It's kind of becoming a truism that music on DVDs is generally better than that released on CDs. The sampling rate shouldn't make that much difference (48kHz DVD vs. 44.1kHz CD), but it does.

And then 5.1 DTS will have more resolution, and more dynamic headroom, than does a CD - and if properly mixed, you really notice. (Sometimes they just make a fake surround from the CD-version, but if they go back to the mastertapes and start over, you get a much better result.)

Here's why it's worth rummaging through second-hand DVDs looking for the early versions of DTS-releases. They had full resolution audio, while it's been capped now, because they wanted to place more content on the disc:

In the consumer (home theater) market, AC-3 and DTS are close in terms of audio performance. When the DTS audio track is encoded at its highest legal bitrate (1,536 kbit/s), technical experts rank DTS as perceptually transparent for most audio program material (i.e., indistinguishable to the uncoded source in a double blind test.) Dolby claims its competing AC-3 codec achieves similar transparency at its highest coded bitrate (640 kbit/s). However, in program material available to home consumers (DVD, broadcast and subscription Digital TV), neither AC-3 nor DTS run at its highest allowed bitrate. DVD and broadcast (ATSC) HDTV cap AC-3 bitrate at 448 kbit/s. But even at 448 kbit/s, consumer audio gear already enjoys better audio performance than theatrical (35 mm movie) installations, which are limited to even lower bitrates. When DTS-audio was introduced to the DVD specification, studios authored DVD-movies at DTS's full bitrate (1,536 kbit/s). Later movie titles were almost always encoded at a reduced bitrate of 768 kbit/s, ostensibly to increase the number of audio-tracks on the movie disc. At this reduced rate (768 kbit/s), DTS no longer retains audio transparency.

Hi, I have Beolab 5 and BS9000. When I feed the labs 5 with SPDIF-cable I feel that the bass is more blurred and diffuse. When i feed the labs5 with Powerlink cables I feel that the speakers get alive with much more bass.

Can someone tell me why there is i large difference in the bass-response between feeding the labs 5 with spdif-cable and powerlink-cable? I have set bass,treble and loudness at neutral when using the powerlink cable.

1. Check that you have the same volume level with both feeds. Even a variation of 1dB sound pressure level will make a difference to the bass perception.

2. If the levels are similar, and the difference persists, then it could be that your BS9000s neutral setting in the tone controls actually changes the frequency curve such that the playback is better for your room; conversely, that the supposedly neutral spdif creates a frequency response that is affected by your room.

3. Try different kinds of music, to see whether this could be related to one recording.

Thank you soundproof for your reply. Do you know IF there maybe are any differences in soundquality between BS9000 Mark I (i have that one) and BS9000 MarkIII when using the digital out(spdf)?

Have you tried this two soundoptions(spdf and powerlink) and noticed any sounddifferences with BS9000 and Lab5?

Regards
Martin

Hi Martin,

There shouldn't be any differences in the quality of the spdif-signal -- it's a pass-through signal from the source to your BL5s. I have a Beogram CD6500 which I take the spdif out of, when I'm using that, and I can find no difference between that signal (from a unit that's decades old now), and modern spdif equipped components.

But there will be differences between your PL and spdif, mainly in that the volume level will be different, with the spdif usually being louder, but that depends upon what level you've set for your PL playback.
So you have to match those levels before you can evaluate the playback quality.

With my setup, I get much louder playback from spdif than from the level for the LINE IN from my surround processor. Whenever I listen to two-channel music, I use the spdif feed. I've set the working level of the BL5s so against the volume of that feed, to avoid having to correct the volume. But when I switch to watching movies, I "tick" the volume up 9 times (!), to reach a similar volume.
That's why you need to be certain that the sound level is matched between two sources - it could be that your louder playback is overpowering the room, for instance. (And the spdif is usually louder than what comes from PL, but that depends upon the level you've set on your audiomaster.)

Thanks for your answer soundproof.

I have tried three other different CD-players (Marantz, Cambridge and NAD) and used the SPDF to the labs5. Even if the SPDF is a pass-thru the sound is different between the three players. The NAD-player had much more bass than the Marantz. The treble in the NAD-player was not so clear as the cambridge-player. So there is a clear difference in the soundquality between different CD-players even if you just use them as a "transport" thru the SPDF. I think it is strange, but it is true. Can you maybe explane why?

Yes. If you use a dB-gauge, you'll find that each player has a different output level.

Shouldn't be that way, but manufacturers manipulate the output, as they know that people will make side-by-side comparisons. (Some even convert the audio from digital to analog, filter it, reconvert it to digital, and then send it out of the unit. Don't know the details of the ones you've used, though). And louder will usually mean better, in that the soundstage will seem larger, the details will stand out more.

I've found that the best thing is to find a signal path that pleases one, related to the kind of music one usually enjoys, and then stick to those components. You get more listening done that way!

(Also, you have to factor in that if you're not using a switcher, to easily switch between sources, but instead are disconnecting one, connecting another, moving back to the listening position -- then it's really very difficult to tell sources apart. The mind adds a lot, trust me!)

Hi again,

I just feel that the bass-response are much more "alive" generally when using PL than SPDF with my BS9000. My room is about 20m2 and there is very much echo (little furniture and wood-floor) in the room. Maybe it is the acustic situation in the room that the labs5 can´t handle correct. Maybe the BS9000 does "something" with the bass and treble when using PL, even if the bass,treble and loudness is set to neutral. What do you think about that?

Here's what I wrote in my first response:

2. If the levels are similar, and the difference persists, then it could be that your BS9000s neutral setting in the tone controls actually changes the frequency curve such that the playback is better for your room; conversely, that the supposedly neutral spdif creates a frequency response that is affected by your room.

I'd be inclined to think that the spdif is the most neutral signal; and it could be that your PL signal is making a change to the bass that helps relative to some room interaction with the speakers.

You might want to try another speaker placement. I moved mine around quite a bit before I found the spot they're in now.

Thank you soundproof for your advise. It is nice to speak to someone who know theese things.

Regards
Martin

Hi everybody,

I'd like to add that many Beolab 5 setups I've seen show that the speakers are placed to near to the wall. The dynamik range is much better if the Beolab 5 are placed 50 to 100 cm in front of the wall. I have placed mine in a big room with a wooden floor and a lot of glass at he walls. These are very bad conditions for a high end setup, but the Beolab 5 are the ones who managed this much better than my Beolab 8000 / Beolab 2 setup. Calibration is the key advantage of the Beolab 5. 

Best,

E.

Hi erg4000,

I have placed my labs5 about 25cm from the wall. I can not place them at another way, because my room is rather small (20m2). Do you have a beosound 9000 connected to your labs5?

Hi Martin01,

my Lab5's are connected to the Beocenter 2 (digitally) and the Beosystem 3 (Beolink). Have you considered that a noise cancellation can appear if the Lab5's are to near to each other and to the surrounding walls ? Our living room is about 88 m2 and it's interesting how different the bass feeling is from one place to another. Interestingly the maximum bass point is asymmetrical  more to the left. The glass wall at the right probably causes a noise cancellation.

Best E.