Alpair 12 Open Baffle Designs

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I posted a while back on the Goldwood's with the Jim Griffin Jordan/AC design on top. Very nice and matches well. Not currently listening to them as I went to the 15" Eminence (actually now the Selenium) with the Alpair 12 on top. More sensitive and a bit more detail. My power amp went out when I switched to the Seleniums, so have not had time to do a real comparison with the Eminence since I am using a spare amp for now, but will say more later.
 
I have started, not really intentionally, a collection of 15" woofers and a bunch of 3" to 4" full range drivers (Alpair and Fostex mostly) that could be mixed and matched to find good combinations. A modular OB that can take the different driver combinations may be my next build.

The older Alpair drivers I have model really well in an OB. I have looked at the new Alpair 7 and 12 and they also look good. What are your impressions of the Alpair 12 compared to the Jordan you also have heard? The big Alpair is an interesting looking driver.
 
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I have both the Alpair 7 and the 12. The most important thing I have learned is to believe what Mark says about them needing over 200 hours to break in. At first, I preferred the 7's over the 12's as the 12's actually seemed a bit bright. Now that they are broken in, the 7's seem a bit thin and the 12's sound awesome.

Not a scientific measurement, just an opinion, the 12's sound a bit more detailed and a bit fuller than the Jordan's. However, again, I look forward to having my AR amp back and having time to do some serious comparisons. That means building an OB for the Jordan's so I am really comparing OB to OB instead of to the Jim Griffin design. Bottom line is that I have no regrets about buying the Alpairs once they broke in.

You can see pictures at AZDIY2009 Detail Photos

Craig
 
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Very nice, wish i was there.

The baffle for Alpair 12 is smaller than original MJK design for Jordan's. Any reason for the change?

cheers
Henry

Available wood. I threw them together in a hurry. Interesting you should ask as I have since added 4 inches on one (out) side and 3 inches on the other (in) side of the Alpair 12 OB with an increase in detail. Don't know for sure if it was adding width or just the break in, but the added width did seem to help.
 
Interesting, maybe the highs drop down so u can hear more detail in mid freq.

I have Alpair 10FR in GM's ML-TL (slightly undersize), and Alpair 10 bass + Alpair 5 waiting to have a house.

I saw this thread 2months ago, which was very intersting, since i always want a clean low bass.

Im trying to figure out which woofer can do. So far the available would be PA audio from thailand which have qts about 0.7

Cheers
henry
 
I have both the Alpair 7 and the 12. The most important thing I have learned is to believe what Mark says about them needing over 200 hours to break in. At first, I preferred the 7's over the 12's as the 12's actually seemed a bit bright. Now that they are broken in, the 7's seem a bit thin and the 12's sound awesome.

Not a scientific measurement, just an opinion, the 12's sound a bit more detailed and a bit fuller than the Jordan's. However, again, I look forward to having my AR amp back and having time to do some serious comparisons. That means building an OB for the Jordan's so I am really comparing OB to OB instead of to the Jim Griffin design. Bottom line is that I have no regrets about buying the Alpairs once they broke in.

You can see pictures at AZDIY2009 Detail Photos

Craig


I totally agree as my Alpair 12 has over 300 hours on and I love them more and more. I could never imagine it sounds so sweet and rich. I suppose to have my report submitted after 300 hours as promised, but I forgot to start writing anything when the system is on. What I need now is a little bit more air at the top.
 

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albertli, funny to see your Goldwood H-frames with OB Alpairs. I have Alpha H-frames with (at the moment anyway) Tangband w8-1808s... i also have unused BIBs but behind the listening spot. If you ever go back to the BIBs you will see they do have compelling qualities too. But currently I am enjoying these relatively modest costing open baffle systems that really cost very little in comparison to the electronics used to power them. I also agree, your pleasantly shaped baffles have a nice organic look compared to the rigidly angular rectangles that adorn my room. Enjoy!

Godzilla
 
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Per Mark's request, I am opening a thread on using the new Alpair 12 in Open Baffle designs. I am using one now and Alberti has also posted, but these posting are in the MLK H-Frame using the Goldwood 1858 thread. We will try to move the relevant posts on using an Alpair 12 OB over here.
 
albertli, funny to see your Goldwood H-frames with OB Alpairs. I have Alpha H-frames with (at the moment anyway) Tangband w8-1808s... i also have unused BIBs but behind the listening spot. If you ever go back to the BIBs you will see they do have compelling qualities too. But currently I am enjoying these relatively modest costing open baffle systems that really cost very little in comparison to the electronics used to power them. I also agree, your pleasantly shaped baffles have a nice organic look compared to the rigidly angular rectangles that adorn my room. Enjoy!

