Paper v. Metal Cones: Subjective Sound Characteristics

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Once again, I am considering a small wide-range driver in the 2-3" range. My primary candidate is the Bandor 50 4 Ohm model due to the specs Doreen publishes on her site. It appears to have qualities am seeking: lightweight cone, pretty flat response, and excellent extension at both ends of the range. Additionally, it is intended for a sealed enclosure, which I prefer.

However, they are not inexpensive and I want to avoid disappointment as much as possible. My concern is that the sound, due to the metallic cone, may ring or sound "mettalic". My previous experience has been with paper, kevlar, and plastic/doped cones. I like the first two very much and find the third kind, subjectively, to sound "slow" and "lifeless". I used Fostex FF85K drivers for a while and liked them very much but found the very thin aluminum dust cap to contribute a "tizzy" quality at the high end.

Has anyone compared the Bandor drivers to those using different cone materials? How about other metal cone drivers in the 2-3" range? I am aware that there are several now available on the market.

Regards,

Karl
 
Karl - if you're not familiar with the process, Bud Purvine's EnABL treatment is capable of mitigating to a great degree the issue you're describing with the FF85K. I'd already been a huge fan of the Fostex line, even before experiencing EnABL for the first time a couple of years ago. On a driver with as low a moving mass as the FF85K, it wouldn't be difficult to overdo the gloss topcoat treatment that is part of the process, but if you're interested, Dave at Planet10 has pretty much dialed that in. This is very magical driver, within its obvious limitations.

I've not heard any of the Bandors, except as part of some very elaborate line array systems and in combination with powered woofers, etc., at VSAC shows a few years back - and even then for too short a time to form any rational impression.

However, I have had occasion to audition a number of the new Mark Audio drivers, including the Alpair 5, Alpair10 and CHR70. Mr Fenlon and crew continue to develop an expanding line of very interesting drivers. The only downside of models I've actually heard to date is the combination of lower sensitivity and impedance - making design of multiple driver systems a bit more of a challenge, particularly for unapologetic aficionados of low power tube amps (e.g. SE DHTs), such as myself.

I mean, I've owned/listened to my fair share of higher power (as in over 8 watts :cannotbe: ) tube power (PSE or P/P), or class A SS or class T amps, some of which are still in my collection - but there's something organically "right" about a synergistic combination of high efficiency full range speakers (whether horn loaded or not) and SE amps that for me overcomes the limitations of maximum SP levels or measurements.
 
wow, you are opening a can of worms.............

poly is soggy, meaning it absorbs detail, but they are adding materials to increase stiffness (talc powder) and increasing detail.

Metal can have multiple resonances. Just because you trap the resonance so it measures flat doesn't mean it isn't there. I remember a discussion on some German forum. The hivi b3s 8khz spike was trapped, yet it still was audible. I bet you can see it on a waterfall.

I could be mistaken but a friend said that the resonance is still there. You can trap it, but that just prevents that frequency from making it ring. But any natural harmonics will set it off. I.e. 4khz would set off the 8khz ringing in the b3s.

Some say paper adds a slight nasaly quality.

What small other cones are you looking at ?

There is the w2-800sl aluminum/magnesium but strong qts, sealed has f3 near 500hz.
Here is a link to comments on the small tang bands.
http://translate.google.com/transla...earch?q=%2B%22W2-800SL%22&hl=en&sa=N&start=30

I just got a bunch of the peerless 830983 on closeout from partsexpress, they are $7.80 each and free shipping with credit card for orders over $100. 4 make about the same area as the 4" tang band bamboo. And the frame size is small at 2.17". I'm not a fan of anodized poly, but the price is good to play with for arrays.

The alpair 5 is on sale for $30 now with 1.6g cone and 27cm2. The peerless is a heavier cone for the area with 13cm2 weighing 1.5g.

People have commented that the alpair 6 has an electrostatic sound. The alpair 5 would have more detail with a much lighter cone weight to area than the alpair 6. I recommend a dual alpair 5 to get the cone area up and lower distortion compared to a single one.

Low sensitivity comes with the territory. It is hard to make strong sensitivity without making the driver have a climbing response. Then again, the climbing response can be not much of a problem sitting off axis and / or 10' away.

Norman
 
I've always been a big fan for Jordans, even though I discovered they could be teaked for better CSD performance. But I must admit the initial look at alpair data, they do seem interesting. If they have similar qualities of the Jordan designed from which they evolved, they should be good. But I have not tested them.

I would think, if they are not continuously played very loud, these metal drivers should be very good. If one plays continously loud levels, probably soft material or some horns might be a better choice.
 
Chris -

Thanks for the suggestion regarding an EnAbLeD FF85K. I've considered it, but I now want to try a good metal cone.

Norman -

I agree with you on poly cones. I like kevlar and paper. I am indeed hoping for increased detail from a very lightweight metal cone driver.

Jim Griffin, on another forum, has recommended the Alpairs. They are very interesting little drivers, especially the 5. If I remember correctly, the midband for both the "gold" and "grey" Alpair 5 units is now much smoother than when when they were first released. I am also intrigued by the spiderless design. However, with all of that said, the Fs for the either 5 is pretty high. I know, you can't have everything... :} At $30/ea, I might give them a try.

Regards,

Karl
 
Karl71 said:
Chris -

Thanks for the suggestion regarding an EnAbLeD FF85K. I've considered it, but I now want to try a good metal cone.

