Nest Theater Part One - DIY High Efficiency Speakers - The DRC BLHs 24Feb20

In a remote and esoteric corner of the audiophile realm lies a particularly rare combination of pursuits - high efficiency full range speakers AND do it yourself. I embarked on designing and building my own horn speakers a month or so ago and now have completed all but the staining and finishing (which I'll need to defer till the weather is warmer)! The speakers sound incredible and can be driven loudly with only a few watts. Bass output is amazing given just a single smallish driver - the power of horn physics. These things, while not too large, are beasts and weigh in near 100# each. This is the first stage of a new theater and listening room for the Nest. The new speakers are being driven so far by a NAD D3045 for testing but will eventually get their own amp and DAC of suitable unadulterated designs.

The design is a back-loaded horn, BLH, and depends on 20 feet of wrapped sound channel within the cabinet to produce the bass frequencies from the back of a full range driver. The Japanese make great transducers and I chose the Fostex 168E∑, an efficient, ~95dB/Wm, full range, 51Hz-21KHz, 2.5#, 6.5" driver. I perused as many cabinet designs as I could find appropriate for this driver and then created a variant of Nagoaka's D37. I refined the horn mouth with an exponential curve and adjusted several internal braces and dampening aspects. I used 9 ply 15mm Russian Baltic birch plywood throughout for the cabinet - the pair required four 5' X 5' sheets. I prepared cut plans for the sheets and had CO Lumber acquire the material and make most of the initial cuts. From a pile of parts I measured, verified, marked and organized the project; I'm building new matching audio shelving too.

The moment of truth comes quickly as one begins to "add value" to each piece with drilling, gluing and clamping. The first effort was to create a mounting for the driver - if I screwed up early here I would just need to cut a new panel with a driver hole. It went fine and the new WEN drill press made nice vertical holes. I used #10-32 screw-in nuts which will accept my #10-32 black machine screws and allow me to install and remove the driver easily. Fortunately the dry fit of the driver was successful.

My basic assembly technique was to use gobs of Titebond III (strong, long working time, water cleanup) spread on with a foam brush as appropriate. Then I'd clamp, measure, and reclamp or screw if needed. I did this for days. The first assemblies were a set of 3 stacked sticks cut into triangular sticks I'd use inside the cabinet for support. Then I built the lower horn mouths.

With my chops whetted I realized I'd need more glue ultimately and bought 2 more pints! The next steps were to methodically glue, align and clamp the outer and sound channel boards & assemblies to one side panel. First though I did a dry fit of all the parts to be attached to the side panel.

After completing the entire internal sound channel on each speaker I added the bottom and braces from internal horn parts to the back panel. I also filled the chamber below the driver with sand. I want the cabinet to be very solid and inert as to producing sound - I just want it to reflect sound, not vibrate and lose efficiency. I also obviously added the binding posts/jacks before buttoning up the second side.

I carefully joined and screwed the second side to each speaker and played the functional (but not finished) pieces for enjoyment and test. Test successful. I actually built two different lower horn mouth designs and can trial and measure each - kind of like tube swapping but actual horn physics altering. I like the expo horn most so far.

As mentioned, these are beasts... I completely covered the side panels each with additional outer panels (lots of glue) and clamped them. I beveled the outer panels for a more finished look ultimately - I'll carry this 45° bevel throughout the pieces in the Nest theater. I also added some base plates and sound isolating feet... again employing the screw-in nut scheme. I reinstalled the Fostex drivers.

The DRC BLHs are ready for listening, finishing and measuring. One can't buy speakers like these unless they were commissioned custom... and then the price would be exorbitant. I know they may have extended range issues at the highest and lowest ends of musical frequencies but wow most of my range of hearing is covered ever so sweetly.

New Pornographers @ The Gothic 15Feb20

The New Pornographers show at the Gothic was excellent. AC Newman brought the whole 7 piece team and slammed great tunes back to back for over 100 minutes - and then returned for a strong encore. Neko Case was great; the last time I saw them, Neko was not present so the renditions tonight were so much better. Plus, Simi Stone, vocals & violin, is a fairly recent addition whom I've heard on recordings but never seen live; she was awesome. Scott Brantley and I were alone from abandonment by other friends enjoying the Avs hockey game at AFA/Falcon stadium. No matter, they couldn't have had a better show than ours. We went right to the first rail for good sound, fine neighbors, and a keen vantage point for the entire show. Even the back up band Diane Coffee had great energy.

Scott & I dined prior at One Barrel and it was very good - we grazed on starters of brie en croquette with blueberry jam, stuffed piquillo peppers, shrimp ettouffe, and carnitas carbonara - chased with tasty IPAs. Recommended.

