stevie

Those EMIT drive units aren't real ribbons, Percy, even though they are often described as such. I agree that they don't sound very good because their distortion is quite high. These go under the name of 'isodynamic' or similar. The voice coil takes the form of an etched spiral of aluminium glued to a thin plastic film, which functions as the diaphragm. I'd describe their sound as 'fizzy'.

In a real ribbon, a pleated strip of aluminium is placed between two magnetic fields and acts both as the voice coil and the diaphragm. The big advantage over domes is that the moving mass is much smaller, which has benefits for transient speed and internal resonances.

Dispersion is determined by the size of the ribbon. An HF ribbon will have wide dispersion in the lateral plane and narrow dispersion in the vertical plane - which can be quite useful.

There aren't many 'pure' ribbons around, as they are quite difficult to design and manufacture. Most of what are termed ribbons are in fact planar tweeters, which is definitely not the same. The Eton is actually a Heil Air Motion Transformer. From what I've heard - and I've heard both the Eton and the Heil one - these probably offer the purest available HF sound.

Back to the Esotar - I regret that I haven't used the 1 inch dome, mainly because it is, and always has been, so goddam expensive. I have worked with the 3 inch dome, (OK but nothing special) and the 1.5 inch Esotar, which was quite stunning. It had a very 'natural' sound (it just sounded 'right') and tremendous drive. It was very impressive but too expensive for me. I've no doubt the 1 inch has similar qualities.

Stevie

Percy

More info on the Eton Er-4.

http://www.dddac.de/op05u.htm

And some info on the esotar...

http://www.merlinmusic.com/reviews/ai_0197.htm
http://www.merlinmusic.com/vsm_wht.htm

There's alot more info on the esotar floating around that isn't from Dynaudio, and for those who can afford the expense/investment(?), it's well worth (imo) every penny. Now if only these darn things can fit in the a pillars...

Percy

stevie

>Now if only these darn things can fit in the a pillars...

That's the big problem. One of the reasons good hi-fi tweeters sound so good is that the designers have spent a lot of time loading the back of the dome. There are a lot of complex cavities in the rear chamber of some of these designs that bring out the best in the transducer.

With a normal (i.e. tiny) car audio tweeter there is no rear cavity to dampen the back wave and that generally means that the sound is compromised.

There are some exceptions, though, made by Scan-Speak, Morel and Seas that I know of. Of these, the Scan-Speak has the largest cavity and the best performance, but is just too deep to fit in the pillars of the GS. The Morel is good but overpriced. The Seas is probably the best neodymium HF unit that would fit into the pillars without any problem. The upper resonance frequency of the aluminium dome has been pushed to around 30 kHz, Percy, well out of the way for even you. I haven't heard it but it's cheap enough to buy just to try it out.

If I knew of somebody who could fit the Scan-Speaks into the pillars, I'd order a pair tomorrow.

Stevie

Percy

The newer Esotar drive units that are used in the Temptation, new Confidence series and Evidence are Neo magnet based. Instead of the huge 5+ inch mounting plate, the neo based ones are, at least what it appears to be, 2 3/4 inch total for the diameter. But unfortunately, they're not readily available unless they're ordered through Dyn directly.

These are the new Esotar 2 drive units. Different cone material, different coating. They're supposed to be the next level up from the Esotar T330D/MD330D.

In that case, I wouldn't mind fabricating some pods on top of the dash for the new Esotar 2's.

Which scan speak tweeter were you talking about?

Percy

stevie

You certainly seem to be well informed about what Dynaudio is up to.

The Scan-Speak tweeter is Model D2904/6000-01. It's just a little bit too deep and the faceplate is just a little bit too wide.

Stevie

Percy

Stevie,

How about just take out the faceplate? Or some sort of mod? Or possibly go custom on the grille and just make another one (extended out slightly) in order to attempt the "stealth" factory look. There are possibilities with this tweeter, but I just need to have one to look at.

A definite project.

Percy

stevie

I imagine the faceplate is part of the body assembly - if not it will be well glued.

I sanded down the faceplate on my current tweeter to fit, but I was able to put Scotch tape over it first to protect the dome. That's clearly not an option here. You could use a soldering iron to cut it, I suppose.

I'd be very interested to see if you can come up with a solution for the depth problem.

Stevie

Percy

There's about 1 inch of clearance with the stock location, and that has to include the height of the dome. BUT, if you're good with a grinding tool, there is a ridge where the stock tweeter "hooked" into that can possibly be ground out. This would buy about 1/4 of an inch, maybe more.

Still have to look at the magnet casing. The bottom of it MAY possibly be removable - just a plastic cover for "finishing" the magnet assembly.

Percy

stevie

I guess 1/4 would certainly help. I doubt if you can take anything off the tweeter itself. I have a Morel 1 inch neodymium here and the back chamber is part of the design - it's filled with damping material. That's how they get the low resonance frequency. The magnet assembly is actually very small and doesn't go very far back at all. (Yes, I've had it apart).

Keep thinking.

Stevie

Percy

What's the total height of the tweeter, including the dome?

Percy

stevie

Difficult to tell from the drawing, Percy. I would estimate between 45 and 50 mm, depending on how much you can bend the connection terminals on the back. The diameter of the body seems to be 41 mm.

A very tight fit.

Stevie

Rico's Revenge

Hi Guys, sorry for disappearing on you... I wasn't in the office yesterday. You all seem to have a very interesting conversation going.

