Coaxial drivers?

Bill F.

Member
2001-11-15 5:25 pm
SW MI
For some time, I've been hunting for a promising set of coaxials, classic or othewise. I'm open to suggestions and firsthand reports--anyone?

flat-out nuts prices have caused me to despair of snagging a set of Tannoys or Altecs.

Anybody have some words of wisdom about modern coaxials from McCauley, Fane, Beyma, Radian, B&C, etc? I'd like to compare specs and buy on the web. Any websites that publish prices and sell these?

Muchas Gracias.

Bill
 

Brett

Member
2002-01-07 6:02 pm
Personally, I like coaxes. They have the potential to sound very coherent, due to the almost point source radiation characteristic. They energise the listening room differently than most speakers because, generally, they have a conical (90 degree) dispersion characteristic, that can remain defined over the entire frequency range, narrowing a bit at the top end. Normal cone/dome systems change their patterns quite a lot over their range, and so gives a wildly varying reflected energy that just sounds wrong to me.

With the two drive units sharing a common axis, they can be 'time-aligned', and that alignment will vary less with the listening position IME. They also make great nearfield monitors (good if you have a bad room acoustically) because the drivers are so closely integrated. I've used my Tannoys like big headphones at 5-6' and they were wonderful. My room at the time was a nightmare, and a rental, so this was an excellent solution.

I've used and/or owned Tannoys on and off for about 20 years. I've heard some of the Altecs in studio monitors from time to time, but not enough in familiar environments, except to say they are good. I don't like the idea of the Altec CD horn extending in front of the cone; can't see it helping the mids, but it must be OK as they made them from Moses until recently.

Tannoys generally are excellent, with the older drivers with Alnico magnets being the best. Up until recently I had two pairs of 15" Golds, sold the ceramics and kept the alnicos. They have just been retired and are on the market.

As to value, I'm biassed, but they still bring good prices because they're good, and very well made. The cost of some mint pre-loved Altec/Tannoy drivers, is barely the cost of a pair of good CD's new. TAD 4001 2" CD is $US1655, TAD 2001 1" is $US 860, JBL 2446 2" is $US620. Some of the older CDs on the market, may not bolt up to current chassis.

Pro audio drivers are generally very efficient, well made, strong, and have high power handling. They're also repairable and often have a long model lifr. Pro's are not fickle like 'philes. They usually have one major problem over domestic units, and that is they have a higher resonant frequency, so less bass extension. Most will have a sub under them, or are designed with a more limited frequency range in mind for the intended application. With most of the pro coaxes, you are also on your own wrt optimum enclosure tuning, and crossover design. Many are used actively with steep filters, needed for high SPLs.

- P.Audio - great value, but sound very average in a domestic environment. Good stage monitor drivers.

- McCauley. Just started to look into these for a project, and they model well, but it looks like you have to use their comp drivers, at about $US900/1200 ea. Beautifully made, great motors. I will email and confirm about the CD's. If I can bolt mine on I'll order a couple of pairs.

- Fane. Dunno much, but come recommended by a friend in the UK. Have found it hard to get full data online.

- Beyma. Again, have heard good reports, but moderately hard to get outside Europe, and the T/S parameters are not useful to me so I haven't investigated further. Look well made. Smallish motors and come with their own comp driver. Personally, I'd rather choose my own. Beyma do make some nice CD's though.

- Radian. Designed as ceiling speakers, but apparently quite good. I personally haven't heard of anyone using them domestically. Stamped steel frame, biggest is a 12", weak motors, low Xmax. Comes with a CD. Radian make some nice CD's like the 475.

- Volt radial. Just released. Potentially very good. Concerned the radial frame will mess up the lower mids. But if you think Tannoys are expensive......

- B&C. I have heard these are the drivers in the Galante Buckinghams now, so must be pretty good. Don't know what is used as the CD.

- PHY-HP. Enigmatic. Uses a 12" with a piezo driven cone. Have heard bith that they're excellent or POS. Probably best in an open baffle. Very expensive.

- Eminence Beta. Cheap and good for the price. The Adire HE 10.1 uses a modified 10" (don't know what CD), and has been well received as excellent value. But having heard other Beta, I can't beleive it's even close to an Altec/Tannoy. Steel frame, weak motors, heavy cones, peaky and resonant. Look at the 15cx.

