TOPIC:

Shifting gears, I managed to program the sync, metering, and gain settings on the Lucid 8824 and tame an annoying power transformer hum it had. The Yamaha DAC arrived as a backup, but I am starting to like the metering on the 8824.

Final tuning tomorrow.

Well it's tuned and done. (Is anything ever done?)

Watched Godzilla (2014): excellent LFE and transient handling.

To to: Rather than use the nanoAVR volume control (which is digital of necessity) I'm thinkimg if getting a Raspberry Pi to talk MIDI to the Lucid DAC for analog volume control responding to IR control.

But, for now, It Is Done.

Nice Always good to be done

I haven't been following every detail, but I'm wondering why the 520i are not further apart? Does that put them too close to the side walls?

More questions - those use the single long ribbon (name I forget), now discontinued?

I like the integration of the surrounds, very acceptable.

The room is 12'6" wide by 14' long. A door opens into. It on the right. The 520i speakers are 7'4" apart. The subs are at the 1/3 and 2/3 positions along the wall.

It's the best I could do. The backwave is sufficiently damped on these such that reflections from the front wall are not a problem. I could add dampening material if I had to.

Speakers are BG Radia 520i L+R, 220i C, and 4x PD6-LCRI surrounds. They use a line array of ribbon drivers to make a line source. The surrounds have a single ribbon driver and two small woofers.

Yes, BG Radia is no more, sadly. They made good speakers. (That, and I love ribbons. These have a nasty hump around 350 Hz but the minidsp takes it in stride. They also take power to drive at 88 db/W/m but they disperse a cylindrical wave so roll off is only 3dB per doubling of distance.) I scored the surrounds on EBay as well as the center speaker. Been waiting for one for about 15 years. It is a feat of structural engineering to cantilever it 13" from the wall on a glass shelf as it weighs 52 lbs.

Screen center to eyeball at center seat is 10 feet.. Center speaker is at ear height, and neck crane angle is 12 degrees. The sofa has headrest at all three positions and the outer two recline.

And one is never really "done". Well, maybe when one is in one's grave. One just reaches points where the answer to "So, can we actually watch a movie yet?" is currently "Yes!"

Here, all amps, except the centre channel amp, are "pro amps", expecting a +4 dBu nominal signal, with 20 dB headroom: 0 dBFS should translate to +24dBu from the DAC (and I have set up the output channels on the Lucid ADA 8824 to those levels). Well, input sensitivity on the pro amps is 1.4V for full power, but like all pro amps, they have input attenuators, and the signal run to them is hotter and then padded down. I have them about 30-40% of the way up (set when I was measuring the room for Dirac Live! calibration with a -20 dBFS signal).

Now, the centre channel is driven by an Outlaw Audio M-2200 monoblock amp, capable of 300W RMS into 4 ohms. While it DOES sport an XLR input, it apparently expect consumer level audio signals of -10 dBV nominal (-11.79 dB lower: 0 dBV = 1 Volt, -10 dBV = 0.316 Volt, 0 dBu = 1 miliWatt into 600 ohms = 0.775 Volts, 20 log(0.316/0.775) = -7.79 dB power difference between -10 dBV and 0 dBu, so -11.79 dB difference between -10 dBV and +4 dBu). Call it 12 dB.

So, I put a 12 dB pad between the Lucid ADA 8824 DAC and the Outlaw M-2200 mono block and it was STILL hot! Like 21 dB too hot. Not sure why, but for now, I applied a 21 dB cut on the centre channel in the nanoAVR DL. I KNOW this will cost me some 3-1/2 bits of resolution, but so far, I can not hear it. I should probably apply the cut in the Lucid ADA 8824 DAC, which uses a voltage-controlled analog amp/attenuator after the DAC chip instead of a digital multiply.

Hmm. The gain in the Outlaw M-2200 is 27 dB, so 1.7V in for full power (300W into 4 ohms). That's 14.6 dB above nominal, and I'm presuming 20 dB headroom, so I need to cut an additional 5.4 dB. Now, "fulll power" to me is 105 dB acoustic at the listening position (THX reference level), the centre speaker is rated 88 dB/W/m, and is 12' away, with a cylindrical dispersion pattern, so 3 dB down for every doubling of distance instead of 6... I need 111 dB at the speaker, or 200W (it's rated 50-250W) so another 1.8 dB down. That's only 7.2 dB of more cut, not 21.

Hmm... 7.2 + 12 = 19.2. Maybe I got sold a bum 12 dB pad.

