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

bullman96 wrote:

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steven, i was thinking about the extremis as a solution to my midbass problems.  will you guys ever be putting out a 4ohm driver?

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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.

kfr01] wrote:

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ould 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?

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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.

bullman96 wrote:

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the sony and kenwood are my amps for my components. fixed my signature. the reason i want 4 ohms is because i am short on power. What would be a good amp for the extremis's? thanks

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Oh, yeah.  I suppose if I had paid attention to those model numbers I would have realized that.  Plus it makes more sense than running a set of Sony tweeters and Kenwood mids.

How much power is that amp?  Why do you think you don't have enough power?  Is it because the mids are bottoming out early?  If that is why then I would recommend running a high pass filter on them.  That will allow you to play them at a higher volume level. 

Steven Kephart

Adire Audio

Personal opinion here.  Many amps will push any driver, including the extremis, to the best sound quality possible.  Look at brand typically known to be honest with their numbers and get one with a reasonable s/n ratio and thd.  Any amp of appropriate wattage for your listening habits with these three characteristics should sound excellent.  The audible differences between amplifiers that meet a minimum level of competency should approach nill.  That said, even very good amplifiers can produce slightly different sound.  However, in my brief experience with audio, these differences aren't measured in 'better' or 'worse' just subjectively different.  I feel the speakers and the application have MUCH more to do with the sound quality of your system than amplification, assuming, again, that the minimum level of competency is met. 

In sum:  I'd spend more money on speakers and their application before looking to very expensive brands like McIntosh.  Even with very expensive brands, I think the audible differences will be near nill.  Those differences that are audible are going to be very slight and very subjective. 

What basis do you have for your opinion?  I think you have none.

MANY MANY amplifiers have dead flat frequency response, higher damping levels than can have an audible effect on sound, and lower than audible s/n and thd numbers throughout the entire frequency range at full rated power. 

Take speakers, a TOTALLY different story.  Even the most expensive drivers in the world cannot begin to approach a completely flat frequency response.  They ALL have higher distortion levels than even moderately priced amplifiers.  Every slight change in listening angle, distance, alignment, and any other number of variables alter their sound quality. 

I think you're dead wrong and that you have absolutely no basis for your opinion.  Please find me some credible reference that supports your view.  You'll find there is none.

bullman96 wrote:

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its my opinion from listening to different amps. i was just asking for an amp that sounded as neutral as possible without shelling out the extra on a second mcintosh. i listened to a mcintosh power some focal comps a couple days back and it was amazing. back up your opinion. i dont state useless numbers unless it pertains to a speaker, the crossover(which should not really be determined by the manufacturers stats, but the application's stats), and the box being designed for. s/n doesnt affect how the amp adds character(or doesnt) to the sound reproduction, which, they all do. i agree in the fact that speaker application makes up a huge portion of the sq in a system. the percentage of the total harmonic distortion on an amp has nothing to do with the color, same with the hu. speakers can be judged numerically, but if you can pick the best amp out of a dozen by looking at numbers, than you must be psychic. i trust my ear backed up by the specs.

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You disappoint me, I thought you'd put up a better counter than that.  :-) You want me to find a reference?  Give me 2 seconds on google and I gaurantee I can find one.  Yep, here it is.  Mr. Linkwitz, an expert in the field of audio reproduction, lists components in order of importance by the effect they have on accurate reproduction of music.  His list is:  1) Loudspeaker  2)  Listening room   3)  [Turntable]   4)  Amplifier  5)  D/A / Transport  6)  Cables, etc.   See Siegfried Linkwitz, Sound Reproduction at: https://www.linkwitzlab.com/reproduction.htm.

