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The Bass EQ for Movies Thread

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Transformers 2 BEQ post updated.  It is so far my fav film for the BEQ process, except for Scott Pilgrim BEQ, which will be coming soon....

 

JSS

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Scott Pilgrim BEQ is shockingly good.  Those guys know how to mix a film and leave very little on the table, besides extension...which the BEQ fixes handily.

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Will the nanoavr be able to put PEQ's on the sub channel like the minidsp 2x4?

 

Also does the output of this effect audussey calibration? Do you have to recalibrate each time you re-eq the bass?

 

Maybe I'll sell my 2x4 and get one if these

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Will the nanoavr be able to put PEQ's on the sub channel like the minidsp 2x4?

 

Also does the output of this effect audussey calibration? Do you have to recalibrate each time you re-eq the bass?

 

Maybe I'll sell my 2x4 and get one if these

 

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

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Ok. I guess I'm trying to wrap my head around it. Goes from br player to miniavr to avr to speakers and sub?

Meow do u make sure the avr isn't touching the signal other than channel levels

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Yes, the receiver is in bypass mode pretty much and I would turn down all the levels as low as possible and control it through the nano and amps. Of course this is for high sensitive speakers.

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Ok. I guess I'm trying to wrap my head around it. Goes from br player to miniavr to avr to speakers and sub?

Meow do u make sure the avr isn't touching the signal other than channel levels

 

Yup.  BluRay -> nanoAVR -> Receiver.  Let the receiver and Audyssey/YPAO/MCCAC/whatever do its thing.

 

You need a BluRay player that converts Dolby TrueHD and DTSHD to 7.1 LPCM.  Many players convert one or the other, but they downmix the other format to 2ch.  I hava a Panasonic BDT460, it converts both to 7.1 LPCM.  Many older BDPs with 7.1 RCA outs also convert both.  LOTS of newer players only convert Dolby or DTS to 7.1, and downmix the other to 2Ch.  Make sure and read the specs.

 

When you playback the movie after loading the proper config into the nanoAVR, turn up the film by the initial negative gain in the correction (usually 7dB).  This will make the listening levels for dialogue equal between normal and BassEQ versions.

 

More BassEQ films will be posted as time goes on.  Not all films can be fixed with BassEQ, but there are some that are significantly better with it.  I will not post a correction unless I feel it is a significant improvement over the original.

 

JSS

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I updated the first post with the films to be BassEQ'ed.  I'll try to post up one every week.  Has anyone tried to do this with the nanoAVR, or am I wasting my time posting this stuff up?

 

JSS

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I updated the first post with the films to be BassEQ'ed. I'll try to post up one every week. Has anyone tried to do this with the nanoAVR, or am I wasting my time posting this stuff up?

 

JSS

I think it is worthwhile though i haven't tried it yet, i intend to when I get my new sub in a few weeks. I will do it via jriver BTW not a nanoavr.

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If the Oppo could support it, you may be able to.  Good Q for Oppo support, because if the DAC is separately processed on another portion of the board than the DTSHD/DTHD decoding, you may be OK.  Otherwise, you would just need an HDMI to analog out converter, but I do not know if they hold up to BossoBass Freq response standards (few things do):

 

http://www.atlona.com/HD570.html

 

http://www.octavainc.com/HDMI%20switch%204x2_7_1audio.html

 

 

JSS

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I updated the first post with the films to be BassEQ'ed.  I'll try to post up one every week.  Has anyone tried to do this with the nanoAVR, or am I wasting my time posting this stuff up?

 

JSS

 

I am in...I just received my nanoAVR but haven't set it up yet. I hope to have it going later this week. I am really looking forward to testing this!

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MAKE SURE you start out at a lower volume level than you normally listen at.  Some of the BEQ films fully test a system nearly to 7.1's theoretical limits.  In case you are wondering, EoT's intro begins to come close to what some of these can do.

 

JSS

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I don't have a NanoAVR, but I do have EQ capability for my sub output.  I am looking forward to trying the BEQ posted for "The Matrix", when I get the time.

