A friend has Dali Ikon 7s. They have both a soft dome and ribbon tweeter and three identical woofers. Yes, probably three times the cost of my M22s. But they sound as close as anything I've heard to the actual studio monitors of original recordings on tape. Some of this is due to the incredible high end with the combination ribbon and soft dome tweeters. I wondered if Axiom had ever considered ribbons. I would put the M22s up against most speakers, except for the high end, which seems a little closed. 'Course it could be other parts of my system, too. Any thoughts?

I believe that was brought up a year or so ago and Alan stated more-or-less that ribbon tweeters are in fact, not that accurate if I recall. Hopefully he'll fill us in....

That's pretty much what I've heard from Ian et al. So yeah, they've tried them, and they're using the things that their tests show sound best.

IIRC, the ribbon takes over from the dome after ~15khz or vice versa, there is a limit/filter they use to run the 2 tweeters. I could also be thinking of another companies design as well.

yes, I think you're right jakewash, they complement each other and are filtered or used with cross-overs to work together. It makes for really lively and stunningly accurate cymbals and percussion.

I think what they were really pointing out is that generally ribbon tweeters do not have as good as off-axis performance compared to domes. However, there are ribbon tweeters out there that trump down tweeters but generally you can get significant performance from a dome tweeter at very little cost which is why manufacturers tend to use them.

Ribbon tweeters have a tendency to be more expensive which is another reason why you see them only in so called "high-end" speakers.

I'm pretty sure that was it doc, off axis performance is not as good, which is why Axiom hasn't used them; as well as the cost factor.

Yes, I do recall that Ian mentioned in a past conference call that their tests showed one issue was the off axis was not near as good as the domes they use.

I don't doubt what Ian says, but it just seems interesting that
this article says just the opposite.

It's about car audio, but the theory ought to be the same. Under ADVANTAGES this is what it says concerning off-axis.

"Greatly improved horizontal off-axis response resulting in excellent high frequency detail retrieval, a more open and "airy" sound, and a wider/deeper soundstage."

Edit: But under DISADVANTAGES it also has this to say, that I just missed until now.

"Limited vertical dispersion. While this can be an advantage, it can also be a disadvantage. The tweeter must be aimed directly at the listening position, otherwise the spl will drop off. Can be a pain to work with if there are 2 people of different height sitting in the car."

So, good horrizontal, but poor vertical dispersion. It would then seem like both a dome and a ribbon would be the best of both worlds.

I dunno. Aside from the (usually) higher price of the ribbon, when you compare a well designed dome or ring rad tweeter in the $50 range from a company like SB Acoustics or Vifa for eg., they appear to have a much smoother freq response than charts of much more pricey ribbon tweeters in the $200+ range and nobody can hear anything anywhere near the freq the ribbons go up to, anything over 20khz is pretty much irrelevant.

Just a thought. What about a ribbon tweeter that's designed to sit on top of an Axiom speaker, that you can swivel up or down a few degrees, and it just hooks up to the same wires on the back of the speaker. Axiom could sell these as an add on for those that would want it.

If that is the case, the ribbons are pretty much a waste.

1. There is not much content above 10-12 kHz.

2. unless you are 19 or female, you most likely can't hear that high.

I don't think it's specifically about frequency range. Frequency range is covered. It's about the actual sound of certain higher frequency instruments that the ribbons to my ears handle better. Cymbals, percussion, etc. And add-on with built in cross over is a great idea. I wonder if anyone anywhere has that.

I haven't seen a ribbon add-on but there are add-on supertweeters available. I would guess a web search would let you know rather quickly if anything like that is available.

Sounds like the Oskar speaker line that employed the Hiel tweeter.

I seem to remember that power handling was an issue and a magazine (UHF if memory serves) managed to easily burn one while testing

I have heard others say that, but I've never listened to a speaker with ribbon tweets. My understanding is that the trade off is off-axis response.

Yes, Onix has done that. Onix ERT (Extended Range Tweeter) is designed as an add-on to an existing speaker. They are ribbon super tweeters that have an adjustable cross over with two settings, 11kHz to 15kHz, and 4 settings for sensitivity, 87.5dB-89dB-90.5dB-92dB. They are about $350-400/pair and available from Onix distributors in North America. LCY-100K is another one and costs about $550-600; Madisound and e-speakers no longer carry it. Townshend supertweeter is a third choice at around $1500/pair. There are others.

Relatively speaking, dome tweeters have good horizontal and vertical dispersion whereas ribbon tweeters have good horizontal but poor vertical dispersion.

But count, the "actual sound" of high frequency instruments is "specifically about frequency range". Well-designed dome tweeters, such as those used by Axiom, do the job within audibly meaningful frequency limits with no significant problem.