[linuxworks]

every so often I hear about the concentric woofer/tweeter (coaxial style) drivers that tannoy was famous for.

I went to see what tannoy has now in this area and it seems that they offer some studio monitors that have the dual speaker config but I'm confused by the fact that they have a 'super tweeter' that is NOT center-aligned!

does this make sense to anyone? isn't the value lost once you take one of the drives off-axis?

or, was this concentric stuff mostly just 'marketing' ?


I have some conventional tannoys (pbm-8) and I'm curious if its worth it to swap them out and try the new concentrics (my pbm's are a good 10 yrs old now).

anyone have any experience to relate on those concentric cone designs?

 

[jazzychu]

Do not how I can really help you. But I have known the Tannoy since the 1970s and if the concentric design can last that long, there should not be any issue, as long as you like the sound. I always wanted to own a pair and did obtain one demo for a few days but had to return to the seller due to a tiny hole in the rubber ring. I since found the planar speakers.

 

[linuxworks]

funny you say that, I have planars now (I think they qualify). magnapan mmg (the mailorder $500ish ones).

one worry I might have with the tannoy is - are replacement parts expensive? can you recone the surround or do you have to junk the whole driver?

and if the concentric design was so great, why did they break it in the current 3 driver series? that seems to be what's in stock at the pro audio stores if you search for tannoy and concentric monitors. I don't even see one that does *not* have that 3rd driver. seems strange to me.

 

[catachresis]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif funny you say that, I have planars now (I think they qualify). magnapan mmg (the mailorder $500ish ones). one worry I might have with the tannoy is - are replacement parts expensive? can you recone the surround or do you have to junk the whole driver? and if the concentric design was so great, why did they break it in the current 3 driver series? that seems to be what's in stock at the pro audio stores if you search for tannoy and concentric monitors. I don't even see one that does *not* have that 3rd driver. seems strange to me.

I've owned Maggies and two other pairs of speakers that had ribbon tweeters. My experience of electrodynamic speakers is that they are fluid, expressive, but unfocused. I can't get into the impact of treble and high-bass unless I get the sense that it's been expressed, exploded, expectorated, expelled from some particular point.

The Maggies were very fine, and the Aurum Cantus monitors were very clean, but my old Spicas and Ruarks sounded more 'natural'. The Aerial 7s sound dynamite for 2-driver speakers. Right after the Aurum monitors, the Aerials kicked my ass down the street. They felt like the proper panacea.

 

[jazzychu]

When I first encountered the Tannoy, I was very impressed by the violin music that store was playing. Back then the ones I saw were only the concentric type and the size were huge. Later, maybe around late 80s, they introduced the super tweeter to handle the highs but I never had a chance to listen.

When I had the demo, funny I actually was impressed by the bass. I remember I played Trinity Session CD by the Cowboy Junkies and instantly from the first track, I heard the ambient sound I have never paid attention before. The recording was done in a church, but I thought I heard something like a railroad station. High fidelity? I don't know. Too bad I did not keep the pair for more listening. I have not heard that sound from my MG 1.6 or any headphones again.

Does Tannoy offer small concentric speakers?

 

[Drag0n]

Kef also uses concentric speakers, and they say it keeps treble and bass on the same axis point as to provide a more solid and stable axis.
Some companies use time alignment by positioning the tweeter an inch or two behind the woofer,assuming the tweeter frequencies are faster and reach your ears sooner unkess you time align the speaker system.
By placing the tweeter inside, it takes care of the horizontal and vertical dispersion, and also since its positioned in the back part of the woofer, it is also time aligned more than if it was placed on the same plane as the front mounting wall of the speak cabinet.

Supposedly, the woofers air movement doesnt interfere with the tweeters smaller and faster air vibrations.
You can also make the speaker smaller because you dont need the extra room to mount the tweeter next to the speaker.

 

[Rempert]

Quote:

Originally Posted by Drag0n /img/forum/go_quote.gif Some companies use time alignment by positioning the tweeter an inch or two behind the woofer,assuming the tweeter frequencies are faster and reach your ears sooner unkess you time align the speaker system. By placing the tweeter inside, it takes care of the horizontal and vertical dispersion, and also since its positioned in the back part of the woofer, it is also time aligned more than if it was placed on the same plane as the front mounting wall of the speak cabinet. Supposedly, the woofers air movement doesnt interfere with the tweeters smaller and faster air vibrations.

I sure hope the time alignment is to compensate for faster response by the tweeter itself. Because if speaker manufacturers think high frequencies travel through the air faster than low ones, they might need to reread the high school physics books...

 

[JaZZ]

Quote:

Originally Posted by Rempert /img/forum/go_quote.gif I sure hope the time alignment is to compensate for faster response by the tweeter itself. Because if speaker manufacturers think high frequencies travel through the air faster than low ones, they might need to reread the high school physics books...

The goal of the «time alignment» thing is to compensate for the phase shift due to the capacitor-induced high-pass filter in the case of the tweeter and the inductor-induced low-pass filter in the case of the squawker/woofer, not frequency-dependent runtimes of sound waves. A fundamental weakness of this concept is the reflexions of the tweeter's sound waves on the cabinet top.

As seductive as a concentric speaker looks like (more homogeneous radiation pattern), it suffers from a similar effect: The sound waves radiated by the tweeter are reflected in the woofer cone. Thus the signals are slightly smeared, and there's a certain degree of coloration from the hollow-space effect. The reflexions can even be (frequency-)modulated by the woofer's membrane movement. Compared to a stand-alone tweeter (without a baffle), high frequencies are usually radiated in a narrower angle, which means reduced high-frequency wall reflexions in comparison to mids and lows. This will compromize 3-dimensionality and realism. On the other hand, the radiation is more uniform -- the polar pattern lacks the typical dips and humps of multi-way speakers (due to interferences) --, which can improve the spatial focus and increase 3-dimensionality.

BTW, Tannoy uses a horn tweeter within the woofer, whose horn length is meant to equalize the phase shift due to the crossover network. This design avoids the above-mentioned cabinet reflexions; in turn it has to deal with horn colorations (hollow-space and multipath effects) plus a relatively directional high-frequency dispersion.

So concentric speakers have their strenghts and weaknesses. Like with many things, it's a matter of preference.
.

 

[Drag0n]

Quote:

Originally Posted by Rempert /img/forum/go_quote.gif I sure hope the time alignment is to compensate for faster response by the tweeter itself. Because if speaker manufacturers think high frequencies travel through the air faster than low ones, they might need to reread the high school physics books...

I cant speak for them......i just wrote things ive read in ads about them.
Could be marketing hype, but many audiophiles have purchased them.