[Kevin Haskins]

Exodus Audio 6.5" Mid-woofer

• 26mm P-P Linear Excursion
• XBL^2 Motor Technology
• Smooth clean frequency response
• Aluminum cone has single small 6dB break-up @ 4.2K
• Smooth, clean Impedance sweep.
• Optimized 0.5-.7 ft^3 resonant enclosures.
• 1.5" Copper VC on anodized aluminum former
• Klippel confired suspension out 13-14mm one-way.
• Price..... lets just say the name will have real meaning to our competitors.

http://www.youtube.com/watch?v=-iGD0p0E42A

[Kevin Haskins]

Some measurement stuff:

No smoothing.... raw measurement in the chamber.   



Slight wiggle at 4.2K representing the cone break-up, and corresponding 5-6dB peak in the FR.   I know it isn't 5-6dB in the above FR measurement but it is on my measurement from the fork-lift at my warehouse.   Worst case.... 5-6dB, best case.... 3dB without any smoothing.     



Plenty of BL, and suspension.




Parameters stable with output, as you would expect given the Kms & BL curve. 





Break-down of the distortion components.   Quick and dirty, dominated by suspension non-linearities.   

[Kevin Haskins]

Here is some more video, with the woofer in free-air showing noise at full clip.

http://www.youtube.com/watch?v=RRSdoHis4rw

[Kevin Haskins]

I've been getting a lot of email on this.   Let me try to respond here to cut-down on some of the redundant questions being asked and save my sanity:

#1  Where is this made?

My vendor is in Asia.  They have several factories and I'm not sure which will be manufacturing this product.   It is a superb vendor, with a great track record and they manufacture for a number of big-name companies.    They were chosen for their track record, in-house engineering, and their willingness to work with me.   

#2.  Do you have distortion data?

No... I don't have a chamber in the USA and you really need a chamber to get reliable data.   For us, the Klippel is more valuable because it tells us the mechanism, not the result.   If you are engineering something knowing the cause is critical because that is what allows you to optimize/improve the design.    A distortion plot tells us nothing except that there is a problem.   It doesn't show us what we need to do to fix it. 

Distortion plots are dependent upon how they are taken too.   If you look at something like Zaphs site or other knowledgeable people taking distortion measurements, they will tell you that the data doesn't necessarily correlate to other distortion measurements.    They are useful, if you are comparing two devices, measured at the same time under the same circumstances.   They are less useful when taken alone without context.     

#3.   Why is there a asymmetric shape in the Klippel BL or the Kms?   It doesn't look like you have a true 13mm X-max.

You have to take the Klippel for what it is.   It is a measurement and all measurements have a range of variability and the device isn't perfect.     If you get a slight 1mm offset, that is actually extremely good.    Most people don't have the experience or the context to comment on good/bad measurements.   Trust me.... these look very good even without the perfect marketing shapes.       

In terms of the x-max, nobody has caught it but the shown Klippel was for a different prototype than the final one.   There have been several revisions.   If you look at the curve, the BL at rest is about 7.3-7.4.    In the final design it is up around 9.8 so the coil has changed since that particular Klippel.    It matters not... it is the same motor and I'll update the information once the production run is shipping.     We would calculate x-max based upon a fairly simple formula.   You take the resting BL, multiply by 0.7, and then trace the curve to see where it crosses.    You will get slightly different numbers forward/back.    The thing to keep in perspective, is that this is out at the edge of usability and we are often talking about 1-2mm differences.    If you assemble a couple drivers you will quickly find it is pretty difficult to insure unit-unit a 1mm tolerance on placement of the coil.    Measure different units off the production line and you might get slight differences in that asymmetry.     It doesn't matter a whole lot because people don't run midwoofers at 26mm peak-peak.   They run them significantly lower.    Look at it this way, you are getting an extremely linear +/-  20mm P-P operation.    The xmax is only a number that is reflecting what you are getting near the limits of operation and you shouldn't be operating anywhere near xmax with this type of device anyway.

#4.   Why is it so cheap?   What gives?   

I'm giving them away near cost.   That is why they are cheap.    I'm doing it because I'm nuts.


#5. What did you sacrifice to get all that linear stroke?

Well.... you don't give up anything other than cost, size and weight.    There is no tradeoff for xmax that sacrifices efficiency.   The box size & bandwidth you target are what really determine the efficiency.    Once you pick those things, the efficiency pops out the other side of the equation.   We could easily make this 90db/1W/1M but it would no longer work in our target application without EQ and it would cost more because we would have needed a bigger motor.     

High stroke drivers don't necessarily give up anything other than the fact that you have to design the suspension to deliver it.   In the past, you also picked up more inductance with overhung VC designs but XBL^2 motors don't necessarily have that same tradeoff.    The suspension can be troublesome for linear distortion issues (cone/surround resonances) but that has been successfully solved in this design.   Don't ask me how, I'm not a soft parts guru but the engineer at the build-house clearly understands what he is doing.   It is smooth, and easy to work with and there is no hidden ugliness.   I have four samples and they measure great on all axis of measurement and they are fairly easy to work with.   

