5.1 or lossless audio

To my ears, it depends on how well made the blu-ray disc is. Lossless audio (DTS-MA, Dolby TrueHD) is only available on blu-ray disks if it's encoded that way. I think a large part of being able to distinguish between lossless audio and compressed audio is how good of a speaker system you have. Our speakers are good for our listening environment but are certainly at the lower end of quality, but they serve their purposes. We watched The Avengers the other night (lossless) and while it sounded really good, I had a hard time distinguishing the quality of the soundtrack versus another blu-ray that had compressed audio. If it were me, I'd go with a receiver that can pass-through lossless audio because you never know how your situation will change and I think the tendency is to keep your receiver longer than your speakers or even your blu-ray player. Lossless audio can be passed via a High Speed HDMI cable (blu-ray player to receiver) but it can't be passed via optical. Optical cables are used to pass discrete 5.1 audio to your receiver from either the internal ATSC tuner of the tv or the cable/sat box.

First - "props" to Otto - you are absolutely right. How much of a difference lossy audio versus lossless audio makes is truly dependent upon the speaker system being used. Well done.

To answer the OP's questions, lossy audio was invented because originally there wasn't enough space on the disc nor a fast enough method to send out the bits to support lossless multichannel audio. So a method was invented to reduce the number of bits and increase the number of channels to 5.1-channels (then 6.1-channel for DTS and 7.1-channels for LPCM, DTS-HD MA and Dolby TrueHD).

Based on numerous studies, it has been shown that parts of audio are inperceptible to most humans. The obvious things are frequencies that are too high to hear or too low to hear (although those can be felt). In addition to those, we have a difficult time perceiving very soft sounds while a loud sound is also occuring. A finger cymbal being hit at the same time a cannon is fired will not be heard. The lossy algorithms take this into account when reducing the sounds to make the bits fit in the available space. Their goal with these algorithms is to 1) reduce the bit count to an acceptable level and 2) make it inperceptible to the average listener.

So, for you to notice the improvement with lossless audio, you would have to have a system that allowed you to hear the differrences. A bunch of little satellite speakers with little dynamic range will not provide an ability to hear the differences. Obviously your own hearing would have an impact as to whether or not you could hear a difference.

Finally, there is no such thing as low-loss audio. The whole idea behind the lossy audio was to save space. Low-loss would not save significant space and would make no sense. Be careful of any source that mentioned low-loss since they obviously are talking outside of their area of knowledge. By the way, Dolby Digital Plus uses more bits than Dolby Digital but is still a lossy audio scheme. It is definately not low-loss. Dolby TrueHD and DTS-HD MA are both lossless audio. The bits output from those two codecs are the exactly same bits that were originally recorded.

The bottom line to all this is the following question: What are you missing from your present system that you think lossless audio and a new receiver will solve? If you can give us an answer to that, we can probably tell you if you are on the right track.

Andy, thanks. always learning

I think you're on the right track with the way you are thinking about the audio improvement.

Keep in mind, that if you ever get to the point you start to say that the cymbals should sound a little sharper or the bass drum not as boomy, it might then be time to reconsider.

Of course you are talking to someone who had the sound pressure wave from his speakers push the light switch on (and it wasn't boomy bass either). It was a Shuttle launch recording and that was enjoyable have accidentally happen.

Like I said, if your tastes change, you can always re-evaluate.

The ‘lossy’ audio you receive via the Optical cable from the BD Player to your AVR will (with a well recorded/encoded disc) offer you a bit of a lift in dynamics over the quality you receive via Optical from your Broadcast and DVD sources.

It is amazing how over sold these various badges are on kit and how they blind folk to ensuring the fundamentals are in place first.

Joe

PS If your BD Player has multi-channel analogue Outputs RCA’s and the AVR has multi-channel analogue Inputs RCA’s for 5.1 you can have the BD Player decode the HD Audio and send it to the AVR that way – you then need to set the BD Player up in terms of telling it what size speakers you have, Sub crossover point and distances to the listening position as the AVR wont ‘process’ the multi-channel analogue.

