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DVD-Audio bass management (1 Viewer)

Rich Malloy

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In the analog realm, the one affects the other. This is something that many folks with experience only in digitally-manipulating those elements may fail to intuit. To put it more simply, one's speaker placement relative to the listening position* -- that is to say "time-alignment the old-fashioned way" -- does have an effect on the volume level as perceived at the listening position. All things being equal [speaker loads, amplification, relative room dimensions], the speaker or speakers closer to your ears will sound louder than a speaker further away. Thus, in some respects, time alignment and level matching go hand-in-hand.

[*and also taking into account room acoustics - distance from walls and other acoustically-impactful obstructions]
 

Lewis Besze

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Time alligment affects amplitude,but a real reason to have it, so that sound arrives at the same time from all speakers to the listener's ears,hence preserves the "intented" soundstage.
 

Chris Cash

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O.K., i'm confused. Isn't time alignment the same as time delay on a receiver. Almost every receiver above $150 has this. Also you mention it being important that all speakers are the same volume level. Thats why you set each speaker with a sound meter from the sweet spot. Maybe i'm missing something. I can do all this except bass management with my receivers settings and it's technology is 6 years old.

~Chris~
 

Lewis Besze

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Yes however when you use the 6ch you wanna repeat the same procedure as you did when you hooked up the DVD player via digital connection.They don't always match "right out of the box".
 

PaulDA

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A few things to note:

One, if you use an outboard bass management solution like the ICBM, you SHOULD NOT use any time delay settings in your player, as Outlaw states this will cause phase issues in summing low frequencies before sending them to the sub. So while the ICBM is excellent for bass management, it doesn't help anyone with speaker delay issues.

Two, some receivers and pre/pros offer a way to apply the same bass management/time delays to their multichannel inputs (via A/D/A) which then gives uniform values to DD, DTS and analogue m/c--this is a good choice for those who have it, who are looking to change their receiver or pre/pro, but is otherwise an overkill solution.

Three, some receivers and players can be linked digitally, via iLink or other manner, to accomplish the same thing. Same advantages (plus all done digitally, one less A/D/A conversion to worry about) but same limitations, i.e. if you're not looking for a new receiver or pre/pro, this is overkill.

Four, live with the capabilities of the player, where settings are limited in bass management, and frequently non-existent in time delay (mostly for SACD).

Fun, eh?

I happen to have a receiver that works as outlined in point two above, but otherwise my budget would preclude me from finding an acceptable solution to this problem (which given the ability to deal with this in DD or DTS for a decade or more is really lame).
 

Rich Malloy

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Chris-V, this is such a confusing issue, and I'm afraid my attempts at explanations have confused it more!

As you've identified, the lack of a digital output for MLP DVD-A tracks (and DSD SACD tracks) makes calibration of any kind very problematic. Moreover, the piss-poor design/implementation of onboard bass management of DVD-A and SACD players (or the complete lack thereof) renders most of these "solutions" (if any) to be worse than the problem. I know that my sorta pricey Sony C555ES's bass management is absolute shit, coming at the expense of a rather large reduction in sound quality. For me, the Outlaw ICBM-1 gave me all the bass management flexibility I need. It solved the bass management problem.

But that still leaves two other areas where calibration is problematic: (1) time alignment; (2) level matching. My C555ES allows for level matching (but not time alignment), but only when the bass mgmt circuitry is engaged. As I said, the results are shit. The reduction in signal quality is too great.

I've read that some players and/or receivers address both time alignment and level matching, and do so transparently. Chris, you say that your 6-yr old receiver can do this? Are you certain??? Could it be that your receiver only does this via a digital connection (or by re-digitizing an analog signal)? That is, will your receiver do time alignment and level matching on a pure analog signal???

Perhaps so, but color me surprised if it does! And I may be wrong, but I do not think that any (much less all) sub-$150 receivers on the market today have these capabilities. Am I wrong?

The good news is that time alignment can be achieved by speaker placement alone. Merely ensure that each of your speakers is equidistant to the listening position. This is no different than back in the day when 2-channel was the only game in town, and both the L and R speakers had to be equidistant from the listening position, both for level matching and time alignment. It's just more difficult to achieve this in a surround setup.

