Kvalsvoll

Agreed, they match. Hopefully they also match for a shelf filter. This means: MiniDSP new filters are valid for JRiver.

Link to minidsp spreadsheet (from earlier in the thread): http://www.minidsp.com/images/fbfiles/files/All_digital_coefs_v1-20101026.zip

SFM filters only apply to a specific plug-in for audacity, you recognize it if you use it. . For MiniDSP, use the MiniDSP new parameters. For older MiniDSP plug-ins, use the MiniDSP supplied spreadsheet to calculate biquads and enter those. Old vs new, it is the q-value that does not match up. For JRiver, we should verify that the MiniDSP new parameters are valid. This can be done by entering a filter in JRriver and compare the predicted frequency response to the one that is calculated in the MiniDSP supplied spreadsheet. I don't remember if this has been discussed in this thread already. You can always use this spreadsheet to verify the response, by entering the filters in the sheet and compare the calculated response to the predicted JRiver response. This way you can get it right even if the filter parameters does not match up, becauase you can adjust according to the calculated reference. The gain + - is to avoid clipping when processing the filters. There may be peaks higher in level earlier in the filter chain, and peaks often will occur at different places. This is because filters affect the phase of the signal as well as the amplitude, the phase shift can cause large differences in peak amplitude. Also, I want to see exactly where it clips, if it clips, when doing the final gain adjustment to bring the level back up. Now you also have the option to leave out the last gain increase, and increase the mastyer volume level instread, just remember to do the gain reduction on all channels first.

Alien3 Special Edition Bass EQ This was the easiest of the Alien films to fix, because it is less severely filtered than the others. Still, it required several rounds to get it right, and it certainly deserves the attention, as the sound is quite good. Overall sound kind of improves for the newer releases, at least partly due to improvements in technical performance of sound production equipment. Less noise, more extended frequency response, and more flexibility for creation of sound design and effects. The problem with this one was to avoid clipping in the LCR-channels. There will be some clipping when the last +6dB gain is applied to make the levels match the original, but it is not really noticeable, because the signals are already distorted on those transient peaks, either due to clipping somewhere earlier in the chain, or simply because this is how the sound design was made. Still, far from todays clipped, compressed and harsh sounding releases. As the waveforms reveal, there is plenty of ulf in this film, so go on and enter the Bass-EQ filters and turn it up. Scenecaps were accidentally made with subwoofer level +3dB compared to the others. Also, the scenecaps include the emergency pod crash in the beginning, and I had this one increased in amplitude by 6-9dB. Alien3 Special Edition l channel original: Alien3 Special Edition l channel BEQ: Alien3 Special Edition lfe channel original: Alien3 Special Edition lfe channel BEQ: Alien3 Special Edition Scenecap start->0:06:31 original: Alien3 Special Edition Scenecap start->0:06:31 BEQ: MinDSP new filter parameters (use the minidsp spreadsheet to find biquads): LFE: low-shelf 24hz q=0.78 gain=12dB low-shelf 24hz q=0.78 gain=12dB LCR: gain -6dB low-shelf 10hz q=0.78 gain=-6dB low-shelf 24hz q=0.92 gain=14dB low-shelf 26hz q=0.96 gain=8dB low-shelf 40hz q=1.23 gain=-1dB low-shelf 100hz q=0.71 gain=1dB gain +6dB Original SFM parameters: LFE: low-shelf 24hz 1.2 12dB low-shelf 24hz 1.2 12dB LCR: gain -6dB low-shelf 10hz 1.2 -6dB low-shelf 24hz 1.6 14dB low-shelf 26hz 1.8 8dB low-shelf 40hz 3.0 -1dB low-shelf 100hz 1.0 1dB gain +6dB

Yes, I like the 2. best as well, and to find out that the sound was quite good and then could be improved to a full-range experience was even better. This level of improvement is rare to find in audio today, it's like going from using 2 larger fronts only, with the accompanying sketchy bass reponse, to a well integrated full-range system with subwoofers. The -6dB/+6dB gain is to avoid clipping when processing the signals, the level is a bit high initially on some few peaks. Alien3 is up next, but I think I will revise the ew for the lcr for this one first, it was the easiest of them to do, but I think there is some improvement to gain by changing the eq a little.

Depends, as you say, many filtered movies have this mid-bass "boom" lift, and this is automically reduced by the filter, because it overshoots and reduces the level. Here I have used several filters, just like you have done, to prevent too much overshoot. None of the alien-films have much "boom" actually, it was basically just this one that had this quite heavy 50hz, but you can't remove it, because that 50hz is the sound design. Just remember that the high-shelf boost-correction can only be applied to the lfe channel, not necessarily obvious to see that, when you only look at the signals from 100hz down.. And it did turn out very well, and just because the potential was so good, I continued to work on it until I got it right, it took looong time. Now, how do you think the next ones are.. because, they are definitely not lesser than this one.