ANYWAY, the point is that analog level and volume control in the Lucid ADA 8824 DAC would be better than the coarse digital level and volume control in the nanoAVR. Especially with the disparity I am seeing. I could level things in the Lucid ADA 8824, and use the nanoAVR for volume control (my current plan), but it would be better to do analog leveling and volume control.

Furthermore, I have two nanoAVRs (and HD for bass management, and a DL for Dirac Live! room correction), and that causes a small problem; both respond to IR remote control codes. I want the HD to ignore them, For now, I covered the sensor, but I wish I could disable IR control on it completely (as a workaround I can program it to recognize IR codes that I do not use).

Now, volume and level control on the Lucid 8824 DAC is a wee bit of a challenge (See how nothing is ever "done"?). As recording studio gear, it is controlled via MIDI Sysex commands. I set the source, levels, and metering (analog out as opposed to digital in) via a USB to MIDI adapter on a Linux PC (amidi is your friend), but was planning for that to be a one time thing. If I want to use it for volume control... I need a PC to do IR to MIDI translation (of all the crazy things...).

Ooh... a Raspberry PI would be PERFECT for this...

So, the saga continues. But at least I can actually watch a movies and listen to music in the mean time.

Power control.

The Crown amps, being pro amps, have an annoying habit of FLASHING THEIR POWER LEDS BRIGHTLY when in standby. No way to defeat this. So, in addition to the TV-sensing power bar to bring up the subs and amps out of standby, I added another TrickleStar AV 4 port smart outlet right at the wall.

IR turns on the outlet, and the rack as a whole. IR or PIR motion detection keeps it on with a 120 minute timeout. The TV sensing power bar plugs into it. So, when seeing first IR rack powers up with amps in standby. Turning on the TV takes them out of standby.

Turning off the TV brings the amps back into standby, the Trickster detects this, and turns off the rack about a minute later. Very cool.

On inactivity timeout (I just get up and leave) the Tricklestar sends a STANDBY command to the TV via CEC on an HDMI port and it turns off. This turns off the subs and puts the amps into standby. After a minute the Trickster detects this and powers off the rack. Also very cool.

About the only downside is powering up all 7 amps and subs when the source is only stereo.

Only thing from here on out might be better amps, better subs and integrating them as separate units, and perhaps a Pi-Rac control and display unit to distinguish between movies and music.

It's bern a journey: the sofa was placed in the theatre room one year ago today.

As for minidsp nanoAVR I would like to see better control and status through published USB or network Ali's fir better automation integration.

Reflections.

As I have noted, a project is never really "done". Here, one can upgrade amps, unify control, etc. But it pays to look back on things and see what one has learned.

1) The AJA DACs seemed "noisy". With SNR specs of 94 dB and THD specs of 85 dB, they were not as good as the used Lucid ADA 8824 at 105 dB. I suppose I could make them work with a strong enough input signal from the nanoAVR, but the DB-25 to XLR snakes get knarly behind the rack as well and there is no easy way to rack mount them, except on a shelf. The 8824 gives me a gorgeous peak meter display for all eight channels which I surprisingly do not find distracting. I had planned to get creative with magnets and black cloth if they did.

2) Volume control. The nanoAVRs control volume digitally, out of necessity. While this isn't bad, it means resolution is lost with attenuation. 6 dB of attenuation equals one bit, so 20 dB equals 3.4 bits or so. I don't find this bad, as my listening range generally fits in a 20 dB window, but it nags me a bit. Better AVRs will do volume control in the analog domain with a VCA (voltage controlled amplifier) after the DAC chip(s) for each channel. The Lucid ADA 8824 does this! However, control of levels (of each channel) is via MIDI, so some kind of controller is needed. Fortunately there are cheap USB to MIDI interfaces, and cheap controllers (hello, Raspberry Pi). Something to consider. Also, I find that the IR sensor on the nanoAVR requires the remote to be rather close (6 feet or so -- at 10 feet it is spotty), and there is no way to defeat it when one has multiple nanoAVRs (I have an HD for bass management, and a DL for Dirac Live! room and transient response correction). I suppose I can program one of them to look for control codes from a remote that is not used, but a "disable IR" command from an attached PC or Android/IOS control app would be nice. As a note, the Yamaha DAC only allows for hard switched selection of -10 dBV or +4 dBu levels.

3) I swear the Dirac Live processing corrects for the THD in the Crown amps: they sound much better, though this could be my mind playing tricks on me, as I have not measured the difference. THD in Crown XLS Drivecore II amps is around -75 dB or 0.02%. Good, but not the best available. Inaudible to my ears and far better than the amps I grew up with.