The other good news is that once you've properly placed your speakers (I recommend the ITU standard for music and movies), you will likely have achieved an acceptable level matching unless your speaker loads/amplification/room dimensions relative to each speaker are not the same! But so long as you've followed the rules of surround setups (identical speakers, identical amplification) and your room isn't vastly different in one area compared to another (for example, no wall boundary on one side), you will have a nicely calibrated setup based on speaker placement only.

But not perfect. Level matching can still be slightly problematic, even in nearly ideal rooms. Fortunately, I think this is a problem most easily addressed by some of the newer players and/or receivers (analog level setting on the 6-channel direct outputs/inputs). But, honestly, I would be surprised to find that your 6-yr old receiver has this capability.
 

Phil Nichols

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If you want to put speakers in certain positions due to room logistics, then you must perform time alignment of the signals (relative to the listening position) electronically via delay circuits somewhere in your system.........and if you want to put speakers in certain positions due to room logistics, then you must also level match the signals (relative to the listening position) electronically via the amps in your system.

I prefer to do the above two tune-ups electronically within my system (DVD player in my case) so I can put the speakers wherever I want (.... within reason with respect to cancellations/reinforcements from waves bouncing off surfaces). I actually do the level matching via equalizers to get the individual frequency bands level matched instead of just using white noise or pink noise test sound spectrums. When I'm done the equalizer settings are all over the map for each channel, demonstrating what a mess I would be listening to if I was to leave audio delivery up to the internal designs of the DVD player, amps, speakers, and speaker placement. This was a real eye-opener when I first did it. If I return all equalizer settings to "flat" or "natural" what a difference in sound - not good at all as compared to the calibrated equalizer settings. I use the Rat Shack digital sound meter at the listening position and a test CD with selectable discrete frequencies that exactly match the filter bands in the equalizers. I calibrate for 75dB at the listening position and then just turn the master volumes up and down for personal preference on each audio source I listen to.

Sounds complicated but really nothing to it once you've been through it a couple of times. I redo it occasionally as components and the room environment change and not surprisingly, the equalizer settings are a bit different after each audio recalibration.

I would do the above even if every component in my system was the best in the world - as the principle still would apply that one must do complete end-to-end audio delivery calibration to ensure that the system as a whole remains audio-transparent at the listening position ...... unless of course you intentionally want your audio system to add some "color" of it's own.
 

Citizen87645

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I just got my ICBM and it's a definite plus. And I'm surprised what a difference one notch can make. I listened to an SACD track with the crossover set to 60 Hz and then at 80 Hz. Vocals sounded cleaner and more natural at 80. I think I even prefer listening to regular CDs through the multichannel input (but then that might be the honeymoon phase of my purchase). I will need to turn off the time alignment settings on my player. I think I did notice some phasing or something a little strange at times. Despite that it sounded noticeably improved.
 

GordonL

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One solution, assuming your receiver/processor has the appropriate pre-outs and your subwoofer has left/right line-level in/out and adjustable crossovers, is to connect your sub between your main speakers, thus allowing your sub to handle the crossover, and configure the DVD player for NO sub and large fronts. No time delay/alignment issues and no ICBM necessary.
 

Chris Cash

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Well.... your right and your wrong. That would work fine for a 2 channel setup. But the ICBM's greatest attributes are for controling multichannel set-ups (like DVD-A and some SACD disks that are 5.1).

~
 

Citizen87645

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Yeah, I was going to say what about my other three channels...

I don't see a way to turn off the speaker distance setting (Pioneer 563A) so I just set them all to the same distance. If anyone has any advice...
 

Kevin C Brown

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The distance settings don't work for SACD anyway in the 563. But yes, setting all distances in the player to be equal would also accomplish that for DVD-A too.

Also, the "crossover" in a sub usually isn't. It was explained on another past thread in the speaker/sub forum, but it's usually just a low pass to the sub, you still get full range to the speakers. Try a search as I was surprised by that too.
 

GordonL

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I forgot to mention that the surrounds need to be set to small which forces all lower frequencies to be sent to the mains. At least that is how Dolby Digital is implemented. Maybe DVD-A is handled differently? Wouldn't make sense though.
 

ScottCHI

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NO! it's "usually" a variable low-pass filter to the sub and a fixed high-pass filter (usually in the 80-120Hz range) to the speakers.

very few subs will pass a full-range speaker-level signal.
 

Kevin C Brown

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Scott- Like I said, if you do a search, that's wasn't the gist of what was posted. I'll try to dig up the thread in a moment...
 

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