Norman -

I agree with you on poly cones. I like kevlar and paper. I am indeed hoping for increased detail from a very lightweight metal cone driver.

Jim Griffin, on another forum, has recommended the Alpairs. They are very interesting little drivers, especially the 5. If I remember correctly, the midband for both the "gold" and "grey" Alpair 5 units is now much smoother than when when they were first released. I am also intrigued by the spiderless design. However, with all of that said, the Fs for the either 5 is pretty high. I know, you can't have everything... :} At $30/ea, I might give them a try.

Regards,

Karl

Karl, take another look at the CHR70 - if these keep getting the great reviews they deserve, they won't remain a "sleeper", but for an entry level product, they're still a helluva value.

Clearly both the FF85K and A5 have their limits and appeals, but FWIW between these particular 2, I'd probably choose the Fostex.
 
frugal-phile™
Joined 2001
Paid Member
Karl71 said:
Alpair 5 units is now much smoother than when when they were first released. I am also intrigued by the spiderless design. However, with all of that said, the Fs for the either 5 is pretty high. I know, you can't have everything... :} At $30/ea, I might give them a try.

Note: The Alpair 5 has a normal spider. It is the Jordan JXR6 (largely designed by Mark Fenlon i believe and certainly the 1st runs manufactured by him) that is spiderless.

The A5 was never intended to be used as a full-range, it was always intended to be used as a mid-tweeter. It is just that us diyers have pushed it into such service. As would be expected from the larger cone the FF85 produces better bass, (but really the A6 is of comparable size). Don't expect anything significant under 100 Hz.

dave
 
Dave -

Thanks for your input. I could've sworn that the Alpair 5 is listed on the MarkAudio site as having no spider.

Yes, the fairly high Fs does bother me alot.

Has anyone tried that new Tang-Band 4" FR that has a flat aluminum honeycomb diaphragm? It is very lightweight and is advertised on the PE site as having excellent dispersion. Its Fs is much lower.

Regards,

Karl
 
I have not heard or tested Bandor drivers, but have tested many metal based transducers so I hope my post can be of some help. In terms of metal fullrange drivers I kept a matched pair of 8Ω MSWs that I will leave from the comparison, matched pair of JX92S and had a normal commercial production run pair of spider-less Alpair 5s I sold. The cone drivers are very metallic sounding but settle within a time frame and have a few other attributes comparable to electrostatics, and bare a sound like small electrostatics according to what local listeners have noted. Once energy storage issues have been corrected a metal transducer can be very good. You may wish to listen before buying, I do subjectively and objectively find the majority of production cone metal drivers sound metallic though not everyone picks up on it. If you are sensitive in respect to breakup, ringing and certain orders of distortion you find the sound irritable. I hope this helps.
 
Hi,

The Audience A3 was developed as a replacement for the Bandors in the line array products. The physical size of the face plate/mounting had to remain the same; everything else was open to the designer's creativity and skill.

One of my OEM customers for Mark Audio drivers will not consider a spiderless driver but I'm not sure if he's explained his reasons.

In general, I prefer paper cone drivers but I'm not sure if I can explain that accurately.

Bob
 
Kouiky -

On paper, lightweight cone drivers do look very good, as long as cone break-up is not apparent. It's the ringing and other distortion types that you mentioned that give me pause. That's why I am not ordering my Bandors quite yet.;)

How did you address the stored energy problem? What size and type of box did you use for the Alpair 5 drivers? Were they the "gold" or the "grey" units? Did you use a sub? If so, where did you crossover?

Regards,

Karl
 
Karl,

I have been using Bandor 4 ohm drivers (2 per side) for the past 20 years. After living with QUAD ESL57s for many years, the Bandors are the closest thing I have heard to the "electrostatic experience", only without the high voltage power supplies.

There is NO metallic quality to Doreen's drivers. I wouldn't hesitate to get more Bandors (if only the price would be as attractive as it was 20 years ago...).
 
Hi Karl,
There's a very interesting question you initially developed on the wider issue regarding the differences between metal and paper cones. While I've been working with metal cones over recent years, I'm now also making paper variants. Much of my research work is on the oscillation and resonance characteristics of cones while under various load conditions. I've developed a method for measuring the resonance pattern at various points on a cone's surface. Sorry I can't go into detail for commercial reasons but I can state that there are significant differences in the way these materials behave.

Many full range paper cones are low mass, usually lower than metal alloys. However, lowering the mass of any cone isn't a pre-requisite for the material's ability to increase its resonance pattern.

The peak-positive and peak-negative resonance wave for paper is flatter than metal alloy for a given input. Think of it as observing the difference between the top of a mountain (sharp) and that of a hill (rounded), paper has a slightly larger radius to its peaks. This effect is largely due to the structural differences between paper and metal alloy materials.

Tests results appear to coincide with the perceptive differences many of us hear between paper and metal alloy drivers. That is, we perceive alloy coned drivers as generators of "brighter" responses while paper units produce "dry" tones.

I should stress that more evaluation is needed using human test subjects of sufficient sample size to reliably associate human response with cone resonance characteristics. Also, it's not all down to cones themselves. Other driver components influence a cone's performance. Nevertheless, the test outcomes so far are reasonably indicative.

For those who know my driver designs, this post gives you some indication of my work into producing metal alloy cones with more tonal neutrality.

Cheers,

Mark.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.