Axiom Home Page Forums General Discussion Home Theater Oppo 103 audio processing

Has anyone used their oppo 103 analog outputs for multichannel audio? I am interested in trying them out because the oppo allows for up to 60ft (or around 45ms) of possible delay between channels. My current AVR maxes out at 30ft.

I am trying to phase align my subwoofers to my mains and I would like to get one more cycle of delay between my subs and mains.

Has anyone tried the outputs? Any drawbacks like flaky onboard volume control etc. ? I don't want to invest in a bunch of RCA cables from blue jeans and reconfigure my rack if it's not worth it from some bug I haven't heard about.

Here is how close I can get with the settings maxed out. I am currently set so they are time aligned, but not fully phase aligned at the MLP (not shown in this plot.) I just need a little more time to play with...

I use it all the time (that way I can watch hockey and listen to SACDs at the same time as my D2v doesn't support simulcast if audio source is HDMI).

Quality is excellent.

get a minidsp 2x4 you gotta have a birthday or valentines or something coming up.

Its Tuesday. Hilariously, Im getting a 2x4. You got a crystal ball over there? But the delay is limited to 7.5ms.

How far away from each other are your subs,thats crazy.Been more than 2 years so i dont recall the maths i used but my subs were only a few feet from the mains and across from each ohter. Now i just keep my subs at the front of the room . GTG

I just use excuses to buy what i want, there's always some BS holiday or special event i cant use to justify. I just ordered a new 6 channel Emotiva amp , 2600 bux no excuse required, its my money.

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Thanks Eric. I will order he cables up and try the oppo out.

Richard, its not really the sub distances I'm correcting for. Their physical location is part of the puzzle, but the bigger issue is the internal latency of the dsp and electronics/driver.

The close mic measured latency from a test impulse to my mains is about 4ms.
The close mic measured latency to subs is about 25ms. The subs dont have a clean impulse, from measuring in room, so its hard to get an exact figure.

Once I add in delay for distance to mlp considering all channels I cant correct for the 25ms. I should be able to get them both time and phase aligned with the oppo and 2x4.

Some might ask "why go through the trouble?"

The reason is when two or more wavefronts converge on a single point in space, in time and in phase, they sum additively, load that point with pressure, and present a cleaner response to neighboring frequencies by reducing out of phase cancellation.

I will post response and phase plots with 'tape measure' setting, 'time aligned' setting, and 'phase and time aligned' setting with impressions later. I can say getting time aligned is the big one to maximise output.

Ill start a new thread so its easier to find later.

"The reason is when two or more wavefronts converge on a single point in space, in time and in phase, they sum additively, load that point with pressure, and present a cleaner response to neighboring frequencies by reducing out of phase cancellation."

This is called Wavefront Acoustics. I can vouch for the reduction in out of phase cancellation. I could not make out the snap of drumsticks on the drumskin or the snapping of strings with my EP600. I don't have that problem anymore with the EP800v4!

So in theory would you want the subs at the same distance for the time alignment instead of like my set up one 15 feet in front with my mains and another beside couch only a couple feet in back of room?

Trevor thats some crayzy azz delay in the dsp what subs are you using. Can you not turn off the dsp and go straight and use the 2x4 to adjust your subs.

Thanks for bringing this up, it something i would have not thought about. I have never hada sub with dsp built in.

Brendo, you dont need to have your subs placed the same distance to your mains, but you would need to be able to delay (advance them stricktly speaking) them independently to align them properly. The newer Denons allow different settings for delay and trim for 2 subwoofers for example. You are really only able to do this for one point in space, and over a narrow band when aligning to mains.

Without independent delay the subs can be aligned to eachother physically by placing them equidistant to your position AND the mains. Otherwise cancellation with one channel or another. Symmetrical setup is really the best to deal with this.