4) The fans in the amps do not come on (well, not yet, and I don't expect them to). In a home environment you are not trying to get as much loudness out of an amp as possible in a PA environment where the audience can be 20 to 200 feet away, so you won't drive them as hard. The compressors do not come on either. These amps are designed to produce loud output, no matter what, and they do take rather extreme measures to protect themselves from melting under significant stress conditions: thermal shutdown is for wimps. SNR is not all that great at 103 dB for the 1502 model (front speakers) and 97 dB for the 1002 model (surrounds), but SINAD is rather consistent at 75 dB down through the first Watt. Certainly for a theatre they are more than adequate, If anything, I would keep them for surround duty and perhaps upgrade to ATI Hypex ncore for the front three channels.

5) I am now a fan of SpeakOn speaker connectors. Not only can you get 2 pole, but 4 pole and 8 pole connectors exist, for multiple speaker banks. The Crown XLS series (and most pro amps) support 4 pole SpeakOn connectors. Not really useful for stereo when you typically run wires in opposite directions from a centrally located amp, but great for running two channels into one cable to a surround speaker banana jack plate sticking out of the wall for the rear and side surround speakers: one amp, one cable (two amps, two cables). Push, twist, and lock.

6) Monoprice sells 100 ft OFC 4 conductor 12ga speaker wire for under $100. That is cheap. White looks better against the carpet if you will run it around the room instead of hiding it in the walls, IMHO, but black is available. (it is CL-2 rated for inwall installation if you want). Mates well with 4 pole SpeakOn connectors.

7) Was going HDMI to SDI to AES/EBU worth it? I think so. It gave me incredible freedom to find a DAC. ADAT would have used a lot less cables, but the broadcast and recording industries rarely talk so... The DSP and conversion "shelf" (a 1 RU rack shelf with equipment stuck on it with double sided tape, including the two nanoAVRs in the front) and DAC take up 3 RU together. You can't find an A/V preamp in that form factor with Dirac Live!. Certainly I can't at a reasonable price. Was it easy? No. I got lucky in finding an HDMI to SDI converter that stripped HDCP (because the silly nanoAVRs want to produce it on output even if they do not see it in on input). I had to go through the pains of thinking I had EDID problems when I had HDCP problems. I had to abandon AJA ADA-4 DACs because they were too noisy. All that took time (and a bit of money). Oh well, live and learn.

More on this: I have, at one point in the system, Dirac Live! corrected audio with black SDI video on a single RG-6U coax cable. Rather easy to deliver that signal anywhere else in the theatre. I was thinking of using SDI audio deembedders at the front and back of the room with local amps instead of having all the amps at the front and running speaker level cables, but the performance of the AJA ADA-4 DACs turned me off of that idea. (That, and an 8 channel studio DAC with peak level meters and a rack of amps looks cool). I might still do something like this if I ever want to relocate the amps to the back for more processing equipment in the front and run two racks.

As with most modern homes, I have cat-5e and RG-6U cabling to each room, from a wiring closet. Hmm: I can deliver that audio anywhere in the house! Rather useless as it is Dirac Live! Corrected for a particular room, but it does not have to be that way.

I could use an HD Fury Integral 2 to split 4k HDMI video to a 1080p down-sampled version with audio. That down-sampled version can drive my HDMI to SDI converter which I can split back to the central wiring closet and locally to de-embed the (uncorrected) audio to AES/EBU and use a DDRC-88D for both bass management and Dirac Live! room correction. So, I'd have to buy an HD Fury Integral and a DDRC-88D. The existing nanoAVRs can be recycled in another room. In those other rooms, I just need to go SDI to HDMI to nanoAVRs to a run of the mill HDMI receiver and speakers.

Not something to do tomorrow, but an idea. Multiple full blown Dirac Live! theatres in the house just showing the same content is likely overkill, but being able to display the theatre content on TVs throughout the house might not be: stay up to date on the movie while making a sandwich in the kitchen sort of thing.

8) What would I like from miniDSP? A few things: cut with the HDCP if the source does not request it. It makes life a lot easier. Publish control specs for network control of your units. It would make automation easier. To dream? A 4k60 4:4:4 nanoAVR DL with BM that passes video through with digital audio outputs for all 8 audio channels: 4 coax and one Toslink, with the Toslink configurable for SPDIF (L+R) or ADAT (all 8 channels at 48 kHz sampling). Rack mountable, please. Perhaps with an input HDMI switch. Optionally Dante on the network port.

Remote Control.