I don't follow the logic of your argument.  You posit that a) amplifier specs are useless but that b) all amplifiers add character or not to the sound reproduction and c) because of this unknown character X amplifiers are more important than speakers.  You make too large a jump from (b) to (c) and disregard the fact that (a) bites you in the ass.  ;-)  You're totally right, amplifier specifications _are_ largely meaningless past a certain point - you help my argument nicely.  As the specifications improve, audible differences in amplifiers decrease.  The next logical step is that as these audible differences decrease, the 'character' an amplifier adds also decreases.  i.e. as their variables approach these certain orders of magnitude that many amplifiers can obtain, and as these same variables between amplifiers also approach one another, the audible characteristic differences heard will approach 0. 

If _you_ can pick out the best amplifier in a room, much less a car (snicker), blind, among an array of competent others, then you, my friend, are the psychic.

If your argument is really just that with McIntosh you _know_ that you're getting a very high end, well built, and accurate product, then fine - I appreciate that.  However, if this is the case, I'd urge you to reconsider your opinion that loudspeakers are less important than amplification. 

T.Hill wrote:

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DYohn, have you had a chance to listen to the RE XXX mids yet? From what I understand they are in the same class as the Extreme6.8's. Maybe Steven can elaborate on that last comment.

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Wow, this discussion went far afield.  No, I haven't had a chance to hear the RE version of the XBL mid.  I understand their 4.5" driver is quite nice, though.

For what it's worth, I used a McIntosh amp because it was what I had available when I intially built my system, although I do agree that they are among the best made amplifiers in the world.  And to add further to the fray, IMO loudspeakers are far and away the most critical component for SQ in a system, but the entire electronics chain will determine the character and quality of what reaches the loudspeakers.  Tube amps are never the cleanest nor the most power efficient, but they do tend to be the most warm sounding (largely due to introduced harmonics) and many people say the most "natural" sounding amplifiers.  By "natural," I mean they sound the most like live instruments playing.  Ths difference is mainly noticable when reproducing acoustic instruments or voices.  In a car, the difference would probably only be important with the engine off and outside noises minimized.

Actually the RE XXX mids are a 6.5" midrange.  I haven't played with them, but from what I hear they don't work well IB in doors.  You need to put them in an enclosure, which can be a problem for most installs.  The 4.5" speakers DYohn mentions above are some full range speakers by Creative Sound Solutions.  Those are a pretty impressive speaker as well.  They were designed to beat out the more expensive Jordan full range speakers Bob at CSS sells.  We had a great deal of interest in them in many fields.  They are one of the best demo's we have to prove that Doppler based IMD is not an issue.  I actually have a pair I'm using as front speakers at home till I finally build my Extremis towers.  Then the 4's will be moved to surround duties.

Oh, and eventually Exodus Audio, who is releasing the Extremis based kits, will be releasing an LCR design using dual Extremis mids, the CSS 4, and the Usher tweeter.  I'm building the crossover for the kit 261's right now at work. 

Steven Kephart

Adire Audio

Any info. you can share regarding the design on the 261 Kit?  xo frequencies?  etc? ;-)

That LCR center promises to be pretty awesome.  Imagine actually being able to set center to 'large' on the receiver.

kfr01] wrote:

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p>Any info. you can share regarding the design on the 261 Kit?  xo frequencies?  etc? ;-)

That LCR center promises to be pretty awesome.  Imagine actually being able to set center to 'large' on the receiver.

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Unfortunately I'm not sure what frequency he chose.  My guess is somewhere around 2.5-3kHz  But the end response was VERY smooth and flat.  It sounded awesome in his computer simulation of the crossover.  I just got the crossovers built and the glue holding them in the enclosures is drying right now.  As soon as that is done we will veneer the cabinets, mount the drivers, and then they will be done.

The LCR will be a fun one.  It is designed as the ultimate center channel allowing incredible extention.  This is important after all since the center channel provides so much of the information you hear in the movie.  The problem of course will be the size though.  But it should be similar to our Kit LCC, but with more extention.

Steven Kephart

Adire Audio

The 261 is an MMT.  My guess is that they will sound the same other than the 261's having even more low end capability.  They are in a 3 foot tall tower though instead of the .75 cubic foot ported enclosure the 61's are in. 

