[Kevin Haskins]

What is the "Woofer Widget"?

The Woofer Widget is a fully programmable signal processing solution.   It uses three AN231E04 FPAA (Field Programmable Analog Array) chips from Anadigm (www.anadigm.com), that I'm working with on several signal processing projects.    Its really just a small box that allows us to showcase our AN231E04 chips configured for pretty much any signal processing solution.

Its a small box, powered by a 12VDC wall wart, has an RCA input/output, USB port, and a 3.5mm microphone jack.     It comes with a mic, and necessary cables for hooking it up along with the PC based software to access the signal processing interface.     It can do a room measurement with a swept sine wave and allows you to view it on the PC.   You can then adjust the fully software configurable settings to perform some room EQ (five bands of PEQ), perform Linkwitz Transform like shelving to extend low frequency response, adjust a fully configurable subsonic filter (6-24db/oct), completely variable low pass filter (6db-24db/oct), infinite phase adjustment, limiting algorithm and just about anything else you would normally configure on a subwoofer amp.    We also have plans for an "Auto-EQ" feature that will set the PEQ bands for you.   

This is all done in the analog world so there is no delay or other DSP related problems.    Its also going to be much more affordable than a DSP based solution.   Figure about $300 retail.

[bpape]

If it does half of what you just said it does and does it well (which I'm sure it will), you should sell a TON of those. 

Good luck. 

Bryan

[Kevin Haskins]

Kevin,

I'm definitely waiting for more! Like when you come out with an MTM open baffle version! I love that Exodus Audio emblem. Maybe  making the enclosure taller (and less deeper) so you can fit the emblem below the woofer? Would look cool, but it might screw up your wonderful frequency response.

That's a serious motor on the EX6.5    . Much better pics 

Best,
Anand.

Ha!   I'm cutting wood for one right now.   Start measurements tomorrow.   

I'm not doing enclosures, I'm too broke and don't have the warehouse space to put them even if I did have an inclination to stock them.    All the designs that use a box  (non-OB) are going to use either Madisound or PE enclosures.     It gives DIYers and easy solution that looks great and I don't have to stock product.   

[Kevin Haskins]

If it does half of what you just said it does and does it well (which I'm sure it will), you should sell a TON of those. 

Good luck. 

Bryan

I'm hoping someone ELSE will sell a ton of them!   

Its really designed as an OEM product and I'm selling it just to give it some exposure.   Its a cool tool though and it works exactly as designed.   Filter functions are all within a couple percent.   The switched capacitor technology for setting the virtual resistors in the chip are nut-on every time.   You get exactly what you design, unlike with opamps with passive pots.       

[bpape]

Sounds like a beauty in an active speaker arrangement...

Bryan

[Kevin Haskins]

Sounds like a beauty in an active speaker arrangement...

Bryan

Evil giggle....   

[ecramer]

Will the speakers and crossover and box plan be available for those of us that like to build our own cabnets

[Kevin Haskins]

Will the speakers and crossover and box plan be available for those of us that like to build our own cabnets

For the cabinet, yes.    The crossover is going to be pre-populated on a PCB so there is no need for schematics and I'll probably leave them out of the docs other than a few suggestions for tweaking it for a given system/room/taste.

[Voodoo Rufus]

Do these compare favorably against the 641s, besides a little less low end extension?

Is it possible or beneficial to mount the tweeter closer to the woofer, or are the effects negligible?

[Kevin Haskins]

Do these compare favorably against the 641s, besides a little less low end extension?

Is it possible or beneficial to mount the tweeter closer to the woofer, or are the effects negligible?

Apples and oranges to some extent.   The 641 being a 3-way and the Kepler a 2-way.   They are also voiced differently in the crossover.   The 641 had a BBC dip so they where more laid back than the Kepler.    In terms of distortion levels its a push.

You cannot move the tweeter much closer.   There is 3/16" between the drivers.   Maybe it looks like more in the picture but that is what the crossover is designed for and I wouldn't recommend changing the stock layout.