Aliens Special Edition Bass EQ And now we enter some more serious low frequency effects, as well as better overall sound for this second of the Alien films. It is a delight to watch at reference because the sound level is right, and still there are occasional peaks here that reaches full digital 0dB. The Special Edition adds some scenes of value for those of us who have already seen the film originally, and thus we know how the story goes - very, very bad.. There is this scene with the vehicle driving around, the ulf is quite well done here, you just need to dig it out. Now you can feel the ground move as the vehicle passes by, and I chose to preserve the growling engine sound. Come to think about it, I may be the first person to actually experience this.. This film was quite challenging, but now I feel the result is just like i want it - restored ulf, preserved engine-growl and upper bass impact, while reduced some of the worst booming around 50Hz. As the measurements show, this one does certainly not lack in the low bass department, and the low bass is mostly quite well done and matches what is going on in the picture. One of the problems doing eq is to ensure the individual channels sum up correctly. The filtering shifts the phase, and then the channels will not add correctly and much of the bass can be lost. If the filters are the same on all channels, all will be well, but here it is necessary to treat lcr different from lfe. To verify that the end result is as expected, I checked the sum levels digitally, and also by playing scenes and recording them, comparing original to Bass-EQ. When it comes to accuracy and objectivity, a measurement always trumps my ears - there is no "palpable bass with authority" about the graphs. Aliens Special Edition l channel original: Aliens Special Edition l channel BEQ: Aliens Special Edition lfe channel original: Aliens Special Edition lfe channel BEQ: Aliens Special Edition vehicle scene original (Recorded from playback, full range): Aliens Special Edition vehicle scene BEQ (Recorded from playback, full range): SL graph of recorded scenes repeat because they are run continuously; necessary to ensure the whole time interval shows. MinDSP new filter parameters (use the minidsp spreadsheet to find biquads): lfe: gain -6dB low-shelf 12hz 1.03 -12dB low-shelf 32hz 1.07 8dB low-shelf 32hz 1.07 8dB low-shelf 26hz 0.90 9dB low-shelf 24hz 1.07 9dB high-shelf 40hz 0.77 2dB gain +6dB lcr: gain -6dB low-shelf 12hz 1.03 -12dB low-shelf 26hz 0.90 8dB low-shelf 22hz 1.07 8dB low-shelf 22hz 0.90 8dB low-shelf 22hz 0.90 6dB gain +6dB Original SFM filters: lfe: gain -6dB low-shelf 12hz 2.0 -12dB low-shelf 32hz 2.2 8dB low-shelf 32hz 2.2 8dB low-shelf 26hz 1.6 9dB low-shelf 24hz 2.2 9dB high-shelf 40hz 1.2 2dB gain +6dB lcr: gain -6dB low-shelf 12hz 2.0 -12dB low-shelf 26hz 1.6 8dB low-shelf 22hz 2.2 8dB low-shelf 22hz 1.6 8dB low-shelf 22hz 1.6 6dB gain +6dB

Yes, but for same sample rate (48K) and same biquad, they give the same frequency response, but the q in filter settings is different. If I use the spreadsheet you sent me, I can calculate q values which fit right into the MiniDSP-provided biquad-spreadsheet, and the response is a match. If I use the same q in parametric filters on my MiniDSP 2x4 with advanced 2-way plug-in the response does not match at all. If I use the biquad calculated in the spreadsheet, the response is a match.