The newer subs probably have less lag than my older svs subs. It would be interesting to see how the Axiom subs behave. It wouldn't surprise me if they were a little better, but probably all powered subs are 20ms or so behind their smaller passive speaker counterparts. If your AVR auto cal sets the sub distance wierd (long) this is likely whats its trying to correct for.

In case that read confusing here is how you would do it without independent delay. I even found an Axiom example.

The delay in the EP800v4 appears to be about 7 or 8 msec at 80 Hz. As Trevor said, the time delay, polarity and phase settings are critical. A difference of 5 msec results in 10 dB of attenuation at my MLP. Ditto with incorrect polarity and phase.

My mistake...the processing delay in the EP800v4 is about 5 msec at 80 Hz.

Thank you for all your knowledge on these REW type details guys.

Having an Anthem Mrx720 I'm still not sure how they deal with subs.
Followed their instructions {set subs SPL to 71 for dual EP500\SVS PB1000} should get them to 75DB. paired. Though I don't think they are treated separately as Denon does.

To Trevor would the Phase adjusting method you explained to us around a year or so ago, Raising the sub distance to the highest SPL. Still be effective in this situation? Or would it just add more delay?

Mojo is finding the 1/4 wave pattern. Guaranteed the latency is greater than 5msec. The reason I know this is he is quoting a frequency. But he is spot on anyway.

The sine wave vs spl test will get you perfectly time aligned but wont account for phase alignment. Strictly speaking, phase alignment requires transfer function measurements, smaart live or equivalent. I dont know if REW does it. I use audiotools. Phase alignment is both onset of transient and cycle alignment. Uber aligned.

Dont despair! Getting a max spl at the low pass setting is dang great! I messed with some stuff today, but the full show and tell needs a little more time. I just got the 2x4 but still boxed up. Tomorrow maybe. Libations for now!

The oppo 103 has severe clipping problems when you set the speakers to small and implement subwoofer bass management. When a strong input signal is sent out the channels distort horribly, even at low listening levels. This is a problem on oppo's end that they didn't seem to be able to resolve I guess. Not good!!

set speakers small
crossover 60hz
debussy invocation off stereophile test disc as example. clipping more than a barber shop.

I had initially thought it was the introduction of the minidsp2x4, but the issue persisted when I removed it from the chain. Resorting back to letting the AVR send signal to the outboard amp from preouts solved the issue. Thank goodness it wasnt the amp!!

-1 for oppo. Not very good guys. frownie face! I was a pretty big fan. Little disappointed now.

And it seems the 2x4 drops the input signal enough that without reducing trim it causes a net loss of 7db in room! Cough..... How the heck is this not something people mention?!

So, maybe for subwoofer eq? Would be fine if you didnt need to reference it to other channels. Dont expect a write up on this one.

Edit: yep. Insertion loss in signal path. So both the oppo and 2x4 have gremlins.....

https://www.minidsp.com/forum/hardware-support/1338-re-minidsp-output-volume-voltage

pulling it apart to change the jumpers now....

It's unfortunate (or fortunate depending on your perspective) you found these problems. I wonder now what my Onk's pre-outs are like.

I don't know what you mean by the quarter wave pattern. I wanted to make sure I minimized a null in SPL at my MLP at the 80 Hz crossover. In my Onk, I set the distance between my sub and the MLP, secured the meter at my MLP, and established the correct polarity by playing an 80 Hz sine tone. I set the polarity such that it resulted in the highest SPL. Then I increased the distance setting until the SPL went to a maximum. Finally I adjusted the phase to ensure a maximum SPL. My phase is set to about 60 degrees. I saw no difference in SPL between 0 to 60 degrees. After 60, it started to dip. Coincidentally, one of my fundamental room modes is at ~80 Hz due to my ceiling.

My sub is 9 feet away from my MLP. The distance setting that resulted in the highest SPL was 14 feet. I thetherefore had to add 5 feet to account for DSP processing delay. This is about 5 msec at 80 Hz.

