Graphs and everything is great...theory is great as well.
But what does it actually sound like at 500Hz..1000Hz etc. In a real world either Home or Car scenario?
Our drivers are known specifically for their exceptional high frequency response. As I'm sure you know, inductance and change in Le vs excursion has a huge impact that becomes more significant the higher you go in frequency. All of our woofers have a full copper sleeve on the pole that greatly reduces distortion and keeps Le nearly perfectly linear throughout the excursion of the driver. This is the same that is done in all of our TD drivers which have proven over and over to be likely the lowest distortion drivers available at any cost within their intended usage. Take a look at the distortion measurements done by augerpro on AVS and DIYaudio.com of the TD12M as well as the Le(x) measurements. Then look at all the other drivers. You will see that no other drivers come close in terms of the Le linearity and low non-linear distortion of the higher orders which come from the motor.
http://sites.google.com/site/drivervault/driver-measurements/tang-band-75-1558se/ae-speakers-td12m
The AV woofers have the same characteristics as the motors are nearly the same, only with a larger 2.5" diameter coil. Since you mentioned home environment specifically, Jim Salk is using a similar custom woofer in the new speaker that is temporarily being called the HT4 or Beast and is searching for a new name.
http://www.audiocircle.com/index.php?PHPSESSID=1gmoda4bk8qj9aa1rr6umoac4ikq2dec&topic=67978.0
He also replaced the 10" driver formerly used in his HT3's with one we are doing for him. Our TD12 is used in his Archos speaker. Jeff Bagby had done extensive testing on the TD12 vs all other possible candidates. His credentials exceed mine. You can see his comments on the driver here:
http://www.htguide.com/forum/showpost.php4?p=398362&postcount=44
All of the testing and results are not my own, but those of others who are qualified to do the testing. I have not published this data myself as others would question it. I am very happy to see that others have finally published third party information validating our own. I don't think there is any question about the high frequency ability of our drivers.
There is something about something being that big re-producing those frequencies that simply do not sound 'right' to the ear. Especially with aluminum...which is why you see all of the great pro sound people using ultra light paper cones and edge wound coils with 11" diameter motors.
I think you may have a misunderstanding of how some things work. The size of the driver or mass of the cone has nothing to do with it's ability to reproduce higher frequencies. The only issue you get into with larger drivers is that as you go up in frequency you get more directional sound. Quite simply to play high in frequency and sound good you need linear inductance. Without it, the response will be different on the inner and outer strokes. This creates high amounts of distortion. High frequency response is also about efficiency. The higher the efficiency, the less power for a given SPL, the less flux modulation, the less thermal issues, the lower the distortion. This means that a larger driver can reproduce the same frequencies cleaner as it has to move less to get that SPL and is typically more efficient. Obviously there are exceptions as a larger driver can be less efficient than a smaller one in cases.
In general though, the "fastest" drivers or the ones with the quickest transient response are the ones with lowest inductance. Dan Wiggins posted this paper way back now that explained it quite well.
http://stereointegrity.com/docs/WooferSpeed.pdf
The Lambda paper entitled "Bl/MMS=nonsense" also talks about the "speed" of woofers and the need for low inductance to reproduce "fast" signals.
http://web.archive.org/web/20010810141852/lambdacoustics.com/library/whitepapers/bl_mms.htm
The reason the big pro companies use light cones is simply for efficiency not high end extension. On the big tours it gets very expensive to bring in more power. You pay union people to setup equipment at the large venues and are charged according to the amount of power supplied. On a big tour like the rolling stones, a difference of 2dB in efficiency on the subwoofers could cost as much at $10,000 more to setup with the union workers.
Also I am not talking about impedance breakups. I'm talking about actually putting the cone, on a shaker table, mounting accelerometers on it, exciting it from 1-4000Hz and recording the data and running through a dac program like MATLAB. This actually tells you where the cone has acoustic excitation and where it is dead. With nothing else coming into play, just the cone itself. Mat lab and accelerometer graphing gives you a great deal of information that is very useful...if you know how to use it. I did some stuff for Boeing a while back on some panel vibration stuff..very cool...learned a great deal about aluminum //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
I agree you can get a lot of good data that way on the cone itself. When you put that same cone in a woofer though, things change. If we hang a cone from a string and hit it with a hammer it can ring like a cymbal. However, once the ID of the cone is attached to a coil, a bead glue is applied to attach the dustcap, and the santoprene surround is attached, things greatly change. The santoprene as well as the various glue beads give a large amount of damping to any resonance of the cone. Any accelerometer measurements would need to be done with the cone in the full driver or they wouldn't be valid.
Also any resonance excited will show up in the impedance curve. You can verify what is going on by looking at a CSD plot of the driver and viewing the decay time at those resonance points. You can also get a stroboscope to actually view what is happening at those resonances. There are a couple videos on the LinearX page here that show both a spider resonance and cone resonance issue.
http://www.linearx.com/products/accessories/LS310/LS310_01.htm
John
