Eminence Flux Density Modulation

[Mr.coil]

Hey Bruce,
Are you still needing those output devices for your SX-980?
I have some...I could come over and test your Christmas fudge for quality...lol
Steve

[Mr.coil]

Ok already...I give...
I have never had much respect for things like: my-space, face-book, linked-in, or any other kind of social network...I have not had the time or an understanding of them, I guess I'm a Plugger.

Anyhow I came upon this site and thought I saw where someone was dissing my product without actually hearing it...If I would have done a little more reading I would have seen where he was actually quoting someone else (who I should have a talk with)...Then to my chagrin...he is a customer...Yikes! I over-reacted...my bad! I guess I need to tighten up my servos, eh?...Naw!

Anyhow I firmly stand behind any, and all claims I have made about FluxTone products. I know I do not understand all the physics behind it, but I know It works because of the 100% agreement by those who try it.

When ever we demo to an accomplished player, who has struggled with various "Gismos" in conjunction with amps that sound great but are just too loud, and have been left wanting, at the very moment when they hear how FluxTone actually delivers what they have been seeking for so long...They inevitable get this huge grin... We call it the "FluxTone Smile" . It is what keeps me going.

Thanks for your input, I look forward to hearing more.

Steve

[Enzo]

Steve, this place is like a local tavern or something. And you walked into it from somewhere else. You have to hang around a little to get an idea of who is talking and what is on their mind. This place is not just a place guys hang out, the people here are interested in amps and actually know a lot. If someone detects a chink in the armor, count on it getting pointed out. But that is nothing personal. And you might be amazed to find out that now and then you will learn something about your own product. I know I have had many educational moments here.

[Bruce / Mission Amps]

Sorry... off topic....

Hey Bruce,
Are you still needing those output devices for your SX-980?
I have some...I could come over and test your Christmas fudge for quality...lol
Steve

Ha ha... Laurie is still perfecting the fudge.
Yes, the Pioneer is still sitting there in the same place under that little work bench...
You're welcome to come by any time of course.
I need to stop by and see Jason at the Erie Airport sometime soon, I should stop over at your place too.

[Mr.coil]

Thanks

[pdf64]

My understanding of the reason Celestion choose not to publish Thiele Small parameters is that for guitar type speakers, those parameters are very non-linear against power, eg the compliance will be different at 1 watt than at 50 watts.
I guess many parameters wouldn't change, eg BL, but what's the benefit of publishing incomplete specs, particularly for an application (cabs designed around Thiele Small parameters) they don't feel is appropriate?
I don't know much about the above, so apologies if it's way off track. Pete.

[Mr.coil]

Hey The only reason we publish them is because they come with the cones we use, and people want to see them...

The most useful application of "Thiele Small parameters" apply to the realms of bass guitars or Woofers. Guitar speakers operate way above the frequencies that are effected by cabinet shape and size. About the only thing that is of measurable importance in a Guitar speaker cabinet is whether it is open or closed back, and where you place the microphone. You can stuff a guitar cab with sound deadening material and get a real change in tone.

It always cracks me up when I see someone trying to make a point about a "ported speaker cabinet" for guitar application. Unless you have a Baritone guitar, a normal guitars lowest freq is about 88 Hz...Way above where any port will have an effect.

Another eye opener for us was when we ran spectrum analysis on various cone assemblies in the same magnet structure...WITHOUT FASTENING THE CONE TO THE SPEAKER BASKET, OR GLUING DOWN THE SPIDER....wow!! There is no change in the performance curve until you get down below 150 Hz!!

Once you get into the business and actually start making speakers, you find out where the line between myth and reality is in a hurry.

Mr.Coil

[Steve Conner]

Well, I think that is kind of unfair. If you put an EVM12L in a sealed box, it sounds kind of thin. If you design a ported cabinet for it, the ports end up resonating around 90Hz, and it adds a good bit of extra chunk to the low E. (Yes, I have an EVM12L and have tried building a bunch of different cabinets to get the best out of it.)

The reason is of course that the EVM12L has an abnormally strong magnet which gives it a low Qts. In a sealed box, it has an overdamped response that starts to roll off up in the hundreds of Hz, and needs a ported cabinet to coax any amount of bass out of it whatsoever.

Which brings me to my next point. Obviously as you turn down the flux on your Fluxtone thingy, the speaker's Thiele-Small parameters will change completely. The Qts will go up as the motor gets weaker. In an open-backed or sealed cabinet this probably works in your favour, the increased Qts at low flux will give a bass boost that compensates the Fletcher-Munson loudness curves and makes it sound subjectively better.

But in a ported cabinet it would go horribly wrong, because these are designed around a specific value of Qts. If you listen to the Rivera speaker shootout video on Youtube, they use the same ported cabinet for all the speakers. When they put in some Jensen alnicos, with their tiny voice coils and weak magnets, they sound kind of nasty with throbbing, distorted bass.

I think you know fine well where the line between myth and reality is, but you choose to spin it in your capacity as a salesman.

[J M Fahey]

I think manufacturers *should* publish Thiele Small parameters (if available), because they are very useful.
Not only for the obvious "official" purpose of building flat response, extended bass cabinets, but because they provide a wealth of information on the speaker itself.
You can 'predict / have a fair idea' of a speaker's sound even before actually listening to it
As of ports in guitar cabinets, they *can* be used creatively, by not necessarily following classic TS ideas.
I often (not always) tune my 4x12" boxes to around 90 to 100 Hz, for the tatooed, piercings everywhere crowd.
They *love* the added chest thumping bass.
Accurate reproduction? No way. I probably have a +4 to +6 dB peak there, not different from what can be achieved with an equalizer but with the big bonus that it works at full power, where it's needed.

[Mr.coil]

Thanks for your input.

