Poll on how people listen to surround

[rondari]

All,

I have created 2 little poll questions, aimed at getting some more
concrete info on how people listen to surround sound.

http://www.ambisonia.com/poll

Should take about 10 seconds to choose the best 2 answers... would very much appreciate if this URL could be passed onto any other groups / forums / lists that deal with listening to surround sound.

Etienne

[rondari]

most of the people answering this poll are coming from the Ambisonics community... (who listen to surround sound mostly without video)

would be great to have more of the doom9 people's opinions. There's a raging debate about whether DTS or AC3 are the better options (DTS can be easily burnt to CD-Audio AC3 cant).

personally, I'm thinking that an AAC option is particularly promising because it can be streamed directly out of a web browser ... and that fast accessibility is a huge bonus.

The only problem is that there is little support for doing digital AAC to the AV receiver.

[Tack]

My HTPC is connected via toslink to my A/V receiver and I prefer either AC3 or DTS since I can pass those through to my receiver. Unfortunately the poll only let me select one of AC3 or DTS, so I chose AC3 for no other reason than there is better support for AC3 in free software.

[rondari]

I know of 2 AV receivers that can handle AAC digitally ....

the Denon AVR-3808CI (quite recent I think) ... and there's a Sony somewhere as well...

If it was possible to stream directly from a web browser, to QT7, and then digitally to an AV receiver ... that would be a killer setup.

Etienne

[Brother John]

I must say I’m not too exited by the whole multichannel mania.

For films putting most of the dialog in front center is the most noticable improvement that really sets multichannel apart from stereo. But that’s about it. Having full 5.1 is nice for some movies and rather pointless for others. I’d never bother with even more channels. Too much of a hassle to set up the speakers and too little gain. For mainstream music stereo is perfectly sufficient. Large orchestra recordings and stuff like that might profit from more channels. Never tried it out, though.

In my opinion DTS is a complete waste of video bitrate. (Hope I’m not starting any flamy discussions with this statement...) Space on a DVD is limited, DTS is huge and not allowed as the only audio track. There are some DVDs that could have great looking video but don’t because the studio decided to put a DTS track on them. So I consider DTS to be a completely useless format for DVD-Video. And that wouldn’t change even if someone did prove a significant quality advantage of DTS over AC3.

As for the poll: I decode in software (ac3filter) and feed the analog signal to my amp. Though at the moment it’s only a stereo setup because placing all speakers in my current flat would be a real PITA. Because of that I mainly use headphones if I watch a movie alone. And then I prefer AC3 because it doesn’t involve any transcoding and thus no quality loss.

[Tack]

Some 5.1 music is quite impressive. Listen to some of Bjorn Lynn's stuff. It's not just gimmicky: it's excellent music with very impressive spatial placement.

[SeeMoreDigital]

If you are intending for people to be able to listen to multi-channel audio via the web, then AAC is the way to go... As doubtless, most people interested in surround-sound will have a PC with a multi-speaker set-up.

Also, if they have their PC connected to a surround-sound amplifier via SPDIF, they can install FFDshow on their PC and set its audio filters to transcode 6Ch AAC to 6Ch AC3 in real time (ie: on-the-fly). Which is what I do ;)


Cheers

[tebasuna51]

I agree with Brother John in DTS/AC3 comparison, I can listen differences to justify the high bitrate and is less compatible.

Actually the best compatible is AC3 like SeeMoreDigital admit when need transcode AAC -> AC3 to play with SPDIF output.

But, of course, the future is AAC. We can output the 6 channels AAC from the PC to a receiver with 6 channel input without lose quality transcoding to AC3. There are also new standalone players with AAC.

My opinion in this poll is clear:

- For high quality lossles formats.
- DTS, obsolete.
- AC3 the actual standard.
- AAC the future.

[rondari]

An other option being considered for distributing multi-channel over the internet is via Vorbis. Vorbis' compression algorythms are, I am told, very modern and comparable to AAC.

Streamed Vorbis in combination with a VLC player embedded in the browser could also allow a very good and easy surround experience. Although there's always the issue of how to get to the surround amplifier in digital ...