Alien Anthology - The first: Alien "Mommy always told me there are no real low frequencies in the alien films.. " BUT THERE ARE... The first of the Alien films has a rather simple sound design compared to many modern releases. There is not much low bass, or bass at all, to find in this one, but overall the sound is quite good, no clipping or excessive compression. I am looking forward to see this Director's Cut version, with Bass-EQ. Now, you may be surprised how I can present BEQ for a film I have not seen, but the process of making the filters does not necessitate watching the complete movie. Initial filter settings are done by measurement and signal analysis alone, then later I find some scenes I use as reference, and re-watch those as I adjust the filters. This of course also means that there may be surprises in the resulting sound experience, even though levels have been monitored for the complete soundtrack. Throughout most of the film there is a 13Hz rumble, seems to occur always when they are in the spacecraft. It is easy to amplify this effect so that it really shakes everything, but that is not a good idea, as it will become tiresome and people can get sick. It is perceived as a pressurising feeling, and then everything shakes when it gets loud enough. I chose to rise the level to make it barely noticeable, with the subwoofers set at +3dB from flat, my usual setting. Now, keep in mind flat does not mean it measures flat, there is a lift towards lower frequencies, so that lower frequencies have the right feel and impact when playing balanced, full frequency range content at reference level. Played like this, at reference level, the pressurising is barely noticeable, and there is a very subtle shake. Overall I did not lift the ulf up to very high levels, and the mid and upper bass is reduced some. The goal is to get a balanced sound, and like this the low bass is now present making for a much better overall sound experience, without sounding too strange or bloated. Bass-EQ filters: NOTE: Q-values is incorrect for MiniDSP 2x4, use the biquad. LFE: low-shelf 30hz q=1.1 gain=10dB low-shelf 30hz q=1.1 gain=10dB MiniDSP biquad for ONE 30Hz Q=1.1 Gain=10dB: a1=1.997108418699020, a2=-0.997117078212166, b0=1.001126540402070, b1=-1.997099056563100, b2=0.995999899946011 low-shelf 22hz q=0.86 gain=12dB MiniDSP biquad for 22Hz Q=0.86 gain=12dB: a1=1.997628030893830, a2=-0.997632182424995, b0=1.001181393803590, b1=-1.997621842887770, b2=0.996456976627460 Original SFM parameters: low-shelf 30hz slope=1.8 20dB low-shelf 22hz slope=1.4 12dB L, C, R: low-shelf 34hz q=0.86 gain=16dB low-shelf 34hz q=0.86 gain=16dB MiniDSP biquad for ONE 34Hz Q=0.86 gain=16dB: a1=1.996732180595880, a2=-0.996740053359426, b0=1.002474784800730, b1=-1.996711280087760, b2=0.994286169066821 Original SFM parameters: low-shelf 34hz slope=1.4 16dB low-shelf 34hz slope=1.4 16dB Spectrum graphs: Original left channel: Left channel with Bass EQ: Original LFE: LFE with Bass EQ:

Note on filter coefficients: You should verify that the q-values entered gives the desired response. For the MiniDSP, there seems to be differences between models, so that the q values are not consistent. However, it seems the biquad-coefficients are consistent and can be used to verify the response. You can use the spreadsheet for biquad coefficient calculation and then enter the calculated biquad instead of entering parametric values like f, q and gain. More specific, the q-values for the MiniDSP 2x4 with 2-way advanced plug-in has a much higher numeric value than those in the spreadsheet. I do not know how other models match up. The solution is to provide values that is correct for the spreadsheet, and then verify by calculating the biquad and enter the biquad into the dsp software. The difference between old vs new is 2: MiniDSP old q = MiniDSP new * 2

The Alien films are finished, I just need to monitor some more scenes, and it seems I don't have the latest updated Bass-EQ files on this computer. The first one can be posted already later this evening, the monitoring is more for comments and advise for alternative filter settings for a slightly different presentation. I am actually looking forward to see them myself, I have only watched specific scenes while doing the Bass-EQ, and I have never seen the special and directors' cut editions.

Coming soon - Alien collection: "Mommy always told me there are no real low frequencies in the alien films.. " BUT THERE ARE... Be prepared for something very special - a collection of classic films, most of them with quite good sound originally, with Bass-EQ they become a full-range, full-dynamics very physical experience. Feel the ground crumple as vehicles pass by, low frequency rumble effects from space-ships and machines that you can barely hear, but you can certainly feel it, real shock-waves from big blast-guns that literally moves your whole body. Those movies have true dynamics, letting you enjoy the sound with no clipping distortion and no excessive compression, giving real impact and realism without excessive loudness. The dynamics were always there, the low bass just need to be found, and there you have it - excellent full-range AND full-dynamics sound.

You wil not be able to fit all the filters needed for some of Maxmercy's otherwise excellent Bass-EQ solutions, the filters need to run in separate slots to achieve the same transfer function. You will however be able to run a modified, reduced, solution, which will improve the film, but the problem is for the heavy filtered ones, they are difficult to fix, and require several filters to get the best result. I have tried some films on the minidsp that controls the subwoofer system, and it only has one or two slots available. Still, this is able to fix many films, like Oblivion, Enders Game. We run a different solution for implementation that is software based with no limit on signal processing. I am now working on the Alien collection, and some of them can be significantly improved using a minidsp or nanodvr, while the most difficult require several filters to recover.