BTW, anyone in the Seattle area come on by and you can hear for yourself.

Steven Kephart

Adire Audio

heh :-) 

I wish I lived closer.  Someone up there stop by Steven's place of work and let me know how huge the difference is between teh 261 and 61 kit.  :-)

Steven, this is also OT, but most of my posts these days are.  Do you / adire / dan / others you associate with 'in the know' have a favorite method of damping speakers?  Particularly the kit61 - I'll be ordering it the second I see it on one of the sites.

Anyway, from the research I've done here's what my current plan is:

Kit design w/ suggested bracing.
Cascade Audio damping Spray on inside.
Egg crate foam on all walls other than the baffle.
Acousta-Stuff as recommended in the kit.

Any other suggestions?  Does that damping spray help at all?  Any benefit to double width on the front baffle for the Extremis?

Damping material will do nothing unless your walls are very thin and flop around (ie sheet metal in cars).  All it does is lower the resonant point below the pass band of the system.  However if you are using proper materials for your enclosure, the resonances are already below that point anyway.  I recommend just using the Acousta-stuff material and make sure it is in the center of the enclosure.  Placing it along the walls does very little as the air speed is greatly reduced due to friction. 

I know that DYohn doesn't like it, but we buy pillows for our enclosures.  This is because we can order them in the specific weight we need and just throw the pillows in the enclosure.  It is much easier to store and distribute. 

Steven Kephart

Adire Audio

Ok, thanks for that.  I hear all kinds of crazy sh*t during my trolling at madisound and diyaudio.  (Multiple layers of 3/4" MDF, sandwiching sand, dynamat, etc between boxes, using cement, fiberglassing, etc.)

Well they are correct with some of that stuff as it makes the enclosure more rigid.  It greatly reduces the flexing of the walls of the enclosure, which is a good thing.  However lining with mass loading pannels doesn't make the walls any more rigid, so it is a waste of money IMO.  

DYohn, I hope you don't think I'm saying you are wrong about Acousta-stuff.  You are correct in that it is supperior.  However from a production standpoint we found that the pillows were easier and gave close to the same performance.  That was all.

Steven Kephart

Adire Audio

Steven Kephart wrote:

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DYohn, I hope you don't think I'm saying you are wrong about Acousta-stuff.  You are correct in that it is supperior.  However from a production standpoint we found that the pillows were easier and gave close to the same performance.  That was all.

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Not at all!  I was serious about "whatever works."  In really critical applications, however, I suggest using real combed wool, actually... and there is some radioactive stuff designed to prevent mold and bugs that works real well but it's illegal in the USA... using actual pillows are an intrigung idea, but I'll bet their relative rigidity makes their damping factor higher than using loose polyfill, and the cover could make a difference too... sounds like another experiment!

Hmm... Makes me want to DIY a 3 way system for my accord...only if I had the money.. :(

kfr01] wrote:

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Ok, thanks for that.  I hear all kinds of crazy sh*t during my trolling at madisound and diyaudio.  (Multiple layers of 3/4" MDF, sandwiching sand, dynamat, etc between boxes, using cement, fiberglassing, etc.)

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DYohn] wrote:

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n really critical applications, however, I suggest using real combed wool, actually... and there is some radioactive stuff designed to prevent mold and bugs that works real well but it's illegal in the USA

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Oh, but there is a way that is not only legal but perfectly safe if used as directed.  Use boric acid dust formulation (available by the bottle at your local drugstore) mixed thoroughly with the animal hair.  The borates will kill the moths and beetles that would feed on the wool, and stays active indefinitely.   A mineral, not a chemical, it remains an effective insect killer because there is no volatility.  Wear a respirator or dust mask outdoors while mixing it into the wool (it will be dusty).  And wash your clothes separately.  Bag the treated wool in a plastic bag and use when needed.  And I would go so far as to say:  use it in sealed enclosures only.