[henryho_hk]

Streamed Vorbis in combination with a VLC player embedded in the browser could also allow a very good and easy surround experience.

I recall in the old D0lby Pr0 L0gic time I tried to compress those soundtracks in Vorbis and the hidden surround signal got scrambled even at Q6~7. Multi-channel Vorbis is a different story of course.

[prOnorama]

In my opinion DTS is a complete waste of video bitrate. (Hope I’m not starting any flamy discussions with this statement...) Space on a DVD is limited, DTS is huge and not allowed as the only audio track. There are some DVDs that could have great looking video but don’t because the studio decided to put a DTS track on them. So I consider DTS to be a completely useless format for DVD-Video. And that wouldn’t change even if someone did prove a significant quality advantage of DTS over AC3.


Wouldn't say it's a complete waste especially if no extras are included on the DVD.

Especially for music DVD's or films in which music plays a big part (like music documentaries) DTS can be great. I have a few full bitrate DTS Music DVD's / documentaries and they clearly beat AC-3 sound wise. :)

For feature films (especially when very long) I think DTS is usually not so important (depends on the content though horror films can benefit from DTS sound effects more than say "talk only" arthouse films)

[nurbs]

An other option being considered for distributing multi-channel over the internet is via Vorbis. Vorbis' compression algorythms are, I am told, very modern and comparable to AAC.

A problem of vorbis is that it only has channel coupling implemented on stereo. So while vorbis is competative with AAC at stereo it is at a disadvantage as soon as more channels are required.

[Bigmango]

In my opinion DTS is a complete waste of video bitrate. (Hope I’m not starting any flamy discussions with this statement...) Space on a DVD is limited, DTS is huge and not allowed as the only audio track. There are some DVDs that could have great looking video but don’t because the studio decided to put a DTS track on them. So I consider DTS to be a completely useless format for DVD-Video. And that wouldn’t change even if someone did prove a significant quality advantage of DTS over AC3.

As for the poll: I decode in software (ac3filter) and feed the analog signal to my amp. Though at the moment it’s only a stereo setup because placing all speakers in my current flat would be a real PITA. Because of that I mainly use headphones if I watch a movie alone. And then I prefer AC3 because it doesn’t involve any transcoding and thus no quality loss.

DTS is a completely different movie experience compared to AC3 if you are using a quality hifi equipment.

I can understand than on a low quality system you won't hear much of a difference.

Compared to AC3, the DTS track has much better dynamics, with deeper and clearer basses, its a completely different movie experience. To me it can make the difference between a good movie and an awesome movie.

I was surprised by this comparison once again just yesterday, with a blu-ray movie that had uncompressed 5.1, AC3 and DTS: the DTS was much closer to the uncompressed sound, with much better dynamics and basses. The AC3 track, as is the case most of the time, sounded flat (of course it had basses, but the sound is flat, lacking dynamics).

The same goes for SACD : DTS has dynamics with deep and clear basses, AC3 sounds flat.

Even on quality headphones the difference between the dynamic DTS sound and the flat AC3 is huge (I test this every couple days as I watch movies with headphones at nights).

That said if you use an el cheapo system or if you have ear problems the experience can be different for you.

[Brother John]

The problem with the AC3 vs DTS discussion is that bias and placebo effect play an unusually big role. For three reasons:

1. DTS sounds louder than AC3 at the same volume setting. And louder always gives the impression of better.
2. DTS has a higher bitrate, so naturally we're inclined to think it has to sound better because it's less compressed. At the same time we forget to take compression efficiency and transparency thresholds into account.
3. DTS is marketed as the mega always-sounds-better audiophile format. And marketing babble has a noticeably influence on our perceptions, though we all like to think otherwise (who wants to admit he can be manipulated?) .

Those problems make a conclusive comparison tricky. The only way is a properly done double-blind listening test, because all other comparisons are very likely to be extremely flawed. If anyone knows a link, please post! I'd be really interested.

Disclaimer: I'm not saying it's wrong to subjectively feel more comfortable with DTS. I say it's wrong to claim DTS's superiority based on probably biased experiences.

