Coaxial driver experiences and preferences

[bigx5murf]

I happen to have a pair of the outdoor speaker drivers. I picked up the speakers for like $7 at a thrift store. I actually haven't touched them since. I'm thinking of building a cabinet for them now.

 

[MattHooper]

I posted this in another thread, but seems more appropriate here:

I used to have the Thiel CS6 which used a coaxial driver arrangement (tweeter mounted in mid). It was generally effective. However I seemed to notice slight interference issues/suckouts if I moved around.

Later I owned the updated Thiel CS 3.7 flagship and currently have the slightly smaller CS 2.7 using the same newly designed coaxial arrangement.
I found the design Thiel achieved with this coaxial fascinating, especially the fact they managed to "flatten" the mid driver to, among other things, reduce the usual reflection problems with a tweeter mounted in the middle. Image here:

http://4.bp.blogspot.com/-TJzTXgsKcZU/UmQ0zUN6MCI/AAAAAAAABUE/Z76CfkaKjDA/s1600/CS3.7.jpg

Here's Jim Thiel explaining the design at the beginning of this video:

I certainly can't speak to the objective success of the approach. But subjectively both the 3.7 and the 2.7 seem to have hit it out of the park. The mids and highs (and lows!) are the most coherent I've ever heard. I can not "hear out" the tweeter or tell-tale signs of separate drivers or frequency exaggerations at all in the mids/highs and acoustic sounds are just amazingly natural sounding. Image precision and density is the best I've heard anywhere. They also maintain this coherence and even frequency over a seemingly wide range of seating positions. Thiel was a smart dude!

 

[bigx5murf]

I've been searching for another pair of later Thiels myself. I only have one of the earliest sloped baffle towers, the 04a. I always found them subjectively amazing for a traditional 2way. The crossovers on each have over 20 components, despite being 1st order! Also ridiculously inefficient.

 

[thewas]

I found the design Thiel achieved with this coaxial fascinating, especially the fact they managed to "flatten" the mid driver to, among other things, reduce the usual reflection problems with a tweeter mounted in the middle. Image here:

Just for the Hifi history interested, Technics had such already in 1985 and it measured and sounded quite well.
https://www.technics.com/global/chronicle/sb-rx50/

 

[Juhazi]

A flat midrange doesn't make a waveguide for the tweeter. Also time alignment with LR2 crossover isn't "naturally" helped. A flat membrane is more prone for resonances.

Measurements of Thiel CS3.7 with flat corrugated mid https://www.stereophile.com/content/thiel-cs37-loudspeaker-measurements

Most Thiel coaxials seem to have been conical thiel coaxial driver

History of Thiel https://en.wikipedia.org/wiki/Thiel_Audio

 

[Juhazi]

An interesting and pretty, modern coaxial driver https://audioxpress.com/article/test-bench-tang-band-speaker-w8-2314-high-end-coaxial-driver

but I would prefer W6 in a three-way speaker http://www.tb-speaker.com/products/w6-2313

 

[thewas]

A flat midrange doesn't make a waveguide for the tweeter. Also time alignment with LR2 crossover isn't "naturally" helped. A flat membrane is more prone for resonances.

True, although with good engineering you can make even with flat membranes a coaxial driver with excellent directivity and resonance control / time decay, https://www.stereophile.com/content/technics-premium-class-sb-c700-loudspeaker-measurements, the experience and research of a giant like Panasonic makes itself paid there.

 

[maty]

I like to see H2 > H3

Somebody explain to me why many do not complain because in too much amplifiers the relationship is reversed: H3 > H2

 

[Juhazi]

---
I also recently discovered the Seas Excel C18EN002. Has anyone built speakers using these drivers? I'm sure they sound great.

Yes this is most to my liking http://www.htguide.com/forum/showth...s-I-m-going-to-go-build-something-quot/page25

I have speakers with other SEAS coaxials, T18 and MR18

This Gradient 1.4 clone is a bit Thielish... 3-way with Hypex FA123 https://www.diyaudio.com/forums/multi-way/322839-seas-mr18-3-a.html

 

[andreasmaaan]

B&C recently updated their range of PA coaxials. Some good looking drivers there. Voice Coil measured a couple of them and they performed quite well (for example here).

The driver used in KEF's current R series was measured by AudioExcite and gave very impressive measurements.

 

[thewas]

The driver used in KEF's current R series was measured by AudioExcite and gave very impressive measurements.

This is from the now "old" R series and one generation behind of the current one which should measure even better.

 

[sfdoddsy]

I also recently discovered the Seas Excel C18EN002. Has anyone built speakers using these drivers? I'm sure they sound great.

Hi. I built a pair of simple wall mounted open baffles using the C18s, crossing to sealed bass units below 300Hz.

Very nice sounding (and decent measurements too).

