[mcgsxr]

This adventure all started early in 2017 when I purchased a kit from CSS in order to revisit speaker building.  I picked up a kit that included some excellent drivers, and the parts to build an Xover for them.  I built that all up, and was OK with the results.  Thread here - http://www.audiocircle.com/index.php?topic=149044.msg1594265#msg1594265

Not being one to leave well enough alone, I decided that although I liked what I was hearing, I wanted to see what else I could conjure, using some of the parts I had, and adding a few more.

I have thought about going active in the past, but up till now never had.

I decided to reuse the 7 inch woofer that came in the kit.  It is the CSS LDW7, a modified Wavecor unit.  I had followed with great interest a west coast Canadian audio company called RAW Acoustics.  Al is no longer in business, but around 12 years ago I heard Al’s speaker called the HT3 in my home.  That speaker used a relative of the CSS 7 inch woofer, so I figured I would start with “cloning” that enclosure.  Al was kind enough to verify my own research about that enclosure, so I went about cutting up Baltic birch and mdf.

Lacking a table saw, I am not able to cut my own full panels, but having invested in a 10 inch miter saw I can now slice more accurate shorter lengths – this simplifies my life a lot, as I can get panels rough sliced at the local hardware store, and then trim at home.

In a dramatic departure from the kit (which used the LDW7 in a 2 way with a modified Aurum Cantus ribbon tweet), I decided to try out a full range driver.  I had in the past really enjoyed the 8 inch Visaton b200 driver on OB, but felt that it was too large and beamed too much for this configuration.  I was specifically looking for a few 4.5 drivers, but happened across a lightly used set of Tang Band W5-2143 5 inch full range drivers in Canada via Canuck Audio Mart.

Those modeled really well in a 0.2 cubic foot sealed enclosure and did look like it would roll off nicely around 100Hz and should be simple to integrate with the LDW7 somewhere between 200-500Hz.

I chose an 8 inch wide baffle for the full range driver, close to the design of the HT3 from RAW Acoustics where the 4.5 inch driver was with a 7 inch woofer and ribbon tweeter.  I stuck with the 8 inch width for the bass unit, as I had already used it in a sealed enclosure for the 2 way and liked how it worked.  Using the same width baffle for both the bass unit and the upper units simplified the look in my mind.

I made my own concessions to build errors, material availability, layout, bracing etc along the way.  I wish the world was perfect, and that my plans could be brought to fruition affordably and to spec.  But it ain’t!  So, each time I found myself backed into a corner with my own mistakes or limitations I took the time to think it through and commit to the solution I figured was best.  These are not speakers destined for production, they will never be sold, and I don’t need anything back from them but a good experiment and hopefully some good sound.

They are largely built from 18mm Baltic birch sourced locally.  There are braces made with ¾ mdf, ½ mdf, and a few of the panels are 24mm Baltic birch or a 24mm combination of ¾ and ¼ mdf.  I used pillow stuffing from Walmart.  I stapled peel and stick tiles to portions of the interior of both enclosures.  I braced what I considered well, and used my drill press and a hole saw to make entertaining patterns that for my eye mixed strength with displacement compromises well enough.

The “finish” is simply rattle can spray bomb.  I sanded the upper units to 400 grit and then shot them with primer.  I waited 24 hours and followed up with 3 coats of satin black.  I sanded lightly with 1000 grit between coats.  The lower enclosures received a sand to 220, and the same primer and satin finish.

The outriggers are simple 1/4 inch flat aluminum sourced at Lowes.  I drilled out holes for the eBay spikes, added some extra bolts to their length to secure them, and sprayed them black too.

The result is not pleasing to the eye under close review.  I am cool with it.  Some of my favorite motorcycles from my youth were well built mechanically and then spray bombed.  I see it as a hot rod approach where you spend the $ where it counts, and do some lip service to finishing the project when the $ runs out.  I love the beautiful finishes I see on commercial and other DIY efforts.  I don’t have the patience to learn to bondo better, and sand for hours, and learn to apply a decent finish – so I don’t bother to.  It’s just me I am trying to please in the end.  These will never find their way to our living room, so it ultimately does not matter to me.  These look great in the low light conditions of my basement!

I intentionally did 2 enclosures per side, as I anticipate my life long interest in building and refining may continue, so to build 1 enclosure for each side would have meant committing to a design for good.  This way I can try OB uppers in the future if I am inclined.

I knew in order to go active I would need a couple of things.  An active crossover, and at least 4 channels of amplification.  I spent tons of time researching pro active crossovers, and the Minidsp.  I decided to get going with the cheap option, and sourced a used pro crossover – a DBX 3 way unit.   I will revisit this in the future, especially as with the higher end Minidsp units measurement becomes integrated.

Along the way I decided to reuse my Audio Refinement Multi 2 amp for the bass units.  For the wide range driver I bought an old Sugden P28 and had it recapped and the input connectors replaced.

I am using my Pioneer AVR as the preamp for now.  I still have the NuForce AVP-16 and may put it back into play in time.  Going active required me to use 2 sets of speaker cables, and so the use of my Pioneer AVR allowed me to just remove my on wall HT mains and “steal” those speaker cables for the Tang Band portion of my new build.

It’s all in the basement anyway, so I have a fair amount of control with limited WAF concerns…

During the time it took to build up and “finish” 4 enclosures, the kit from CSS really did come a long nicely.  I listened to it for 8 months before removing the woofers and installing them in the new ported enclosures and trying my new creation for the first time.

