[craig sawyers]

I have to say, these may be the ugliest speakers I've ever seen. For me personally, even if these were the best sounding speakers ever made, I'd cringe every time I opened my eyes and had to look at them. Something right out of the 1960's Jetsons. I like contemporary styling by OMG these are awful. 

The Jetson's comment cracked me up

[craig sawyers]

This is way off topic - for which apologies.  But if you want to see ugly, try this for size:

http://www.6moons.com/audioreviews/westernelectric/2.jpg

Made by Electronluv http://www.electronluv.com/ .  All of their stuff looks like a lesson in anatomy.

[JLM]

This is way off topic - for which apologies.  But if you want to see ugly, try this for size:

http://www.6moons.com/audioreviews/westernelectric/2.jpg

Made by Electronluv http://www.electronluv.com/ .  All of their stuff looks like a lesson in anatomy.

Beauty is in the eye of the beholder.  This is a good excerise in form following function design. 

But domestically acceptable?  - Not so much   

[tortugaranger]

Now that we have our CNC router/mill up and running again I've been able to move our 0.32 cubic foot boathull speaker cabinets closer to completion.

The baffle has now been bonded to the body. While not visible in these pics we lined most of interior with heavy felt. Being our first boathull build we had to figure things out along the way. Note the clamping cradle. Without that cradle it would have been tough clamping on to a curved surface.    The zebra wood veneer is turning out to be an outstanding match for the baltic birch laminate body. Fine sanding and poly oil finishing comes next. Note that the speaker terminals are not yet installed. These speakers will use an external crossover and will be set up for bi-amping.

I'll post one final set of pics once they are completely done.

 

[tortugaranger]

Here are pics of the finished "boathull" 0.32 cubic foot speaker cabinets. Made of milled baltic birch plywood with zebra wood veneer on top, bottom and baffle. Body is ellipsoid (boat hull) in shape - 1 inch thick walls. Finished in about 10 layers of gloss poly oil.

Woofer is a Scanspeak Revelator 15W/8530K00
Tweeter is a Scanspeak Revelator D2905/990000

Customer wanted these built without crossovers so unfortunately I'm not going to get to have a proper listen before shipping them out...but that was the arrangement. They are set up for external crossover/bi-amping.

There's a reason most speaker cabinets are simple rectangular boxes - cheap and easy. These are neither. Very unique and quite stunning to look at. Each cabinet is unique with its own laminate pattern depending on the random nature of the baltic birch in the plywood.

Our next build will be a set of floor standers, probably 44 inches tall, 13.5 inches wide with 10" Audio Nirvana full range drivers. Considering making those with continuous integral baltic birch all the way around - no separate front baffle to attach. That build will become our standard design.

Please contact me if you, or anybody you know, is interested in a set of custom make cabinets using this construction technique. At this point we're only planning to build these to order.

[craig sawyers]

Morten - those are things of pure beauty!  Truly superb

[mresseguie]

"Considering making those with continuous integral baltic birch all the way around - no separate front baffle to attach. That build will become our standard design.

Please contact me if you, or anybody you know, is interested in a set of custom made cabinets using this construction technique. At this point we're only planning to build these to order."

 Very interesting idea! I'll tuck this away till I'm more ready to consider this for myself. Thank you, Morten.

[tortugaranger]

Morten - those are things of pure beauty!  Truly superb

Thanks. They came out better looking than I'd hoped for. The zebrawood veneer really complimented the baltic birch laminate. Also, the hardwood ply took on a really nice look after a few coats of finish. I tried both satin and gloss but the gloss won out. Probably around 10+ layers of poly oil - I lost count. 

[tortugaranger]

We just posted an article on the boathull speakers on our website. It can be found here: http://www.tortugaaudio.com/custom-boathull-speaker/

[craig sawyers]

We just posted an article on the boathull speakers on our website. It can be found here: http://www.tortugaaudio.com/custom-boathull-speaker/

You're certainly right in the article about rectangular box speakers.  Back 25 years ago I was Tech Director of Wharfedale, the UK speaker company.  And the thing that dictated the size of a particular speaker was how the cutouts fitted with minimum waste out of 8 x 4 sheets.  The sheets were veneered on one side, and a high speed router cut an 90 degree V almost all the way through, but not quite.  So the box would fold up with glue down the V, and the veneer wrapping round the edge.  At that point we were shipping 50,000 pairs of Diamond 4 each year alone - and that was only one model.  We even vacuum formed the cones, wound the voice coils and built every darned driver right on the shop floor.  This was a big factory!

