1056 bass management

[Stev]

Hi I have been trying a few different configurations of bass management and have found that the sub xover in the 1056 appears to be filtering LFE at the sub xover setting - I was under the impression from reading posts here that it only applied to bass below the xover settings of speakers set to small ? I found this by setting mains,center,and surounds to small with a 40hz xover - not what I would normally use - and found that going from a 60hz - 80hz sub xover makes a big difference on a 5.1 dts music dvd. given all speakers are set to small and xovers to 40hz this means the 1056 is filtering LFE also doesnt it ? Please correct me if I'm missing something - but i've seen many posts on sub xover and was sure that the LFE was unfiltered ? By the way the xover on my sub is set to max (160) so it plays everything.

Steve

[Kevin D]

The LFE is not filtered. On a 5.1 disc, all the bass is not just in the .1 channel, in fact there's a lot of bass in the other 5 channels. So when you are changing the crossover and still have the speakers set to small, you are still changing the amount of bass redirected to the sub.

You would have to set everything to LARGE (which then only sends the .1 channel to the sub) and then run the same tests. In order for you not to be influenced by bass in all the other channels, you would need to disconnect all your speakers and just leave the sub. To be even more precise, you would need an RTA meter to view exactly what was coming out of the subwoofer.

Of course, I've all ready done that on my 1098, that's where we got the info that the LFE is unfiltered. I played a .1 pink noise track and regardless of what the subwoofer crossover was set to it always got a full signal (0-200hz, by spec the .1 channel doesn't go higher). Is this guaranteed to be the same for the 1056? No, but it should be.

Kevin D.

[Stev]

I will try again with all speakers set to large. But as all small speakers were set to 40hz wouldnt that have meant that only bass below 40hz would be redirected to the sub ? If this is the case then changing the sub xover from 60hz to 80hz while all small speakers are set to 40hz shouldnt have any effect should it ? I'm aware that there are roll off/on from the xover points.

Steve

[Kevin D]

They're quasi independent. So with all set to 40hz, everything below 40hz is cut. If the sub is set to 40hz, everything from the speakers 40hz and below is sent to the sub. If the sub is set to 60hz, the speakers remain the same (40hz and below cut) but everything 60hz and below gets sent to the sub, essentially doubling the 40-60hz range (both the sub and speakers get 40-60hz).

What I'm not sure about is what happens when there is a gap between settings. I'm pretty sure there would be a gap in sound, ie with all speakers set to 120hz and the sub set to 40hz, nothing would get 40-120hz. So you wouldn't want a large gap, unless you have a room that really boosts the region where the gap is.

Like you said, since this isn't a brick wall, it will be hard to exactly set where it needs to be without an RTA meter. That's why it's best to set everything to the same setting for movies. For stereo it's a little easier to set it up by ear.

Kevin D.

[Stev]

I just tried it with all speakers set to large - therefore the only signal being sent to the sub is LFE(.1) correct ? And it is definetly filtering LFE. Switching the sub xover between 40hz and off as this is only one step shows a very notable difference in bass. Obviously the sub's own xover is set to max for all of these examples.

Steve

[Stev]

Be interested to know if anyone else has noticed this ? As I normally have the sub xover set to 60 hz it appears as though i may be missing a fair bit of LFE.

Steve