speakersrs w/ 125WR/FR drivers often with AC2si ribbon

[Variac]

There was a thread regarding the RAW get-together in Canada, and the most interesting designs seemed to involve the new 125 drivers designed by Adire I believe, and sold by CSS and RAW. Many of the speakers demo'ed by RAW used the 125 with the Aurum Cantus 2si ribbon tweeter.

Sadly the original thread seems to have disappeared in the latest outage so I am starting this thread to discuss using these drivers.


Reports are that the 125 has exceptional potential, but might need work to achieve that potential. I own a pair of the AC ribbons in my Basszilla speaker, and THEY seem exceptional also.

Planet 10 and I are quite intriged by the idea of using separate amps for the 2si ribbon tweeter and the 125's because the tweeter is much more efficient than the mid/bass. We suspect that choking down the tweeter so much does not help its sound, and that a complex passive crosssover on the 125 might also not be optimal.

The 2si is so efficient, that a very low power amp - possibly tube-, possibly chip, possibly Aleph, would power it fine. These days DIY audio has lots of group buys on amps that would power the tweeter and 125 well, so bi-amping needn't to be reserved for only very expensive systems anymore IMHO.

My hope is that we work out a good module with these two drivers, with an active or passive crossover before the amps. the module could then be used in different combbinations to create various designs.

Might be nice to base our experiments on boxes that are the same sizes as readily available premade boxes, so people wthout shops could duplicate them....

EDIT:
A request as the thread starter: I'd like to see "IMHO" used at least once in each post on this thread

[RAW]

Ok As I said before the model of ribbon is a OEM not the G2Si as noted.But if you are going after the G2Si that is fine.

As well Dan from Adire helped design the HT2 and HT3 in final product not for CSS but RAW Acoustics.

All of these designs will be and are only sold by RAW Acoustics.Not CSS,or Adire.

It was important for me to have Dan's input in the xover designs of them as well as all the measurements of all my finished product to have a no questions asked about measurements.As well Dan does know a few things about designing xovers.

Raw designed the layouts everything down to what drivers ect Dan only had his hands in the xover designs as well as the measurments.

If you look at the WR125S and ST drivers off axis response you will see why I picked a 2way even in the HT2 (MTM) as well as the HT3 (TMsidefiring Extremis tower) at 4k the WR125 is 10db down off axis.


Al

[leadbelly]

Can anybody comment as to why there seems to be a recent (last year or so) flurry to use the newest batch of low cost ribbons with what are essentially full range drivers? Jim Griffin's design, the BassZilla Platinum, now with the WR125's? Or to put it another way, a ribbon isn't necessarily the 1st thing you would think of to just help the top end of a FR driver, so why the interest? Is it a matter of fashion, taste in drivers, or is there some subtle aspect to them marrying well which is not readily apparent?

[RAW]

I di not have any other intention of using the ribbons in my designs ofther than a 2 way.
-The Wr125S is a wide range still not fullrange driver!
-Those listening to them say they are great but could use a tweeter.
- Wr125S and Wr125St do not have a good off axis responce for fullrange use a good reason to use a tweeter with them.
The XBL^2 motors help with the drivers being so clean but still needs a tweeter.
As well why not use a ribbon for that upper end clean rich sound that produce without being harsh of lacking detail that most dome tweeters do.

I will say 9-10 people who have listened to the WR125S with softdome and the ribbon have picked the ribbon.

As well having the clean mids and smooth detailed lower mid punch the 125s and 125ST have why not use a ribbon it warrents a very good tweeter
Kind of the match and stick, left and right

Al

[planet10]

Originally posted by leadbelly
Can anybody comment as to why there seems to be a recent (last year or so) flurry to use the newest batch of low cost ribbons with what are essentially full range drivers? Jim Griffin's design, the BassZilla Platinum, now with the WR125's? Or to put it another way, a ribbon isn't necessarily the 1st thing you would think of to just help the top end of a FR driver, so why the interest? Is it a matter of fashion, taste in drivers, or is there some subtle aspect to them marrying well which is not readily apparent?

It all starts with -- what is the best midrange -- a good full-range. Then... i'd like to have the extra extension on the top (& possible the extra dispersion) that an independent tweeter gives... hence the ribbon (+ the fact that now that the chinese have gotten into ribbons you can actually afford them).

What Jim & Al are doing are just 2-ways, but they are being smart and picking the best possible midbasses.

Despite what Al says about the off-axis, the WR (IMHO) still sounds best run wide open. In this case a good cone tweeter or a horn will, theroectically, make the best match, but there is something about a real ribbon....

dave

[planet10]

Originally posted by RAW
Ok As I said before the model of ribbon is a OEM not the G2Si as noted.But if you are going after the G2Si that is fine.

But the closest we are going to get -- unless you will sell kits without XOs -- is the G2si.

dave

[Cal Weldon]

Originally posted by RAW
I will say 9-10 people who have listened to the WR125S with softdome and the ribbon have picked the ribbon.

I guess I'm that tenth person.

Sorry ol' buddy, but I was thinkin' of using 'em with a 94 dB titanium dome.

Them there ribbons are for people who still have good hearing.

Cal

[planet10]

Turns out the thread that spawned this one is beyond resurrection, so i have started a replacement... Northwest Audio Review June 4,05 at RAW Acoustics Take II ... to recover at least part of its content.

dave

[planet10]

Originally posted by Cal Weldon
I guess I'm that tenth person.

Hydralics Cal. Hydralics




dave

[Jim Griffin]

Dave and Al have discussed why it makes sense to pair the CSS WR125S or the Jordan JX92S with a small ribbon like the G2si. I went through the decision process in the design of the Jordan JX92S and AC G2si ribbon speaker. Some of my design notes are in the write-up at:

http://www.creativesound.ca/pdf/JX92SG2siDesignPak.pdf

Essentially, the Jordan JX92S--while the best sounding of the reasonably priced truly full range drivers--is a little rough in its treble response. Plus any wide range driver will start to beam--narrow its horizontal dispersion starting in the upper mid-range and extending into the treble area. The small ribbon adds a sparkle to the highs and widens the dispersion so that you create an exceptional speaker.

I suspect that the forthcoming CSS FR125S (the full range version of the WR125S and ST series) will be good on axis across the treble area will also suffer from a bit of horizontal beaming. No if you always listen on or near axis with either the Jordan JX92S and likely the FR125S, you may not desire for more dispersion.

Bottom line: including a small ribbon will extend the highs for wide or full range drivers that have the guts to go low. Thus, you create an exceptional speaker.

Jim