm thinking the Alpairs will likely be used in the same manner, if not 150hz..ish.
 
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I got a chance to start the cabinets yesterday. After all the research and questions on cabinet choice, I decided to go with the slim ported enclosures on the Mark Audio website.

I was at my local lumber store and picked up a few nice boards of cherry and a sharp looking piece of well figured tiger wood.

We ran the tigerwood through the bandsaw a few times to pull a few nice sheets of 1/8" thick veneer before laminating them to a 3/4" mdf core.

Were going to use the veneered panels as front and back baffles and use the cherry as sides and top. To allow for wood movement without splitting any panels we had to use veneered baffles front and back which will be set in flush with the sides and tops.

Here's where we stand so far:

Sides and tops ripped down and flipped to ensure the panels wont bow.

8732920308_7495c61581_b.jpg


Front and back baffles veneered and clamped up.

8731800663_2947a96809_b.jpg


After a few hours in clamps.

8732923046_61dcc90ea0_b.jpg


Makeshift adjustable circle cutting jig.

8732916158_4f75453841_b.jpg


And thats about it for now. :D
 
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I'll have to peek through some FAQs to see how to upload directly. I have them hosted on Flickr at the moment.

Click on the "paper clip" icon to the right of the smiley face icon at the top of the reply dialogue box. Upload your pictures directly from your comp. There is a file size restriction thou, so no posting 1.5 meg pictures.;)

jeff
 
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