The non-linear distortion performance above 500hz is remarkably low. 3rd order and higher products are almost non-existant. It's also noticeably absent of any intermodulation distortion. Is there some reason the smaller drivers are "cleaner" in this respect than the 7" one's?
I'm not sure the ridge at 3khz is a problem, since it's already nearly -30db down in level.
Not sure what the dip is... isn't baffle step since nearfield swamps out any baffle effects.
The only confusing thing is LE curve looks like a driver that doesn't use copper in the motor? Although the inductance is quite low.
With a cap in place at 800hz, it sounds alot like a powerful tweeter
Here's a wild guess on the Le 'shape'. Some motors, like Seas Excel, use copper above & below the pole piece. I think this little Vifa/Trius just uses copper above the pole ... probably depends on size & shape of the copper as well ? Heck I dunno
I'll copy my suggested homework assignment from another thread
1. Grills ... we need grills for these that fit well! Fostex K308 comes so close ...
2. Group-buy from N-core. I'm gone for two weeks, perhaps Rutger can discuss with npdang? Hope this suggestion is not out-of-line ...
Rutger made me aware of this discussion, so I thought I´d put in some notes on the Trius.
They are very close in design to one of the stock TG9 units and are indeed made by Vifa.
What originally attracted us to this model was it´s suitability as a dash mounted speaker. The wide dispersion makes it work well even in quite off-axis assemblies and the fairly long excursion capabilities of this driver makes it able to handle frequencies that virtually no domes can touch. We have tried it crossed over as low as 160 Hz w. 12 dB slope with good results (altough you do pay a price in maximum output.)
The fact that it extends so well in the top end leaves you a lot of feedom when it comes to tweeter selection, position and not least important crossover frequency. As has been pointed out here you can use it without a tweeter with surprisingly good results, but adding a tweeter from, say 8 kHz adds a bit more shine to the sound.
Another bonus is that it has very compact dimensions, one of our compeditors sell a 2,5 dome midrange with about the same external dimensions.
Downsides, well the frequency responce pretty much tells the story, that 2,2 kHz resonance peak I would very much liked have been able to gotten rid off.
It can make some voices sound a bit harsh if left uncontrolled.
In the end I opted for a faily large and smooth resonance peak that would be easy to control with an eq or an "paralell trap" circuit.
Thanks for your interrest!
Ncore Acoustical Solutions
On grills, we have a new grill for it coming out, but it is not the mesh type grille, it is actually a water cut steel plate that spouts our "N"-shaped logo.. Not exacly subtle, but pretty cool imo (I´ll fix up some photo tomorrow)
Another thing, the frames on these units are made out of injection moulded plastic. That allows for a bit of creativity when assembling them, but is not the stongest material known to man so a bit of care when mounting these is advised.
The above mentioned grills also incorporates a 3 mm thick steel reinforcement plate.
Sorry for the lousy photo, but it gives an idea of the visuals of the grille, I´ll get a better one to post this weekend. The one in the link above is not really a grille its just a trim ring.
On the group buy, of course we can do something there. One thing though, all our produts comes with a european style warranty, if it brakes in it´s intended use within a year we´ll fix it. If you do something stupid you are on your own. To define stupid is up to Ncore.
Erik, in your opinion is the passive circuit posted on your website for the trius suitable to be used on the vifa driver?i cant get the trius in a group buy since i am in australia but i am able to get the vifa here. I don''t know if this is a question you are willing to answer (trade secrets and all) but i was wondering if you could tell us what the differences (if any) are between the trius unit and the vifa?
BTW that is a very nice grill. I am very sure you have sold werewolf on these speakers now
Do you think this Trius midrange would do well in my active front stage with an LPG 25nfa tweeter in the kickpanel? A Peerless XLS 8" is going in the doors for midbass duties.
I am looking for a midrange that will play down to a low enough frequency to blend well with my XLS midbass, but at the same time allowing enough room for feet, clutch, and the parking brake in my '04 Cadillac CTS-V. I want to start fiberglassing some kickpanels asap.