Firing it up for the first time was a fascinating disaster.    I had run the uppers on their own before and knew that they sounded good.  Trying to integrate them by ear proved an interesting journey.  I took the time to read more about the pro Xover, and soon tried reversing the phase of the upper speakers vs the bass units.  Instant massive improvement.  I fiddled with the Xover point for a bit, and settled on 240Hz at 24dB per octave.  I massaged the gain on the woofer enclosure and soon found a spot I quite like.

Perfect?  Of course not.  Pleasing to this whack job?  You bet   

Many thanks to Bob at CSS for his assistance with parts and Al from RAW for his generous sharing of ideas from his own explorations.
 
Below are some pics of the 6 month build process.







For those of you paying attention, yes that is my "spray booth" fashioned out of drop sheets and my shed!


Now the lower units build up:

[Norman Tracy]

Very, very nice mcgsxr. Thanks for sharing, always in the mood for such well considered DIY.

[randytsuch]

Very cool

Have you thought about getting a mic to help setup the crossover?

You can get a calibrated mic from cross spectrum.
The usb mics are more, but then I don't think you need a preamp.

At some point, I got a Dayton emm6, and a mic preamp from ebay.

Then you can use rew to make in room measurements.

Randy

[mcgsxr]

Thanks guys.

I plan on eventually going with a minidsp unit that would include the purchase of a usb mic and REW s/w.  That combo in Canada runs around $400-$500 or so.

The pro xover I am using was a $75 Kijiji find.  Good enough to get the project making noise and help me understand if what I had put this time into was worth any further investment, or was a lost cause!

I finally played music through this setup last weekend, so I now will sit and enjoy as I plan the future configurations.

I still have a set of the Aurum Cantus ribbon tweeters sitting around, and extra amp channels so theoretically I could try a 3 way including those tweeters.  I will sell them off if I decide I don't need them.

If I remain happy with the sound over the coming months I will plan on the minidsp as the next phase.  I need to decide if I miss tweeters of any kind or not.  If I don't, I can buy the cheaper 2x4 minidsp.  IF I feel I need to go 6 way active, then a more complex minidsp will be in the cards.

I am satisfied at the moment with how the woofer and wide ranger integrate.  I have had a lot of speaker and speaker/sub combo's over the years.  This setup needs no sub for me.  A pair of those 7 inchers in slot ported boxes make all the bass I need.

[jparkhur]

Nelson will soon be issuing a diy B5 crossover in a variety of costs.  Might be something to look at also.

[mcgsxr]

I have spent some time listening, and have had a good friend over to see what he thinks.  We spun a variety of rock, jazz, trance and blues to see what came of it, before our usual pool playing.

1.  We both agree that the ported bass from the 7 inch woofers is suitable for this room.  Solid foundation.

2.  We both like the sound of the mids from the bamboo TB 5 inch wide ranger.  They produce really nice sound.

3.  Neither of us disagrees that there is a lack of ultimate highs.  Compared to conventional mid/tweet combos there is a lack of sparkle and upper end detail.

I will consider how best to integrate the ribbon tweeters I have (Aurum Cantus modified CSS units).

Could be fully active - I have the amp channels and my pro Xover is a 3 way.  I have read though that one should use a cap on a tweeter even when running active to prevent any "oops"...

Could bring in the tweeters passively above the TB 5 inch driver.  Would likely require buying the time of a person who can test and develop such a passive Xover.  There are 2 excellent options for this withing 50 miles of me.

Could sit back and enjoy the music for a while.  That's the easy option after 8 months of speaker building!

[mresseguie]

Hi, Mark.

Those are great looking DIY speakers!

Question: what did you use to line the insides of the cabinets? It appears to be grayish/blackish.

Thanks,

Michael

[JLM]

Where did you get the design for the bass cabinet?  It reminds me of my Fried A/6 speakers that I. M. (Bud) Fried called a "line tunnel" (perhaps a simplified transmission line).

[mcgsxr]

mresseguie - I did not want to pop for the international shipping to try out Danny's No Rez.  I used peel and stick tile.  I also stapled it to the inside of the speakers, as I noticed that the "stick" was not very sticky.  I know that others have gone this route, and then applied foam or another absorbent layer over the tile.  In my case I did not.  I did not want any polyfill near the port.  I did stuff other parts of the speaker, those that were "contained" by bracing.  The No Rez is reputed to be excellent, and I would have chosen it for sure but for the shipping.  I have had mixed results with costs shipping stuff from the US to Canada.

JLM - the design of the woofer boxes was based on Al Wooley's (RAW Acoustics) HT3 design.  I demo'd those speakers at my house a number of years ago, and was quite taken by the bass.  My speakers use a very similar woofer (Al used these woofers in some of his designs) in a 0.75 cubic foot box tuned to 30Hz.  Al's design called for 28Hz, but I was running out of interior volume to try to extend my port to hit that number.  Al did produce both round and slot ported versions of the HT3 and other variants using the same woofer, so I figured I was going to be close enough.  I am for me.

I don't know enough about enclosure design to know when a slot ported design begins to act like a TL.  I recall reading something about it over the years, but cannot put my finger on it at the moment.  I wanted a front ported design based on where in my room I wanted to place the speakers, and I have had good experiences with slot ported designs in the past.  I find they are less likely to produce chuffing type noises at higher volumes than some round ported designs.

I set out to build well braced enclosures, and am very happy with the outcome in that regard.  They do vibrate, but less than the commercial designs I have had in my home.

The whole thing was an experiment to try my hand at building enclosures close to known spec.  I learned a ton in the process.  These are my 10th or so build, and I still keep learning tons about the limitations of my equipment, and my knowledge.  It took me months longer to complete than I expected, and the finish work is pretty grim compared to good commercial products.  But I am happy with the bass and mids.  Very happy.

I can see that they can be optimized/further tuned with a tweeter in some way over time to make me happy.  So time and $ well spent so far.