maxmercy

October 15, 2012

Here is Immortals Peak/Avg, from the data in Excel, as the databass grows, we will be able to compare any film to another!

JSS

PS - The 18Hz spike is from every time the Epirus Bow is drawn and fired. Powerful effect.

EDIT - New no-rolloff PvA trace graph added. Here's the breakdown for Immortals:

Level - 5 Stars (115.95dB composite)
Extension - 5 Stars (1Hz)
Dynamics - 3 Stars (24.85dB)
EDIT - Execution - 4 Stars - This film would have been just tremendous if it didn't clip noticeably. The mix team supposedly did it on purpose, as it was supposed to be an 'over the top' mix, but they ran into the buss limiters on many scenes.

Overall Rating - 4.25 Stars

Recommendation - RENT. You may like this film. The battles between Gods and Titans are pretty good. I will not own it, but I have it on loan from a friend.

JSS

October 14, 2012

Repeat post, sorry.

JSS

October 14, 2012

Well folks, I got it to work. I can pull data from a SpecLab peak average graph, and I did a test-run on Immortals:

Immortals Bass Power

Overall Peak Power 535.7

0-10Hz Peak Power 28.4

10-20Hz Peak Power 60.4

20-40Hz Peak Power 99.8

40-80Hz Peak Power 183.8

80-160Hz Peak Power 163.3

Overall Average Power 31.8

0-10Hz Average Power 1.6

10-20Hz Average Power 3.6

20-40Hz Average Power 6.6

40-80Hz Avergae Power 10.6

80-160Hz Average Power 9.5

The power ratings are in PaHz. I essentially did a numerical integration to find the area under the curve for the peak and average graphs from 0-160Hz, and for each octave specified. Now we can have a truly apples/apples comparison for films.

One caveat: I do rolloff below 7Hz, -3dB down at 5Hz, and off the cliff under that. But for relative comparisons, this should be a very good tool.

As far as star ratings, Immortals gets 5 star extension, 5 star level, but 3 star for execution due to the clipping involved, which I believe is in the sattelite channels,average star level of 4.3. Overall buy/no-buy is a coin toss for me. Some great scenes, though, if you can ffwd through the BS parts.

JSS

October 14, 2012

Looks good to me, but bosso needs to chime in as it looks like you have a rolloff below 10Hz.

Great news on the data front. I will be able to grab data from peak/avg graphs, with the help of a program called DataThief, an autotrace program. It will allow me to gather data on a film's peak/avg content and find out relative sound power per octave. It is time intensive, and if someone knows of a better autotrace program than DataThief, please let me know. Bad part is for datathief to be able to track the trace well, it is not a pretty looking trace (black and white graph, mainly).

I have an out of town conference to attend and a 1 hour lecture to give next week, so I will be out of the loop for a while, no data until then. I will start the data gathering with recent and known great bass films in about a week or so.

JSS

October 13, 2012

Ricci,

What will happen is Bosso will provide the specific demo scene caps, I will provide peak/avg, and I will tinker today to see if I can actually extract data from it, to be able to calculate peak and average power per octave, and the ratings will come from both. Note that subjectivity is still a part of the ratings, as one of the 5-star measures is subjective, as well as the final 'buy' or 'no buy' rating. I am going to rearrange the first post to show this.

JSS

October 12, 2012

SpecLab accounts for the decimation at the I/O stage in the FFT Settings dialogue box, and updates with proper bin size and freq range.

I say we have a few different star ratings, with an overall rating given last.

Overall LF Content Star Rating is an average of several different 5/5 star possible ratings:

A. Level

B. Extension

C. Execution/Appropriateness/Use of LF

Then a final 'buy' or 'no buy' rating given with everything else taken into acount, like how good the film was, rewatchability, etc.

The objective ratings (if I can get them to work this weekend) may also play a part.

I intend to do Peak v Avg graphs and hopefully overall LF Power as well as LF Power Per Octave for each film rated. The ratings will probably be a mix of subjective and objective for an overall star rating.

Any other suggestions?

JSS

October 11, 2012

Bosso,

Due to the cheapness of my BDP and sound card, My sound card cannot accept a digital in, and outside of stereo, there are no further analog outs on the BDP. I think that until a new BDP is purchased, the receiver's roll off may just have to be dealt with.

I was playing with the Nuttall windows and FFT settings yesterday evening, and I have come to an impasse:

1. Continue with FFT length of 1024 decimated by 48, which will give me single Hz resolution capability but that has a 1 second Window time, or:

2. Use an FFT length of 512 decimated by 48, which gives a resolution of 2Hz, but window time is halved, therefore it is better at graphing transient sounds like explosions.....faster rise time for each bin.

What do you guys think? For a peak/avg graph, I am leaning to the latter. I'll run some comparos on known scenes/trailers this weekend.

