[David Ellis]

Following my realization of improved midrange when unloading the 7" W18 with the 12" SCC300 woofer, I decided there must be a product between the 1801 and the whopping huge speaker with the 12" SCC300 woofer.

The primary focus of this project is to improve on the 1801 sound quality in a cabinet that is aesthetically appealing and fairly easy to contruct.  It might be viable to re-use many/all of the 1801b with this speaker, but I am not confident of this yet.  

There are many possibilities, but I am fairly confident the L26 woofer will be a winner in about 80 liters sealed.   This volume includes a dedicated chamber for the midrange.  I will test the improvement of an open back midrange in this application.   The dimensions will be 11" wide 40-42" tall and 16-18" deep.  The sides will be venner and the front will have a black baffle from 1 1/2" thick MDF and a substantial roundover.

The woofer will be either the SEAS L26 or W26.  Both of these woofers have a stiff cone, good voice coil breathing, and a very large 2" voice coil.  I believe the latter issue is very significant.  At the relatively low @250hz crossover point I don't believe the W26 will sound better than the L26.  Nonetheless, I will test this and progress appropriately following evaluation.  The W26 surely looks better, but I don't think it's wise to add $100/pr cost for the aesthetics of a pretty phase plug.  I chose these woofers for evaluation because they are the only high quality drivers available with a stiff cone and a 2" voice coil.

[jackman]

Very cool Dave!  Are you speaking of a three way with a ten inch?  If so, do you envision a base cabinet that could be used as a stand for current 1801 owners?  I realise it would not have the open back midrange but some additional low end might be appreciated by some folks.

Good to see that you are back on your forum!  I like reading your posts.

Jack

[Figo]

How long will the development take?  I was just about to go for a 1801 kit, but this idea of a 3 way...

will there be a kit?

please please let there be a kit!

[David Ellis]

Good questions Jack.  Thanks for asking.

Yes, the L26 and W26 (i.e. 26cm) are both 10" woofers.

I don't plan to purvey a woofer cabinet for those currently using their 1801 cabinet and wish to continue using that cabinet.  This is because fitting 80 liters completely under the 1801 is very wide and boxy.  I suppose some angles might make it look okay, but this is very complicated in the workshop.  The only real possibility for such a setup is a wide box similar to the B&W Matrix 801.   This look was pretty cool about 15 years ago, but I don't think today's women appreciate this wide boxy look.

I think that "slim is in".  My wife does too.  The new cabinet will be 11" wide.  This is much narrower than a projected 15-18" wide necessary for a deciated woofer cabinet under and exisiting 1801.  I think 11" wide is marginally acceptable for most women, and wider cabinets become exponentially less tolerable.

Digressing...  on the soapbox.  My position on loudspeaker WAF should be very obvious.  Women want speakers that look nice.  While most of them can discern quality sound better than men, the women don't care much about sound quality.  They simply care about the appearance of their living room when they entertain guests.  Conversely, men desire cool loudspeakers having tolerable aesthetics that sound killer.  Both of these perspectives are valid and I considered both of them in this cabinet/design.

Back on track...Current 1801 owners wanting implement this loudspeaker speaker will have to build a completely new cabinet.  The additional effort for a full height cabinet will be minimal.  They'd have to build a woofer cabinet anyway.  Building a bigger cabinet will be a little more work, but not anywhere close to a serious endeavor.  The 11" wide cabinet will be very straightforward and easy to build.

" I realise it would not have the open back midrange but some additional low end might be appreciated by some folks. "

Yes, I am sure the low end will be a little cleaner, and the shallow roll off of the sealed woofer will match much better in-room.  However, what really surprised me was the midrange improvement when Doc and I unloaded the W18 below 250hz.  It was cleaner.  I would have never guessed this would happend, but it did.  I am confident this same impact will be present when using the L26 or W26 woofer.  I plan to use a very similar crossover frequency and put the woofer very close to the floor.

[Figo]

sounds sweet

I was gonna build my own cabs anyways.... just looks like maybe I'll have to put using the fancy mappa burl veneer on hold.


any ides on pricing?

[David Ellis]

Well...  I'd like to say it'll be done by late summer, but other things are taking longer than expected.  Maybe late summer?  I'm not inclined to provide a solid date simply because of the reasons addressed in the string titled "life and priorities"

There will be a kit.  My hunch is the cost will be about $1050 if the L26 woofer works.   Quick math might indicate that this figure seems high.  It's not.  Crossover components dividing the midrange and woofer around 250hz are not cheap because the values are very high.  Using good components down low is also significant.  I'll be using 14ga air gapped ERSE Super Q inductors and big Axon capacitors.  These big capacitors might be bypassed with smaller Sonicaps, but only if the Sonicaps help matters.

Bypassing is theoretically advantageous in areas where a WIDE frequency pass is desired.  Time domain issues are a significant factor herein.  The very best example are coupling applications in amplifiers/preamplifers/CD players.  The impact here is huge.  The midrange frequency pass in a loudspeaker is much more narrow.  If bypassing doesn't improve sound quality adjacent the big Axon capacitors, I won't purvey bypassing to my customers.