Dynamic compression, limiting, clipping, too loud overall sound level. This is the most important issue with sound quality today. Music is now improving, while movies have not yet seen the top. In the days of 24-bit lossless you get soundtracks with actual resolution more like the 8-bits game music from early days of computing. Awareness and knowledge about how sound works and how we perceive sound will help. Continuing in the loudness direction will drive people away from cinemas because they find the sound annoying and uncomfortable, and people like me will not buy movies with 8-bit sound simply because I don't like bad sound quality. And the "home-nearfield" mixes, with even more compression and louder dialogue certainly does not help.

Many classic movies can be worth to watch again, but unfortunately they are not up to todays standards in sound, most notably the bass is lacking. Good news is that many of those can actually be improved so much that the experience will match many newer releases. They often have good dynamics, no clipping and severe limiting, and often some low bass can be found buried low down in level. I am now working on the Alien collection, especially the first movies have literally no low bass at all, but - surprise! It is there, you just need to dig it out. To make it sound better overall is quite a challenge, but I think it can be done, and results so far are very promising.

Always good to see rising awarness on the loudness-war issue with movie sound, and your post here SME sums up quite a few good points. There are many recent releases I will never buy because the sound is obviously destroyed, it is impossible to undo dyniamic compression and clipping.

This is correct. The purpose of Bass-EQ is to restore the natural balance, with no added artificial boost at the lowest frequencies. If you run a house-curve with boost at low freqs, because that sounds good on your system, your playback colume, in your room, then a movie with Bass-EQ should sound similar in balance to one that is flat.

I don't use JRiver, so I have no detailed knowledge on functionality, but I assume it is quite superior to a avr+bd-player system, where you now can implement Bass-EQ easily and also make adjustments as you find necessary on-the-fly. I run a system with XBMC, so I have no audio processing capability on the computer, but still superior as media source. This is the future - avr in software, all processing on the computer.

Thank you for the feedback, interesting to learn what others get out of this. From your impression it seems like the goal of the BEQ is fulfilled - to retreive the lost very low frequency bass. You say there is not a very huge difference in the sound, other than in certain scenes and sound effects. And that is very correct, the purpose of BEQ is not to change the tonal balance or try to create sounds that was never in there to begin with. Most of the bass range will remain unchanged, but when there are low-freq content, it hits louder, heavier, harder, more natural. The level of improvement will depend on the capacity of the playback system - for larger, more dynamically and lower freq capable subwoofers the difference will be greater. Also, it is not quite as simple as measuring the freq response to get the full picture of how the low freqs are reproduced. At very low f, <<20Hz, the tactile feedback from floor and furniture is very important for perception, and at slightly higher f the sound field velocity-pressure properties plays a significant role. So, different systems may actually sound and be percieved as different even though they measure exact the same using a mic sine sweep measurement. Dynamic capacity is also very important, and for ref level full-range playback most realistic systems will compress the signal when large peak signal levels at the very lowest frequency occurs.

Thank you for the feedback, and it is interesting to see you use JRiver. I hope the BEQ information provided is compatible and useful with JRiver, the MiniDSP filter parameters should be compatible.

If your system is properly set up, I would not be too concerned about headroom issues. The bass that is retrieved is amplified in level from a very low level to begin with, and even though the gain may be >+20dB, the end result is something similar to a non-filtered. Most of the solutions I have posted can actually be done without reducing the level (digital level) and still will not clip. Occasional clipping in the subwoofer signal is not likely to be heard, something you can confirm by looking at the waveforms from released films. What is true, though, is that there will be much more low-freq content, and this will cause problems if there is no limiting or filtering in the chain. Even the largest system will have less headroom at the very lowest frequencies, but of course if the output capacity is large enough, there will be no problem runnig these signals through. A good system will have filtering and limiters set to enable use of whatever headroom and extension is possible, while protecting drivers for over-excursion if signals with too low frequency to be safely repoduced occurs. It is true that the benefit is greater for systems with very low extension, but for many movies there will be significant benefits for typical systems capable of down to around 20hz. Here I have no systems with extension down to 10hz, what I actually have also depends on what configurations and subwoofer units I am testing. Still there is a night and day difference from something that has full frequency content compared to something filtered at 20hz. A very important parameter for performance is dynamic headroom - it does not help to have very low frequency extension if dynamics is lacking.

Added the LFE channel plots in the Bass-EQ thread.

I thought Super 8 was in this thread, but when I checked now I can not find it. I did Bass-EQ for Super 8, but I did not do a chart according to appropriate settings to make it comparable.

Bass EQ works independent of any room-correction like Audyssey.

+1 to that, ref ongoing discussions on calibration issues, with the theatrical you know what you have, and at least it has the best possible dynamics and sound quality.