 

[beefkabob]

In some ways as good as the best electrostatic speakers I've listened to -- perhaps slightly less detailed and controlled, however the most natural sounding presentation I've heard. The sound that I heard through these was so open and uncompressed -- effortless like a ribbon panel.

Is any of this measurable? Like where on the spinorama or other charts can I find detail, control, or natural sounding? Open? Uncompressed? Effortless? It just seems like more psychoacoustics to me.

 

[Frank Dernie]

Unfortunately, I don't know many folks with Tannoys, so I don't have much ears on experience.
The crowd I fell in with are mostly Altec, JBL, and RCA fanboys I developed a rather expensive taste for many things Altec, as a consequence.
The dynamics, effortlessness, and midrange "real-ness" of the Duplexesare superb (and, by modern standards for loudspeakers, even affordable).

This is very country specific. There are a fair few Tannoys here in the UK and I have never seen any of the US models (it could well be they were never exported, the US market being huge they perhaps didn't feel the need)
There was a "fashion" for old Tannoy drivers in DIY cabinets several years ago here and I heard quite a few at an enthusiast show.
Pretty good I would say. Theoretically there will be directivity and cone breakup problems but they certainly didn't ruin my enjoyment!

 

[Frank Dernie]

Dunno -- my understanding, though, is that's essentially the way the Lowthers work. The Lowthers' whizzer cones aren't strictly parasitic (as I understand it, which is minimally), but actually have a portion of the "main" VC winding driving them.
EDIT whoops, it's the polar opposite of the Lowther design -- inductively coupled, eh? hmm...

That said -- y'all ever heard Lowthers? They're -- an acquired taste, I'd opine.

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The Lowthers date back a long ways (late 1940s)

http://www.lowthervoigtmuseum.org.uk/history.html

Lowthers are very coloured. Rather like a big version of a 1940s radio.

 

[mhardy6647]

Lowthers are very coloured. Rather like a big version of a 1940s radio.

I don't disagree -- they can sound scary-good with some program material & sources, though -- well recorded mass choirs, e.g. They nail plainsong, IMO

They're horrible with multitrack mono, highly processed 'pop' music, though (again IMO).

There are also so many different flavors of enclosures that it's hard to make a blanket statement, other than -- that they're an acquired taste.
I am not a huge fan (although I like the iconoclasm of using Lowthers, I must admit).

 

[Frank Dernie]

I don't disagree -- they can sound scary-good with some program material & sources, though -- well recorded mass choirs, e.g. They nail plainsong, IMO

They're horrible with multitrack mono, highly processed 'pop' music, though (again IMO).

There are also so many different flavors of enclosures that it's hard to make a blanket statement, other than -- that they're an acquired taste.
I am not a huge fan (although I like the iconoclasm of using Lowthers, I must admit).

The acoustas are the ones my great aunt had.
Their FR would exaggerate the frequency area plainsong exists in, so putting it in the spotlight.
I liked them a lot actually, lovely tone
Maybe I am using rose tinted ears though, none I heard later were as enjoyable as those I heard visiting my much loved aunt!

 

[milezone]

Is any of this measurable? Like where on the spinorama or other charts can I find detail, control, or natural sounding? Open? Uncompressed? Effortless? It just seems like more psychoacoustics to me.

Maybe psychoacoustics, couldn't say for sure. Effortless is the primary quality I would associate with these speakers though. Where as many speakers across the cost spectrum from cheap to ultra expensive are not effortless sounding, the Tannoy's are and I was playing them fairly loud. I don't have a means to measure the speakers unfortunately, though I recommend you have a listen if the opportunity presents itself. I've listened to and owned many speakers over the years, my favorites being Quad 57s and Acoustat Xs with servoamplifiers which I modified extensively. My primary speakers are an older pair of Genelecs -- the 1029s which I enjoy quite a bit. I plan to upgrade to one of the newer coaxial models hopefully fairly soon. In addition I plan to build at least a couple different speakers in the next year or two. Were I to plop down some cash on a vintage speaker, the Tannoys, or maybe Altec coaxial speakers though I haven't heard them, would be at the top of the list -- over even electrostatic/true ribbon panel designs as the vintage stuff is too unreliable and these vintage paper cone alnico coaxials are just as good and maybe better -- more preferable to my ears -- in some regards. When the time comes that I start building some speakers I'll hopefully have some test equipment and will provide measurements if I get my hands on a pair of the aforementioned vintage drivers.

 

[beefkabob]

Yeah, I have no idea why you prefer this or that. The vocabulary you use is meaningless.

 

[milezone]

Do you have some sort of beefkabob with me? I'm just stating the observations I made with me ears. Not claiming any scientific merit behind these observations though others seem to share similar favorable of opinions of the speakers in discussion. In any case very sorry I offended you with my meaningless vocabulary.