[tortugaranger]

You're certainly right in the article about rectangular box speakers.  Back 25 years ago I was Tech Director of Wharfedale, the UK speaker company.  And the thing that dictated the size of a particular speaker was how the cutouts fitted with minimum waste out of 8 x 4 sheets.  The sheets were veneered on one side, and a high speed router cut an 90 degree V almost all the way through, but not quite.  So the box would fold up with glue down the V, and the veneer wrapping round the edge.  At that point we were shipping 50,000 pairs of Diamond 4 each year alone - and that was only one model.  We even vacuum formed the cones, wound the voice coils and built every darned driver right on the shop floor.  This was a big factory!

50,000 speakers month!! Now that's production with a capital "P". Good times!

[craig sawyers]

50,000 speakers month!! Now that's production with a capital "P". Good times!

It was per year, but still a big number.  We used to make close to a quarter million drivers each year to feed the speaker production.

You will be not at all surprised to find that Wharfedale (and Quad too) are now owned by the Chinese.

[tortugaranger]

Here's a CAD rendering of the full range boathull speaker cabinet. Note that unlike the initial bookshelf design the baffle will be integral and not a separate attached panel.

[DaveC113]

Cool... I'd put a flat spot for the binding posts so they can be side-by-side and build bracing and damping into the design too...

[Folsom]

Yes, those binding posts might be awfully difficult with large, maybe stiff, speaker cables.

[tortugaranger]

Yes, those binding posts might be awfully difficult with large, maybe stiff, speaker cables.

I don't understand the concern here regarding large/stiff cable. Not that I disagree, I simply don't comprehend how the over/under binding post configuration might pose a problem especially if they're sufficiently spaced that would be somehow less of a problem if they were side by side. 

Also, to Craig's earlier comment, creating a sufficient flat spot on the given curvature to allow for side-by-side binding posts has its own issues. First, keep in mind that the walls here are 1.5 inches thick. Let's say we create a flat spot sufficient for binding posts 3 inches apart. Given the degree of curvature those posts would have to be considerably longer possibly exceeding available lengths of most/all binding posts. Flat spots would also create a more complex surface to smooth and finish properly. Anything is doable of course but need a very compelling reason to create new problem in order solve a problem that may not be one (or that I don't recognize as a problem - yet).

[tortugaranger]

I've now tested the Audio Nirvana 10" Classic driver in a conventional rectangular 2.8 cubic foot cabinet with mixed results. The level of detail and clarity coming from this driver is really amazing...outstanding in fact. But....the amount of mid/low level bass has so far been disappointing. It produces bass but not as much especially when I compare it to the 8" Super running in a much smaller 1.5 cubic foot cabinet which produces impressive bass. I've been discussing this with Dave at Audio Nirvana who is baffled (no pun intended) by this since his experience suggest the bass with the 10's and bigger cabinet should be yuuuuge!

Until I can resolve this performance issue, I'm not going to produce a boathull cabinet for the 10" Nirvana Audio driver. On the other hand, perhaps the smaller 8's in a 1.5 cabinet is the way to go. Smaller and better fit for most living rooms but will need a stand to get the driver up to ear level.

[tortugaranger]

One acronym - DSP (Digital Signal Processing) has most definitively solved the lack of mid/low bass with the 10" Audio Nirvana full range drivers in the 2.8 cubic foot cabinet. I secured a miniDSP 2x4HD ($190). This is their latest and most updated model and is reportedly far more powerful than the original 2x4 ($80). I used it to add a +3-5 dB low end shelf boost starting at 200 HZ and below and this immediately filled out the weak low end. Remarkably effective. All the bass/slam you could reasonably ask for while retaining the phenomenal coherency and detail of the Audio Nirvana Classic full ranger driver. I do realize that for some audiophiles the use of digital anything is nothing short of audio blasphemy but while the luddites gnash their teeth I will be enjoying the hell out of these full ranger speakers.

I located the 2x4HD between the DAC output and the amp. In this configuration the 2x4HD converts the analog into digital, manipulates the data digitally, and then converts it back to analog. So essentially I have a DAC-ADC-DAC in this instance. This is obviously not ideal but it was the simplest way to get the 2x4HD up and running. The 2x4HD also accepts Toslink or USB digital input so my next step is to take my DAC out of the loop and check performance with the 2x4HD by itself as a DSP/DAC.  I understand they make a model that you can put upstream of your DAC as well - the nanoDIGI2x8K ($155). This would keep all processing in the digital domain with no additional ADC/DACs within the unit. 

[tortugaranger]

I've received a few inquiries on the full range boathull speakers so here's an update.

