Blu-ray downmix to 5.1 DTS via optical/coax SPDIF?

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ilovemusic

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# 274863 20-Nov-2009 23:51

Bass management is a con !
(As are most of the room correction programs built into AVRs).

All it does is put extensive DSP networks between the original recording and the listener.

If you want hear the soundtrack as it was supposed to be heard you do not want to re-route the bass away from the channels where it was recorded.

NB; the .1 channel is NOT a bass channel !
Its for low frequency sound effects, meaning its not always active.
DVDs that lumo all the bass into the .1 are simply WRONG and shouldn't be pandered to.

IIRC some of the uber-Denon and Pionner AVRs can manipulate the analogue MC input, so don't know how analogue they remain as such fiddling is usuallu done in the digital domain.

Most high end audio manufacturers follow the KISS prinicple, its about time home theatre did the same.

Physically putting your speakers in the correct position, setting them all to large and manually setting relative levels will pay bigger dividends than electronic fiddling.

richms

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# 274979 21-Nov-2009 15:56

You cant set a majority of speakers to large and have them get to the correct levels at all - There are stuff all domestic home theater speakers that will even deliver any content down at 45Hz, let alone 20, and the ones that are "flat" to 45-50 or so, are ported to get that response so absolutely must have a high pass to remove anything below their tuned frequency so that they do not bottom out. On a large speaker its a subsonic filter, on a typical home one its a filter well with in the audible band.

In addition, the sweep test used to get the response graph is normally 1 watt - if you are lucky, the large transients of explosions etc is usually pushing 40-50 into a speaker at reference levels, more if its not a very efficient one. That total power across all the harmonics of the explosion/gunfire will cause bottoming out unless the fundamental and possibly the next few are removed and sent to a driver that can handle it.

Next you will be trying to say that you shouldn't have a crossover in a speaker. The bass management is exactly the same as an active crossover, which is something the audiophool industry is finally waking up-to being a good thing rather then the 100+ year old passive ones that they have loved to over-engineer with absurdly overpriced capacitors and inductors made from BS wire that's been the the audiofool marketing speak machine with meaningless specs.

I doubt that you will find _any_ consumer speaker that will fit into a typical house that can deliver reference levels while playing full range on a typical action movie scene without problems, let alone those that like things a little louder than that.

And of course the AVR's are going to manipulate things in the digital domain, its a better performing way to do the required operations. To do the same stuff in the analog domain is either impossible or prohibitively expensive.

Most "High end" audio follows the BS ignore engineering approach because their market is those with lots of money and no knowledge so can get away with their spurious claims that their way is better than an engineered solution that can be proven to give a flatter response to the listener.

Richard rich.ms

ilovemusic

1255 posts

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# 275025 21-Nov-2009 19:56

Bass management is not same as an active crossover.

Active crossovers do not re-direct bass frequencies from one vector to another, appreciably altering the perceived soundfield.

If there is significant bass information recorded in the left rear channel I don't want it re-directed to my sub sitting in front of me.

I don't know what sort of speakers you're used to but I've setup plenty of HT systems using domestic full range speakers at all vectors and even small bookshelves for surrounds with no problems at all when run as "large".

The key is to use quality products not your usual HN or TM dross and to setup properly.

Keep everything simple, match the speakers to the rest of the system and the room, set levels manually using an SPL meter and your ears.

richms

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# 275051 21-Nov-2009 23:06

Show me a consumer speaker that will hit even 80dBA on concurrent 25, 45, 65Hz signals without appreciable distortion and I will be very surprised. That sort of IMD test is almost never done or published because it shows the whole weakness in speaker design and at the levels it would pass the tests with a sane figure, it would be probably below a watt of power into it.

The bass in a normal house is non directional since the wavelength is longer than the room below about 80-100Hz for most sized rooms, even higher if you are in a student apartment sized place. To try to attach any relevence to direction of the bass in those situations is just foolish. Even in a large room the only way that people can locate the subwoofer is either because its making too many harmonics because its a crap sub improperly loaded or driven (like most consumer subs), or it is just making things vibrate in its vicinity.

Seperating bass out and sending it to another driver is a crossover. It is called that all the time in car audio, its only home stuff that invents more fancy terms like bass management to make it sound like it is worth the extra $500 on an AVR.

Richard rich.ms