Yeah, I was pretty bummed when neither worked out of the gate. By the time I found out the minidsp could be changed via jumper settings I wasnt in the mood. To be continued!

You found time alignment. You are close. Keep adding cycles till the sound locks in. You will hear less ring/hangover from my testing. It will feel less enveloping but more agile and taught. Less of a wash over the room. The physical impression is a shift from slam to rippled slam. More defined pulses.

Here is an article that explains things better than I can.

https://www.prosoundweb.com/channels/live-sound/time_phase_alignment/#

What I meant with 1/4 wave was you found the relation of changing delay by the corresponding time of an 80hz quarter wave. From peak to null and so on.

1000ms/80Hz= 12.5ms/cycle
12.5ms/cycle X 1.13ft/ms= 16.25ft delay/cycle
16.25/4= 4.0625ft delay per 1/4cycle

Then you added -60 degrees rotation, equivalent to subtracting 1/6 of a cycle (-2.7ft) from your advancement of 14ft. So your actual setting is something like 11.3ft or 8.629ms net.

Its really better to leave the dials at 0 degrees and normal polarity and do exactly as you did by adding AVR channel distance onto your sub physical distance. Adding distance to the subwoofer is really shifting it forward in time relative to the other channels -good. The phase inversion/dial on a sub cannot advance, only stall the signal -not as good. So each setting of AVR distance (advance) vs physical dials (retard) work against eachother. I hope this makes sense.

The oppo setting for phase alignment was 35.3 ft plus one cycle at 60hz. In room it was 52.5ft. The calculated value was 54ft. Pretty close. One drawback of the oppo was being unable to feed analog test signals fhrough its processing. I'll never be totally sure on the oppo but it sounded really great.... Until it met a 0dbfs signal from a test cd. Blorch!

At one point most people were buying minidsp balanced model for the higher output voltage. If you look at the operating instructions for the balanced unit you will see it can do 4v and also adjust input sensitivity

This 800v4 is tight, TIGHT, TIIIIIGHT!!!

And it pulses and drenches the
entire space with infrasonics when it's asked to. I can't possibly see how it can get better. Truly! It's a dream sub for movies and music.

Actually I am finding the extreme lows and infrasonics a bit hard to take. I've seen some descriptions of bass labelled "transparent" and that's a very fitting description for what I hear. BTW, it is not set hot nor cold but rather calibrated at the same level as all other speakers. There is simply no comparison to the 600v2.

Told ya so, ha!...

TAM

Imagine if you upgraded to the v4!

Hopefully the DSP is programmed to filter out "the brown note"

You know...there is such a thing.

The new house to build sound, with simple wiring, reduce the number of equipment principle, searching for a long time, feeling OPPO Blu ray functions, video, audio, network is more balanced, but people are more concerned about the 2 audio performance, and MARANTZ SA8005, NA8005, which is better?

Awesome!

I would buy the one with the features you need. They are all great. Oppo must have fixed the analog output issues in the 203/205 players. I still consider the Oppos a video first device.

I cant imagine buying or recommending a product without spotify support, so I would lean that way personally.

I just finished listening to Infrasonic Dreams by Bassotronics. I thought the 800's drivers and cabinet were coming unglued and I could localize the bass. Nope! It was my bathroom door moving to the beat. The 800 was rock solid - no extraneous sounds from the cabinet or drivers.

Although I had my Onk's volume at about 1 W/channel, the track still managed to make me feel a little sick and disoriented.

BTW, I have usable bass down to 10 Hz in my room. I suppose that makes sense given the longest dimension of my room is 30 feet.

Lol. I like it.

Maybe a dual sub build is in my future

I can't wait for the LFR800!

SUCK MY SUB-BASS, boys (and one Sonicfox).

Mojo at home. Since this thread is pretty well hosed now

Lol

That just about sums it up, Trevor.

Sorry about bassgasming all over your thread.

If I ever win the lottery I'll but you guys an EP800

It'll stay at my place but we'll share it,lol