For those who might read this thread in the future, while the Onkyo TX SR 502 won't provide bass management on its external multichannel analog inputs, there are many other AVRs that will provide bass management with external multichannel analog inputs. These are usually the higher priced units from a brand and include higher-end Denons back to those manufactured in 2003.

So, check your owner's manual to determine whether bass management with the analog multichannel inputs can be done in the AVR. If it can't then use the BD player's (DVD player's) capabilities instead. Never use both the AVR and the BD player. Using both the AVR and the BD player for bass management is an excellent way to muddy-up the sound.

If you are playing SACDs or DVD-Audio discs (or music Blu-Rays) then the difference between lossless and lossy audio can be breathtaking. But, that requires a system that can take advantage of the extra information and someone listening who will notice the difference. It isn't just dynamic range either. It's the clearer high end and the smoother bass. When you look at a reconstructed Dolby Digital waveform (compaing against the original audio), the reconstructed Dolby Digital waveform often overshoots in at high levels as compared to the original recording. This results (usually) in the high freqencies not having as clean of a sound as they started with. Kind-of shrill instead. When you drop that many bits, something gets lost and that's the result.

Whereas with lossless audio, there is no reason you can't hear exactly what the audio mixing engineer heard (assuming the mastering engineer didn't change anything). These can be crisp and clear recordings. Where an instrument actually sounds like the live instrument.

While I don't think this matters for most people, I didn't want to "sell short" the benefits of lossless audio. When I make BD discs, I try to include a lossless track because there may be someone who watches the disc who will enjoy hearing the sound the way I did when mixing it (it's a fun hobby).

I guess one good test would be if someone thinks that MP3 sound is good enough, then there is no real need to worry about lossless audio quality.

While I agree with all of the technical aspects voiced by folks in this thread to me the issue is one of aesthetics. Lossless audio is the way the movie is intended to be heard, lossy audio is a compromise. Perhaps this is not as major of a factor for you as it is for me.

Most people who move into the 3D world of presentation will purchase a AVR that passes 3D content. Of course there are ways around this, people will route the HDMI video from their Blu-ray player to their HDTV or projector while using the optical or coaxial output (assuming their player has this option) to their AVR. I have gone through many receiver upgrades over the years and each has brought new features I have been very satisfied with. It's your money and your decision.

That movies were intended to be heard this way is a major misconception. Movie theaters have used AC3, DTS and SDDS for many years for multichannel. It is only recently that lossless has made it to some movie theaters.

In addition, the soundtrack in theaters is mixed differently than Blu-Ray. It is very unusual for the same mix to be used for the home release as was used in the theaters. Theaters are (usually) a much bigger room, filled with people (hopefully) and with multiple side channel speakers and usually at least four back channels. In addition, the speaker layout behind the screen is usually different than a home theater. So, all of these combined make for a different environment than the home and therefore a different mix. You could, however, that despite these compromises, most (not all) producers/directors consider what appears in theater to be what they indended (audio and image - maybe not content).

Now, if you had said that the lossless mix is closer to what the mixing and mastering engineers heard, I'd agree with that. But, only if you also have the same (or similar) setup to what they used. I don't care how good the lossless mix is, nobody will notice the difference if it is played through 5 2-inch cubes and a 4-inch "sub".

This is, of course, how THX was born - an attempt to certify that reference components and material matched at home what the producer/director/mixing engineer / mastering engineer all heard and saw.

Yes, of course, that is what I meant in my original post. Sorry I wasn't concise enough for you. I am also aware of the history of sound in movies.

If people want to listen to movie sound in the lowest common denominator that is their choice. The intent of my post to the OP is if he is striking out in new direction (3D) he should at least consider purchasing a new AVR for lossless sound. My assumption was that his Polk speakers were of a high enough quality to justify this upgrade.

Sounds good (pun intended).