JSS

October 10, 2012

Bosso,

I gotcha. The main discerning feature is the scale on the left for the freq response of each, very low spectral contamination on Nuttall, at the expense of a slightly lower resolution, but the resolution can be played with by FFT length and decimation. I'll mess with it this weekend.

Ricci,

I have always used the Soho54's Audio Test DVD's -0.5dBFS LFE tones to calibrate SpecLab, but some films have not clipped individual frequencies, but have clipped the amplitude graph, which I suspect is because of channel summation, not just LFE content, so I plan to use the same tones but have them only come to -10dB on my new peak/avg graphs. I am confident that I will be able to extract data from the screen caps, to really do some apples/apples comparos, much like your CEDIA best/worst output graphs.

What would be good bass ranges/categories? Here are some suggestions:

Sub-10Hz = Deep Infrasonic

10-20Hz = Infrasonic

20-30Hz = Very Deep Bass

30-40Hz = Deep Bass

40-50Hz = Bass

50-100Hz = Mid Bass

100-200Hz = Upper Bass

or all by octaves:

Sub-10Hz = Deep Infrasonic

10-20Hz = Infrasonic

20-40Hz = Bass

40-80Hz = MidBass

80-160Hz = UpperBass

We would be measuring total peak and average signal power for entire films in each range. One problem is my signal chain rolls off starting at 7Hz, and is 3dB down at 5Hz, and falls off the cliff below that, so my Sub-10Hz power ratings may not be as accurate, but will be good relative measurements. I may be able to compensate for that if there is a way to do a 'loopback calibration' type of thing in speclab....I'll research it.

JSS

October 10, 2012

Bosso, I have downloaded your speclab settings, and I will make some changes for peak/avg graphs, but overall, I like them. A few questions though:

1. Why Nuttall windowing? Wouldn't Hann or Gauss be a better compromise?

2. I intend to to Peak/Average out to 200Hz, even if individual graphed scenes only have stuff out to 120Hz. I imagine your settings are best for 0-120Hz?

I have an idea to quantify the LF content, depending on whether or not I will be able to extract the data from the P/A graphs. With the new SpecLab version's way of graphing individual FFT bins, I may be able to use an autotracing program to get the data and comparison via REW or just Excel may be possible. If I am able to export to a vector drawing program, overlays comparing one film to another may be possible.

By adding up the areas under the peak/avg curves for a given freq range, we can literally compare one track to another numerically (0-10Hz, 10-20Hz, 20-30Hz, or the full 0-200Hz). Films/tracks with more average overall content will have more overall bass, films with high peak and lower averages will have less scenes with high signal strength. If we really want to get technical, we can do a 'loudness scale', by implementing ELC, but that may prove to be too difficult.

I will have a tutorial on how to do Peak/Avg graphs hopefully by this weekend.

JSS

October 9, 2012

Bosso,

Question: How much headroom do you leave on SpecLab caps? Because if for some reason a mixer shoves nearly full scale content into each of 7.1 channels, you could get a larger signal than the equivalent of a 0dBFS signal from the SW out.

According to Soho54's calculations, a 0dBFS LFE only signal should come only to 115dB, if any speaker is set to small and also has the same, coherently summing 0dBFS signal, it adds to this total, with a grand total with 7.1 channels being an impressive 125.13dB. I will from now on calibrate my peak/avg graphs to read -10dB on SpecLab with the -0.5dBFS signals available on Soho54's Audio Test DVD, so that means I'll be re-doing a few Peak/Avg graphs in order to be able to do apples/apples comparisons. Good thing I have Netflix by mail...

The template scheme for individual scenes is REALLY nice. Real nice.

I'll d/l your settings for SpecLab and check them out. I think you use a slightly slower scroll speed than I do, but you want whole scenes, not second-to-second variability like the Peak/Avg demands.

Anyone know a good program to be able to trace out the information on peak/avg graphs and import them to another graphing program for comparisons between tracks? Or a way to make a BMP file 'transparent' and overlay it over another?

JSS

PS - Josh, got the avatar sorted out.

October 9, 2012

This is the first of it's kind objective measurement tool for comparing the bass in movies - it's totally apples-to-apples. (The measurement methodology AND content below 2.5 Stars is at the bottom of this post.)

No longer do you have to rely on some website's review of the bass in a movie. Who can decipher what "aplomb" and "bombastic" and "incredibly deep" and "teeth-rattling" and "room-shuddering" really mean, anyway? Now you don't have to.

The links below will take you to each movie's measurements. If a link doesn't take you to the right measurement, reload the browser by hitting F5 or just click on the address bar and hit "Enter." If you find a bad link, post about it and we'll investigate!

Updated December 12, 2015 - Here's a Google docs spreadsheet with the current list. To sort, goto View-->List.

5-Star Films:

9
Edge of Tomorrow
Everly
Flight of the Phoenix
Hellboy II: The Golden Army