- PHL. Look good, but Fs is quite high for a large driver and 1" CD could be a limitation IMO, but can use other CDs. No idea of cost or availability.

-SEAS. They make some little 6.5" units with a dome in the middle, a bit like the current KEFs (which I reckon are aweful too). The two pairs I've heard, sonded like my car speakers. Low sensitivity, gutless motors. Yuk.

Hope that helps. Probably missed some though.
 

Bill F.

Member
2001-11-15 5:25 pm
SW MI
Thanks Brett,

You covered a lot of bases.

Ouch. Some of the prices you mention make Tannoy golds seem reasonable. Do I understand correctly from your post that all gold monitors aren't AlNiCo? What'r you selling yours for?

My application will be an open-baffle dipole with 4 15s per channel taking over below 200Hz. So, in this case, a higher Fs/Qts less-bass coaxial would still be OK.

leaving some margin for the open-baffle rolloff, I just want the coax to project unmitigated sweetness from 100Hz up.

How bout a source for raw coaxials on the net?

Bill
 
I think you will find that most coax cross well above 200. If you are going to use 4 15" drivers per channel I am sure you can get a mid or two in there and some ribbons on the same SPL level. I have Altec 604s and don't like the harshness of the horns. I have 12" and 15" pairs of Stromberg Carlson with paper tweeters that don't have the harshness but distort at fairl low levels. One I am very fond of is a Knight triax that I had in an Aristrocat cabinet. Every once in a while they come up on Ebay but the prices have really gone up because of the quality. The only compression drivers that I truly like for tweets are the EV 35s which you can find mounted in EV drivers and some made by EV for Knight.
 
You could always follow the approach that is currently best exemplified by the 12" PHY-HP.

PHY-HP12.jpg


Find a nice extended range 8, 10, or 12, do a dustcapectomy, and add a cylindrical phase plug with a tweeter on the end. This could span the range from Frugal-phile(tm) like cost on up into the stratosphere.

I am working thru a project right now with the Pioneer 8" and a naked piezo cone (similar to what the PHY uses). I just have to figure out how to run the wires -- a vented pole piece that needs blocking would be nice but alas the Pioneer doesn't have one.

There are some nice alnico FR that can be had for a song on eBay (i know cause i sell some of them) that would make real good mules (or surprise you and you end up just listening to them) -- releived of having to strain on the bottom by all those 15s they could really sing.

dave
 

Bill F.

Member
2001-11-15 5:25 pm
SW MI
David T,

There are some nice mids and ribbons out there, but I want to stick with concentrics in this project because I feel they offer unique off-axis benefits, especially in the crossover region. Mounting it on an open baffle, I'm hoping to get a really close dispersion match with my dipole bass array.


Dave,

I love your idea of a DIY PHY! Why didn't I think of that? I bet there's a creative way to mount a coaxial dome tweet in a modified version of my experimental phase plug frankenstein driver.

Bill
 
Brett covered the co-ax thing pretty well. I have a pair of Altec 605As from the early 1960s and at times I prefer them to my big VOT-Edgarhorn rig, they just sound "right" so very often. Radian makes a 15" co-ax with cast frame and 2" throat driver, last time I checked it retailed for about $450 each at Image in Rockford Illinois. I heard the Adire HE-10 at the Midwest hornfest in Ohio last month and it's a pretty good speaker and unbeatable for the money IMO, uses an Eminence compression driver and woofer. PAS makes a woofer with horn for co-ax use, you supply your own compression driver. Gallante uses this in their Buckingham, don't know what compression driver they use though. A friend is currently playing with some 15" Tannoys, he doesn't like the sound so far, he's still messing with crossovers. He won't play them for me till he gets them right. As for the Altec 604-605; it seems every model (there were many) has it's partisans. Some guys go ga-ga over the 604Bs from the 40s and early 50s, some like the Cs and Es and some think the later ferrite magnet Ks with the radial phase plug and CD horn are best. I know a guy who uses 3 604Bs and 2 604Cs in his HT. And some prefer the 605 to the 604. Mastering Lab made a crossover for 604s that some report improves the speaker, there are plans out there on the web for it. But you can't lose buying old Altec or Tannoy co-axes, if you don't like them you can sell them in no time, these drivers have substantial and fanatical cults.
 
