Size of Midrange Drivers

Why, in this day of super materials, do designers still use
mini midrange drivers?

a midrange driver will start beaming (sound thru it will be very directional pretty much like a focused light beam) at a certain frequency.
The bigger the diameter of the midrange, the lower this frequency of beaming.
For example, when I used to own B&W DM604S2 they had a 7" midrange & the frequency that the Kevlar mid would beam was in the region of 1800-1850Hz.
It was distinctly audible - when I would listen to Frank Sinatra (whose voice is deeper) the vocals would be in line with the speakers. When I would listen to Diana Krall (whose voice is higher pitched), the vocals would pop out in front of the speakers while the other instruments would stay back in-line with the speakers.
I had a long discussion in the AudioAsylum with other B&W owners & found that they were experiencing the same thing.

A large diameter mid is not a good thing - the mid needs to be flat frequency response beyond both the lower & upper x-over frequencies. And, only the electrical x-over ckt should be rolling off the mids i.e. the mechanical failure of the mid should not be rolling off the mids (in addition to the electrical x-over). If this does happen, the x-over response of the speaker will be highly uncontrolled & will be signal dependent. Signal dependent behavior of any electrical or electro-mechanical system is a very bad design. The speaker will have a lot of phase distortion - which means the speaker will impose its distortion onto the music signal & will destroy the timbral & tonal nature of the music. Listening to music thru such a speaker will be a complete displeasure (atleast for me).

08-21-14: Timlub
Hi Dweller, A few answers....
The obvious, we use a mid range to play mids... smaller than a 4 to 5 inch will normally not play low enough to cover the entire vocal range... many drivers above 5 inch have cone break up or frequency response that will alter the upper vocal range... In an ideal world, a midrange will cover the entire vocal range... No crossover in the vocal region, smooth to no phase shifts and smooth accurate frequency response are most easily found in that 5 inch range.

good to read that what I wrote in my post above agrees with this part of your post....

08-21-14: Dweller
Ptss: So you're saying that most of everything emanating from a symphony orchestra can be reproduced by a five inch driver?

A symphony orchestra has a very large range of frequencies which extend well beyond a 5" midrange driver.
So, no the 5" midrange driver cannot reproduce all those frequencies.
the speaker would need to be multi-driver where the midrange will reproduce everything in the, say, 300Hz - 2500Hz region (assuming that the midrange driver's freq response is flat over this region & that there is no cone break-up).

I think we're just brain-locked into the current paradigm and are waiting for our "Einstein" to show us the way to the next level.

The Einsteins have come & gone. I believe it's up to you to understand why certain driver choices have been made for the various speaker designs. See if you can talk to your speaker designer or tech support of your particular speaker & see if he is willing to share his thoughts on the driver choices of your speaker. It might be enlightening to you....

08-24-14: Dweller
Hey! Tannoy! You've only been making speakers since 1926 so take some more lessons because somebody on this web-site thinks you and I are "confused".

Stop making your $55,000 Kingdom Royal until you get straightened out and start using 5" midrange drivers!

(dang this is fun!)...

Dweller, you asked the question & when info has been given to you, you don't want to learn! There seems to be disbelief on your part. Why ask the question if you don't want to learn??? Just curious to know...

This info from 2 websites: tannoyspeakers.com & tannoy.com (it looks like you haven't spent much time reading it..)

The first Dual Concentric loudspeaker, designated the monitor black, and designed by Tannoy's chief engineer at the time, Ronnie H. Rackham, appeared at the London Radio Show in 1947.

It was in 1926 when Guy R. Fountain (GRF) perfected a new type of electric rectifier with the aim of designing a charger more suitable for use in the home.
I really don't know when Tannoy built it's 1st speaker but it wasn't in 1926.

the following info is about the Tannoy Kingdom Royal loudspeaker from Tannoy's website. Read a little about the Kingdom Royal's drive unit - scroll to the middle of that webpage & look under "Drive Unit":

The crossover to the DC’s high frequency unit occurs at an exceptionally low 700Hz to ensure the majority of the vocal region is handled by the new tweeter.

The Tannoy Kingdom Royal has NO MIDRANGE driver contrary to what you seemed to allude to.
Their new HF compression driver tweeter is doing all the midrange.
Like you seemed to indicate - Tannoy is not foolish & they wouldn't put a 12" midrange! The 12" unit does upper bass to 700Hz & the lower bass unit does the bottom-most octave.

You know, Shakey might have a very valid point.....

To clarify: 700Hz er certainly part of the midrange (indeed the lower part of the central mids), and voices typically contain a lot of energy even lower in the frequency spectrum.

no dispute here Phusis. I was not stating otherwise. Merely stating that the bulk of the midrange freq is handled by their new tweeter. Yes, freq below 700Hz is handled by the 12" mid driver which seems to be more suited to the lower freq. Tannoy smart as they are did not try to do any more midrange with the 12" driver - that was my point.