Thanks for coming out for a great evening Scott! Set List from the Gothic:

1. Falling Down the Stairs of Your Smile
2. Sing Me Spanish Techno
3. You'll Need a Backseat Driver
4. Dancehall Domine
5. Sweet Talk, Sweet Talk
6. The Bones of an Idol
7. Whiteout Conditions
8. Colossus of Rhodes
9. You Won’t Need Those Where You’re Going
10. The Laws Have Changed
11. Higher Beams
12. Avalanche Alley
13. Testament To Youth In Verse
14. Backstairs
15. Dreamlike and on the Rush
16. All the Old Showstoppers
17. Adventures in Solitude
18. Champions of Red Wine
19. Play Money
20. Moves
21. The Bleeding Heart Show
22. Mass Romantic
23. Challengers
24. Brill Bruisers
25. Letter From An Occupant

Skiing & Beer-Off 10Feb20 & 13Feb20

I made some more outings at Keystone while the weekdays have some soft snow. I was on my own on one occasion and out with the Schwab team on another. Along with skiing came some spa soaking and brew comparison. I tried several west coast hazies... they are a bit less hazy and more hoppy/bitter than NEIPAs. My friend dubl-D mentioned Modern Times was a favorite brewery in San Diego so I grabbed their Mythic Worlds, a new LaCumbre release called Terminally Chill, as well as a new Crooked Stave entry named Magnitude DDH, to get Colorado involved. I'd have to rate the Modern Times best, and it is good for a single hop. The Magnitude was next yet still a smidge "sweet" for this bake-off. Last and surprisingly not too good IMO is the LaCumbre. I'll have to acquire more of this style over time to really judge them better - I've had a few others but not many. Power to the hop.

 

Ridin' With DD, Buildin' The Shop, And Listenin' To New Tunes 08Feb20-09Feb20

I got the rare pleasure this season of riding with DD to Breck and partaking of 30" of new snow there. We had a good time and enjoyed the freshies but endured long lift lines and were aced from the alpine, which never opened this day, due to avy control and winds. We departed early and dined at Highside, a good newish brewery in Frisco.

 

 

In pursuit of a new project I've needed to build out the shop in Silverthorne. I traded up to a new router with table, I've added a drill press with laser and work light, I've upgraded soldering station with temp control and new magnifying glasses. New tools are exciting at least to me... task appropriate always improves results.

I'm excited for two recent music drops beyond some of the cool stuff performed at the Oscars last night. Firstly, Alex Lahey delivered a grunge-like piece called "Sucker For Punishment" and announced some US tour dates. Unfortunately there is no Denver stop on the tour, yet. Secondly, a very good acoustic set was dropped on NPR's Tiny Desk from the stellar emo team from the Valley of the Sun, Jimmy Eat World. They even perform The Middle as the last song - the whole thing was excellent - Jim Adkins voice is still very fine. Click through below.

A Day For The Big Boy Boards @ Breck With Yoho And Lunch With MLC 07Feb20

Wow - Jim Yohanan and I skied Breck in 30" of fresh snow today. At 19" to start the day I donned the big boards @ 142mm underfoot. They were great but the rub is that due to the continuously falling snow, the alpine sections never opened. Sure the wind was a bit high but it's really that ski patrol couldn't bomb the tops for avy control. Nonetheless, awesome with the best runs off of Pk 10 - Falcon skiers right - teep and deep.

On the way to Summit I was pleased to grab Matt Coffin for lunch and even got to meet some work-mates and check out his sweet cube, building and view. Big data for real estate seems to work. It was very nice to see him.

Ultra High Definition - High Dynamic Range TV 04Feb20

As I investigate the latest in TV like 4K, 8K, UHD, HDR, etc. I drilled on where content comes from, who delivers it,  what the implications of it are on infrastructure and how human perception deals with it. As to content and who delivers it...

1. Broadcasters and mainstream OTA channels (ABC, CBS, NBC, FOX, CW, PBS, etc.) won't be doing anything anytime soon. OTA digital will get you 1080p (1K), and Rec 709 color gamut (8 bit), at best, for some time to come. While some initial camerawork is done in 4K, transmission mostly is not. The cost to upgrade the whole camera, recordings, decoding, & transmission systems is daunting.
2. Very few satellite or cable channels offer 4K content, but there is some stuff there. 
3. DVDs are 480p, Blu-Rays are 1080p and you need to get up to Ultra Blu-Ray to get more. Mostly I sense folks say "who cares" and don't buy a new disc player with each new iteration, just so they can buy a few expensive new discs. When I went to Blu-Ray I did so 'cause an old player died and I own like two discs.
4. The content is coming mostly from none other than Netflix (and the other over the top content builders and streamers, like AMZ Prime, Hulu, etc.). You need to upgrade your Netflix service to premium ($17/mo vs $12/mo) to access the 100 or so titles available in UHD, but they keep making more.