[JDUBS]

Kevin

How about vs. your previous 61, a similar sized two-way?  I love my 61s.  Their bass extension is absolutely unreal for a monitor.

-Jim

[Voodoo Rufus]

What is a BBC dip?

[TerryO]

What is a BBC dip?

VR,

This is from the Harbeth website FAQ, and can be considered authoritative.

Best Regards,
TerryO

The 'BBC dip' is (was) a shallow shelf-down in the acoustic output of some BBC-designed speaker system of the 1960s-1980s in the 1kHz to 4kHz region. The LS3/5a does not have this effect, neither in the 15 ohm nor 11 ohm, both of which are in fact slightly lifted in that region.

According to Harbeth's founder, who worked at the BBC during the time that this psychoacoustic effect was being explored, the primary benefit this little dip gave was in masking of defects in the early plastic cone drive units available in the 1960's. A spin-off benefit was that it appeared to move the sound stage backwards away from the studio manager who was sitting rather closer to the speakers in the cramped control room than he would ideally wish for. The depth of this depression was set by 'over-equalisation' in the crossover by about 3dB or so, which is an extreme amount for general home listening. We have never applied this selective dip but have taken care to carefully contour the response right across the frequency spectrum for a correctly balanced sound. Although as numbers, 1kHz and 4kHz sound almost adjacent in an audio spectrum of 20Hz to 20kHz, the way we perceive energy changes at 1kHz or 4kHz has a very different psychoacoustic effect: lifting the 1kHz region adds presence (this is used to good effect in the LS3/5a) to the sound, but the 4kHz region adds 'bite' - a cutting incisiveness which if over-done is very unpleasant and irritating.

[TerryO]

Some additional thoughts on the use of the "BBC" or Gundry dip. While the Harbeth description includes the frequencies 1kHz to 4kHz, many designers, that have experience, will have favorite variations of the "dip," usually starting around 2kHz, and will often also introduce a slight roll-off in the treble. A truly flat frequency response from 20-20k in an "artichoke" chamber is usually way out of kilter in the real world of floor bounce, cabin gain, reflections, etc., and is often the reason that the graph doesn't seem to equate to good sound. Some of the best sounding speakers don't measure flat and were actually designed that way. If you find this confusing, it's because it is .

Best Regards,
TerryO

[Kevin Haskins]

Kevin

How about vs. your previous 61, a similar sized two-way?  I love my 61s.  Their bass extension is absolutely unreal for a monitor.

-Jim

The Kepler is smaller and more efficient.   The EX-6.5 is 88-89db/1W/1M so its a more sensitive driver than the Extremis was.    I'd say the Kepler is has a good 3db more efficient.    It also gives up about 5db of extension as the tradeoff but you still get a respectable mid-30s response in-room which is still exceptional for any monitor this size.    I found most people where using subs with the first generation kits and going with a more sensitive driver was a calculated trade-off based upon how MOST people where using them.   I think it was a good one.

On-axis response is almost the same.   The Kepler has more presense though because of the wider dispersion.   The crossover is nearly an octave lower so the off-axis response is wider and you get more midrange-upper midrange output into the room.   The tweeter is playing more of the response in comparison to the 61s.    The off-axis response is smoother on the Kepler.    

[Kevin Haskins]

What is a BBC dip?

What Terry said....    its a dip you put in the response on purpose.  Voicing a loudspeaker is making choices about how to tailor the response to get a given "sound".   Most people focus on the on-axis measurement but the off-axis response has a tremendous effect on loudspeaker voicing.   You can have flat on-axis response and have a loudspeaker that sounds laid back (example would be a single driver loudspeaker with a rolled-off top-end power response) or you can have the same measured on-axis data and have your ears bleeding (compression driver on a horn).    You learn to balance things to get the sound you want.   There really is no such thing as neutral because you cannot really know exactly what the recording engineer was listening to in terms of loudspeakers nor their room.   

