B&G's for mids?
 

I have a dream; to build my own dipole speakers with 3-4 x 12" GR Research servo's per side for basses, and Magneplanar 3.x ribbons for highs. DEQX will handle the crossovers and level/phase corrections.

For the mids I have been thinking of B&G's, and I have a few questions for you guys:
- What would be the best B&G driver to fill the gap between ~200hz to ~3khz? Line of NEO-10's, RD-50, or what?
- Can any of B&G's actually go down enough for GR's? NEO-10 are claimed to play down to 150hz, but on the other hand, I have read discussions that maybe they should be crossed over near 300hz or such.
- What's your opinion on this whole idea over all; would it be a good combination or not? Are there some probable pitfalls to be aware of?

NEO 10
 

Attached is the response of the NEO 10 from Parts Express specs.
This is from 1/2 meter away, and it looks like pure dipole, no baffle area around it.
If you build an array of these with maybe some more baffle, that out-of-phase cancellation will come in at a lower point than 1kHz, and you would still get that airy dipole sound if you manage the back wave.
Pitfall: The upper peak has to be dealt with using a trap of some kind. I have two NEO 8s on either side of a tweeter and they have a similar peak. They will be in series and I was able to make one filter for both, but something has to be done because it adds a raggedness to the otherwise exemplary sound.

If you haven't obtained the GR's yet, I encourage you to hold off and do some more research on the low frequency section - those will sound way too schlubby compared with the BG's.
More opinion:
Bass gets cancelled out in most any dipole system because it is non-directional and the out-of-phase sound from the back radiates spherically along with the sound from the front. Ask the guys here to suggest a musical, well-damped combination of woofers and box(es) that is the equal of your mids and highs.

I think that DEQX could handle that quite well?

Thanks for the comments, paulfx!

I have tested many many high class box subs, and on my opinion, none of them matches Maggies well enough. I don't know the word "schlubby ", but pretty much all box subs have sounded too slow and boomy for me. They just didn't disappear to the sound stage. And it might also be quite problematic to match dipole to the monopole, since their acoustical behaviour in the room is so different. So dipole is surely the way to go for me.

The best box sub (below 2k$ atleast) that I have heard with Maggies was Rythmik Audio's DS-12, using GR's 12" servo driver. It was the only one that was even close to the speed and accuracy of Maggies, so it might be a good choice for dipole setup also. I also have read many many very positive reviews for Maggies & GR's. So I was thinking that if it can match Maggie's mids, it might also be a good option with B&G's.

But; what's your suggestion for the better bass driver to match B&G's??

I will have respectfully disagree here. The GR servo woofers sound fantastic, but as is always the case, proper adjustment and integration with the other drivers is the key. I have heard them many times and they were always fantastic. I was very close to using them, but in the end, stretched to a 4 way configuration and run the Rythmik 15" servos under 60 Hz.

Also, if you are going to use any of the Neo series drivers(which I highly recommend), I would recommend to NOT solder them. Use push on terminals. You can solder those to the wire if you do not have a good set of crimpers. Or do both!

Greg

DEQX Box
 

Wow, just checking out the DEQX processor/crossover. That is something else... For four and a half bills US I hope so!

The combination of GR Research 12" OB woofers and the Neo 10s- along with the Neo 3 tweeters (albeit a custom higher-sensitivity version)- has been used very successfully in the Serenity Acoustics Super 7.

Yeah, it seems that NEO-10's really are a good match for GR's.

But how about RD-50? Can it go well down to 200hz, if steep (48 or 96db) crossovers from DEQX would be used? Twelve pieces of NEO-10 is quite expensive setup anyway, and two RD's could be bought for under half of the price of NEO's.

No idea on the RD series apart from what I've read I'm afraid. It depends how wedded to the (semi?) line source format you are though. In terms of radiating area and sensitivity you wouldn't need six BG 10s to equal one RD-50. In fairness though, you would probably want to use tweeters with the BG 10s, which is an additional cost.