I find the nanoAVR remote control relatively weak: I have to be 3-4 feet from the unit for it to have an effect (I have been using it temporarily for volume control). I am not sure if this is because the batteries are low, the remote LED is weak, or the nanoAVR sensor is insensitive.

Other than that, my theater is working flawlessly: watched "Peppermint" (a revenge movie with Jeniffer Gardner as the protagonist) in glorious 7.1 surround sound yesterday. I swear that Dirac Live! pre-corrects for the little bit of harmonic distortion that my Crown XLS 1502 and 1002 amps have.

Well, it's been a while. I have actually been enjoying my theatre instead of building it, though I must admit to having a bad case of upgraditis now that it is done.

Given the use of Crown amps and Klipsch subs, I am surprised at how well it sounds, even on two channel music. The worst link in the chain are the crown amps with SINAD of around 75 dB (0.017% THD), though you can't tell by listening. Watched "Sweeny Todd" with my daughter last night, and then stayed up until 1:30am listening to music. I am happy with it, and I suppose, that's all that should matter, and yet...

I had been thinking about either upgrading the ported Klipsch subs for a pair of sealed 12" (less amplitude, but tighter) as the Klipschs (Klipschen?) are turned way down, or adding a pair of sealed subs in stereo to fill in the rolloff on the Radia 520i fronts, and move the Klipsches to the rear for strictly HT duty. Then it dawned on me: the Radias don't roll off THAT much to 80 Hz and the miniDSP can probably EQ the droop (and probably why it sounds so good). So, I can concentrate strictly on non-directional bass.

While the thought of a DBA is seductive, I can't see myself installing four subs inwall at half room height, two each at the front and rear of the room. I think two good sealed subs would be better. The question then becomes front or rear of room.

My daughter, of course, thinks I should get a bigger TV. I will admit the 52" is small at 10 foot distance, and a 75" would be ideal. Half-decent mid-range ones run around US$1800 for LED models, though even a mediocre entry-level $1100 4k model likely runs rings around the ten year old set I have. Of course, no local dimming for HDR at these prices. And, I know: they eye can't resolve 4k at ten feet.

At one point I was thinking about FOUR 12" subs, but only because a miniDSP 2x4 balanced could blend them nicely using MSO to develop PEQ for them. Yet, I think if two is enough, four would be too much. Then again, one can never have enough LOWER (as opposed to louder) bass. And the DBA idea rears it's head again. Right now I just split a single signal to the two subs at the front of the room and it works. surprisingly well. I guess I got lucky with room modes. Of course, I only have three seats of seating in the 12'6" W by 14' L by 8'6" H room.

Sound-wide I could probably benefit from a better DAC and amps, at least for stereo listening: the Crowns are fine for HT duty (and no, I have never had the fans kick in). I have been eyeing an Octo DAC8 PRO and a two channel Benchmark amp, but the latter is some serious coin. I think the bigger TV would come first.

So, what do others think?

On edit: *drool* www.yumpu.com/da/document/read/51602667/...chmark-media-systems

Building subs is a good project, I'd do that Put two drivers per box in dual-opposed.

Dual opposed? I'd be more inclined to use two separate subs (as I am now), but sealed. Though, the Klipschs (Klipschen?) 12" ported subs work surprisingly well at the 1/3 and 2/3 positions in the room. I have considered replacing them with sealed subs to be "tighter" and more "musical", especially in the 80 to 100 Hz range (The Radia 520i front speakers start to roll off around 100 Hz, though have reasonable output down to 70 Hz).

For a while I tortured myself with thoughts of two stereo subs just to augment the Radia 520i speakers to "fill" the range from 70 to 100 Hz, but realized that the roll off is gentle enough that the miniDSP Dirac Live EQ probably takes care of it: even as my system is, it sounds amazing. Also, I'm driving the fronts with a Crown XLS 1502 amp, with a SINAD figure of 75 dB (not that I can hear it, as that is THD of 0.017%) -- hardly an audiophile amp (but arguably better than an old Carver TFM-22 that served me for 32 years, with a SINAD of 46 dB (0.5% THD).

So, that leaves me with subs strictly for LFE and bass-managed content below 80 Hz sent to them. Surrounds are actually only about 6 dB down at 50 Hz. That leaves me wondering if (a) the two ported 12" Klipschen at the front are enough, (b) ported subs are good enough, (c) whether I should consider four slimline on-wall 12" subs in a DBA, managed with a minidsp 2x4: the room is small enough with few obstacles (really the narrow Radia 520i front speakers which should be acoustically transparent at sub frequencies) that a DBA should be effective. It would look cool, but would it be necessary? (I'm guessing probably not).