Please understand that my goal with both of these future 3-way projects with bigger woofers doesn't rise from an inadequate 1801.   The law of diminishing returns applies here.  I still believe the 1801 will perform wonderfully for 99% of listners enjoying classical and jazz music.   Heck the 1801 does a darn good job with John Lee Hooker too.  The 1801 is an excellent speaker that I could still live with for a very long time.  The other 3-way projects rise from competent design ability, and the realization that moving real air with a real woofer is something that a 7" simply can't do.  I realized this at CES 2002 (yes, 2002).  Yes, it takes me that long to matriculate a new project.

Hopefully I addressed your concern/question.  Please let me know if I missed anything salient.

[Figo]

sounds good.


Thanks for the quick answers

[audiojerry]

Dave, the biggest issue, which you've identified is the 250 hz high pass. Very large value, high quality caps are needed, and obviously will be very expensive. Good idea to use bypass caps. The biggest concern is loss of midrange transparency and time domain issues.

I think that's why I gave up on large 3 ways and went back to way's. It's a compromise either way.

[David Ellis]

Jerry,

I recall you having just about everything in your listening room for experimentation.   I am not sure you ever a/b tested the same midwoofer with/without the bass applied.

Initial testing with the SCC300, W18EX, OW1 revealed a midrange situation that was a pleasant surprised initially, and had pleasant results upon completion.  No bypass capacitors will were used.  The favored "transparency" was a no-brainer to my ears and to Doc's ears.  Unloading the midrange below 250hz is a winner.

I'm at a slight loss concerning why this didn't happen for you.  Hm, what was the 3-way that failed in the midrange?

I thought the midrange of the Burmester B99, Joseph Audio Pearl, and Kharma 3-way sounded really top-notch at CES 2002.  

Dave

[EProvenzano]

I may be a bit off topic regarding 3way designs, but I too noticed a slight improvement in midrange clarity when I high passed my 1801's.
It took a bit of experimenting but I found that high passing the 1801's at 80hz was ideal for me.
65hz did not allow my SCC300's to flesh out the bottom end to my liking. I enjoyed them playing a little higher.
I also noticed that the SCC300 did not play as cleanly when crossed as high as 100hz. To clarify, I believe this was relative to the speed and accuracy of the W18.
Crossing at that magical 80hz mark gave me the added midrange clarity and fully fleshed out the first octave without losing any bass detail.

My 1801's are crossed using a Marchand XM44 with 24db/oct symetrical slopes, to a pair of SCC300 subs in 3.75^3ft enclosures.
Couldn't be happier right now!....well maybe if I could finish veneering my subs I'd be a little happier  

One note: i have not upgraded to the 1801b crossover. Honestly, I've not found the need to. Maybe this is because I'm crossing the 1801's to the SCC300s, maybe its because I have my speakers only 1.5ft from the back wall...I don't know but I'm not compelled to upgrade.
I'm enjoying the detail of the 'flat' tweeter response with the 1801a xo, and I'm not sure I'd notice a benefit with the added baffle step compenstion of the 1801b.
What do you think Dave, should I add this to my list of things to do?

Thanks

[David Ellis]

If your 1801s are close to the back wall and the woofers fill in the bottom end nicely, the 1801b will be a waste of your $.

I recommend spending that $ on a house cleaner for you wife.

How are the twins sleeping?

Dave

[Al Garay]

Good stuff guys!

Dave, I personally would spend the extra $100 to get the Excel W26. They are a beautiful match to the W18s. Looking at the cost of the total project, the actual component cost is not as significant as the labor of love building the cabinets, applying the finish and hours/days/years of pride admiring their beauty. That's why I did not hesitate to spend more for the solid Honduran Mahogany baffle and upgrade electronics. I have a supportive wife. The looks are very important to her.

Instead of a 10", have you considered dual W22s? Then the cabinet size will be closer to 9" wide or about the same as the 1801s. If I recall correctly, the Wilson Watt Puppy's also used dual 8" drivers for the bass modules.  I like the upgrade options available with the W22s... later in life, they could be used for the mids in a MTM dipole combined with SCC300 or W26s for the bass module.

For now, I am very happy with my 1801s and the single 4.0cft SCC300 sub. I do have Jackman's SCC300 waiting for another amplifier. I'm not trying to use the subs as speaker stands. They're going on the corner as plant stands...  following wife's request, I will make them taller and narrower  closer to outer-dimensions: 14"Wx16"Dx38"H.

Al

[David Ellis]

Good questions Al,

I considered dual W22s, but won't do this. There are several downsides to dual W22s.  

1.  The cabnet would actually have to be slightly bigger for about the same result.  The commercial cabinets are actually wider than I propose.  This is okay for the commercial guys.  They can swiftly knock-out the angles for a sexy top cabinet with their CNC mill.  It makes the whole speaker look much more tolerable.  Unfortunatly these sexy angles aren't easy for they home builder on his table saw.  They are very difficult and time consuming.  

Hm, now that I consider this,  I wonder if these commercial companies use the same cabinet maker....  checking... // they have different dimensions and the JA cabinet looks much better IMO.  They probably don't use the same cabinet maker.  Also, on a side note, I think the JA Pearl speakers sounds considerably better than the Wilson Watt.