 

I do have a request.  Instead of merely reporting on those examples with peaks > 7.1 channel dBFS, can you give us the actual peak value, relative to 7.1 channel dBFS?  For example, I currently have about -3 dBFS headroom, so if the BEQ version of "The Matrix" hits 7.1 channel full-scale at reference level, then I will need to play at -3 to not clip.  Hopefully it's not too much trouble to add that information.

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Hard to do, as I do not have the data handy for most, and getting it would take me around 2 hours for each film I do not have the data handy for.  I generally BEQ to avoid >128dB peaks, and if they happen, I will mention it.

 

If you are only modifying a SW out, then everything changes.  In order to preserve levels, you either need lots of headroom in your DSP out, or you need to turn everything in the AVR down by the correct amount of dB (usually -7dB) prior to the DSP unit.  This is why I prefer nanoAVR.  Everything in the real AVR stays the same, you just load the config (nanoAVR has 4 config slots), and turn up the MV on the real AVR by +7dB and enjoy.

 

In your case, I would never play at greater than -3dBRef equivalent (or +4dB on the MV) for any BEQ film, unless you will monitor carefully.

 

JSS

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Hard to do, as I do not have the data handy for most, and getting it would take me around 2 hours for each film I do not have the data handy for.  I generally BEQ to avoid >128dB peaks, and if they happen, I will mention it.

 

It sounds like it's not worth looking at BEQs you've already done.  How do you actually verify that peaks remain < 7.1 channel dBFS?  I think you'd need to either simulate the filters in software or sample the output of the NanoAVR when driven by the film audio.  Then combine all channels (with +10 on the sub), find the peak value, and verify that it is within the correct limit.

 

 

If you are only modifying a SW out, then everything changes.  In order to preserve levels, you either need lots of headroom in your DSP out, or you need to turn everything in the AVR down by the correct amount of dB (usually -7dB) prior to the DSP unit.  This is why I prefer nanoAVR.  Everything in the real AVR stays the same, you just load the config (nanoAVR has 4 config slots), and turn up the MV on the real AVR by +7dB and enjoy.

 

I agree with you that the nanoAVR is better for BEQ than using an EQ on the AVR outputs.  Of course, I don't own one and don't anticipate buying one for a while.  I prefer the MiniDSP 2x4 and recently acquired 3 OpenDRC-AN units to the nanoAVR because I am using them for room correction.  I believe the nanoAVR is flawed for room correction, but clearly it is in the better place in the signal chain to re-EQ original sound tracks.

 

As for headroom, it does not make sense for me to implement the gain adjustments you suggest for each EQ.  In fact, it makes me more likely to clip my AVR output when trying to compensate using the master volume.  This is probably true for anyone using device(s) that EQ bass-managed output.  That doesn't mean that I don't have to worry about clipping at all.  However, I can easily prevent it by not turning the master volume up too high, which doesn't work when using nanoAVR.

 

In your case, I would never play at greater than -3dBRef equivalent (or +4dB on the MV) for any BEQ film, unless you will monitor carefully.

 

For me, this would be avoiding MV > -3 without monitoring.  Thinking about it a bit more, I believe I may have full 0 dB 7.1 channel FS headroom in the sub-out chain, so it's just the AVR that can clip, and if I implement BEQ in the post-processing chain, my AVR won't come into play at all.  Whether my subs have enough headroom depends entirely on the signal.  For most of the range, the amps have soft-limiting, which limits distortion a lot.  I estimate my "clean" upper bound on output to be at least ~120 dB for most of 20 Hz and up, based on CEA data, my minimum-phase room response, and my EQ filters.  I put quotes around "clean" because I'm not sure how to properly measure distortion in-room.  When I recently experimented with CEA test tones and the RTA in REW, I noticed that the noise level (the "N" in THD+N) was much higher than expected, presumably because my house was making such a racket as it shook.  What I should have done but didn't was to look at SPL to see power compression because my sub amps soft limit above 30 Hz or so.  I have excellent room gain between 20 and 30 Hz.

