Aurum Cantus tweak is a ..dead in the water

jules · « **Reply #20 on:** 31 May 2007, 04:54 am »

Hi Kyrill,

I notice xover point for your Aurum Cantus is 2000 Hz. The bloke who designed the Aurum Cantus was, I believe, formerly the designer of the Raven ribbons and they do look very similar. I've noticed that Orca [the Raven company] formerly maintained that their ribbon was good down to 1800 Hz but after some time, they raised that to 3,500 Hz ... quite a difference! I understand that the problem is/was that over time the lower range stuff was too much and the ribbons gradually stretch. If you think all the stretching is happening due to amp switching then my post is irrelevant, but it is hard to see just how much movement a ribbon makes during music and yes, pure Aluminium ribbons can stretch even if they are easy to replace.

I've been using Raven R2s [3500Hz low] for a couple of years now and they are still ok although I do have a passive xover protecting them from thump.

jules

kyrill · « **Reply #21 on:** 31 May 2007, 08:45 am »

thx jules important news

yes the thumps did stretch them

i think i finely spray them with C37 varnish on both sides. It will make the ribbon heavier so the 40khz will be rolled off, no problem

the dried varnish will make the ribbon much less stress sensitive and the tone of the music MUCh more natural
I am convinced of that, and... if it fails ( but it won't) then I go back to the default solution

see: http://www.ennemoser.com/
Kyrill

jules · « **Reply #22 on:** 1 Jun 2007, 12:41 am »

worth a try Kyrill ...

I did read that somebody used the wrapper from a Camembert cheese in an emergency and thought it sounded better than the original

jules

kyrill · « **Reply #23 on:** 3 Jun 2007, 11:46 am »

hi Jules

it is possible

the ribbon is a loose piece of aluminium thin foil pressed in zig zag style. i can replace it with any kind of metal thin sheet with the same dimensions The zig zag shape i think is not for the sound or better dispersion, but to lower its resonance freq. the _-_-_-_ shape ( connect the lines in yr mind) lowers the tension between the end points . If you pull them apart too much the shape will give in and eventually becomes straight before the pressure in the foil will build up. This way the pressed zig zag form acts like a buffer. The resonance freq is therefore 400 hz. way under its operating freq.

The downside is that the force in the thin aluminium foil to keep its structure is, is rather low. All too easily you can stretch bend aluminium of 0.1 mm thickness. If i blow too hard on the tweeter it will be too hard..

However ( off topic) Endemoser's theorie that metal is not a nice carrier of sound still holds. A violin is nice because of its wood structure.. Can you imagine how awful a violin will sound if made from aluminum? On the other hand a trumpet made of wood..will not sound ugly or even dull if you force the wood to "behave" like metal. That is exactly what speakers are doing. the current and control of the amp forces the ribbon or woofer to behave like a trumpet of copper or to behave like human vocal chords by mimicking/copying most of the relevant "audio" properties of the original source while vibrating. In doing so however, it cannot oppress 100% its own audio properties. Especially metal is bad in this.

paper and wood ( carbon based) carriers or copiers of sound are the most pleasing and natural sound carriers to the human ear and i believe that empirically. According to Ennemoser the best material for speakers therefore is paper and or wood ( both with negative structural properties as being a speaker)

The ribbon is made of aluminium and less musical than a conventional paper dome tweeter, but
it never sounds like a tweeter! you swear the object of sound is in the room. The attack and delay ( or is it decay?) times are so fast. the distortion so incredible low.

SO i am in the business now to paint(!) the fragile ribbon to change its characterics more into a carbon based material and destroyed already two ribbons in doing it. They are so fragile. Kitchen aluminum foil is sooo thick compared to the ribbons. I swear, like a real Uri Geller, i looked concentrated to one ribbon and it deformed right in front of me, or did i miss the brief moment that with a big plunge a droppel of my precious sweat fell on it like a landslide? I don't know..

AKSA · « **Reply #24 on:** 4 Jun 2007, 10:46 pm »

Kyrill,

My golly, this sounds more fragile than brain surgery...... good luck.

And even if the Ennemoser lacquer has density around water, it is viscous, so is likely to form a layer well over 50 microns - so this would very considerably add to the mass of the ribbon, and may even be heavy enough to deform it.

The odd thing is that the ribbon is electrically very robust. How often do we see this in electronics - electrically strong, mechanically fragile - like an electron tube!

Do keep us posted. This is fascinating, it really is.