Godzilla

I love my BIB too, but too bad my very best friend took my drivers for his new project. I thought it would be better for me to look for a pair of new driver for the box - for the coming big screen tv system.
That baffle not only looks good, but sounds good too. I would make another pair with slimmer on both sides, and see if I'd have better highs.

Albert
 
hayenc,

Thanks for posting on these 2 drivers.

I too am interested in both and wonder with regards to the 7 and 12. Is the difference between them much what one would expect given the relative sizes. That being the 7 has a little more sparkle up top while the 12 has more weight through the bass and mid frequencies?

I realise this is a vague way of putting things but its the best I can do :)

That 12 has a really big basket!

Cheers!
 
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I have had some system problems and will be on vacation for a few days, so responses will be sparse. First, both drivers need time to break in. They change more than any other driver I have had. And so, I have not done quite the critical listening after break in that they need. I am finding that the 12 seems to hold its own with the sparkle on the high end while having the added weight. Will say more in a week or so.

Craig
 
I have a pair of Alpair 12 still in the box, destined for a future project.
I'm very interested in exercising them along with a pair of Goldwoods in this design until I'm ready. This looks very cool.
I'm a FR guy. I don't like the plate amp solution mostly because the power cords violate the WAF. How would one ideally drive this combo? I've never bi-amped or used digital crossovers and have never built a passive crossover, though I could be spoon fed ;) Shopping for gear doesn't violate the WAF :)
Looking at the Behringer site has just made me dizzy.
 
Hi Speed,

Here's my newbie experience with an active crossover. First, I read that MJK has pre and power amps that already use XLR, so he just adds the crossover inline and is done. Like most, my gear is just normal consumer-style RCA.

There is a ~12db difference between pro XLR and consumer RCA. There's also an impedance difference. A simple XLR-to-RCA straight-through adaptor is not the best solution. So the next choice is level/impedance matching with *gasp* an external box. The boxes start at about $50. The convenient ones will simultaneously convert (a) one stereo pair of XLR-to-RCA and (b) one stereo pair of RCA-to-XLR.

In my case, source output is stereo RCA, that gets converted to stereo XLR which goes into the crossover, and out come two pairs of stereo XLR's (one pair to the woofer amp, one pair to the fullranger amp). All told, I needed two $50 stereo boxes (each of which can do simultaneous XLR-to-RCA and RCA-to-XLR in stereo), 6 XLR cables plus 3 pair of RCA cables.

One other note: cheap plate amps don't necessarily have a high-pass built in -- they might just have a knob that adjusts the low-pass to the sub-woofer (and do nothing else). That's what I found on my cheapo plate amp anyway.
 
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Finally have my BAT preamp with new tubes, and the AR VT-130 repaired so I am back in business. Have to say that for the last month, I have been listening to the Alpair 7's in OB. They are breaking in nicely and still have a bit more detail than the 12's and as they break in, the lower mids are more solid. I tried the H-frame woofer below them with the Selenium drivers instead of the Eminence Alpha, and got too much bass with much less detail. So for now, just enjoying the 7's. Just swapped my PH5 for a Peter Daniel Phonostage and was impressed by the improvement in quality. The 7's were definitely up to showing that off.
 
>>> I have started, not really intentionally, a collection of 15" woofers and a bunch of 3" to 4" full range drivers...

LOL... i can relate.

>>> I am back in business. Have to say that for the last month, I have been listening to the Alpair 7's in OB.

Glad you are back in business and listening again.

>>> I tried the H-frame woofer below them with the Selenium drivers instead of the Eminence Alpha, and got too much bass with much less detail.

Thanks for your observation!

Honestly, the H-frame with some kind of open baffle setup on top could be the ultimate home speaker. If you have the room for H-frames they do an amazing job in the bass - full and rich - not like expensive audiophile 8" drivers or single 12" powered bass subwoofers sitting in a corner. Choose a 15" or 18" H-frame and have fun experimenting with your choice of full range drivers on OB... you can even play with sealed or ported boxes with any combination of drivers atop your H-frames bc they act as speaker stands.

MJK did a wonderful job when he shared his H-frame experience!

Godzilla
 
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