 

Where I'm most at risk is in the 10-20 Hz range because my subs are ported.  I use an infrasonic low-shelf filter in my custom EQ to protect them.  I chose the gain (-2 dB, IIRC) by assuming I won't be playing a signal with concentrated 10-20 Hz energy at higher than roughly -10 dB 7.1 channel FS at reference.  I actually used data from this site to come up with that figure.  So far, this has been a good compromise.  I'm flat to 20 Hz and get audible extension to 12 Hz, yet I don't notice any playback issues.  I tend to be extra careful with films that approach this limit, but with most of these, I find "0" to be too loud for my preference anyway.  With BEQ (and perhaps the movie EoT), this may change.

 

I do recall enjoying "The Matrix" at closer to "0".  Apart from the weak bass, it has a very nice dynamic soundtrack.  I imagine it will sound incredible with the deep bass restored.  I am wary of that big peak at 14 Hz.  Is that in the dojo sparring scene between Morpheus and Neo?  I think I've noticed it, just barely, even without BEQ.  I will definitely proceed with caution!

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I ensure that the track will not go over the 7.1 channel spec limits (unless otherwise noted) by tracking the bass-managed (without lowpass) signal in the digital realm.  What a DAC does to it I cannot vouch for, and there are instances of DACs inducing what is known as 0dBFS+.

 

You must understand this is a process that has been nearly 2 years in development, and I do this in my spare time.  If you were paying for the EQ solutions, I would definitely offer up immediate data about your concerns, but that is not the case here.  Some of the earlier films I created solutions for I no longer have the specifics for.  Basically, use the configs and formulas at your own risk; I cannot guarantee the safety of anyone's equipment.  If you have any misgivings, simply do not attempt this.  If you have a ported sub, I wouldn't try ANY of them without steep high-passing, and even then, you are robbing yourself of much that the BEQ'ed presentation offers.  These EQ solutions are aimed for the folks who have <10Hz capability who want to know what was filtered away in a release with obvious shelving filters in the ULF regions.  They are not trivial solutions to devise in many cases, and are sometimes much more complicated than a simple 'house curve', sometimes not.

 

 

JSS

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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.

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You must understand this is a process that has been nearly 2 years in development, and I do this in my spare time.  If you were paying for the EQ solutions, I would definitely offer up immediate data about your concerns, but that is not the case here.

 

No problem, and thanks for doing what you do here!

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A very important parameter for performance is dynamic headroom - it does not help to have very low frequency extension if dynamics is lacking.

 

+1.  Very important to have the headroom available.  As I get time to do so, I'll get a very bare bones ULF-Test Disc made so people can find out how much headroom they really have to be able to play some of the hotter BEQ films.

 

JSS

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I updated the first post with the films to be BassEQ'ed.  I'll try to post up one every week.  Has anyone tried to do this with the nanoAVR, or am I wasting my time posting this stuff up?

 

JSS

 

I've been lurking in this forum for some time now.  I've used your BEQ settings in JRiver, so thank you for all your work.  From my perspective, at least, it's not a waste of time  :) .

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Post your impressions on the EQ settings compared to the original, and if you also run a house curve or LFE trim hot as well.

 

JSS

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Earlier today, I ran "The Matrix" with BEQ.  Before giving my impressions, let me describe my system.  I'm running two subs ported at around 16 Hz and two (quasi) near-field mid-bass modules.  All told, I am flat down to 20 Hz, -3 dB at 15.5 Hz, about -13 dB at 12.5-14 Hz, which is what I consider to be the audible lower limit.  Note that the infrasonic response figures are very rough as room influence and seat-to-seat variation is very strong.  The seat right of the MLP is only actually -10 dB at 12.5 Hz.  Using this response curve, I have enough headroom to handle just about any existing program material played at reference level.  My system is calibrated so that at "0", a -20 dBFS sine sweep plays at 85 dBC in the bass and gradually drops about -6 dB from 120 to 20000 Hz.  Using this target curve helps tame the strong high frequency dynamics my system and room provide, which reduces perceived loudness and brightness and makes most sounds including dialog more natural and intelligible.