#6:  Why the rising inductance? 

Inductance is a complicated topic.   Suffice it to say, without the rising inductance we would have had a rising response.    In general, you would want a flat inductance curve for a full-range driver or anything designed for upper midrange or HF response.   That is not the design intent of the device.   In terms of distortion, inductance is only an issue at higher frequencies unless you get flux modulation in the motor, DC offset/rectification and other voodoo motor stuff.    As you can see from the Klippel distortion analysis, Le contributes the least amount to the THD of all the non-linear factors.   BL & Cms non-linearities are the bigger sources of non-linear distortion.   Improving Le wouldn't give us any meaningful improvement and I'm not interested in spending my time/money on something that doesn't make an audible difference in the final product. 



That is it for now.

[Kevin Haskins]

Looks like I have a couple more:

#7:   Why didn't you use a paper cone?  Everyone knows that aluminum cones ring and sound jingly jangly,  poly cones sound like Tuperware, and paper sound smooth and tasty.

For the cone material junkies, I'll give you my quick and dirty philosophy.    Cones don't sound unless it affects the response.   There is no correlation between the material used, and the various subjective things that people describe.    The measured response, on/off axis, and the distortion spectrum, with power, are what determine the subjective result.     Most of what people think about cone materials is wrong and there is ZERO research showing any correlation between cone material and the myriad of public opinions.   

#8.   Do you have plans for other versions with higher efficiency?   Do you have plans for a car audio product (4-ohm, shallow mounting depth)?  Do you have plans to run for office?

The answer is no, no and NO.   :laugh:

This is the one and only 6.5" format driver I'm producing.   There are no other small-format drivers in the works either (<10") that I'm willing to talk about.    The only projects I'm working on are a couple non-traditional drivers and subs, nothing else I'm willing to share at this point.   
 

[Kevin Haskins]

These are the parameters for people who missed them under the Z curve.

Re: 6.2 Ohm
Fs: 44.4Hz
Qms 6.7
Qes  .47
Qts  .44
Mms: 26g
Cms  0.49 mm/N
Vas:  11.9L
Sd:  131 cm^2
BL 9.76
SPL: 85.3 dB/1W/1M


Here it is in .75 cubic feet, tuned to 30Hz with a 25Hz subsonic filter Q=0.7 so no gain.   This would be the "deep reaching" version where you go for maximum extension.   The slight tapering FR matches up good with projected boundary/room gain so this would be smooth & deep.    I based this upon my active version which uses a pair of LM3886s so 100W keeps it from bottoming with the 25Hz filter.   Certainly great extension to 25Hz region in-room and good SPL considering the size of the device.   

[Kevin Haskins]

And... one more video.

http://www.youtube.com/watch?v=piUxOpCGAHA



Price.... $40 per driver.   

[Carl V]

damn 

[poseidonsvoice]

Holler just whenever you get a kit out! At that price, everyone should be able to afford it and I don't mind having a minimonitor to show off to friends that plummets down to 25Hz!

And...at $40/driver, I will certify you as magnanimous and nuts!  Couple this with the new SB Acoustics SB29 soft dome and you've got a world beater!

Anand.

[guest1632]

Exodus Audio 6.5" Mid-woofer

• 26mm P-P Linear Excursion
• XBL^2 Motor Technology
• Smooth clean frequency response
• Aluminum cone has single small 6dB break-up @ 4.2K
• Smooth, clean Impedance sweep.
• Optimized 0.5-.7 ft^3 resonant enclosures.
• 1.5" Copper VC on anodized aluminum former
• Klippel confired suspension out 13-14mm one-way.
• Price..... lets just say the name will have real meaning to our competitors.

Hi Kevin,

So, ... how do these new woovers sound versus the ones you designed for the Kepler model? Are you then going to release a kit around these new woovers? Also a rebuilt model?

I presume you have stuck these in boxes. So how do they sound versus the ones for the Kepler ones? Thanks. Are you finally gonna use this new tweater you have been working on as a total speaker?


Ray

http://www.youtube.com/watch?v=-iGD0p0E42A

[Kevin Haskins]

So, ... how do these new woovers sound versus the ones you designed for the Kepler model? Are you then going to release a kit around these new woovers? Also a rebuilt model?

I presume you have stuck these in boxes. So how do they sound versus the ones for the Kepler ones? Thanks. Are you finally gonna use this new tweater you have been working on as a total speaker?


Ray

I don't know.... never listened to them.   We don't design things like that.   

I know you get filled with all kinds of information about using listening trials to get the "magic" formula but I'm an engineer, not a witch doctor.   There isn't a woofer we have designed yet that I had actually listened to before pulling the trigger on a production run.   

Once I actually get to the design stage of the finished speaker, then I do listening trials.   That is mainly tweaking the crossover to preference though and it is minor changes in voicing.    I could design a loudspeaker without ever listening to anything but a chirp from the measurement system.