[TerryO]

Kevin's absolutely right. There is, unfortunately, no set of numbers or a formula that will create a certain sound in all instances. It would simplify matters tremendously if there were, but it isn't that simple. This is where the judgement, experience and taste of the designer comes in and why some "brands" of speakers always seemed to be good'uns and others are sort of hit or miss.

I've heard a number of Kevin's, I mean Mr. Haskin's, speakers and have always thought that he made intelligent choices when it came to his designs. There are many (some quite well known) that don't, at least in my opinion.

Best Regards,
TerryO

[Kevin Haskins]

I've heard a number of Kevin's, I mean Mr. Haskin's, speakers and have always thought that he made intelligent choices when it came to his designs. There are many (some quite well known) that don't, at least in my opinion.

Best Regards,
TerryO

Well thank you Mr. Olsen.     A lot of it comes down to personal choice based upon listening so we have not yet removed the art of loudspeaker design into the realm of a pure science.    There is a final judgment of the sound that is a purely subjective call to decide upon the final voicing.    It helps to understand the mechanisms involved to make intelligent design choices though.   

I think your going to like the dipole.   Once I get the DPL-10s in place I'll let you take a pair to the NW Audio Society meeting.   I see that your writing articles about speaker design for the club newsletter.    Oh boy....

[Voodoo Rufus]

So essentially you're subtly alter the frequency response in the midrange (?) region to give the speakers a certain characteristic sound? I look at the frequency response graphs and they look very flat, but some of that is due to the drivers and some due to how you voiced the crossover it would appear.

I always thought that the goal was perfectly flat on/off-axis response in order to reproduce the recording exactly, which seems nearly impossible given listening room characteristics. Hmm.....

[TerryO]

So essentially you're subtly alter the frequency response in the midrange (?) region to give the speakers a certain characteristic sound? I look at the frequency response graphs and they look very flat, but some of that is due to the drivers and some due to how you voiced the crossover it would appear.

I always thought that the goal was perfectly flat on/off-axis response in order to reproduce the recording exactly, which seems nearly impossible given listening room characteristics. Hmm.....

VR,
That is often the stated goal and it's perfectly valid as far as the theory goes, but the reality is much different with so many variables, often working against each other. Room effects/gain, eigenmodes, diffraction, and so forth, all have effects that play havoc with the spectral balance and we've only just begun

Other than a pulsating sphere floating in space (where do you set your chair?), there isn't much chance that on and off axis response will be the same. And then comes the biggest problem of all... the listener. Is your hearing perfectly flat? Well, the fact is that everyone is different and the designer is working for a good average at best.

The Fletcher-Munsen Effect will have to come into the equation at some point. How loud will the speakers be played, and what is the dynamic component of the music?
Most Audiophiles spurn tone controls and loudness contouring, which actually can help to correct for this, so the speaker designer has to make a judgement call on this one as well.

The fact is that a flat frequency response on your electronics is welcome, but as studies have indicated, most people tend to like speakers with some contouring and perceive the sound to be more life-like.
A somewhat dubious example of this would be my near SOTA system/listening room, namely a pair of Sennheiser 580 headphones (the speakers and room) connected to an Aiwa receiver's speaker terminals through a precision voltage divider. The Sennheiser's were tested by Audio Magazine some years back and had a "very" flat frequency response. The Aiwa receiver has a digital display for the bass and treble stepped controls and is thus easy to determine the levels and settings, as well as repeat them. At the levels that I listen to music, a 2-3dB boost in the bass and a slight boost in the treble (1dB) turned out (after lengthy trials) to be my preferred settings in a "controlled" environment that only headphones can offer. It may be that there's something wrong with my hearing, but it convinced me that "I" like some contouring.

Now that you've been initiated into the Inner Sanctum with the acquisition of this arcane knowledge, I must insist that you never reveal these "secrets" to anyone outside The Brotherhood, as they are ill prepared to cope with this knowledge and could easily be driven to dispair.


Best Regards,
TerryO