 

I played the DVD as I don't own the Blu-ray yet.  (It is rumored that Dolby Digital tracks are high-pass filtered at around 16 Hz.  I personally have not seen evidence to back up this claim, one way or the other.)  I started playback at -6 dB master volume but eventually adjusted the MV all the way up to "0".  I noted that the track has a Dialnorm value of -4, so assuming they are otherwise the same masters, one would have to play the Blu-ray track at "-4" to achieve the same playback level as "0" on the DVD.  I usually use dialog to judge what playback level is most appropriate, and at my chosen playback level, the dialog sounded about right if not a bit quiet.

 

Overall, I think the BEQ improved the listening experience, but the improvement was not as much as I was hoping for.  The BEQ does its part to bring out the bottom end, when it's there, but a lot of sound effects seemed to be completely lacking in the bottom end or even lacking bass entirely where I'd otherwise expect to hear it.  Here are comments on specific sound effects, in roughly chronological order:

  • In the first part of the movie, I noticed little change with BEQ.  The bass section in the score was a bit stronger and the wind outside the building were Neo works had a bit more force, but that's about it.  Unfortunately, the truck at the very start didn't see any benefit, but I think it was lacking in mid-bass too.
  • The thunder definitely sounds much better with the BEQ!
  • I like the infrasonic ambiance on the ship.  I like the atmosphere it lent to the scenes.  Of course, I have a roll-off below 20 Hz, so foor those with more extension, that sound effect may be excessive.
  • The difference with BEQ was pretty subtle until the sparring in the dojo between Morpheus and Neo.  Among the biggest bass hit in the movie is when Morpheus bashes a hole in the floor with his knee.  It is strong enough to perceive without BEQ, and I'm guessing it is responsible for the 14 Hz peaks in the PvAs.  Despite the considerable boost in level this effect got, I don't think the BEQ improved things here.  The trouble is that there's little in the way of higher harmonics to reinforce the 14 Hz and give it definition.  Had it been coupled with some good mid and upper bass slam, I could have accepted that he just put his knee through a floor, but it was not to be.  I also thought the effect was too disproportionate to the others.  There were plenty of other martial arts moves depicted in the film that should have thumped us a lot harder than Morpheus putting his knee through the floor.  Oh well.
  • The bass continues to run thin through the the scenes that follow.  As the heros flee the ambush after Neo visits the oracle, some gas canisters provide a surprising thump when they are lit that sounds rather out of place against gun shots that are largely void of bass.
  • I note little change in the fight in the lobby.  The elevator bomb seems to have a bit more rumble.  The helicopter sounds weak.  My system can't really produce a well-defined helicopter blade fundamental, but I usually notice the pressure build if nothing else (just like I do when the real ones fly over my house).  Here there is nada, but then it gets a lot better.
  • The scene where the helicopter crashes into the building is the audio highlight of the film, and I think the BEQ made a massive improvement!  Before, it always sounded a bit held back, like the sound is overloading or something.  With BEQ, the thing really pops!  It actually sounds like it looks like it should sound!  This scene may be reason enough to use the BEQ.
  • From here on, the bass remains quite good.  Hand to hand fighting provides plenty of deep thumps and slams.  The sound of bullets moving through the air in slow motion is very palpable.  The synergy between the deep bass bursts and front-to-surround pans is excellent.
  • The sentinels *do not* walk softly upon the hull of the Nebuchadnezzar.  I must say, they don't look as heavy as they sound!
  • The EMP blast provides one more good low-frequency harrah!

In all, I think the BEQ improved the presentation, but I also think it brought to light a lot of flaws in the original sound design.  This is to be expected when reversing filters as those filters tend to hide flaws from the engineers doing the production work.  For all the great bass brought out by the BEQ, I was very disappointed that so many sound effects were completely lacking.  Despite the much improved PvA, the movie still sounds bass shy to me, simply because so many moments were missed by the sound designers.  It's still a great soundtrack considering when it was made, but it does reveal how far we've come since then.

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