Our contenders for today are the Jurassic Park DD THX laserdisc, the DD DVD and the DTS DVD.

Investigation's intend:

• bass on the DVDs seems to be a lot less thunderous than it was on all of the previous laserdisc editions (DPL, DD, DTS)
• the DTS DVD is particularly weak, probably a mastering error? Even the Dpl track on the DTS DVD seems to have, at times, more bass than the DTS track, which is highly uncommon.

Description:

• the infamous T-Rex scene
• upper window is the left channel, lower window is lfe channel
• pink is LD, red is DD DVD, turquoise is DTS DVD
• lfe data above 120hz is irrelevant!!!

Analysis:

• the left channel seems to be about equal from 100hz up to about 10kHz
• the DTS track drops about 10db above 15kHz, typical for a DTS 768kB track encoded with the CAE-4 encoder
• the LD has a indeed more bass below 100hz in both the left and the lfe channel; e.g. about 6db more in the left channel from 20-40hz; about 4db more below 40hz in the lfe channel
• while the DD and DTS DVD seem to be about equal in the left channel, the DTS lfe channel is recorded 3-4db too low; i already noticed and measured this right when the DTS DVD became available, in the meantime, it seems DTS is indeed scheduling a corrected repressing; we shall see
• while correcting the DTS DVD to the level of the DD DVD would be a step in the right direction, the new version will hopefully use the LD mix
• is the LD cooked up or the DVD toned down? My guess is, the DVD is crippled. While some early DTS LDs have been said to be cooked up, this is not the DTS but the DD LD. The DVDs seem to have less bass than any version of JP i ever heard, including the theatrical run, DTS, DD, DPL laserdiscs and even the VHS tapes.

• the flocking of birds scene
• upper window is the left channel, lower window is lfe channel
• pink is LD, red is DD DVD, turquoise is DTS DVD
• lfe data above 120hz is irrelevant!!!

Analyzis:

• this is slightly different than the T-Rex scene; the LD left channel seems to be about 2db louder from 100hz up to about 5kHz; from there its even increasing up to 4db at 15khz, seems like the LDs still have the theatrical boost in the highs, suggesting the use of CinemaEQ (THX)
• again, the DTS track drops about 10db above 15kHz
• the LD has also a more bass in this scene here, surprisingly a lot more in the left channel below 20hz
• again, its easy to see that the DTS lfe channel is down about 3-4db's in general; on top of that the DD DVD has more bass below 25hz in both the lfe and the left channel

• again, the flocking of birds scene
• upper window is the surround left (SL) channel this time, lower window is bass, which means both lfe and rerouted bass from all other 5 channels below 80hz
• pink is LD, red is DD DVD, turquoise is DTS DVD, blue is the Dpl track on the DTS DVD
• lfe data above 120hz is irrelevant!!!

Analyzis:

• the SL channel looks similar to the left channel before; the LD is generall 2db louder and has more bass below 100hz; interesting is that the DTS track seems to have the most bass below 20hz in the rears? So they rerouted the bass from the lfe and main channels to the surrounds, how brilliant! :O)
• looking at the bass comparisson in the lower window, which is both lfe + rerouted bass from all other 5 channels, you can see that the LD has the most bass, followed by the DD DVD and then the DTS DVD; the DPL track is slightly different in nature, having less bass in the sub 20 region, but more than both other DVD tracks in the 20-35 region; truly remarkable

• T-Rex scene against Titan A.E. helicopter fly-over
• upper window is the left channel, lower window is lfe channel
• pink is LD, red is DD DVD, turquoise is DTS DVD
• lfe data above 120hz is irrelevant!!!

Analyzis:

• So, is any version of Jurrasic Park a real gut wringer by todays standards? If you have a capable subwoofer that reaches clearly under 40hz, lets say 20hz or even 10hz, then NO; 30-40db more from 5-20hz is like the difference between a mosquito fart and a earthquake :O)

• both DVDs don't live up to the LD
• the DTS DVD has a mastering fault (lfe 4db too low), which is probably corrected soon
• the lack of bass on these particular DVDs in not a bass management issue; lecture of proper bass management is very, very important, though, a lot of people don't use it optimally, which can hinder their bass enjoyment tremendously
• if you really want to show off the bass performance of your system, use Titan A.E. (opening or ice field), or Toy Story 2 (opening)

Best regards
Bjoern Roy