Cheers,

Hugh

kyrill · « **Reply #25 on:** 9 Jun 2007, 03:13 pm »

hi

i ordered 4 new ribbons from e-speakers.com NY and like the original 4 spare ones i got when i bought the tweeters, they were folded into a papermatchbox kind of box. which is at least 3x shorter than the length of the aluminium ribbons itself. Maybe E-spakers get them like that from Aurum Cantus itself who "tortures" those ribbons during shipping and or stocking in inadequate boxes. Carefully with relative blund heavy stomp fingers from a giant, I unfold them from each other and try to keep straight those shining babies of 0.01 mm thick-->0.00004 inch!! they are appr 12 cm long and 0.8cm width

So i tried to "bath" now 2 ribbons,instead of painting them w. a fine delicate brush. The pressure of the brush can already deform them.. Bath them in 66% turpentine and rest with C37 varnish. you cannot bath them completely as the ends of the ribbons should conduct electricity. Of course out of the bath they bend and are too full of varnish
To get the extra paint off AND preserve their delicate form is as difficult as, ehh to keep a 26 yrs. young maiden escaped from a convent, away from the men

They have a 3D structure like a ladder.every step fills too much with paint. With a bare needle i "wipe" off the ribbon laying on its side, hold in that position because of my left finger and thumb.

Finally they were dry and they were bend!! The viscose like drying chemical forces bend them slightly..no straight line at all. Ah well i assembled them in their happy house and lost 50% of their 3d structure in the process. You have to stretch them in order to put them in place. I stretched them a bit over the top ( in spite of 1000 warnings in my head before the act)

No harm, the extra stretch will raise a bit the resonance freq, as i see it, the AKSA will take care of that. However to put them exactly in the space between the two magnets,they have to be exactly straight, and they weren't. They were not dried straight. And cant force the delicate aluminum to go against the dried varnish. By the way the varnish layer is at least 10 times thinner than the ribbon itself.That was a good job. A very faint golden glow over the alu. DOnt want to make the ribbon more heavy.

Ennemoser warns that to sound musical the C39 varnish needs days to dry and sounds best after a month,3 months a year..and keep on sounding better, the older it gets.

Ah well, i put the tweeters back in their structural context. ( the painting alone cost me 4hrs, the assembling 1 hr, normally 20 minutes for 2 tweeters) set the Aksa's on life, put the tuner on classical musique and YES, the o so barely discernible metal sound of the aluminum was completely obliterated from my room!!

And with it ALL transpency, life, dynamics, space -->completely DULL 2D radio shack muzak!!

So i wait a 3 day for an improvement, then a week

kyrill · « **Reply #26 on:** 21 Jun 2007, 01:45 pm »

ah well

i removed the ones i painted before as i was not content about the symmetry of their stretch
so i bathed a sec pair ( my 3rd pair painted w C39) Och och what a pain..
i dried them for 24 hrs so the paint is dried to the touch but not really dry so i can stretch them to
assemble the tweeters. I did. The left tweeter was reasonable success . 7.5 out of 10 points i give myself
as it was not really perfectly parallel to the magnets.
So i begun extra careful with the Right one.. and oh no i stretched it a bit to much. An involuntarily movement of my hand stretched it 3 mm too much!! I folded it a bit ( worse than painting) to shorten it, but the paint was working against it I folded it alright, but not perfectly in a straight line. which it wasn't from the beginning. Grr, 0.00005x inch aluminum is really fragile. Well l finally got it straightish in the tweeter housing and with the massive aluminum holder i screwed it to one of the two holding post. and did not get it not-to touch the magnet 4 inch further down the line. So i unscrewed it and O h nooo the C39 glued it so much to the housing that in removing the block it destroyed that part of the ribbon which is used to hold on to the housing. So my gruesomely bathed ribbon was now a full 3.4 inch too short.. I lengthen it by using the 3M electrical copper foil tape . Not ideal but it works. Finally assembled i see that the ribbon still touches barely the magnet on 2 places. It was impossible to get the faint curve out of it as the varnish "pushed" any gentle correction back in its previous but wrong structure. Ah well back in the speaker housing i got the same terrible muffled sound

after 3 day slowly the highs came back. And now 10 days or so later it sounds very musical but strange. one day too much highs but not transparent. onter day too less highs but transparent. then 2 days in a row very transparent and sweet but a touch to friendly and then the next day cpmpletely different. This is normal and needs 10 weeks to settle according to ennemoser. I have to recalibrate the crossover again but that is easy with the DEQX/

Am i glad i did it? I still dont know. Need another 8 weeks of evaluating and maybe in the future i will assemble a Decware SET tube amp of 2 watts but with non painted default ribbons (15$ a pair) as the Ribbons are 100db sensitive to 1 watt. I will buy first Hugh's LF and listen how that sounds with the C39 ribbons. Unless DEQX analyses the treated ribbons as garbish, meaning not damped anymore. The original ribbon damped itself within 2 mS, if now because of wrong tension, placement or weight it is above 4 millisec, i remove them.

kyrill · « **Reply #27 on:** 23 Jun 2007, 12:01 pm »

"The Lifeforce has a much diminished thump, tiny by comparison, because the input diff pair is operational almost from switch on as it's powered from a current source.