Mold is not treated for like this....but if the air is so wet that mold spores can grow then the speaker will be ruined anyway, I would think. 

I just now thought this treatment up and haven't seen it written of before.  We (in the pest control industry) do, however, use treated mineral fibers for insulation.  But this application is unique.  The post above gave me the idea.  So, opportunists, feel free to contact me for rights to produce.  As this is published today, consider it Patent pending!

Did I stray O.T.?  lol

kfr01] wrote:

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p>heh :-) 

I wish I lived closer.  Someone up there stop by Steven's place of work and let me know how huge the difference is between teh 261 and 61 kit.  :-)

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Ok, I just finished the set that is going in my boss's house.  It is very similar to the 261, however it uses a less expensive tweeter than the Usher.  But it is voiced the same.  After listening to them for the last hour and a half, I want to change my previous recommendation to you.  I recommend you getting the 261's for now and see how you like them without a sub.  I really don't think you need one for music.  They are that incredible in their bass response.  I tortured them with some bass cd's, the 5th element soundtrack,  Mickey Hart; Planet Drum, and other bass heavy tracks.  They are the first 6.5" based speaker system that will resonate your chest cavity.  We use a 3" port for a reason after all.   But I say save yourself some money and listen to them first without a sub.

I do want to get someone on here to take a listen and give their objective opinion on these things.  But I truely am blown away.  They sound better all around than even the Wilson Watt Puppies I demoed ($20k speakers).  The ambient sounds are very much enveloping, the imaging is right on and even extends a little beyond the speakers, and they just aren't fatiguing to listen to; even at very high output levels.  I was going to wait to build these for my apartment.  But now I can't wait.  I have to have these things.

Steven Kephart

Adire Audio

DYohn] wrote:

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p>and there is some radioactive stuff designed to prevent mold and bugs that works real well but it's illegal in the USA...

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Well that's too bad. Can you imagine how rigid your enclosure would be if you had to line it in lead?

And becides, it's not like my kids aren't going to turn out as freaks anyway having my genes.  So why not have some fun with it?

Steven Kephart

Adire Audio

Glad to hear you are happy with the sound.  There is little more satisfying than building something like a set of speakers and being really happy with the results.

I have always thought Usher loudspeakers are over-rated and over-priced.  They sound way too mushy for my taste, like an old AR8 with a silk dome and no definition.  For tweeters, stick with Morel, Scan Speak, Peerless, Seas, Onkyo, Silver Flute, B/G, JBL, Eminence, Fane... the drivers most of the big boys use.

The speakers I heard tonight, and I will be building for myself use these tweeters: https://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=277-408&DID=7  I guess the Usher is a superior tweeter since it can play louder and has a little less distortion.  But I really liked what I heard of the Peerless tweeters, and at a quarter the price they work for me. 

Steven Kephart

Adire Audio

I suppose since this thread has already gone off topic, I will add another one. 

There is an online magazine called Momentum produced by another car audio forum.  In one of the articles people ask questions on the "chalk board" and my boss answers them.  These range from speaker selection for a system to which underwear is better (you think I'm kidding, but I'm not).  Here's the link: https://forum.soundillusions.net/article.php?a=223

I figured some of you techies might enjoy it. 

Steven Kephart

Adire Audio

DYohn] wrote:

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p>Glad to hear you are happy with the sound.  There is little more satisfying than building something like a set of speakers and being really happy with the results.

I have always thought Usher loudspeakers are over-rated and over-priced.  They sound way too mushy for my taste, like an old AR8 with a silk dome and no definition.  For tweeters, stick with Morel, Scan Speak, Peerless, Seas, Onkyo, Silver Flute, B/G, JBL, Eminence, Fane... the drivers most of the big boys use.

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One of the reasons I posted the above link was because of some of the comments my boss made about tweeter selection.  Do you think the issues you heard with the Ushers could have been caused by the crossover?

Steven Kephart

Adire Audio