[Bigmango]

If you don't hear the difference between AC3, uncompressed PCM and DTS there can be 2 reasons:

1. you are using a very low end system or

2. your ears don't work as well as they should. Many people are born with bad sight and need to wear glasses, and in the same way many people don't hear as well as others. Also, many dont hear as well anymore due to having listened to music too loud or because of firearms or many other reasons.

If you wear glasses and don't see as well as someone else it doesn't mean that the one that sees better is having a "placebo effect", as you say. The same applies to your ears.

Many say 128k MP3 sounds as good as a CD. I tell you, 128k MP3 is lacking dynamics, the sound is flat.

The same goes for AC3. Of course AC3 sounds good, but compared to PCM or DTS it lacks dynamics.

As it goes with MP3, compress it less and it will sound as good. Or compare the dynamic range between a low end and a high end loudspeaker.

But anyway, these discussions have been going on on websites and audiophile forums & magazines for ages and the outcome is always the same: DTS sounds better than AC3, and AC3 is compatible with more systems. The audiophile industry (SACD, Audio-DVD, ...) also confirms this. So I think we are wasting our time talking about this "again".

Brother John, I am not trying to convince you. If you are happy with Ac3 that's the only thing that counts.



Edit: also quite often (but not always) the studios work more on the DTS track to add more effects compared to the AC3 track. So, DTS often (not always) also has a better soundtrack.

[tebasuna51]

...
Edit: also quite often (but not always) the studios work more on the DTS track to add more effects compared to the AC3 track. So, DTS often (not always) also has a better soundtrack.

This is true, but clearly is a commercial issue to cheat the users.

This is a old discussion and here we talk about encoder efficiency (quality/bitrate) not about low end or high end systems or ears.

BTW. What is "dynamics" for you? Volume, dynamic range, high frequency?

[Soulhunter]

Many say 128k MP3 sounds as good as a CD. I tell you, 128k MP3 is lacking dynamics, the sound is flat.
Dont forget the awful compression/quantization artefacts!

For the "how you listen" thing...

For multichannel stuff [mainly movies n games] I go: PC -> 7.1 Amp -> 7.1 speaker setup [which works for 5.1, 6.1 and 7.1]. For stereo music its: PC or CD player -> 7.1 Amp -> Headphones [good cans are hard to beat for 2ch music] or I let my amp mix it to 3x2ch + sub for background music [like... on partys, or when you get private with ya girlfriend, lol]. Regarding the audio formats: For music I prefer MPC, tho most of my audio is MP3 [192kbps +] for compatibility reasons... For movies the AC3 stream sounds good enough for me, I care more about the image quality here!


Bye

[shon3i]

768-1535kbps, on that bitrate all codecs will sound excelent and will have dynamics. DTS is totaly useless and obsolete, realy it have cleary better quality than AC3 @ 384-448kbps, but AC3 @ 640kbps and E-AC3 @ 640+kbps can make better results, and will be more compactible in future. I know 640kbps isn't compactible with DVD standard, but PCM is aways better soulution then ;)

[Brother John]

@Bigmango
Unfortuantely your typical audiophile magazine/website is especially likely to fall into placebo, bias and marketing traps. Just think of the ridiculous cable voodoo for example.

At the end of the day the choice is between possibly lower video quality and possibly lower audio quality. I'm a visual guy and most of the time would happily lower audio bitrate to have more space for video.


In future DTS might get a boost because it's one of the mandatory audio formats of both blu-ray and HD-DVD.

[Tack]

I'm not aware of any double blind control tests with dts and DD5.1 that were conclusive one way or the other. I'd be keen to read about this if anyone has any links.

Doing a fair test is difficult or impossible because dts and Dolby tracks are usually (always?) mixed differently. Perhaps how the tracks are mixed is considered part of the dts experience. In any case, with a fair test I'd expect to see volume differences taken somehow into account. Obviously I don't mean messing with the dynamic range, but adjusting some base level.

[SeeMoreDigital]

Hmmm...

Way off topic guys!