Quote:
Originally Posted by
naturephoto1 
I have made comparisons of stock versus upgraded components as I have previously mentioned, though many will argue that the testing was not adequate. I am hoping to have the opportunity to get together with some of the AVS members sometime in the not too distant future.
Rich,
First off, I must say that I've really enjoyed your level-headedness and civility in these discussions. You have been much more civil and respectful than some of the other posters you're conversing with. Kudos to you for that.
Do you use the analog or the digital circuitry in your 885? IOW, is your Oppo 83SE connected via the analog MC outputs/stereo analog outputs, or is it connected via HDMI/optical/coaxial digital? If you are using the analog circuits, (as I suspect you are), you're not really playing to the strengths of the Onkyo 885 pre/pro, and you're playing to a glaring weakness of the Oppo, (more on that in a second.) The 885's biggest strength is in it's digital signal processing, Bass Management and Audyssey MultEQ XT capabilities. However, these are all performed in the digital domain, and the MC analog circuit bypasses these processes entirely. (The analog stereo inputs can be digitally processed, or the processes can be bypassed, at the user's discretion.) Either way, if you're not using any of the digital signal processing in the 885, I don't think you are using it's strongest attributes.
More importantly, I'm not sure what TUC can "upgrade" in the analog MC signal path because, AFAIK, that circuit is a simple "pass through" with gain. There just isn't much in there that could potentially benefit from an "upgrade."
In terms of the "glaring weakness" of the Oppo 83SE, if you're using it's on-board Bass Management, that is a totally messed up BM scheme. It's *supposed* to be an 80 Hz crossover, but, in fact, the crossover frequencies are different for the HPF and LPF. In addition, the crossover slopes are just bizarre:
From the Audioholics review with measurements:
Quote:
Oppo only gives you one choice of crossover frequency; 80Hz, which is supposed to apply for the subwoofer Low Pass Filter (LPF) and the High Pass Filter (HPF) for all speakers set to small. This is fine for most applications and we like to see the filters exhibit the following roll off characteristics per THX for optimal subwoofer to satellite speaker blending.
HPF: Fc = 80Hz 12db/Oct roll off with -3dB pt at 80Hz
LPF: Fc = 80Hz 24dB/Oct roll off with -6dB pt at 80Hz
Unfortunately neither player followed this recommendation. In fact, they were both different from each other which again was puzzling though not surprising since no DVD / Blu-ray players we've bench tested with the exception of Denon flagships (ie. DVD-5910CI, DVD-A1UDCI) actually exhibit the correct specified cut off frequency and roll off characteristics.
http://www.audioholics.com/reviews/t.../oppo-bdp-83se
I can't copy their table of crossover points and slopes but here is a summary:
- The 83 Had an LPF of 130 Hz and 16 dB/Octave slope, and an HPF of 100 Hz and 12 dB/Octave slope.
- The 83 SE had an LPF of 143 Hz and 18 dB/Octave slope, and an HPF of 90 Hz and a 13 dB/Octave slope.
None of those crossover points or slopes makes any sense. Oppo states the crossover is *supposed* to be an 80 Hz crossover, but clearly it's anything but. I tried to help a friend integrate his subs using the Oppo's 83SE's analog MC outputs and its' BM scheme. I found that it was virtually impossible to get it right.
In addition to the BM issues, the 83SE's "summing" of the re-directed bass with the LFE was channel was found to introduce very high levels of distortion:
Quote:
What was perplexing however was the outrageously high distortion from the subwoofer channel of the BDP-83SE. We double checked this with the built in digital Oscilloscope feature of the Audio Precision and could see visible clipping of the test signal. The output signal level was 2.7Vrms so we knocked the subwoofer trim down -10dB figuring the opamps were hitting the rails causing it to clip, and retested. The sub output level dropped to around 1Vrms but was still clipping hard. We retested using a -20dBFS test signal and boosted the subwoofer level to +10dB which would give us about the same 1Vrms output level that clipped the subwoofer channel before. This time the distortion levels were similar to the other channels (< 0.05% THD + N). What this told us was that the BDP-83SE was not properly handling 0dBFS digital output levels when recombining into the subwoofer channel.
Bottom line, if you are using the Bass Management in the Oppo and bypassing the Bass Management in the Onkyo, you are likely not getting optimal Bass Management, and you may be introducing huge amounts of distortion into your subwoofer channel. (OTOH, if TUC's "upgrade" of the Oppo 83SE fixed these problems, then the upgrade could be totally worthwhile. Wouldn't it be nice if TUC would at least provide this kind of insight into what their "upgrades" consist of? Does the OSD of TUC's "upgraded" Oppo have any changes to the menus or the Bass Management choices? Does it offer any other crossover frequencies, or any other indication that the BM issues were sorted out in any way?)
In addition to the issues with the BM signal processing, the Oppo's Speaker Distance settings are rudimentary and difficult to optimize. From the manual:
Quote:
Since the delay is calculated based on the distance difference from each speaker to the listener's position, it is important to set the distance for the front speakers first and then the other speakers. Anytime you change the distance of the front speakers, the distance of the other speakers will be automatically adjusted to maintain the same distance difference.
Distance between the surround speakers and the listener must be shorter than or equal to that between the front speakers and the listener. In case the channel delay settings cannot match your speaker configuration, please set all distances to the same and use your receiver/amplifier to set the channel delay.
Getting the speaker distances correct can have a
huge impact on sound quality, and the Oppo's inattention to this important detail is very disappointing. Nonetheless, if you use the Onkyo's internal digital processing, you can set the Distances to within 0.2 ft of the correct distance, (as opposed to the Oppo's granularity of just 1.0 ft increments.) You can also set each speaker's distance without regard for its' distance relative to the other speakers in the system.
I know it may seem that these basic settings are less important, and that "audiophile tweaks" like cryogenically treated cables, "audiophile grade electrical outlets," and disc de-magnetizers etc. can have a bigger impact. However, in my experience, if the "BASIC" fundamental settings of speaker/subwoofer levels, distances and crossovers are optimized, if room acoustics are addressed, and if high resolution room correction is employed, there will be very little left for the audiophile tweaks to improve.
Many audiophiles seem to disdain Digital Signal Processing, (BM, levels, distances, Room Correction, etc.), as "another veil in between the listener and the music." On the contrary, I find it to be the set of tweaks that optimizes the listening experience.
I would still love to hear your system with all it's audiophile tweaks, and to have you hear mine, with all it's DSP tweaks.
Craig
.
