What fullrange for OB?

Hi all,

I've just ordered 4 Alpha 15 and was thinking about using an fullrange above the Alpha15, but what would you choose? I read alot of threads on this and more diy-forums but can't decide anyway...

I've planed to use 2 Alpha 15 in an H-frame per side, use a passive crossover (12dB/oct) cutting at about 150-200Hz. So the fullrange need to atleast be used down to 250-300 Hz.

Visaton B200, TB W8-1808 and Fostex FE206EN are all good candidates, but how are they different in sound-style?

I may use them nude, in other words; without baffle.

Very grateful on any comments!

Best regards
Mikael H
 

ScottG

Member
2003-02-04 12:23 am
US
Hi all,

I've just ordered 4 Alpha 15 and was thinking about using an fullrange above the Alpha15, but what would you choose? I read alot of threads on this and more diy-forums but can't decide anyway...

I've planed to use 2 Alpha 15 in an H-frame per side, use a passive crossover (12dB/oct) cutting at about 150-200Hz. So the fullrange need to atleast be used down to 250-300 Hz.

Visaton B200, TB W8-1808 and Fostex FE206EN are all good candidates, but how are they different in sound-style?

I may use them nude, in other words; without baffle.

Very grateful on any comments!

Best regards
Mikael H


Without baffle requires a LOT of eq.. and a lot of spl/excursion.

At the very least you should consider a 3-way, but IMO your best solution is to have someone else do all the "heavy lifting" for you:

NaO Note Details
 

jerome69

Member
2008-02-18 11:33 am
Lyon
Hi all,

I've just ordered 4 Alpha 15 and was thinking about using an fullrange above the Alpha15, but what would you choose? I read alot of threads on this and more diy-forums but can't decide anyway...

I've planed to use 2 Alpha 15 in an H-frame per side, use a passive crossover (12dB/oct) cutting at about 150-200Hz. So the fullrange need to atleast be used down to 250-300 Hz.

Visaton B200, TB W8-1808 and Fostex FE206EN are all good candidates, but how are they different in sound-style?

I may use them nude, in other words; without baffle.

Very grateful on any comments!

Best regards
Mikael H

Hi

use them nude ? it will be not possible go down to 150Hz.

My choice 1. W8-1772 2. B200 3. FE206EN

Add a Horn tweeter (96dB) will be better

;)
 

ra7

Member
2009-02-07 6:47 am
Davis, CA
I've tried the Audio Nirvana standard 8s in an OB with a supporting alpha15. I've also tried the JX92s, Alpair 6.

My favorite is the AN8. Superb midrange and everything else is very good. Alpair 6 was very good too, but is limited in excursion capability. I don't like the JX92s.

You have chosen the correct crossover point... keeping it down at 150 Hz or so gives the vocals to the full range driver, where it will excel.

For reasonable SPL levels, go for at least a 6 inch driver and >90db/W. The larger fostexes, lowthers all meet this requirement. I would definitely recommend the AN8... lowthers on the cheap.
 

Tea-Bag

Member
Paid Member
2006-02-08 2:32 am
Kennebunk
I'm planning to build a very similar project. Mine will incorporate Alpha 15A's with MarkAudio CHP-70 fullrange drivers (or maybe CHR-70). Crossover to be somewhere in the 300Hz range, depening on what sounds/measures best. However being a baffle-less hanging/swinging system, SPL output will be fairly low.

I've been playing with 4" drivers on OB,
Compared to 8 inches drivers, the less dynamics and smaller soundstage just dont cut it in my fairly large room. I would stay 8" like RA7 suggest. The 3" fostex's beat out the 4" CHR70s in OB.
 
I've been playing with 4" drivers on OB,
Compared to 8 inches drivers, the less dynamics and smaller soundstage just dont cut it in my fairly large room. I would stay 8" like RA7 suggest. The 3" fostex's beat out the 4" CHR70s in OB.

Surely you have a valid point. I however am far from planning to fill a large room with sound. So for my purposes 4" will do. So far I like the sound of the CHP's, but it's easy to change drivers should I want to. After all there is no baffle to modify :D

4" may not be enough for the OP, but I thought I'd mention my plans here, as they are rather similar.
 
Of the drivers mentioned i'd put the B200 ahead (with phase plugs to sort the HF disperion issuse). FE206 would be my next choice, but very low Q may hurt with a low XO. W8-1772 would be my last choice, the W8-1808 i liked better all round and it is better suited parameter wise to OB.

Personally i'd use a smaller driver with better mids and top... Alpair 12 would ba good candidate (keeping the driver largish), but at a lower efficiency.

On that last note, measured efficiencies of B200 are 91, and W8-1808 is 92. FE206En comes in at 96dB, A12 at 89 dB.

dave
 

ScottG

Member
2003-02-04 12:23 am
US
Yeah you probably right! But with a baffle and passive crossover, what would you choose for driver?

..completely un-baffled, that would be tough to say..

Here is a driver similar to the already mentioned Audio Nirvana 8's, but it has a better motor, much more linear excursion, and it has a rising lower-mid freq. response below 400 Hz:

Dayton PS220-8 8" Point Source Full-Range Neo Driver | Parts-Express.com

It would need a lot of correction at higher freq.s however. :(

The Omnes Audio L8 is another possibility that counters it's low x-max with a high qe. (..a lot cheaper construction than the Dayton however.)
 
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I've been playing with 4" drivers on OB,
Compared to 8 inches drivers, the less dynamics and smaller soundstage just dont cut it in my fairly large room. I would stay 8" like RA7 suggest. The 3" fostex's beat out the 4" CHR70s in OB.

Yes, I agree with this. The smaller drivers create a much smaller soundstage. This is especially irritating on a OB in a moderate sized room. When you switch to a larger driver, the difference is obvious.
 
With CHP only available in Japan, Germany, and Oz, you may well want to consider EL70 which was developed on the earlier CHP. (and save yourself some shipping)

Oops, jwmbro i see that despite US flag you are in Germany. EL70 should still be a consideration, available in Europe from a number of vendors including Henkjan.

Military? (then APO would equalize shipping),

dave
 
Personally, I like the Jordan JX92S, but I use them in a very small room and they have a quality of sound that I can only attribute to the metal cone. They definitely need the bass support, which I do not have yet.
I will try the B200s in the same set up soon, so maybe I can compare. It is just a 20" wide baffle, but it is a nice easy sound (digitally equalized).
 
Oops, jwmbro i see that despite US flag you are in Germany. EL70 should still be a consideration, available in Europe from a number of vendors including Henkjan.

Military? (then APO would equalize shipping),

dave

Nope, not military, just here as a student. I already have the CHP's in fact, playing in their box, in order to accelerate the break-in before I build my speakers. Still lacking the Alpha 15A's though, so no build progress yet. Not that it's particularly tricky to build a frame to hang drivers from :D. Will be sharing pictures of my construction once I make some progress though. Not the first project on my list I must admit.