Jen, I hope this helps!!

Cheers,

Hugh"

erghh i must have missed this one. Hugh are you implying that with the LF directly coupled to the Aurum cantus ribbons, i do not need a cap in between to protect?

AKSA · « **Reply #28 on:** 23 Jun 2007, 12:26 pm »

Kyrill,

The quote is certainly correct - thanks for drawing attention to this earlier comment.

However, I would not be prepared to confirm your question until you actually try it, because experience has shown that there are occasions when predictions on the known facts are wrong.......

So, my suggestion is that you try it; it should be fine, but I'm still prepared to be surprised.

Cheers,

Hugh

kyrill · « **Reply #29 on:** 23 Jun 2007, 01:13 pm »

ah yes dont sell the girl before you have shoot it or was it bear?
am just curious Hugh
Yu offer a trade benefit when customers trade in their AKSa pcb soldered and well and in mint condition when they buy a LF

Very nice and will bind previous Aksa owners

But what do you do with all the trade in AKSA' pcb's? maybe something for a future 7 channel Home theater amp?

kyrill

kyrill · « **Reply #30 on:** 23 Jun 2007, 07:25 pm »

ah well

days of work poorer but a lesson richer.

It sounded musical and nice, almost no magick. Too friendly. i suspect it does not stop as fast as it used to
i finally measured it and found severe ringing the first 0.6miliseconds. it stopped in 1.2 milliseconds but during that time the original signal (non painted ribbon) had a clean one half overshoot now it had dozens in the first half millisec.

A price too much for me too pay. So i stripped my ribbons but unfortunately i had no spare ribbons anymore, so i used two tweeters i got from the kitchen speakers.. and had to callibrate them too and waht do i see? they had the same ringing over 1millisec and stopped within 2 millisec, so they measured worst than my "tweaked" ribbons. They sound also less sweet. but the ribbons are in the dustbin already ah well

i have to order another 2 pair..not practical to paint a ribbon aa

Geoff-AU · « **Reply #31 on:** 24 Jun 2007, 12:42 am »

kyrill, sounds like quite a mission you have set for yourself there! If the ribbons are as fragile as you say then none of the typical methods (brush painting, spray painting, or dipping in paint/lacquer) will work well, because the layer applied is too thick.

The thing that came to mind for getting a thin layer on stuff is electrocoating, I was under the impression that you could only use it to plate metals with other metals but it seems the alchemists have figured out how to apply it to all sorts of processes like applying paint to things! So if you are still keen on fiddling, perhaps it is worth researching

AKSA · « **Reply #32 on:** 24 Jun 2007, 04:12 am »

Kyrill,

I'm sorry to hear of your sorry ribbon saga. Not nice for you.....

I have to say that electrodynamic speakers have really come a long way in the last ten years. I'm very impressed with the two drivers used in the VSonics, the 830884 8" woofer and 810921 1" tweeter, they are head and shoulders above any of their previous drivers, just amazing.

Ribbons used to be superior, but now I honestly believe that their fragility and durability make them a second choice with the variety of very, very good conventional drivers now in the market.

Quote

Yu offer a trade benefit when customers trade in their AKSa pcb soldered and well and in mint condition when they buy a LF

Very nice and will bind previous Aksa owners

But what do you do with all the trade in AKSA' pcb's? maybe something for a future 7 channel Home theater amp?

I have quite a few now in storage. Most are well made, and very good propositions both for durability and for resale. I will on sell them at a price midway between the kit price and the trade-in price; they will all be checked out first, so this will be a good way of buying AKSAs. More detail on this will be posted on the website in due course.

Cheers,

Hugh

andyr · « **Reply #33 on:** 24 Jun 2007, 05:20 am »

Quote from: AKSA on 24 Jun 2007, 04:12 am

Ribbons used to be superior, but now I honestly believe that their fragility and durability make them a second choice with the variety of very, very good conventional drivers now in the market.

Cheers,

Hugh

Now now, Hugh,

There are ribbons and there are ribbons! The (5') long ones as used in some Maggies, Apogees, those Aussie ribbon hybrids that DSK used to have and what seems to be a superb new Apogee replacement coming out of Greece - the Analysis Audio Amphitryons - are not particularly fragile as long as you feed them with an amp which is not clipping and don't vacuum your speakers!

