[Kevin P]

Ok... this has taken far longer than expected.  I think my original ETA was April of 2003 and here it is September already.   As of right now I have 25 units sitting in the warehouse but we are still waiting on the final design/delivery of the packaging.  Shipping 125lb boxes is no fun.  

In terms of reviews I'm sending a unit off to Tom Nousaine for some independent third party measurements/testing.   Mr. Nousaine has measured just about every sub of significance in the last 10yrs and he has a standard test proceedure that has been applied to every one.  It seems to me that his methods are the most appropriate & fair to compare our product with others on the market.  

After Tom is done we are sending the unit to Mike Knapp of Home Theater Talk fame.  I met Mike last year at CES and he seems like the perfect gearhead to give it a subjective view from a user's standpoint.   Mike has lots of exposure to subs and is knowlegdable enough to do it right.  He also has a killer reference point in his 4 Tempest IB set-up.  

http://www.hometheatertalk.com/



The naming contest is still on if anyone wants to take a shot at naming the product.  

And just a little teaser.... here are some measurements taken at the Adire warehouse last week.  







http://www.diycable.com/images/tumult.gif">







Blue is the anechoic response of the box and the crossover, in free air (well, our parking lot).

Green is the anechoic response of the box and the crossover, with boost engaged.

Red is the nearfield in-room response of the box and crossover.

Black is the nearfield in-room response of the box and the crossover, with boost engaged.

Smoothing for free-air is 1/2 octave; in-room is 1/6th.


This is with an unmodified Keiga 1000W amplfier.  From looking at the response curve we pretty much have thrown out the idea of modifying the amplifier.   It just is not necessary and would only increase the product price.  We might get a snitch more low-end but the cost/benefit would be poor.  The only good reason I can think of for doing it is for marketing fluff.

ETA for shipping?  I've given up on giving ETAs.  Learned my leason.... they will be ready when everything is done.   Packaging, manual and preparing the HTML for the web site are all that is left.  

Thanks for everyone's patience.

[BE166]

Are you planning to release an international version of the new sub?

[MaxCast]

Hi Kevin, what is the crossover setting and slope?

[Jack Gilvey]

These plots are with the infrasonic filter inact? Doesn't appear to have any effect in the anechoic plots. Looking forward to actual Nousaine numbers!

[Kevin P]

BE166:   Yes... the amplifier is 110/220V switchable.   Shipping cost will be scary though.


MaxCast: It has 50-100Hz variable crossover setting.  Keiga doesn't share the specs on the crossover but from looking at the response curves you can make an educated guess.  The Tumult itself is flat WAY above our pass band so the roll-off in the response curve above 100HZ is largely the result of the electrical crossover in the amplifier.   There is also a resultant hump that is characteristic of the system response so the roll-off isn't entirely electrical... but we can still make a guestimate.  The response graph above was taken with the variable crossover setting at the 100HZ position (notice the system starts to roll-off anechoic at approx 40HZ).   We are about 6db down from the peak at about 88HZ, 12db down at 150HZ and 24db down at 240HZ.     This is showing a touch more than a 2nd order roll-off so I'd guess the electrical at 2nd order and the additional roll-off is due to the rest of the system (driver + box).  

I like the Keiga amplifier with just a couple exceptions.  I'd like a continuous variable phase adjustment and the other thing I'd like is a shallower mounting debth and a variable EQ like the DT300.  

The power is adequate for our application.... actually the amp starts to clip just before we bottom the driver, which is good.  Due to the XBL motor design you just don't get any of the typical objectionable distortion levels seen in normal drivers until you are right at the limits of the driver.  If your amp doesn't clip before this point it is easy to destroy one of these XBL drivers.   In your typical sub the distortion starts to give you a warning well in advance of its limits.  The clipping in ours gives the user a warning to turn the thing down.  Of course you have to be stark raving mad to want to run this thing to its limits in a standard listening room.   We have an open 1500 sq.ft space in my house and I can run 20HZ test tones into the thing at scary levels.   I've clipped it once and that was by trying to do it.

[BE166]

Kevin,
Do you have a rough idea of when you expect to get feedback from Tom etc?

[Kevin P]

Jack:  Yes... that filter is in these measurements.  I don't have an explanation for why it doesn't have more effect.   Kind of surprised me.

BE166:  No idea....  it mainly depends on how long Tom takes to do his stuff.

[modwright]

Looks like you have a winner there Kevin!  I appreciate the measurements and the conditions of the test.  It looks like this unit will work VERY well for music and HT and I may have to talk with you about one for my own personal HT at some point .

Take care,

Dan W.

[Kevin P]

Dan W:     Wiggins & Hyre deserve the credit.   I just did the footwork and spent the money.    You can give it a listen at VSAC to see if it meets your approval.    I'm sure we can work something out.  How about an Absolute Truth mod for my Philips?