Adam...I was referring to the Morel Supremo(s). They had a write up in Car Audio and they received "the highest marks given to a tweeter yet." Please don't get me wrong, I am NOT one of those "I read it in a magazine" guys, who think that evrything between a cover is gospel. (Especially after reading a "Subwoofer Special" article where they told the world that ohm level of a subwoofer is not important and should be the last thing considered!!??? WTF???

Anyway, they retail (suggested) for $499.00 a pair. I had my car semi apart to check on clearance for the kicks yesterday and all of this may have been a mute point. I don't think I'll have room for both a 5 1/4 and a large format tweet. Unless we can figure a way, I'll probably move my Quart Q tweets down with the 5 1/4" and leave another 5 1/4" in the factory door location playing mid-bass x-over provided by the Q-series Midbass passive. (I guess I just answered your question on active or passive) I've been researching custom passive x-overs but I get nervous as I am not as well educated in that field as you guys seem to be.

If I were to go to an active XO, what would you guys recommend? Also, if I go with an active, would there be different settings so I could have one setting that is "safer" for everyday cranking, and a more delicate setting for competition.

Thanks...

T

Rico's Revenge

Hi Stevie! I have a Clarion VRX610 head unit (flip out monitor), Clarion 6-disc Changer and a Sony PS2 for sources.

(Extra video is provided by 6.5" Mobile TV monitors in the head rests.)

From there to an Audio Control EQL (I have an Orion DEQ-30, but I don't know if I'll replace the EQL quite yet) an Orion 800.4 running mids and highs, an Orion 900.2 running the sub.

MB Quart 5 1/4s in the stock locations in all four doors...the front are separates with the tweeter in the factory pod and the rear are coax. The sub (Treo SS12.22) is in a fifth-order band-pass firing through a tuned port in the rear deck. Its pretty simple and basic, but that is what works best!

I've been scoring near max on mid-bass which is why I don't want to mess with it, but my largest problem has been with stage focus. When a voice drops low, the stage pulls toward the doors. Still I've been doing very well (USACi Basic) and have gone 5 for 5 including a couple double-point shows.

T

Percy

Todd,

The thread turns out to be more brainstorming than anything else! Here we have Eton, Esotar, Morel, Infinity, Scan Speak and a few other names of tweets or variations of. Quite a bit of mish-mash of the high end.

Morel Supremos look like they're LOOSELY based on the MD130 Dyn tweet. As mentioned before, Morel liscenses some (but not all) technologies from Dyn. This includes their hex coil technique, alumimum former and their own variation/material for their textile dome. I noticed the mag mentions the magic word..."yet". Best bet is to try before you buy if possible.

What were they smoking when they mentioned the "ohm level wasn't important"? Is this one of the classic Clark/Navone writings? Not to get too off track but here we have Clark which has the attitude of "I INVENTED car audio" (kaf kaf) and Navone who tries to sell his name for some second rate (imo) components. Okay..I'm off the high horse on those two.

Crossovers. Main advantage of active xovers are their flexibility. You're able to tune "on the fly", change slopes, frequency and level settings from the listening position. Sure beats having to go back and forth from the drivers seat to the trunk to get the right levels. Also you can run each driver with it's own channel of amplification, though you could do this with passives. Flexibilty is the main point of the actives. Some cons...MOST, if not all of the actives that I've run across are NOISY. I had to mod out my McIntosh MEN456 with some Black Gate caps and different op amps. Helps ALOT. There is a small amount hiss and I've heard feedback from the owners of the Orion DEQ30, MEN455/456 and a couple of other units that I can't recall off the top of my head about the slight hissing noise. The only three xovers that I've run across with ZERO hiss or noise would be the following...

Sony XESZ50
Sony XDP4000X
Alpine F#1 Status PXAH900

I'm sure there are other extreme high end units out there that won't have any noise to them but I have yet to run into them.

Now for the passives. If I had the room and the space to run full passives I would. Here's why. With most "out of the box" crossovers you're looking at a relative cheap coil and cheap caps for parts. MBQ has some of the most generic parts for their HX25 tweeter, but they get the job done. But once when a car is tuned out (hopefully with an active...more flexibility), I'd go to a passive with HIGH end parts. Main reason is NO OP AMPS or any other circuitry to "get in the way". With an active xover, the signal has to go through op amp buffers, then to other generic resistors, caps, inductors and other IC's that control the flexibility/frequency desired. By the time this is done the signal then has to go back out to an other op amp buffer and then, finally, to the RCA jacks. There's quite a bit of stuff to get in the way. Now if you're dealing with HIGH END parts such as Hovland Capacitors (they're around 50 bucks EACH), Alpha Core air inductors (13 bucks on up), Vishay or Caddock resistors (lower ESR), then all you're dealing with are the xover components and not really anything else. More of a simplistic approach. (Don't forget about the impedance correction circuitry ...very important!) You'd have a better sounding system with the high end parts, if applied correctly.

So, to recap my babbling...
Active. Flexibility in level adjustment. Flexibility in slope selection. Possibility of phase adjustment. Cons...moocho components to contaminate the signal.

Passive. Can get expensive with high end parts. Better sounding if built correctly. Has "insertion loss" in that it will take a certain amount of power up. Takes up more room.

For tunability purposes I'd stick with the active.

Percy

Rico's Revenge

So to recap your recap ( )...

optimum situation would be to borrow an active x-over for a couple days and completely tune the car, then give the active back and build passives reflecting the same values.

It will probably be next month, but I'll let you know how things are working out! Great input, Thanks!!