RSX 1055 two channel analog bass management

[pjdami]

Sorry if this is a repeat post (did a search to no avail) but I have a question about my 1055's bass management. I am using Transparent analog cable interconnects between my 1055 and RCD 961 cd player. I have Polk LSi 15s as mains and a Polk PSW 350 subwoofer.

When I use the analog outputs from my cd player to the receiver am I defeating the receiver's bass management? In other words, does the receiver send a full signal to the mains no matter what?

I heard that this was the case, but when I switch from Large to small at the same crossover level 60 hz, I can hear a definite difference in sound. Right now I am using 40 hz crossover to the sub with the mains on small (LSi 15 -3 db is at 32 hz).

I'm just a little confused about the wording on page 17 of the owner's manual that states "2CH mode allows you to hear 2 channel stereo recordings in their original format using the analog source". So I was wondering if this is implied to mean that the analog signal is not crossed over.

thanks for any input in advance.

Paul

[Danbry39]

That's a good question and I'm not quite sure on the answer, but I would think that certain processing still goes on with the Rotel. For instance, I have an analog feed from my CD player to my 1066 pre-pro and I can still process the sound (Dolby pro logic II, etc.). It still redirects sound to the sub. So, I think the analog out means more that you're using the DAC's of the CD player over those of the Rotel, but that other processing still goes on.

Anyone, feel free to correct me on this if I'm wrong.




Keith

[pjdami]

Thanks Keith for the reply. The basic question that I would like answered is if the main speakers get a full range signal no matter if you have the speaker set to small or large. I can hear a difference when I switch between the two. Its just the wording in the manual that has me a little confused and some opinions of others that have told me that the analog signal from the cd player does not get processed by the receiver's crossover and the mains get a full signal regardless. From my ears though, I don't think it is the case. When I set the sub to max the bass gets really boomy which would indicate that I'm getting bass to both sub and mains. When I switch the mains to small and sub to yes, this combo sounds the best.

Paul

[Danbry39]

Your speakers should not be getting a full range signal if they are set to small, with the sub set to yes, and a crossover frequency set. What version of firmware do you have?

Anyone, am I missing the boat here?




Keith

[wng]

I believe if the incoming signal is analog and the receiver is in "2 ch" mode, then it is "analog bypass" and the RF and LF speakers get a full-range signal whether they've been set to "small" or "large." The subwoofer, if it's on, plays a copied signal below the set crossover.

[Danbry39]

Thanks wng,

Any ideas as to why he hears something different when his speakers are set to small? As usual, I'm confused. I would have thought that, even on an analog feed, the lower frequencies would have been channeled away from the speakers to the sub in two channel mode.




Keith

[Scarp]

I just did a test on my RSP1066.
I have my dvd player (Onkyo DV-SP800) hooked up both to the analog dvd input and the digital coax input. I switched between large and small on both the analog and digital input. I set the crossover in the 1066 to 120 Hz, to absolutly hear the difference.

Results:
Small setting:
- Analog, the speakers gets full range! The sub gets a copy of everything below the crossover. You should use the subwoofers crossover in this case (set it to 1.5 times the -3 dB of your front speakers) to avoid duplication of bass or turn the subwoofer off.
- digital, the speakers get everything above the crossover (and also a bit below it because it isn't a brick wall). The sub plays all below the cross over. Turn of you subwoofers internal crossover.

Large setting
- Analog, subwoofer gets no signal at all. Fronts get full range.
- Digital, subwoofer gets no signal at all. Fronts get full range.

I don't hear a difference between large/small with subwoofer off on the front speakers. Switching quickly isn't a good idea to hear the differences. I suggest listening to some track for a longer time in both modes.

Hopefully this clears up the confusion abit

[Danbry39]

Thanks a lot Scarp for taking the trouble. It helps clear things up a lot, although I always felt the bass management worked with two channel analog and really wish it did or at least we had the option of choosing what we wanted to do in this regard. I prefer the DAC's in my CD player and, if I'm understanding this correctly, I will have to use the DAC's in the Rotel unless I want to set the sub to do the crossover or turn it off. Is that correct, or am I again confused?




Keith

[Scarp]

Keith,

What exactly do you want? You want to use the DAC of your cd player, you want your subwoofer to handle the range that your speakers cannot handle right?

So you setup your fronts as small, which will make the Rotel copy bass to the subwoofer. Now you do not want doubling, so the subwoofer should only play the range that your front speakers cannot handle. So lets suppose your fronts have a -3 dB at 40 Hz, then either you set the crossover your subwoofer to 60 Hz, then your fronts and subwoofer will have a small overlap but not too much. Your subwoofer will let you hear all the low frequencies.
You can also use the crossover of the Rotel pre-amp, however there is no filtering of the lower frequencies below the crossover on the front speakers (in contrast to digital usage, where this *is* done).

So, you are correct

[Andrew Pratt]

What I did when I had the 1055 was to set the subwoofer to off in the setup menu for 2 channel that way I didn't get any bass going to the sub. Since we have the ability to adjust the sub level for each sound mode simply lower it to the point where it says "off" and then when ever you set it to stereo it will be a true analog stereo mode with no subwoofer.

[pjdami]

thanks everybody for the responses. Scarp thanks for going through the trouble.

This feature actually irritated me a bit when I first heard about it. I would rather use the DACs in my RCD 961 over the 1055. I also spent a good bit of money for Transparent interconnects for analog sources.

I will try the 60 hz crossover again with the mains set to small. I still can't believe Rotel did this. I would love to have the two channel crossover including the sub for an analog source. My firmware is the latest I believe (i updated about three months ago) V1.4.9030305.

Thanks for the suggestions,
Paul

[wng]

pjdami, I did what Scarp did months ago and I back up what Scarp said. There is no difference between "large" and "small" settings on bypassed (unprocessed, e.g., DPLII) analog signals.

Before HT, stereo systems didn't have DSP. If one had monitor speakers instead of full-range speakers, the person would've needed to obtain a subwoofer and use the crossover facilities on the sub. Following this, the SX 1055 (and other Rotel HT controllers), in 2-ch mode, preserves the full-range analog signal from CD players. If (digital) bass management is desired, the signal would have to be ADC'ed, which defeats the purpose of having the dedicated CD player. The alternative is to copy the full-range signal from the CD player: ADC the signal, process it below the set crossover, re-DAC, and send it to the subwoofer to cater to those who want a subwoofer to complement the natural roll-off of the front speakers.

[Andrew Pratt]

There's actually a 1.50 firmware now available. See the FAQ for details

[Danbry39]

Yeah,

Thanks all, especially Scarp for going above and beyond. I think I'll go Andrew's route and set the sub for off during two channel.

Love threads like this!!!




Keith

[Scarp]

Andrew's solution only works if you only intend to use stereo over the analog inputs! If you set your fronts to small and set the subwoofer channel to "off" for Stereo, then with digital stereo inputs you'll end up with no bass at all (below the crossover)

The way the bass is routed to the subwoofer is intentional. It gives you the possibility to use a subwoofer with analog inputs, this is more or less the same what is also available on the multi-channel inputs (without the resistor cut), however there is an additional LFE input which ruins that idea.

I think its really neat to have the ability to use your subwoofer on analog inputs.

Andrew, maybe you can answer this, but when reading the manual of the 1098, i got the impression that on the analog inputs the 1098 will do an analog-digital conversion and do bass management in the digital domain and then convert back. And this can be bypassed by the analog-bypass mode. Thats exactly what would have been nice on the 1066/1055, but the current solution is still fine. Just use the subwoofers crossover to make sure you have no bass doubling.