Bill,

one solution you should consider is the "cheap" Fertin FR driver. It can be had for around $600 a pair and is reputed to boil most competitors in oil. Cannot tell, have not heard it, but i do know the big Fertin, the fieldcoild version (about $1500 a pair).

I have mine running since 3 weeks or so in an intermediate open baffle made from corrugated cardboard. Apart from dynamics/transients which are quite normal, slightly over the average (as far as one can tell with such an instable baffle), they boil any speaker in oil i have heard so far. No tweeter needed, really not. And they are seduuucing :) and PRaT, well, just correct, just natural.
In a way making you think of your last speaker as a tormenting instrument.

I am almost exactly planning to do what you plan: having an open baffle for the FR and having another folded opien baffle for a pair of 18" Beyma to make a subwoofer. One per side.
From measurements a friend did, an open baffle not insanely sized delivers not much below 100Hz. Subjectively, this is quite another thing. However, a subwo is badly needed. I am expecting slightly reduced horn dynamic from this speaker without horn-typical compression distortion.
 
dice45 said:
you should consider is the "cheap" Fertin FR driver. It can be had for around $600 a pair and is reputed to boil most competitors in oil.

where and who is reputin' this? I can't find much comments about Fertins except for you. Btw, what are you using for powering your coil?

Also, do you think your driver would sound good in a horn like the Jericho or Big-Fun?

thanks, -Brad-
 
Brad,

well, the Fertin's are sorta underground thing. TMK, the company is run by a former desinger of professional speaker drivers. He fulfilled his dream to manufacture a 1st class fullrange speaker instead of accepting retirement. He has several models, the cheap FR has a permanent magnet, all others including a gorgeous 18"er have field coils. His FLB38EX is a direct replacement for the famous Altec 416A parameterwise.

They do not have much promotion and no english wbsite exists. Me personally is so convinced of the driver that i might get get in contact with Monsieur Fertin and see if he is interested in promoting his drivers a weebit more effectively with an English website and a very convincing open baffle speaker.
On the Fullrange spaeker fiorum there was one guy (Justin) who bought the cheap Fertins and was raving about them.
i trust my ears instead of regarding reputations; few people had even heard from Fertin last Xmas when i was pondering which FR driver to buy. I tried them out (FLB20EX, field coil) , bought them at once, never looked back. Honestly, this fieldcoil driver has cured me from my horn lust.

The reputation i was referring to came from french JoeNet buddies who had heard them already and whose ears i trust, too. And competitors manufacturig quality was awful whereas Fertin had a flawless quality record accoring to the French guys' reports.
Recently my buddy Hartmut (hifidaddy) reported the cheap Fertins were used for public adress purposes, too, and they had fantastic low end sonically.

TMK, the driver is not suited for horn use; the inner suspension is not airtight like a Lowther or other typical horn driver.
Moreover, as the driver has +/- 3.0 mm of linear excursion, methinks this would be a waste.
The driver is ideally suited to run in open baffle mode. But you can adjust Q via the FC supply voltage to your needs. THe driver should do fine in a vented or closed enclosure. But nor as fine as in an open baffle. Efficiency: 98dB/W/m

Manufactuing quality is atleast as high as Altec in their best days.

Field coil PS: currently i use a regulated power pully with an LT1085. I put some effort into getting the ripple before the reg down and the charging currents of the electrolytics, too. no need to change it sonically, but i plan to try out how a 0.2H / 2A choke sounds in series with the field coil (theoretically the FC should give best results with constant current supply, not with constant voltage supply). The field coil is consuming 1.5A at 12.9V.