My default starting point for this project was to use Audio Nirvana's 10 inch Classic full range driver a their plain vanilla 2.8 cubic feet (~79 liter) cabinet with a 6 inch port and no port tube, just the ~0.75 wall thickness of the front baffle. It was never my intent to actually use this as the final cabinet, only to use it to guide to next steps. The final cabinet design will be a stacked "boat hull" shape using layers of milled baltic birch. Thus the entire cabinet except for the tops and bottoms will be sanded and clear finished baltic birch edge grain. The walls will be ~1.5 inch thick laminate with periodic cross bracing. Stiff, stiffer, stiffest. You won't be hearing this cabinet, just the driver. 

I've run several cabinet design calcs which more or less conclude that the ideal cabinet for this driver would be ~ 12 cubic feet with an F3 well under 30 Hz. A monster size box that is too big to be practical for what I'm looking for. Hence the 2.8 cubic feet box which when you see it standing there in front of you still looks plenty big. 40" tall by 12" wide by 13.5" deep.

With a 6 inch port the design calcs call for a port tube length in the 8-12" range. I currently have no port tube other than the 0.73" baffle itself. I've experimented with an 8" quick and dirty port tube made of stiff thick walled paper rolled into a tube reinforced with duct tape. Ugly as sin but fairly solid. Did some with and without listening and my conclusion was the port tube was not noticeably effective. Quite possibly a proper tube would lead to a different conclusion. By my hunch is that while a longer tube may provide incremental benefit it would be rather modest at best and adds additional sonic complexities.

After further playing around with the miniDSP together the Room Eq Wizard ("REW") software (http://www.roomeqwizard.com/) and a real time analyzer (RTA), I've arrived at the following adjustments and thoughts.

1) The 10" Audio Nirvana Classic benefits greatly from the application of a high shelf PEQ starting at 400 Hz with -6 dB reduction in gain. Some might call this a form of baffle step compensation. 

2) Whether it's the driver, the room, or combination of both, there was a noticeable boominess in the mid-bass. After running REW and loading the adjustment filters into the DSP, the boominess was completely gone. The filter was a fairly complex peak followed by big notch. Huge plus and a snap to implement with REW and the miniDSP.

3) Overall bass satisfaction benefits from adding a low shelf PEQ boost from 100 Hz down with a +2 to +3 dB gain. Adjust to suit. Cranking it up further really pours on the bass.

4) After further work with the DSP, RTA etc. it's quite clear that de-emphasizing the 2.5-5k range by ~2 dB resulted in enormous improvement by smoothing out a somewhat overly bright presentation in this audible range. This wasn't obvious based on the RTA but the benefits were most clearly evident while listening to live tracks and switching this filter in/out of the mix.

I should add that the room these speakers are in is arguably on the large size. Vaulted ceiling central great room with integral kitchen area. Plus the speakers are at least 3-4 foot out from the wall. In a smaller room with speakers closer to the walls the above adjustments may not prove optimal. Which only goes to further support the efficacy of DSP in achieving optimal performance. One size rarely fits all.

While further tweaking of the DSP may yield yet more improvements, this full range driver in a plain vanilla box with a DSP in front of the amp is producing the best sound I've ever heard from a speaker. Or let's say as good a sound as I've heard from any speaker regardless of price including anything I've heard at shows.

This presents a quandry in terms of how to best package this together. One the one hand, offer the 10" boat hull full range speaker together with a preconfigured DSP in a separate box? Or...make this a powered speaker with integral DSP?

Regards,
Morten

[brj]

DSP solutions don't seem to change quite as fast as DACs, but they still change often enough that I don't know that I'd make the preconfigured DSP the only option.  Some might want to use that DCX2496 they have sitting in the closet...

DSP performed on a computer front end source component is not uncommon either.  For example, I implement the needed driver EQ for my active speakers by defining the points in RoomEQWizard and then saving a convolution filter at its highest resolution setting, which I then import into HQPlayer where it convolves the filter with the music stream, upsampling everything via poly sinc filters to my DAC's native DSD128 input rate.  (HQPlayer runs on my modded Mac Mini, fronted by Roon for the sake of its impressive interface, and I have an analog line level crossover handling the frequency splitting duties between drivers.)

Note that you may want to talk to potential customers about the amp with which they intend to pair these speakers if you don't integrate an amp.  Perhaps the impedance is benign, but +5 dB of boost at lower frequencies may put undue stress on an amp that is marginally sized, if otherwise spectacular.  Avoiding that potential challenge is one advantage to the powered speaker configuration...