- Written by Chris Heinonen
- Published on 24 April 2012
The Cambridge 751BD Universal Blu-ray Player On the Bench
Given the components of the Cambridge 751BD, I had high hopes for how it was going to perform on our bench tests, and in no way was I let down. It came very, very close to pulling down a perfect score on the Blu-ray Bench Test, with it occasionally losing the lock on the Super Speedway test clip, and the fact that other players are just slightly more responsive. The responsiveness issue is likely due to the quiet, dampened drive mechanism that takes a bit longer to find a track, but once it does it was dead silent in use. I’ll take the trade-off of a slightly slower seek time for better in-use performance myself.
The one thing I did not is that some wedge patterns showed a little bit of edge enhancement that I was able to eliminate by setting the sharpness control to -16. This didn’t seem to make lines fuzzy or scenes less detailed, but instead took away a slight bit of edge enhancement that the Cambridge was applying. I’d recommend doing the same on the unit if you use one.
On the HDMI Bench Test, the Cambridge also flew through, with practically perfect results. The YCbCr results were 100% perfect at both 422 and 444, and the dE values for the RGB data was under 0.1, which is so insignificant as to not even merit consideration as a detriment. We have recently improved the processing of the HDMI Bench Test so that we can now fully analyze all the results, and not just a subset of them, so the data presented is even more accurate than before.
We also have a new way to present the Blu-ray HDMI Benchmark Data, with images showing the reference data at the top, and the player data at the bottom. As you can see here, the top and bottom are identical, so the images are really quite boring to look at.
The Cambridge was also very fast at loading titles. The only result that wasn’t elite was Toy Story 3, which has the most disc seeks of any of the tests. Other than slightly slower track seek times, the Cambridge can hang with anyone in speed tests.
Of course people are buying the Cambridge 751BD for its audio performance as well, and on the bench it really did not disappoint. Results were fantastic all around, with a low, flat noise floor all the way out and numbers there were good at all sample rates. I ran some initial tests with all the various filters and the results were very, very similar on the bench, so I ran the rest of them on the Linear filter. I would suggest that anyone that buys the player listen to all the modes on their own and see which they prefer. The bench tests indicate that all will offer excellent performance.
Regardless of sample rate, these all measured right around 0.0008% THD+N with over 100 dB of headroom, which is an excellent result for any CD player, and especially for a Blu-ray player.
Here we measured in the 0.0013-0.0014% range with 100 dB of headroom again, which was still excellent for the 10 kHz THD+N result. You can see the noise floor is flat all the way out, without a slow rise up or other artifacts that some players can have.
IMD performance with 19 kHz and 20 kHz test tones was also fantastic, with very small side peaks, and 90-100 dB of dynamic range again.
IMD performance with the 60 Hz and 7 kHz test tones was also fantastic. The levels were higher with the 24-192 tones, but still very, very good overall. The noise floor was low and the dynamic range was very high. In the end, the Cambridge 751BD was a stand out performer on the bench tests.