Our contenders for today are the Lost World DD THX laserdisc, the DD DVD and the DTS DVD.

Investigation's intend:

• Compared to the LD version, both DVDs sound louder overall. If this discrepancy is compensated for, the LD seems to have a bit more oompf in the bass. The overall difference is not as profound as with JP!
• The 2 DVD versions don't seem to have the -4db LFE difference that JP showed.

Description:

• Cliffhanging Ropes, Falling Trucks (not by Ang Lee)
• DD DVD vs. DTS DVD
• upper window is the left channel, lower window is the lfe channel
• red is DD DVD, turquoise is DTS DVD
• lfe data above 120hz is irrelevant!!!

Analysis:

• first and foremost, this graph reveals that the Lost World DTS DVD does not have the LFE channel recorded 4db too low as was the case with Jurrasic Park
• the lfe channel seems to be almost identical; the typical -3db @ 90hz characteristic of the CAE-4 DTS encoder can be seen; again, the data above 120hz in the lfe is irrelevant
• the left channels shows that the mixes used for the DD and DTS DVD seem to be identical in the above 120hz region, but the bass response is completely different, so bass effects have been remixed in one of the 2; later we will see that it is the DTS mix that might be the correct one, or at least the 'original'
• while the DD track seems to have considerably more bass in the sub 20hz region in the left channel, thats mostly irrelevant because its in the -50 to -60db range anyway; the bass in the lfe completely masks the bass in the mains as it is at least 10db louder
• the typical -10db @ 15kHz characteristic of the CAE-4 DTS encoder can be seen here also

Description:

• Cliffhanging Ropes, Falling Trucks (still not by Ang Lee)
• DTS DVD vs. DD LD
• upper window is the left channel, lower window is the lfe channel
• pink is LD, turquoise is DTS DVD
• lfe data above 120hz is irrelevant!!!

Analysis:

• from the characteristic in the left channel you can see that both were transfered from the same basis mix, but were completely different EQ'ed over the frequency spectrum; while they are identical at 30hz and within 1-2db's from 120-180hz, the new DVD mixes (both DD and DTS) are around 4-6db louder from 40-100hz and from 200-10k hz; so basically the DVDs are ~5db louder in the above 40hz range
• while the LD mix has more bass (10-25hz) in the left channel, the DTS DVD mix has more in the lfe channel; remember that this is a logarithmic scale, adding both lfe and left bass will result in about the same amount on both!

Description:

• T-Rex at gas station
• DTS DVD vs. DD LD
• upper window is the left channel, lower window is the lfe channel
• pink is LD, turquoise is DTS DVD
• lfe data above 120hz is irrelevant!!!

Analysis:

• the left channel shows a similar picture than in Graph No.2: while they are about equal at 30hz, the DTS DVD mix is again around 5db's louder on average from 40hz-15khz
• but in this scene, the LD is also 5db short in the lfe channels 30-80hz range?

• T-Rex at gas station
• DD DVD @ -4db vs. DD LD
• upper window is the left channel, lower window is the lfe channel
• pink is LD, red is DD DVD

Analyzis:

• now, since most people adjust their volume on 'average' loudness (like dialog, music etc.), rather than on 'peak' loudness, a fair comparisson between the LD and DVD would be with the DVD turned down those 5db's that it is louder on average; note that this seems more appropriate than turning the LD 5db up; why? because the LD sounds fine at reference levels, while both DVD scream out at your; it seems obvious that the DVD's were 'pushed' 5db, rather than the LD 'toned down' 5db, just my educated guess
• anyway, you can see that i turned down the DVD only 4db instead of 5, which would have been better; also it would have been better if i had used the DTS DVD here again instead of the DD DVD, because as said above, the DD DVD has a different bass mix alltogether;
• when the LD and DVD mix are compared at these similar average levels, the LD clearly has more sub 35 hz bass than the DVD; that might explain why the LD is still favored by some; the fact that the DVD has more bass in the left channel from 35-80hz is due to the fact that the DD DVD was used, which as i said, is a completely other mix (see analysis Graph No.1); if i had used the DTS DVD here, the LD would have had the same amount of bass above 35hz and the here visible difference below 35hz
• BUT keep in mind that this scene had ~5db less bass in the lfe than the DVD! If i would have done this '-4db comparisson' in the first 'falling truck' scene, were the lfe in both is similar before the compensation, the result would have been that the LD showed more bass upto 100hz

• the Lost World DTS DVD doesn't have the mastering fault that was found on Jurassic Park DTS DVD
• probably for loathed downmix reasons, the DD DVD has a completely different bass mix in the main channels, while the lfe channel seems to be very similar; so it doesn't seem as if the bass that is lacking in the main channels of the DD mix were merely pushed into the lfe; single bass effects in the main channels were completely altered (reduced in level or shifted to higher freq.)
• both DVDs are too loud, listening to them at reference level is a shrill, screaming experience; the answer seem to be that the main channels on both DVDs are recorded 5db louder from 40hz up;
• the LD mix is a lot better balanced; its much easier to listen to at reference level, i think its the original 'correct' mix; if the DVDs are toned down to a similar average listening level as the LD, they lack bass
• so JP DTS lfe channel had a 4db mastering error; both JP DVDs were completely lacking bass; both LW DVD are recorded too loud; when compensated for, they also lack bass; why can't they simply give us the original mix, damnit!

Best regards
Bjoern Roy