So other than premium over the top services and a new 4K TV, what do you need to partake? Really just sufficient bandwidth on your internet connection (and WiFi if that's your final leg to the tube). Netflix recommends steady 25Mbps but that's probably overkill... others require less. I wanted the very specific calculation of pixels on screen, of certain color depth, at a certain refresh rate to Gbps broadband needed.

First I needed to understand UHD and HDR characteristics. There are three primary vectors on which UHD-HDR TV advances from HDTV: resolution, color depth and dynamic range. Resolution refers to the number of pixels on the screen, color depth refers to the number of colors that can be displayed by a given pixel, dynamic range refers to basically brightness - how black is black and how white is white.

• Pixel resolution of UHDTV is 4X that of HDTV (1096x732) at a minimum of 3840×2160 and potentially 4400x2250 (where some pixels are likely inactive), or even twice that again for 8K TV

• Color gamut of 4K TV (the standard is called Rec 2020 and is represented in at least 10 bit depth) is 1.9X the size of HDTV. It is getting closer to the human eye's ability to process colors (shown as the full colored shape in the graph above). HDR10+ is announced for 8K TV and requires 12 bit color depth. TVs with these larger color gamuts are often said to have Wide Color Gamut or WCG.

 

• Dynamic range is a ratio between the smallest and largest of something; in this case, levels of brightness or luminance values presentable on a TV display. The numerator and denominator are best measured in nits (amount of light output equal to one candela per square meter, cd/m2 - a standardized measurement of luminous intensity). Visually there is a big difference looming here - brightness and contrast count - much darker blacks and much lighter whites. Standard dynamic range (SDR) TVs have a dynamic range of about 6 f-stops (200-300) and HDR TVs have a range of 11 f-stops (~1000) and Sony has demoed even much greater. Remember, every f-stop gives you 2X the prior so HDR TVs delivery 10X the luminous intensity range of SRD TVs. Cameras have long been able to capture and record with very high dynamic range, like 14 f-stops but our displays are only now coming close to delivering that for viewing. If you've ever experienced the dark scenes on your TV, where you can't really see what's going on - these will get much better on newer HDR sets and content. Recognize too here that good high speed HDMI cabling will be needed.

These differences MAY add up to huge visual impressions for us, and elicit wicked visceral responses, but when and where can we really perceive them? HDTV was studied extensively when being readied for launch and we know human visual acuity can delineate 1 arc-minute. This led Lachtey to devise guidelines for how close one should sit to a 1080p HDTV panel for immersive viewing. Our eyes have 135° of angular range, mixed viewing suggests we sit to cover 30° of viewing and THX (cinema standards) suggested 40°. So I set up my 77" diagonal UHD/HDR TV seating at 8'-10' and it was perfect. Given human visual acuity I can now move seating in 50% to 4'-5' for the best experience. Wow! This will mess with my acoustical sweet spot too. Staying at 8' would just mean I didn't need to get a 4K panel (ignoring brightness for a bit).

All fine, here is the bandwidth calculation, approximately: 4400 horiz X 2250 vert X 60 Hz refresh means 594M pix/sec need updating! Chroma sampling at 4:2:0 yields ~11Mbps (but some suggest 7.2Mbps is sufficient). In any event, I have this all covered in my $35/mo 15Mbps downstream feed - and the content at these target levels won't really be here for a while.

Falcon Ride With Kala & Brantleys And Congrats To Chiefs 02Feb20

What a glorious day to ride - Kala & I met the Brantleys for a ride on the AFA today. I peeled off near the top parking lot to acquire the dirt for the ride down. Yea, I sold my cross bike so they were light with low rolling resistance and I was "heavy" (in so many ways) and on my full suss SB95 with mechanical and rolling disadvantages. The descent was a hoot. I was wetter and dirtier than my mates at the bottom but I bet I had more fun on the ice & snow & mud. Kala and I then tried the new Chuys up north - it was good. And, we laud Andy Reid and Mahomes for a keen comeback win at the SuperBowl - we wrestled that win with the new, excellent as always, La Cumbre Project Dank for Winter.

I pulled out the Broadaxe to tune it in the morning for the ride but discovered a full-on crack in the top tube beneath my protective sheath and underneath as well. Alternatives are DIY, $300+ pro repair and hassled shipping, or $1200 new frame. Manufacturers of course say new frame for safety's sake but repairs are possible. I must've busted it on last year's Canyonlands trip - bummer. None of these could be done in an instant so I unearthed the Yeti SuperBike, pumped in 25# and set out; too, I ordered the repair epoxy & carbon fiber and mold release fabrics 'cause I'm that guy. Sheesh.