For the Jericho or the Big Fun you need a Lowther, provided you can handle the Lowther's longterm listening fatigue. Or you try out the German AER, which is not as spectacular as the Lowther but a bit more lame and boring and otherwise as good as the $$$ Lowthers (PM2A or EX4).
 
dice45 said:
I am almost exactly planning to do what you plan: having an open baffle for the FR and having another folded opien baffle for a pair of 18" Beyma to make a subwoofer. One per side.
From measurements a friend did, an open baffle not insanely sized delivers not much below 100Hz. Subjectively, this is quite another thing. However, a subwo is badly needed. I am expecting slightly reduced horn dynamic from this speaker without horn-typical compression distortion. [/B]

The dimension is 17'x18'x10'. Woofer is Focal Audiom 15'. I'm using electronic crossover at 100Hz. In room freq.response is -3dB at 25 Hz. However, I'm also using another 12' woofer on top with slightly smaller enclosure. My point is that the size of a baffle doesn't really have to be big. No frequency correction was required.
 

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What about the PHY-HP KM30? They're also recommended for open baffles. Harvey "Gizmo" raved about it (as he does about most Alnico drivers). Outside of the lack of listening fatigue, how would you characterize the sound of you Fertin compared against the Lowthers? I want the next set of speakers I build to be my last.

thanks for the help, -Brad-

dice45 said:
Brad,

well, the Fertin's are sorta underground thing. TMK, the company is run by a former desinger of professional speaker drivers. He fulfilled his dream to manufacture a 1st class fullrange speaker instead of accepting retirement. He has several models, the cheap FR has a permanent magnet, all others including a gorgeous 18"er have field coils. His FLB38EX is a direct replacement for the famous Altec 416A parameterwise.

They do not have much promotion and no english wbsite exists. Me personally is so convinced of the driver that i might get get in contact with Monsieur Fertin and see if he is interested in promoting his drivers a weebit more effectively with an English website and a very convincing open baffle speaker.
On the Fullrange spaeker fiorum there was one guy (Justin) who bought the cheap Fertins and was raving about them.
i trust my ears instead of regarding reputations; few people had even heard from Fertin last Xmas when i was pondering which FR driver to buy. I tried them out (FLB20EX, field coil) , bought them at once, never looked back. Honestly, this fieldcoil driver has cured me from my horn lust.

The reputation i was referring to came from french JoeNet buddies who had heard them already and whose ears i trust, too. And competitors manufacturig quality was awful whereas Fertin had a flawless quality record accoring to the French guys' reports.
Recently my buddy Hartmut (hifidaddy) reported the cheap Fertins were used for public adress purposes, too, and they had fantastic low end sonically.

TMK, the driver is not suited for horn use; the inner suspension is not airtight like a Lowther or other typical horn driver.
Moreover, as the driver has +/- 3.0 mm of linear excursion, methinks this would be a waste.
The driver is ideally suited to run in open baffle mode. But you can adjust Q via the FC supply voltage to your needs. THe driver should do fine in a vented or closed enclosure. But nor as fine as in an open baffle. Efficiency: 98dB/W/m

Manufactuing quality is atleast as high as Altec in their best days.

Field coil PS: currently i use a regulated power pully with an LT1085. I put some effort into getting the ripple before the reg down and the charging currents of the electrolytics, too. no need to change it sonically, but i plan to try out how a 0.2H / 2A choke sounds in series with the field coil (theoretically the FC should give best results with constant current supply, not with constant voltage supply). The field coil is consuming 1.5A at 12.9V.

For the Jericho or the Big Fun you need a Lowther, provided you can handle the Lowther's longterm listening fatigue. Or you try out the German AER, which is not as spectacular as the Lowther but a bit more lame and boring and otherwise as good as the $$$ Lowthers (PM2A or EX4).
 
Sounds like Dice-man is saying the Fertin's don't have any such "hole" in their response. I wish it wasn't so difficult to find other people with experience with these "exotic" drivers - Fertins, Phy's, AERs, etc. It's hard to make an educated purchase since you can't find reviews, hear them first, and I assume there's no money back gurantee.

... and day ain't cheap!
 
Planet,
Here's a good quote from Gizmo's review...Quite the opposite of saying there's a "hole" in the sound... :) What kind of amplifiers were being used whn you heard them?

"Be an existentialist: If you love DHT SETs you have NO choice. You must experience,
just once in your life, the thrill of a dual concentric high impedance/high
efficiency alnico magnet speaker. Be warned…life will be different after
this experience. This is the only speaker which will do the job right, and
I hope every tube amplifier designer, speaker designer and music maniac hear
this speaker…it will help the revolution."

full ... http://www.meta-gizmo.com/Tri/speak/frog.html