And the sound that comes out of these ribbons might be equalled by a conventional tweeter plus a super-tweeter, but I doubt by just a single driver.

Regards,

Andy

AKSA · « **Reply #34 on:** 24 Jun 2007, 06:05 am »

Thank you Andy,

We need coffee.......

Any chance this week?

Hugh

ShinOBIWAN · « **Reply #35 on:** 24 Jun 2007, 12:21 pm »

Quote from: jules on 31 May 2007, 04:54 am

Hi Kyrill,

I notice xover point for your Aurum Cantus is 2000 Hz. The bloke who designed the Aurum Cantus was, I believe, formerly the designer of the Raven ribbons and they do look very similar. I've noticed that Orca [the Raven company] formerly maintained that their ribbon was good down to 1800 Hz but after some time, they raised that to 3,500 Hz ... quite a difference! I understand that the problem is/was that over time the lower range stuff was too much and the ribbons gradually stretch. If you think all the stretching is happening due to amp switching then my post is irrelevant, but it is hard to see just how much movement a ribbon makes during music and yes, pure Aluminium ribbons can stretch even if they are easy to replace.

I've been using Raven R2s [3500Hz low] for a couple of years now and they are still ok although I do have a passive xover protecting them from thump.

jules

The RAAL 140-15d is not only better sounding than the Raven but also has the ability to be stretched back into shape after deforming. Just apply heat from a hot air gun and the ribbon is taught and back within tolerance once again.

ShinOBIWAN · « **Reply #36 on:** 24 Jun 2007, 12:28 pm »

Quote from: andyr on 24 Jun 2007, 05:20 am

There are ribbons and there are ribbons! The (5') long ones as used in some Maggies, Apogees, those Aussie ribbon hybrids that DSK used to have and what seems to be a superb new Apogee replacement coming out of Greece - the Analysis Audio Amphitryons - are not particularly fragile as long as you feed them with an amp which is not clipping and don't vacuum your speakers! And the sound that comes out of these ribbons might be equalled by a conventional tweeter plus a super-tweeter, but I doubt by just a single driver.

Regards,

Andy

Maggies, Apogee's etc. aren't a true ribbon. You can't compare them to the durability of drivers such as the Raven's, AC's on so on. You've also got the very tough planars which people also band around as ribbon's.

andyr · « **Reply #37 on:** 24 Jun 2007, 12:42 pm »

Quote from: ShinOBIWAN on 24 Jun 2007, 12:28 pm

Maggies, Apogee's etc. aren't a true ribbon. You can't compare them to the durability of drivers such as the Raven's, AC's on so on. You've also got the very tough planars which people also band around as ribbon's.

WTF are you talking about, ShinoBIWan?

My Maggie IIIas - and all the 3.X series, and the 20/20.1s - consist of a mylar panel which has the bass and mid-range wires glued to it ... plus a separate 5' long ribbon supported in a metal "cage". So they are planar-ribbon hybrids, if you like. So are Apogees.

Other (smaller) Maggies are typically just planars ... although Magnepan marketing confuse the picture by referring to "quasi-ribbons".

Regards,

Andy

kyrill · « **Reply #38 on:** 24 Jun 2007, 12:48 pm »

Hy Andyr

Still ShinOBIWAN is right

A true ribbon has no glue or wires . Itself is the electrical transducer. If you look carefully ad yr midrange panel construction it completely resemble the same structure as your so called "ribon" only mire sturdier and heavier wires I had maggies too

ah wait if yr ribbons have no glue or wires.. i read it wrongly

So they are in fact ribbons?

ShinOBIWAN · « **Reply #39 on:** 24 Jun 2007, 01:10 pm »

Quote from: andyr on 24 Jun 2007, 12:42 pm

Quote from: ShinOBIWAN on 24 Jun 2007, 12:28 pm

Maggies, Apogee's etc. aren't a true ribbon. You can't compare them to the durability of drivers such as the Raven's, AC's on so on. You've also got the very tough planars which people also band around as ribbon's.

WTF are you talking about, ShinoBIWanker?

My Maggie IIIas - and all the 3.X series, and the 20/20.1s - consist of a mylar panel which has the bass and mid-range wires glued to it ... plus a separate 5' long ribbon supported in a metal "cage". So they are planar-ribbon hybrids, if you like. So are Apogees.

Other (smaller) Maggies are typically just planars ... although Magnepan marketing confuse the picture by referring to "quasi-ribbons".

Regards,

Andy

Was that really called for? PM me if you want to talk shit.

Your arguing semantics. My point was that the Maggies et. al aren't true ribbons at all which you've referred to them as. And drawing comparison about the robustness between the differing types is misleading. I think Hugh was referencing just true ribbons when he questioned their usefulness.