2.  Dual W22's are more expensive.

3.  The impedance drops to 4 ohms with dual W22 factory spec units.I think Jeff Joseph's remarks about this are dead-nuts-accurate.  Please read these remarks:

http://www.josephaudio.com/specs.pearl.html

Dropping the impedance to 4 ohms bumps the sensitivity rating by 3db, but makes the load much more difficult for amplifiers.

It is obvious that Jeff Joseph is using W22s with 16 ohm voice coils in parallel or W22s with 4 ohm voice coils in series.  If I had $10k to spend on a custom driver this would be an option.  Fortunatly the newer L26 or W26 drivers will do about the same thing with much cost involved.

4.  If the cabinet was 9" wide, the depth would be about... 25" deep to obtain 90 liters.  The appearance would be awkward IMO.

I think plant stands are a great idea for subwoofers.  If the cabinet are solid the plants won't vibrate and land on the floor.  If vibration is a problem, I suggest poster putty on the base of the plant's pot.  Poster putty is good stuff.

[Al Garay]

Good points.

Keeping with the 10", perhaps the Peerless CSX that Dennis uses for his MBOW1 3-way is a good low-budget alternative.... even the XLS would be less moneny than the W26... but not as good looking.

Al

[David Ellis]

Al,

The cone on that CSX woofer is VERY floppy.  Lynn Olsen was keen to point out that floppy cones are inadequate for good bass performance.  I have heard this driver and it fits Lynn's criteria for floppy cones and poor bass resolution nicely.  It worthy of a $3k commercial speaker - little more.

I haven't heard the XLS, but the T/S parameters are totally inappropriate for this application.  If I wanted very low sensitivity and a F3 around 60hz in a car, the XLS would be fine.  It is intended for small cabinet applications.

Eventualy I will build a budget line of kits, but this is a loooong way in the future.  When this happens the drivers will be better than the XLS and more appropriate for hifi than the XLS.

Caveat: with a complex bass compensation circuit and an additional amplifier per woofer the XLS is viable.  Sigfried Linkwitz has accomplished this with good success.

Dave

[EProvenzano]

Thanks for the advise Dave. I figured the changes were subtle, but I wanted to make sure you hadn't changed your mind after living with the b xo a while longer.

The twins are great and sleeping through the night for the last 5 months! We're lucky parents   .

[Al Garay]

Hi Dave,

I think you should strive for the best and keep with the best components and drivers. Dennis Murphy has a good gig offering quality designs using budget drivers.

Thanks for the information,

Al

[dayneger]

Just out of curiousity, would one of Adire's new 10" drivers with the XBL^2 motor be interesting for the bottom end?

18mm of linear one-way excursion seems to fit the bill for moving a lot of air and apparently it works well in a fairly small enclosure.

Dayne

[David Ellis]

Just out of curiousity, would one of Adire's new 10" drivers with the XBL^2 motor be interesting for the bottom end?

No,  

I couldn't find this specific driver, but these woofers are intended for subwoofers.  They are great in this application, but their T/S parameter set favors boooooom booooom.  I am not seeking boooooom boooooom.  Drivers with extreme low frequency spl often drone in room.  This is bad.   I am seeking wham wham.  This follows less voice coil heat and higher sensitivity found in the SCC300.   More importantly, their sensitivity/BL/Speed is poor.  Most of them hover around 85db at 4 ohms.  While this isn't terribly important for the bass, it sucks down the speed of the midrange and tweeter too.  The low impedance is directly proportional to increased heat and thermal compression.

Another issue is the suspension.  I have learned that spiders and surrounds are purpose built.  Longer throw spiders/surrounds incur a distortion penalty.  I cannot get specific numbers about this, but have run this past a few very credible industry guys.  They agree this is true.  

Please understand that these Adire drivers are very good units.  They just aren't suitable for the bass in a 3 way speaker IMO.  Also, these remarks are tertiary.  There is certianly MORE to the discussion of bass drivers.  If you have quesitons or concerns, please continue the thread.

//  I did more looking and found the 10" Brahma.   The sensitivity is 82.3db - ouch.

Drivers are a compromise.  Ya' can have yer' cake and eat it too.

Dave

[dayneger]

Hi Dave,

Thanks for the response!  I'm afraid I don't know the slightest thing about speaker design, so it's interesting to get these kinds of answers.

The new drivers aren't on the Adire site right now, but at least one of them is an OEM unit.  Here's a link with more info on the CSS site.  DIY Cable uses a similiar unit in their new mini WMD.

Another issue is the suspension. I have learned that spiders and surrounds are purpose built. Longer throw spiders/surrounds incur a distortion penalty. I cannot get specific numbers about this, but have run this past a few very credible industry guys. They agree this is true.

How are the spiders adding to the distortion?  I thought linearity of the motor was the driving factor in long-throw woofers, which is where the Adire motor structure is supposed to be an advantage.

So Wham! Wham! can't be achieved with a driver like this?  Or only under 80 Hz?  Can the W26 move enough air to do the job under 80 Hz?

Thanks for your inputs!

Dayne