Initial impression: Adire Extremis 6.8

Initial impression: Adire Extremis 6.8 mid-woofer

I was able to obtain a set of Adire’s new mid-woofer, the Extremis 6.8.  This is an 8-ohm video shielded 7” driver designed for high-end midrange and mid-woofer usage in home theatres.

I use a set of Scan Speak 8525 woofers in my car as mid-bass drivers.  These are also 7” 8-ohm speakers, so my initial test plan was to drop the Extremis drivers into their locations and do a side-by-side comparison.  The Scans are mounted in front kick panels that form 0.3 cu ft sealed enclosures, and are driven by an older McIntosh MC427 amplifier, with a third order electronic band-pass crossover between 80Hz and 350Hz.  The band from 350Hz on up is handled by my Seas Reference comps in the doors.

I received the Extremis speakers (very fast shipping direct from Adire, by the way) and looked at them.  These are handsome speakers with black metal frames and magnet cover.  The tinsel leads are very heavy gage and long, due to the long excursion capabilities of the speaker.  They are about ¾” apart and not near any frame components, so there appears to be very little chance of them shorting out.

I pulled one of the Scans and immediately noticed a potential problem with my planned test.  The Extremis speakers are about the same diameter, but they are at least an inch deeper.  Whether this is due to the superior excursion capability or to the video shielded magnet assembly I don’t know, but they would not drop right into my kicks as I hoped.  The magnets hit the back of the enclosures before the flanges could seat.  Damn.

I decided to go ahead as much as I could as I was anxious to get some sound from the speakers.  I secured the Extremis in place with a couple of 2” long screws and wired it up.  Knowing it was not in an enclosure I was very careful not to turn things up too far, and I didn’t have that much hope for good sound, but I was surprised.  The Extremis was nice and punchy and produced quite a bit more SPL than the Scan Speak.  I lowered the high-pass on the crossover down to 20Hz and noted the Extremis seemed to hit down to about 60Hz with ease.  The sound got pretty flabby down low, but without an enclosure that is not surprising.  I then turned the low-pass up to about 4Khz and disconnected the Seas woofers.  Again, I was surprised at how clean and clear the Extremis sounded.  They tended to get a bit thin in the upper midrange, but again without a proper enclosure this comment is a little unfair.

The only negative comment I have is their physical size.  If Adire produces a car audio version of this driver with mounting depth closer to 3” than to 4” and without the video shielding, and probably at 4-ohms, I believe it could become a new favorite for high-end comps.  And at the very reasonable price of less than $100 each, the performance for the price seems very good indeed.

Bottom line is I was pleased with the results of this unscientific test and look forward to my next step which will involve building a 2-way vented bookshelf system with them and testing them in their intended use as HT mains.

Wow, thanks for the review David.  I can't wait to hear your thoughts and measurements when you get the HT speakers are done.  Unfortunately there is no way of shaving anything off the mounting depth, even by removing the shielding cup.  Having so much excursion comes at that price.  We did our best by using the neo magnet.    

Steven Kephart

Adire Audio

The current 8-ohm drivers are more than ready now.  The only thing you'd gain by a 4-ohm version is better power utilization, and an 8-ohm driver will keep your amp much cleaner sounding.  The speaker seems darn efficient and with only about 10 watts going to it was really nice sounding.  I only suggested a 4-ohm version for auto-specific usage since that's the current "industry standard."  Alas.  :)

We are planning on bringing in the Extremis with dual 8 ohm voice coils as well, so in a way yes we will.  However the mounting depth may be an issue, so you may want to check that as well.

Although to be honest, I would recommend using them in place of your Kenwood mids.  The extremis mids are good up to about 5 kHz.  However we recommend crossing them over at around 3kHz due to beaming issues.  Will your Sony tweeters go down that far without an issue? 

Steven Kephart

Adire Audio

DYohn, thanks for the sharing your experience w/ the board!  Would you be willing to share a little more about the design you plan on using for your HT speakers?  Crossover type / point / tuning freq / etc?  What are you using for the tweeter?

I also have a pair of Extremis drivers on hand and hope to build the 2-way kit (Kit61) coming out soon (crossing fingers).  I look forward to sharing my listening impressions when I have completed the speakers.  I hope to build both a prototype ported and sealed speaker, select my favorite, and carefully complete the pair I'll keep.

I'm using a set of Morel MDT-20 tweets (that have been sitting in a box on my shelf for oh, about three years) and a 12db/octave Butterworth crossover at 3200Hz.  I'll use a set of 0.75 cuft ported enclosures.  Since I am lazy and not a very good carpenter, I will probably use a set of pre-fab 0.75 enclosures rather than build my own.  I haven't modelled the system yet to determine port size.