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tinitus 24th September 2009 02:33 AM


Originally Posted by CLS (

Qts can be tuned low by very soft suspension and the low fs it causes.

Which would make a perfect hifi woofer for closed box design

So, it's possible that a driver with higher Q has a stronger motor than a driver with lower Q.

I dont think that will be by such a large margin as you imply

In some horn related articles, we can read the same driver recommendation -- low Q + high fs. This more or less guarentee a strong motor.

And where does mms fit in ?

Isnt that only partly true
You are leaving out many variables

tinitus 24th September 2009 03:51 AM

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Sorry, I know this isnt the right thread for this, but anyway

CLS, this woofer is the only one I know that may fit your theory with soft suspension, low Fs, low Qts, yet have a weak looking magnet
Mind you, the size of a magnet doesnt tell the whole story
Different kinds of magnet quality
Magnet/motor designs can be magnetized to differnt levels, achieving any Qts, within limits ofcourse

This German 10" is by some regarded as very good for closed design, and some would even say its hard to find better
Soft suspension/low Fs is the key to a good working closed design
It would, like you imply, sort of, probably be a big mistake to use it for BR designs, even though Qts appears to be low
VAS is like GM said, quite big
I know of no other woofer with such specs

Back to fullrange :shutup:

tinitus 24th September 2009 04:25 AM

The main difference on these two Tangband 8" seem to be the different airgap, and Xmax, which results in the different Qts

CLS 24th September 2009 04:39 AM

Yes, sorry my previous statements were too rough. There're indeed lots of variables. I generalized too much.

Such a thumb is too big and wide for ruling things.

Pit Hinder 24th September 2009 04:42 AM


> Sorry, I know this isnt the right thread for this, but anyway <

Why not? "Fullrange" doesnīt have to be "single driver" - "most important driver" might hit the spot.

So, if you donīt mind Monacor (I keep waving their flag whenever I can) spending your money on quality rather than on cosmetics, and they are available in your part of Sol3...1000DK ~140€? Combine it with

Xover low and, if you donīt mind the size, you might have some fun.:D

CLS 24th September 2009 07:23 AM

OK, here I got 2 examples for comparison:

Data of A is Lowther DX4 measurement obtained here somewhere (I remember it's tested by MJK). Data of B is published specs which I have some problem opening the file of my own measurement file (by WT3)... It's a 7" Focal mid.

Both are good for horn loaded (Oris 150, at least). I've been using the B. About DX4, I don't have 1st hand experience, but I have listened to PM4, which is excellent and should be similar to this DX4...

As can be seen on the table, both have very light Mms, and quite strong BL (for their sizes).

While Qes = ( 2 * pi * fs * Mms * Re ) / (BL ^2 )

So if all others being equal (or very close), then fs is directly proportional to Qes. Before this, fs is controlled by mass and compliance (Mms and Cms).

Here we can see the fs : Qes of A vs B:

58.3 Hz : 0.218 vs 119.9 : 0.414

They look very proportional. In my eyes, the major difference is the compliances of their suspensions. One is (relatively) softly sprung, the other is much stiffer. This alone makes the fs 2-fold, then the Qes follows.

It's possible to make a driver with very compliant suspension (or heavier Mms)to get a same Qes of B unit (0.414), then its fs must be way lower and the motor must be much weaker.

This is what I previously meant, Q number can be misleading in judging if the unit is suitable for horn loaded.

GM 24th September 2009 03:50 PM


Originally Posted by CLS (
This is what I previously meant, Q number can be misleading in judging if the unit is suitable for horn loaded.

I'm sorry, but your conclusion makes no sense to me. Consider that Prof. Leach's compression horn math only uses Fs, Vas, Qes, i.e. *effective* motor strength, and since normally you only horn load the driver's point source BW, its gain BW is from Fs to 2*Fs/Qes. So from this, how can it be misleading?


CLS 25th September 2009 02:44 AM

Ah! you beat me. And thanks for pointing that out.

I should say "Q number *alone* can be misleading..... " (it'd look better now)

I feel sorry for these posts. Now it seems an even bigger hole by trying to make up the previous careless mistakes.

I think you, Mr. GM, are hard to be misled, but believe me, and you know it, people are constantly looking for simple rules and easy ways to get things done...


OK, then, how about a horn without compression? The [2*fs/Qes] still holds?

I don't have any hard evidence (precise measurement) to prove, but what I've experienced is quite differe from the [2*fs/Qes] upper limit. And please forgive my ignorance, is the gain by directivity control (projecting into limited space) considered by that equation?

I'm not sure if the copy here is legal, for your reference:

The <Edgar Midrange Horn> can be seen there. I believe almost everyone here has read that article.

I was encouranged (or seduced) to step into the horn world by that. Mr. Edgar also mentioned in the article that the performance of a real horn in the real world can be somewhat beyond what that equation describes. I concur that according to my own experiences.

I believe many other things get involved here, except the 'real horn loading', there are also the gain by directivity control, and the free escaping sound waves from the driver... etc. All these contribute to the overall outputs.

I'll dig out some of my previous measured data to see if I can make it clearer....

Godzilla 25th September 2009 02:51 PM

I wonder how the the TB compares to the Seas full ranger for sonics?

The TB might be a bargain or the Seas might be overpriced?

Meanwhile i am totally enjoying B20s with dustcaps removed. I even turned off the tweeter (temporarily) bc i hear enough treble... a blind test between B20, TB and Seas would be fun. All these driver can be stuck into simple sealed or ported boxes.


Godzilla 25th September 2009 05:01 PM

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There are many more but here are three full range drivers sure to please ranging in price from around $30 to $900... I must admit I have been enjoying the B20 without dustcap for the last few weeks even without a tweeter and they are very satisfying. Not perfect, but enjoyable and musical. I like how this driver is tweakable... the TB looks fully tweaked already and the Seas i wouldn't dare cut up.

Personally, i think my standards (while pretty high) have been reduced as i listen to music more for enjoyment than critically. The full range driver 'thing' really lets you relax into the music when the right driver/cabinet combo is in place. From cheap TB and Pioneer's to more expensive Fostex hearing nice mids really satisfies... even if it isn't perfect. But nothing is. IMO, adding crossover components to even very expensive drivers at around 2k just spoils everything. I've given up on it for quite some time.

Good sound can be had for cheap these days... but it can still be expensive. As a community, we've begun to drive the market to produce these lovely drivers. I expect a trickle down effect from the Seas and TBs in the coming years. Just hope it's before my hearing goes.


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