What's to learn is oftentimes to unlearn, keep an open mind, and be willing to go against accepted (read: rigid) norms.

good advice Phusis. I keep an open mind while keeping Physics in my mind at the same time. Hopefully you do the same....
Timlub tried to explain some of the physics to you but it went over your head. I tried too in my very 1st post & it looks like that went over your head as well.
Well, you can take a horse to water but you cant make it drink...

700 Hz wavelength is over 19" long, so a 12" driver wouldn't even be close to beaming. Tannoy knows what they're doing, but apparently you refuse to catch on, even with multiple corroborating explanations.

johnnyb53, I get it. the point is do the likes of you & Dweller get it?
Once again: Tannoy smart as they are did not try to do any more midrange with the 12" driver - that was my point. Hopefully you got that?
thanks.

but while I appreciate your addressing "physics" I believe you adhere to them in a rather non-flexible fashion that cares more about numbers than, it would seem, actual listening impressions - or at least you're without the positive experience of a 12" playing midrange above 1kHz, in which case I respect. I just don't share the same experience.

I have a fair bit of world-wide listening experience & have listened to a lot of speakers (& a lot of electronics) yet to but yet to have a positive experience of a 12" midrange playing midrange. If you look at my systems I do own a Tannoy DMT10Mk2 which has a 10" playing midrange all the way up to 1.4KHz. It sounds good for the most part & is just fine for the use that I've put it to but when I had a time-coherent speaker with a 4.5-5" Eton midrange, the Tannoy was nowhere near that quality.

Johnnyb53, thanks much for the clarifications.

08-25-14: Dweller
Thanks guys for trying to teach an old dog new tricks.
I'm looking for a way to get a more life-like listening experience.
You're trying to tell me why I can't have it.

it appears to me that you have, very broadly speaking, 2 choices:
a speaker with large diameter midranges (like 10" or 12") that are crossed over in the low midrange region &
a speaker with a more conventional 4-5" midrange driver crossed over at the upper mid-bass

The large diameter driver speakers seem to be made of proprietary drivers - from Altec Lansing, JBL, Tannoy, RCA, Westinghouse & your former Audio Artistry Dvorak. If there are any other names other members can please chime in. And, these drivers, being proprietary are not available to the general public for other speaker manuf to make speakers. So, if you are convinced that a large midrange is what you want you'll have to go with these limited speaker brands.

OTOH, you can have a perfectly fantastic realistic/life-like listening experience with a 4-5" midrange if you get yourself a time-coherent speaker. This is a really -l-o-n-g- discussion & I will NOT go into it here. Please read the "Sloped Baffle" thread (which has some 220 posts) here in the Speaker forum.
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1403209611&&&/Sloped-baffle
Concentrate on Roy Johnson's posts as to why time-coherence is important in music playback & how it maintains the correct information in the music signal & why it delivers a realistic/life-like music experience. There are a few speaker manuf making these time-coherent speakers so unfortunately once again a limited choice. That's the way it is - most speaker manuf do not understand the physics to make a time-coherent speaker - they think that time-coherence is one of many parameters that can be traded-off with some other speaker design parameter. It is not! Either a speaker is time-coherent from the get-go or it is not. The speaker manuf needs to select time-coherence as the design paradigm & then solve all the speaker manuf issues within the time-coherence paradigm.
It is my belief (becoming firmer & firmer as I listen more to various systems & talk to others & their disappointing listening experiences) that large amounts of phase distortion from the speaker is what's destroying people's listening pleasure & causing people to make remarks like

I'm looking for a way to get a more life-like listening experience.

If you had a time-coherent speaker you wouldn't be saying this. Of course, not everyone participating in this thread has a time-coherent speaker & not everyone in this thread is complaining of a lack of realistic experience. I.E. many people with NON time-coherent speakers are very happy. I'm finding out that today a lot more people are dissatisfied compared to the year 2002/2003 when I was 1st exposed to time-coherence. So, it's good to see that more people are realizing that the life-like experience is diminishing. This awakening is good - hopefully it'll make the speaker manuf change their design philosophies....

Phusis,
thanks for the info & the excerpts from the 6mooons.com review. If nothing else, the speaker finish is very nice to look at.
In a similar view both in respect to "Made in Austria" & beautiful looking finishes - at RMAF 2013 I heard a very nice sounding stand mount speaker by Brodmann Acoustics called the FS from their Festival Series. In that hotel room it did much better than its floor-standing bigger brother which they were playing on Sunday morning. Some links to that speaker:
http://brodmannacoustics.com/index.php?id=116

http://www.stereophile.com/content/brodmann-acoustics-festival-series

Maybe I liked it 'coz it has a 5" midrange?? LOL!! :-)
here's a nice write-up on that speaker:
http://hans-deutsch-akustikforschung.com/pics/tests/avmentor.pdf
Look at its step response - exactly what a time-coherent step response should look like (note that it uses a 6dB/octave slope).

Phusis, we agree to disagree (which is just fine with me). :-)
I'm happy that you subscribe to some Nathan Lewis' opinion on this matter but it's just his opinion & I have no idea what his exposure & knowledge of audio is?