Building a 2x12 full-range. Driver choice?

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Hello all,

I'm planning on building 2 2x12+1.4" cabinets similar to the Speaker Plans x12 but sized accordingly based on my drivers. At first I want to be able to use them full range, then down the line I plan on building some subs (probably the PAL 12 from this forum) to go along with them. So I need help with the driver choice. I'm playing mainly house/disco/some techno. No dubstep wobbles here so the low low bass is not a priority.

I'm mainly looking at the
Eminence Delta Pro 12-A

I've also looked into something in the Fane Sovereign series like the Pro 12-300.

Any recommendations for high efficiency, low-cost ($150 USD max per driver) and a decent amount of thump? Also must be readily available in the US.

Any other general tips as well? This is my first system building project and I want to make it a good one.

Thanks,
D
 
Deltapro12-A is awesome, with impressive chest hit, but slightly muddy.
If you try to use fullrange all by itself or with a piezo tweeter, you will be
wishing for more midrange clarity, and equalization won't give it to you.
Two would also be extremely heavy.

I'd put about 4inch wide slotted baffle in front, to extend the bandwidth
before directivity severely changes. You can cross to your 1.4" a little
higher if you have the slot over the 12's.

You might also look at Beta12LTA with a whizzer cone. They sound much
better than you might imagine, lighter and cheaper and less muddy than
DeltaPro12, if a few decibels less loud and bone crushing...

You might try to DIY yourself a slotted acoustic lens for the 1.4".
Check pics in the review comments to see the lens structure inside.
http://www.parts-express.com/pe/showdetl.cfm?partnumber=294-2840

----

Yeah, slots cause ragged response above 1/4 wavelength front to back
or side to side, or cavity resonance. But it can be equalized! No slots is
something you fix EQ in one place, rips your head off somewhere else...

And a flat baffle (180degree waveguide) supports no high order modes.
There are no semi-parallel surfaces to bounce back and forth between,
except the walls of your room...
 
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Just incase you couldn't locate the specific pic I was talking about.
 

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Hey Ken,

Thanks for the in-depth reply and advice. A couple newbie things.

Do you have an example of a slotted baffle in picture form? Having trouble imagining that.

Also the acoustic lense you mentioned. Is the purpose of this to increase dispersion of the comp? What other effects does it have on the sound?

While we're at it, any recommendations on a suitable compression driver? This is something I could spend a bit more on if it's worth it. I'm not dead-set on the idea of a 1.4", but from what I've read a 2" can be overpowering and shrill sounding.
 
Its a board (or two) with a 4inch wide vertical opening gap
right down the middle. Assuming your 12's are stacked on
top of each other for the same reason...

A 12" speaker is too wide to use its full bandwidth potential.
Because it is more than 1/4 relevant wavelength in width, it
will sound quite different everywhere in the room. No matter
how "smooth" it is in one place, you can't equalize it to sound
same at two different angles. Thus a slot to narrow the width.

The slot is going to make all kinds of strange things happen
that won't sound right played flat. But it can be equalized,
and the same equalization will be valid anywhere everywhere...

Where I say a quarter wavelength, you can get away with 1/2.
Some narrowing dispersion is acceptable, you just don't want
it to be the dominant problem.

If you make the slot too narrow, since its not a proper phase
plug, cancellations behind the bafflle can become an issue.
Seems about 1/3 of cone width gives the highest compromise
corner for each kind of weirdness. About 844Hz. But you can
continue to play above 1/4 wave (with some equalization) to
1/2 wave, or about 1688Hz. Should be high enough to meet
your 1.4"

You can make a slot even narrrower than 4", and use even
more EQ, and go even higher with uniform dispersion. But
cancellations that drop out too completely can't be EQ'd.
And too much EQ sounds weird cause it shifts phase....
So this is not a trick you can milk too much more out of.

DeltaPro12A can go to 4K, and Beta12LTA can go to 8K on-
axis if you don't care to listen anywhere else but one chair.
Making it work right everywhere is a little more interesting,
and you have to make an opening more narrow to get there.

As for 2" sounding shrill, that's a narrowing dispersion too.
You make slotted waveguide like shown above, or use a
horn with a narrow slot in the throat, it becomes EQ-able.
http://www.parts-express.com/pe/showdetl.cfm?partnumber=294-424
http://www.parts-express.com/pe/showdetl.cfm?partnumber=264-327
http://www.parts-express.com/pe/showdetl.cfm?partnumber=264-328

Horn or waveguide with 2" throat and no slot is gonna have
coverage abnormalities above 3376 (1/2 wave at 2") that
can't be EQd to sound same and right at different angles.
Not quite that bad cause its round, not all so wide across.

I see no problem with 2" (or even 3" if such things existed)
compression driver with uniform a directivity lens and well
matched EQ. I don't see how thats possible without a slot.
But theres a "SEOS" waveguide with no narrowing slot that
also claims to do so. Maybe or not with a 2", but you might
research into how those work also.

Also read this thread. Especially the pic on post#8...
http://www.diyaudio.com/forums/full-range/238556-slot-over-speaker-offset-increasing-directvity.html
 
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With a 5" slot in front, DeltaPro15A might be lighter than a pair of DP12A's...
Eminence Delta Pro-15A 15" Cast Frame Driver 290-512

If you threw both your 12" money at a single 15", KappaPro and KappaLight
would then also not be entirely out of reach...

As for surface area: 532.4 cm² x 2 is greater than 856.3 cm² x 1, but...
Man, I just don't want to remember two DeltaPro's in the same cab.
I don't know how to express that is not a safe one man lift...
 
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I would go for the B&C 12HPL76, even though Parts Express has them at $28 per driver over your $150 each goal. I think they are worth it. Maybe you can buy 4 of them for $150 each, if you shop around. They are 99 db 1 w /1m, and handle 350 watts rms, 700 watts peak. One tuning gives a f3 of 70 Hz in a 0.62 cubic foot enclosure. For a pair, that's about 127.5 db continuous, and 130.5 db peak. And they weigh only 6 lbs each !
Any pair of HF drivers with a sensitivity around 107 db, and a power handling of 110 watts rms should keep up nicely. There is a pair of B&C DE85TN for sale on another forum for $150 each. They are a 2" throat, but the diaphragm is 3", not 4" like some JBL 2" drivers. The larger throat allows lower crossover point, and the loss in extreme highs can mostly be compensated for with eq.
B&C drivers are some of the most high fidelity pro drivers available, IMHO .
Another good HF driver comes from Radian. They don't make woofers as well, though. So, I think an all B&C system would be a home run, first try.
Good Luck !
 
LOL ! My poor writing skills. What I meant was, Radian does not make woofers which are as good sounding as the compression drivers they also make. IMHO, B&C does a better job of keeping all of their component offerings sounding consistantly excellent. (Maybe using what they learned by supplying parts to the very demanding Nexo speaker company..
Member Kenpeter has some good points about 12" drivers and their inherant faults. These are worse with a 15" crossed over to a HF driver as a two way system. Nexo, in fact, resisted for years offering a 12" 2 way system - but when they did, they used a phase plug we affectionately nickname the "dogbone". Look at it on their Geo S12 system, illustrated on pg 3 of this:
Welcome To Nexo - Nexo
Very effective, and simple, without as many of the potential resonant artifacts of fully slot loading the driver.
 
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