Hanging & Driving The NOnken Surrounds 09Dec23

Hanging The NOnken Surrounds... In deploying the NOnkens to the left & right surrounds locations I needed secure permanent installation spots that were out of the way of walking about and very strong to carry the weight. I chose to hang them from the wall above heads and point them at the seating properly. I think even Bro Brown can walk under them. Note that the full NestMT image is distorted and the NOnkens appear strange due the focal length... the direct head on images of the hanging NOnkens shown later are more representative of the install.

The NOnkens are 35 pounds a piece and in investigating mounting hardware I was immediately drawn to the pro PA stuff enabling suspension via a 35mm cup/pipe system ~ these had 5X or more the carrying capacity of other mounts and held up to 100# each. It's a widely used standard mounting system in theaters, stages, and mobile kits and most PA speakers these days have the cup built into the base. Enter the BiGalleons, adjustable powder coated steel mounts affixed to the wall via 6 substantial anchor bolts (which get covered up nicely). Each surround was outfitted on the back with an external mounting fixture I fabricated... I used 1 1/4" conduit (which had the proper ID to mate to the BiGalleons' "pin"), a block of leftover Baltic birch, U bracket holders lined with old bike tube rubber and a tapping screw (that goes into the hole to register the speaker to the "pin"). I bought and returned manufactured external mounts as they didn't allow the desired optimal mounting in the room ~ would've lowered the speaker and limited it's angling. My fixture screws into the back of the DRC NOnken and I can angle appropriately and install the surround almost right at the ceiling level. My mount will be proud from the wall a bit more but that's fine. I checked my angles and my working idea first, to assure all would fit OK, sure it was in ink :); 𝛼 = 51.3° and β = 54.5°. Installation went fine but I did needed quite a bit more 12 gauge oxygen-free zip cord speaker wire (I eschew all those expensive audiophile low loss cables for my own builds with banana plugs); 12 gauge is pretty big but this is a long run.

Surround Signaling... I purchased a Denon S570B on Cyber Monday for a good price - Denon should do audio well and they claim full 8K/UHD support, if I need that. It allows me to get surround decodes (DD 5.1 or D PLIIx) and power (since I returned the Schiit amp) for the surrounds. Why do I need decodes you might ask. Unfortunately, during comprehensive testing of the used Dolby DP564 I discovered that one of it's surround channel analog outputs doesn't work. Investigations online indicate that this 20 year old gear does tend to have this analog out failure mode ultimately. Therefore, the Denon decoder will be used for the surrounds ~ same algorithms after all; fortunately it has it's own time delay capability so I'll be able to dial that in cleanly for the surrounds. Initial testing of the Denon and new surrounds went well... I'm delivering 2 ch PCM or 5.1 DD to the S570B via COAX Spdif (big orange) from the Felston. Optical from an HDMI audio extractor would work too.

The NOnkens  are a decent size and hefty but the install went fairly smoothly into their spot. I still need to finish the NOnkens and hide the cabling but else I am online with 5.1.

Initial NestMT 5.1 Impressions... Holy soundfield! While I was wary of the final outcome, the new NOnken surrounds make the NestMT expansive; my mind is blown. The 6 high performance full range Fostex drivers in my custom back loaded horn and bass reflex Onken cabinets deliver the goods beyond reason ~ sure, they're augmented by Viawave/hi and Hsu/lo and even some signal processing but who cares if it sounds this cool. The recent expansion from 3.1 to 5.1 is ear-opening and unexpectedly good. The derived and direct surround sound from the Denon box is fine and clean. Listening is a blast however it is late so I will leave remeasuring and resetting delays for an update.

Measuring The NestMT 5.1... I rebuilt EQ in Dirac for the L/R mains (with Veriwave tweeter & Hsu sub) just for good measure ~ not much change. I then measured the center channel and surrounds and checked the impulse measurements to assure the delay is right between them. They are the about the same distance to my ears and fortunately not much tweaking is required. There is not much processing delay difference in the AVR for surrounds and in the DP564 for centers; what is needed can be done in the Denon AVR. I also remeasured the processing delays between mains and center/surrounds, which are handled in the Felston, for each source; they are again about the same as set prior for just the center. I won't bore you with the delay measurement graphs and settings... I'm just gonna provide the composite sweeps and their average. The "mains" graph includes the sub & supertweeter with the new Dirac EQ. The centers and the surrounds have no EQ applied and the surrounds are being measured off-axis of the mic. The new NestMT 5.1 system is amazing but I do note the 5dB baffle step shout from the surrounds 1KHz-4KHz and may want to address that with specific EQ.

The BOnken come NOnken saga made my move to 5.1 channels in the NestMT a tough road. The project to even hang the NOnkens, as described here, was very challenging, with its own hiccups along the path. It is worth it but I am glad it is almost over.

Update 31Dec24... I'm dissatisfied enough with the surround signaling (it was thin and odd derived from PCM 2 channel) AND the performance of the NOnken surrounds (described prior) that I have removed and decommissioned the speakers and have redeployed the drivers elsewhere for now. I will design something better from scratch and will seek better 5.1 signaling somehow. Matt will get the AVR and the surround hangers are very solid and will remain on the ready for reuse.