Bear in mind that one major reason for getting a mid-range (or better) modern receiver is its room equalization software. Whether Pioneer's MCACC, Yamana's YACC, or Audyssey (used by Onkyo/Integra, Denon/Marantz and NAD), it can make a noticable improvement in the accuracy of the sound provided by your speakers in your room acoustics when compared to a receiver or pre/pro without it.

The correct way to wire LFE is go straight from the receiver to the subwoofer. This way the bass management is being performed by your AVR, which will know the distances and levels of your other speakers. That should be your only audio cable going to your subwoofer.

Composite video jacks - because many of us still use it with older equipment. I still have cassette tapes that haven't been converted to digital that still work. Occasionally (maybe once a year) I need to look at an old VCR tape for historical purposes and really don't have the time to convert those 100s of tapes. All of those require the legacy connections.

Also from a custom installation setup, the composite video output jacks can be used to indicate whether a component is on or off to a remote control base station.

Good luck with the new AVR. Don't forget almost every current AVR has an "owners" section in the AVRForum where you can rear other user's experiences with that receiver before purchasing.

Let's backup a bit. Bass management is a term used to describe how bass is divided between your 5 main speakers and the subwoofer. Normally this is done in the receiver because the receiver is the only one who "knows" how big each speaker is, how far away each speaker is and (in more modern receivers) the best frequency response for each speaker. The subwoofer has none of this information.

However, there was a time when not all receivers had an LFE output (or bass management). In order to get around this limitation, subwoofer manufacturers put a band-aid into their systems allowed a speaker-level signal to be sent to a subwoofer. This speaker level signal would then be continued onto one of the main speakers. This wasn't a great idea since it meant that the frequencies produced by the subwoofer would also be produced again by the main speaker. To get around that, subwoofer manufacturers provided a rotating knob that cutoff upper level frequencies being produced by the subwoofer so as not to generate those frequencies when the main speaker was also generating those. That's the knob you saw.

Now if bass management is being done by the receiver, then there is no use for either the speaker level wire or the cutoff frequencies since that is all done in the receiver and more correcly done than any subwoofer will ever do.

For the best possible sound, remove any speaker wiring going to your subwoofer. Connect the RCA plug from the LFE output of your receiver to your subwoofer. Take the lower frequency cutoff knob and turn it to the highest frequency possible (basically no cutoff). If you have a second frenquency knob that one probably won't impact the sound (it's a lower frequency cutoff knob for the main speaker) since you are no longer using the speaker outputs. Check your owners' manual if you are unsure of which direction to put the knobs for no effect.

Finally, when you get your new Onkyo, run the automatic (I think it's Audysee) setup. Use at least three listening positions even if they are close together. That system isn't perfect but it will get you close to an optimal sound. You really want to let the receiver handle everything and only have speaker wire going to the five main speakers.

Polk has excellent customer support. Also don't forget about "Club Polk" which is their online forum. I've refurbished early/mid-1990s big Polk speakers using what was available in Club Polk.

Which way to turn that knob will depend upon whether it is a high pass or a low pass filter. You want the subwoofer to get the biggest range of frequencies possible and then let your receiver limit the frequencies. I've never heard of a sub that disables the high pass or low pass if LFE is connected, but it's worth a check.

What model is it and I'll see if I can look it up?

I have to admit I hadn't see a sub with a dedicated filter bypass input. From your new Onkyo, use that bypass input for the LFE. If you want to be extra-sure turn the filter clockwise to the highest number (120Hz) as well, but that shouldn't be necessary.

Finally set the phase to 0 degrees. If after you have everything setup and tested, that would be a good time to try phase at 180 degrees, Compare the bass response at 0 and 180 and choose whichever one sounds the smoothest with a low male singing voice. Normally 0 degrees will be better but your room and the subwoofer placement may cause that to change.

Also when setting up your Onkyo's Audyssey system, set the subwoofer volume to its middle volume level. Then let the Onkyo do the rest.

Good luck - I think you'll really like your new system once it is setup.

That's great to hear! Enjoy your new system.

I'll bet that when you play "older" things, you'll start to notice sounds that you hadn't heard before.