HELP with driver selection for existing enclosure

[fazman]

Hi everyone, I was hoping to get your help in selecting a suitable driver for my next project.
Current cabinet houses an 8" driver and the enclosure size is approx. 1.3 cubic inches with a slot port at the back which is 12" long by 9" wide by 1" in diameter. The cabinet is existing and cannot be altered at all. Actually the cab is an older Energy 22 Reference Connisseur.
The tweeter I already have... it's a Vifa XT Ring Radiator. The crossover will be an Acoustic Reality crossover which is a derivitive of a series crossover. I've had some experience with these crossovers and I like the results I had.
So the 8 inch driver must have a well behaved roll off (very smooth)
I was thinking something that may have a paper cone but it's not necessary. I like lots of midrange detail but not at the expense of solid bass.
Budget, I'd say no more than about $150 per driver.
Some of the initial thoughts I had were maybe an Usher driver or maybe one of the offerings from SEAS.
Maybe you guys can give me some suggestions at what I can look at. I don't have any box moddeling programs so I'm hoping someone can assist me in that department.
I really don't want to make a mistake when I purchase these drivers so all the help I can get would be appreciated.

Let me know if there is more info that I need to provide to help someone make some recommendations.

Thanks so much for your help gentlemen

[BHTX]

Which Vifa XT exactly?
http://www.madisound.com/catalog/adv...imageField.y=0

Not for sure if it applies to all of the XT tweeters, but as far as I'm aware, the XT25's will definitely work best when crossed above 2 KHz, preferrably higher, mainly due to a very steep and steady increase in harmonic distortion below that freq. Obviously, that should be something to consider during your search for an 8" woofer to mate it with. Although subjective, wiith an 8" woofer, often times the lower the xo point the better. Are you dealing with a fixed crossover point as well? Of course, the simple fact that you're dealing with a ported enclosure that supposedly can't be changed could make things a little difficult here, but we'll see.

First thing that came to my mind was the Seas P21RF/P (H511) 8" poly cone, used in the Seas Cygnet kit.. supposedly has potential for some really good bass response too..
http://www.madisound.com/catalog/pro...roducts_id=834
http://www.madisound.com/catalog/PDF/seas/H511.pdf
http://www.madisound.com/cygnet2.html

Anyway, I'll do some simple modelling while taking your specified enclosure into consideration and see what I can come up with. Hopefully you could make it work with this driver. I've checked several other 8" woofers that came to mind, but I don't think they'd have nearly as nice midrange performance as the H511. Even this driver's midrange probably won't be spectacular by any means when compared to smaller midrange drivers, but I think you'd be hard pressed to find better out of an 8" driver for less cash. If you haven't looked already, I think you'll find that most 8" woofers won't even come close to working in a 2-way.

[BHTX]

If the box volume and vent dimensions you gave are absolutely correct, with no end correction or other variables considered, bass response should look fairly similar to this if you were to put these drivers into the enclosure as-is, without any modifications done to it. Tuning would be around 39-40 Hz..

[BHTX]

Group delay. Obviously, this isn't exactly ideal. Slight modification to the interior of the cabinet to reduce volume will be necessary. Keeping the same vent size, doing this will also raise the tuning frequency. You would need to figure out a way to add to or replace the current vent to lower the tuning frequency just a few Hz or so, as well as reduce the interior volume of the enclosure to around 1 cubic foot or less.

[fazman]

BHTX, thanks so much for this info. It looks like it would be a pretty good option. The Vifa ring radiator is the TG 30 04.
I've had a few Vifa poly cones before and although I think they can sound very good, I don't know if I want to go the poly cone route again.
I was kind of thinking something paper (treated) or maybe even a metal cone, but if I went metal then I would have to nix the whole Acoustic Reality crossover and go with a traditional parallel circuit. I'm ok with that, it's just my whole thinking process about this will have to change
I'll investigate this driver a bit further.

I'm also thinking about another option that I came across that interested me. The Dayton Reference metal cone driver with maybe the matching Ref tweeter? I know there was a sealed version of this done but I can't seem to find the link to it anywhere. I wonder if this version can be done in a ported version to fit my cabinet