[guest1632]

So, ... how do these new woovers sound versus the ones you designed for the Kepler model? Are you then going to release a kit around these new woovers? Also a rebuilt model?

I presume you have stuck these in boxes. So how do they sound versus the ones for the Kepler ones? Thanks. Are you finally gonna use this new tweater you have been working on as a total speaker?


Ray

I don't know.... never listened to them.   We don't design things like that.   

I know you get filled with all kinds of information about using listening trials to get the "magic" formula but I'm an engineer, not a witch doctor.   There isn't a woofer we have designed yet that I had actually listened to before pulling the trigger on a production run.   

Once I actually get to the design stage of the finished speaker, then I do listening trials.   That is mainly tweaking the crossover to preference though and it is minor changes in voicing.    I could design a loudspeaker without ever listening to anything but a chirp from the measurement system.

Hi Kevin,

Sorry you took me so literally. I just wondered after looking at all the specs if you had a chance to listen to these woolvers in a finished speaker. I should have said that. Yeah, I know you just don't stick a speaker in a box, and hope it works. It both the box and the drivers together like cenergree. Nope, I don't get a lot of information that way. I haven't heard a good speaker in a long time. Haven't been around stores to hear them.

I'm sorry that the Keplers did not work out. I was looking forward in buying a pair. I was mainly wondering if you were gboing to make them as a finished product. It seems that you worked so hard on them, only to discontinue them as a kit.

Ray Bronk

[Kevin Haskins]

So, ... how do these new woovers sound versus the ones you designed for the Kepler model? Are you then going to release a kit around these new woovers? Also a rebuilt model?

I presume you have stuck these in boxes. So how do they sound versus the ones for the Kepler ones? Thanks. Are you finally gonna use this new tweater you have been working on as a total speaker?


Ray

I don't know.... never listened to them.   We don't design things like that.   

I know you get filled with all kinds of information about using listening trials to get the "magic" formula but I'm an engineer, not a witch doctor.   There isn't a woofer we have designed yet that I had actually listened to before pulling the trigger on a production run.   

Once I actually get to the design stage of the finished speaker, then I do listening trials.   That is mainly tweaking the crossover to preference though and it is minor changes in voicing.    I could design a loudspeaker without ever listening to anything but a chirp from the measurement system.

Hi Kevin,

Sorry you took me so literally. I just wondered after looking at all the specs if you had a chance to listen to these woolvers in a finished speaker. I should have said that. Yeah, I know you just don't stick a speaker in a box, and hope it works. It both the box and the drivers together like cenergree. Nope, I don't get a lot of information that way. I haven't heard a good speaker in a long time. Haven't been around stores to hear them.

I'm sorry that the Keplers did not work out. I was looking forward in buying a pair. I was mainly wondering if you were gboing to make them as a finished product. It seems that you worked so hard on them, only to discontinue them as a kit.

Ray Bronk

I'll have some other speaker designs, probably at lower price points so I can get some volume.   I don't know about finished designs at this point.    The bottom line on any product in my lineup, is that it has to sell at some minimal level to justify doing it.    If it doesn't sell, it goes no matter how much work I have in it. 

I've not listened to this new midwoofer even though I have four samples with anything but test-tones and chirps at this point.   I'll be updating some new speaker kits using it but I've been busy with documentation on all the new subwoofers.    Once that is done, I'll get back to speaker fun.

[Voodoo Rufus]

Any chance of a floor-stander kit involving this woofer?

Why no Neodymium magnets this time? Cost?

[Kevin Haskins]

Any chance of a floor-stander kit involving this woofer?

Why no Neodymium magnets this time? Cost?

Yes... down the road I'll have a monitor, floor stander, center channel, in-wall etc...    I'm going to change direction on some of the kits.   I'll publish design but I probably won't sell all the parts.   The crossover components are essentially commodity products.    I don't plan to stock thousands of dollars worth of crossover components when you can go direct to Madisound or Parts Express and pick them up.     

So... there will be published designs, and drivers, but no complete kits.    That allows me to keep the price more attractive because I don't have to stock the parts.   

And yes... no Neo because of the cost.   Right now people are extremely price sensitive and I'm adjusting my product makeup to account for that change in the market. 

[hoxuanduc]

Please have an MTMWW  aa, or at least an MTM!

Duc

[Voodoo Rufus]

Please have an MTMWW  aa, or at least an MTM!

Duc

^^ This. 

[persisting1]

Please have an MTMWW  aa, or at least an MTM!

Duc

+1

How can these only be $40 a piece? 

[Kevin Haskins]

Please have an MTMWW  aa, or at least an MTM!

Duc

+1

How can these only be $40 a piece?

You can pay extra if you feel the need.  The Haskins budget is in need of it.    I'm officially moving up to the full-sized 15 passenger van because of the impending arrival of another couple kids. 

 

[dyohn]

NICE looking measurments Kevin.  This is a 6.5?!??!  When will they be available?