[pdf64]

'I think manufacturers *should* publish Thiele Small parameters (if available)'
Is there an issue of non-linearity of various parameters against power?

[Mr.coil]

Alloe alloe, PDF64,

Are these questions for FluxTone or are we just chit chatting?

I think a mfg should publish whatever they have useful to the normal customer, as long as it is not reveling company secrets. That info is not paid for with a simple product purchase.

For instance...We pass along any info we get from the cone mfgs, as those cones create the same curve with our magnetic structure as the original.

Please lets not get into the argument that one magnet can tell how another magnet was created! (They do not care, they just push and pull according to their strengths.) That argument is venturing into that "LaLa land" where there are those who purchase speaker wires ($18,000.00 each) that the ends are labeled..."Speaker" and "Amplifier"....as if the outer orbit of an atom knows what direction that free electron came from!!!

Your second question...is a bit fuzzy for me, I think I have answered this before...Many, many times...The spectrum analysis curve of our products remains the same over their rated power band, and over their variable output as well.

Remember FluxTone is about preserving the tones and delicate overtones that are created Via the over driven "tube, transformer, voice coil team". If there is any difference in tone..it would be more than 90 dB down from where the changes are noted from other attenuation systems like...odor eater, soup cooker, power supply adjusting, tone spunge, energy scaling, resistive, pillow in from of your speaker...or you fill in the blank.

The only time there is a significant difference in "Tone" via power, is when you drive the cone past its recommended X-Max. Then you will get sounds that are not coming from your amp....the only sound attenuating system that will preserve those tones is a closet with a microphone.

Thanks for the interest and banter...

Keeping it light...Mr.Coil

[Steve Conner]

Well, it is a good point. Thiele-Small parameters are only good for calculating the frequency response of woofers up to a few hundred Hz. The character of guitar speakers comes from the presence band, in the kHz range, and it's correct to say that the cabinet doesn't matter any more. Having said that:

Does the frequency response really stay the same when the magnet strength is changed? How low a frequency did you test down to, in what kind of cabinet, and was it a tube or transistor amp driving it? (or are these company secrets?)

I've seen guitar speakers on the Eminence website with the Xmax listed as 0. To me this says that they made the voice coil the same height as the gap, so the magnetic structure is non-linear at any power level, because any excursion will result in part of the coil leaving the field.

I suspect a lot of the famous Celestions are the same. It's pointless trying to specify T-S parameters for that, and Celestion don't even try, but they seem to sound great anyway.

[J M Fahey]

Hi Steve/Mr Coil. AFAIK we are *always* chit-chatting and thinking aloud; great things come out of that informal brainstorming.
Anyway, the main idea isn't even that, but having fun.
I always considered that any question or idea expressed here is broadcast for everybody in general, unless specifically addressed for some particular guy.
Even so, often anybody else answers if he finds he can add something useful, large or small. Fine with me.

Dear PDF, most parameters are not dependent on power (moving mass or weight, Equivalent Volume, magnetic density, resonance frequency, etc.).
I see (although I have not measured it) that compliance ("elasticity") will be lower with higher excursion.
It's easy to check: as suspension and cone edges stretch, that becomes harder to do, and past a certain level the cone movement reaches a limit.
Not that bad, it may avoid voice coil banging against the back plate or shooting forward leaving the gap.
There is only one parameter which both has influence and is measurable: the Voice Coil DC resistance.
At high power levels, it may double, which is a lot.
It kills damping but much worse, causes power compression, the elegant way to say that the speaker loses *a lot* of efficiency.
Another justification for using 2 x 4x12" (100W each cabinet) instead of a single 200W speaker.
Jimi (still) rules.

[Mr.coil]

Mr. Conner,

Yes it does! all the way down to -25dB. 100% of our customers agree with me. Out of the 1,000's of folks we have demoed to...No-one has ever said, that it does not do exactly what we say it does. Heck we have been scrutinized by Premier Guitar, Vintage Guitar, and Guitar Player...they all agree as well.

However, in our nit-picky lab setting, on some loosely suspended cones when you get down to the last 3 dB of attenuation (-22 to -25dB)...the free air resonance comes into play, as It becomes a little more prominent while the rest of the spectrum continues to fall.

I suspect this is the case because the magnet becomes so week that it looses control of the cone, because its mass becomes unwieldy. But with the tighter suspended cones its almost unperceptive. Anyhow that's way down at the bottom of the range. The only time that comes into play is when you are trying to tame 50-100 watts for bedroom use.

We test down to 20 Hz.

Both closed and open...when you close mike it does not matter much up in the guitar spectrum...so we usually test in a closed back...about 1.5 ft

Although a FluxTone speaker will turn down a transistorized amp, just like a tube amp, we do not consider them the targeted amplifier system. They do not have tubes, and output transformers that when over driven, gets into a tug of war with the voice coil, and creates the 2nd harmonic distortion that FluxTone is preserving while turning down the SPL.

Transistor clipping creates predominately 3rd harmonic distortion, which is not as desirable to most, as 2nd harmonic distortion. So a transistor amp is better suited for stomp boxes that can emulate various sounds. They can be turned down quite easily.
Because of this computerized technique, 95% of players have no use for FluxTone.
But if you have and like sound of output tubes doing their thing...and want to turn down 25dBwithout changing the tone...well its us, or the closet and a mic.

I enjoy the line up of Celestion, because of how deep they scoop certain frequencies Via the smaller diameter cone area becoming out of phase with the larger outer part of the cone. This is done with thinner cone paper. That is not to say the thicker cones do not sound great..they do...just different, I like the accuracy they project. It always comes down to the player anyhow. I like players that use a guitar cord as the only thing between them and the amp. I think dinner is ready..I am outa here!

Thanks for the thoughts,
Steve