1055 Bass Mgmt revisited

[hal]

(1) Given a universal player like the Denon DVD2900 with fixed crossover 80Hz for bass mgmt, is it likely preferable to perform bass mgmt on the Rotel (with adjustable crossover frequency) or to leave the BM to the Denon?

(2) Are signals < 100 Hz fed by the RSX1055 from channels set to "small" into channels set to "large" (i.e. from small surrounds to large fronts?) Is this a problem in a system with only fronts/surrounds or does it only become troublesome when there's a sub in the mix?

(3) Is #2 the issue that plagues the 1066 and for which the "resistor cut" method has been promulgated?

(4) Is there an equivalent fix for the 1055 (preferably one that involves a switch instead of a cut resistor!)

(5) Any other positives/negatives about using this HT receiver / Universal DVD pairing?

[Scarp]

hal,

first of all the bassmanagement problem only occurs on the analogue multi-channel input. So for everything coming into the stereo analogue or the digital inputs the bass management works as advertised.

What the multi-channel input does is copy from all inputs the sound under 100 Hz to the subwoofer. This effectivly doubles the the sound (since the sound is send both to the subwoofer and to the speakers). This was done to be able to use the subwoofer in multi-channel music/movies that do not use the LFE (.1) signal. Note that it is only relevant for DVD-Audio (MLP) and SACD, who both cannot be outputted on a digital cable (with a few exceptions offcourse). Many SACD/DVD-Audio titles don't use the .1 actually.

(1) For all but analogue multi-channel (i.e. sacd/dvd-audio multichannel) you should just use the digital output and let the Rotel do bass management. Actually the Denon won't do bassmanagement on things being send to the digital output. The the multi-channel input is more or less a passthrough (with exception of the bass doubling on the sub).

If you do not have a subwoofer, you should turn off the subwoofer in the Denon, this will make it pass the subwoofer channel to the Front speakers.

If your speakers have the same frequency range you can also just keep them at "large" setting and set the crossover on your subwoofer such that the sub takes over where the speakers cannot go anymore.

(2) For the multi-channel input these large/small settings are not used. When there is no sub, there will be no problem.

(3) The 1055 has the same problem as the 1066, since the processing parts are the same for the two. The resistor cut will remove the bass doubling from the multi-channel input.

(4) Also the cut ... look in the topic, its not exactly at the same location as the 1066 cut.

(5) Don't know.

Note als that I personally didn't notice the bassmanament problem until I knew about it from this forum. Since I currently do not have a subwoofer, there is not a big problem. But when I did have a sub, I set it up such that i hardly noticed any doubling.

[hal]

Scarp,
Thanks for your reply. It sounds like the bass doubling remains an issue for us SACD/DVD-A listeners. Have any of the firmware upgrades been able to address this? I would think that the crossover point and even the ability to turn this "feature" on/off should be software, not hardware, determined? [However, the fact that Rotel was performing the BM mods on 1066 for customers that requested it makes me think there may be no software solution]

Do you have a link for the 1055 BM fix? I don't recall seeing one.

[Scarp]

There is no software/firmware fix for the bass doubling problem. This problem is only there on the multi-channel inputs. With the latest firmware version all other BM problems have been fixed.

Indeed Rotel in the USA has been doing the resistor cut when an owner wishes so. Too bad the european distributors don't do this as well (actually the dutch distributor advised against it and said I would void warranty if I did it myself).

There is a topic about the 1055 fix ... (i couldn't find it quickly)

[Danbry39]

Here you go.




Keith

[hal]

Under what circumstances would having bass management implemented the original way (all frequencies < 100 Hz from all channels copied to sub) but helpful? Is there any good reason to have a switch put in instead of cutting the resistors? [Perhaps there's concern about some yet-to-be-discovered unintended sonic impact of the resistor-cutting technique?]

[SomaJoe]

Under what circumstances would having bass management implemented the original way (all frequencies < 100 Hz from all channels copied to sub) but helpful? Is there any good reason to have a switch put in instead of cutting the resistors? [Perhaps there's concern about some yet-to-be-discovered unintended sonic impact of the resistor-cutting technique?]

The only case I can think of wanting the original configuration is listening to a 2 channel analog source (connected to the multi-input), having two 'small' speakers for your main left and right, having a sub to handle the lower frequencies, and knowing that you want your crossover at 100Hz.

Mine is out being cut now.

-joe




Joe's HT

[Kevin D]

I suppose if the majority of your speakers couldn't produce much under 80hz or so and the disc didn't have a dedicated .1 channel, you would still want the bass to go to the sub.

I put a switch in mainly because I was all ready in the unit and it would only take about 15 more minutes to do..

Kevin D.

[Scarp]

If you cut the resistors then you won't be able to use the subwoofer on SACD/DVD-Audio discs that do not use the LFE (.1) channel. You would want that so, you can setup your subwoofer such that it takes over the lowest frequencies, i.e., you use the crossover of the subwoofer.

[Andrew Pratt]

Scarp that would only be true if the DVD player didn't have its own Bass managenment...which most now do so having a true analog by pass in the Rotel makes the most sense.

[Scarp]

You are entirely true Andrew, but at the time of the creation of the 1066, there where not that many players with bass-management.