A bigger issue for me is how I got my 7.1 signal digitally from HDMI: I used an HDTV Supply HDMI to SDI converter that strips HDCP, and then an SDI to AES audio de-embedder. From there I can use pro 8 channel DACs, etc. I'm tempted to buy another if mine gives up the ghost because, honestly, I don't know how long such a DHCP stripper will be available. It also only supports 48 kHZ 24 bit audio and 1080p video. The latter is not a problem today because better source components will have an "audio only" HDMI 1.4 output that may have video, or black, with 8 channels of audio. It does mean I can't do ATMOS, and does require the source component to output 48 kHz LPCM audio over HDMI, but almost all do (they decode Dolby and DTS internally). Readers will know that I struggled with HDCP in the miniDSP nanoAVRs because, although my Oppo 103D did NOT use HDCP on the audio only HDMI output, the nanoAVRs insisted on applying it on output even when not present on input. Most HDMI to SDI equipment will not accept HDCP-protected content. The HDTV Supply unit was the only one that does.

That left me wondering if I should just get a "good" A/V preamp, and settle for the analog outputs. I'd get ATMOS that way (If I wanted it). I could always convert to digital with an 8 channel professional ADC/DAC (most go both ways) if I wanted and stay digital until conversion just before my amps (ironically, the Crown XLS amps have a DSP section for high/low filtering and thus introduce an A/D/A stage at 48 kHz). The thing is good A/V preamps are (a) expensive and (b) often loaded with feature I don't want or need). It took me a while to learn the lesson of "who cares" if it is analog or digital as long as the THD and SNR specs are good and signal runs are short (even long analog runs are not so bad if they are balanced, and capacitance is EQ'd). Though, I am still biased toward keeping audio digital as long as possible. I've looked at SPDIF mods by JVB digital for bluray players and switchers, though the latter is only available for an Octava 1080p60/4k/24 switch. I wonder if my pro equipment would balk at the SPDIF as opposed to AES subcode.

If anything, I think I should focus on (a) bigger TV, (b) better equipment for two channel listening (amps and DACs, though there are very good 8 channel DACs available by Okto and Benchmark (the latter a 16 channel DAC with 2 channel averaging for very impressive specs). Right now I am using a Lucid ADA 8824 ADC/DAC with 105 dB SNR and -86 dB (0.005%) or -100 dB (0.001%) THD (depending how you measure) and am contemplating using the VCA in it for volume control instead of the nanoAVR. The Benchmark DAC16 measures THD+N = -120dB, 0.0001% @ -3 dBFS input, SNR = 129 dB A-weighted (SNR = 135 dB A-weighted in 2-channel mode) and has variable output in 1 dB steps. Of course it runs $4k but does support 16 channels. It would deserve a Benchmark AHB2 amp (< 0.0003 % THD+N (-110 dB) at full rated power, 20 Hz to 20 kHz, 132 dB SNR) for the front two channels. Another $3k.

I know the Crown amps are mediocre, but there are two things I like about them: (a) input attenuators -- I can run the balanced lines to them at +4 dBu with 20 dB headroom, and attenuate at the amp input to combat line noise if I have a long run, (b) Speakon speaker connectors. Certainly, this works well for surround duty. (I have two 35' Monoprice 4 conductor 12ga OFC runs from front of theatre to back.) I note that the Benchmark AHB2 uses XLR inputs and Speakon outputs as well.

One crazy idea, with my current subs is this: (a) mix half the bass-managed LFE signal into each of the rear surround channels, (b) move the two surround amps and two subs to the back, (c) high-pass the rear surround channels to their speakers in the Crown XLS 1002 that serves them, (d), parallel run (the Crown XLS amps have 1/4" TRS parallel outputs on the inputs for amp stacking) the full-range rear surround channels to the dual subs and low-pass filter at the sub. The filtering choices will be more limited than in the miniDSP, but should be adequate for surrounds and LFE.

rhollan wrote:

Dual opposed? I'd be more inclined to use two separate subs (as I am now), but sealed.

Well, none of that is contradictory...

Oh! I thought you meant two drivers in a single enclosure in an isobaric configuration.

Behind the front of the room is the laundry room. I could run two or four wall mounted subs open to the back...

Right now I am thinking about a larger TV and signal chain processing.

Is media room lounge furniture design for the bedroom only? Actually, I bought it last month and put it in my guest room. But my friends were making fun of me that it's for the bedroom only. I ordered it through 4seating coupons .