[CUclimber]

It's a TXS-R601, if that matters.


I only have a 2.1 channel system hooked up to it at the moment, but I've found that it really doesn't sound that good if I put it on plain old Stereo mode. There is significantly less bass output in Stereo compared to All Channel Stereo mode. The manual doesn't say anything about why this would be, so I'm asking the experts on here.


Any ideas? The funny thing is that it sounds "normal" on the All Channel Stereo setting, and there really isn't enough bass in Stereo mode. I went through all of the setup menus to make sure that the mains were set to small and the subwoofer was being used, and everything looks normal.


Any ideas?

 

[Jedi]

...not all receivers put a signal out on the LFE/Subwoofer channel when playing sources that are other than a digital signal. Some only do so if you configure the subwoofer a certain way during set-up. You might check your Onkyo manual to see if something along these lines may be the problem.

 

[CUclimber]

The Onkyo manual doesn't mention anything like that, unless I'm missing something obvious.


The subwoofer does get a signal in plain Stereo mode, but it's just MUCH lower than in All Channel Stereo. In both modes the crossover is set the same, and all of the speakers/sub settings are the same.


And for what it's worth, the cd player is only using L/R analog outputs to the reciever. It's an old Sony 5 disc changer with no digital outs.


??

 

[LessisNevermore]

It sounds like your receiver allows different settings for chanel volume in each mode.

(stereo, all ch. stereo, etc.)

Check your SW level in both modes, especially if you have boosted the level in the multi-chanel mode.

 

[Malor]

There are two modes in the Onkyos where the DSP is taken out of the loop, to give you the best possible quality for 2-channel. Because there is no DSP involved, there is no bass redirection, so your stereo signal is sent purely to your mains. This gives you the cleanest possible 2 channel music, but if you want your sub running, you'll have to go into the 'normal' listening modes.


As I recall, without going and acutally checking, the two non-dsp modes are Pure Audio and Direct Stereo. Pure Audio even turns off the display.... everything possible is turned off to cut down on noise. I can't think of what the name is for basic stereo listening plus DSP... if you can figure it out, great. If not, PM me, and I'll try to give you specific instructions.

 

[Ovation]

On my Integra receiver (based on Onkyo 701), the sub is active for two channel listening if you use the "Stereo" setting (as long as the sub is on in the setup menu, large or small makes no difference for the mains). The two settings without DSP are "Pure Audio", which works as Malor describes and "Direct", which is basically the same but the display remains active. I've not noticed this issue, but will try a few experiments to see what happens.

 

[JorgeLopez11]

That's interesting. Some receivers (the Denons at least) use a parallel signal when Pure Audio is selected in order to use the subwoofer. I mean, one signal is not processed digitally by the DSP (with the exception of the AL24 processor if you have a digital input) while the other goes directly to the crossover array. Then you have Pure Audio reproduction and your sub is still active


It would be a good idea to check how the Onkyos are operating when Pure Audio mode is selected.

 

[CUclimber]

Well I think I have this figured out, but it still leaves one question (skip to the end for it).


According to the manual Stereo is the most realistic and unprocessed signal from this reciever (I don't have the Pure Audio setting, that's only on the 701 and above). Direct is technically the cleanest but it doesn't put out any signal to the subwoofer which seems pretty silly to me.

All Channel Stereo must be doing some sort of DSP; I'm guessing that it increases the subwoofer's output in order to compensate for having the other 6 speakers putting out a full signal. Because I'm only running a 2.1 channel setup at the moment this was causing the 'woofer to get an unnaturally strong and enhanced signal.


Which leaves me with the question:


If I put the reciever on plain old Stereo mode (where I plan on keeping it until I upgrade to a full surround setup) I need to increase the gain for the subwoofer in order for it to sound right. Right now the sub's gain control is turned up to the half-way mark, and the reciever is set for a +5dB gain for the sub. Am I better off doing this in the reciever, or by just turning up the little knob on the sub's amp? What difference would it make? Is there a right or wrong way to increase the gain for the sub?


Thanks for all your replies!

 

[LessisNevermore]

If I put the reciever on plain old Stereo mode (where I plan on keeping it until I upgrade to a full surround setup) I need to increase the gain for the subwoofer in order for it to sound right. Right now the sub's gain control is turned up to the half-way mark, and the reciever is set for a +5dB gain for the sub. Am I better off doing this in the reciever, or by just turning up the little knob on the sub's amp? What difference would it make? Is there a right or wrong way to increase the gain for the sub?



If the sub volume is good when watching movies, I would turn it up inside the receiver, a little. You may have to turn the sub amp up and then reduce it in your movie mode. (whatever works for you)


Side note, what input are you using for cd's? Are you using a cd player, or dvd to listen to cd's? I've noticed when using analog in's,(on the dvd player) the volume had to be turned up to match the digital side, but I generally just use the digital in's. My cd player is in semi-retirement because everything just sounds better (on my setup) through the dvd player.

 

[Malor]

Well, it's pretty normal for a powered sub to require a lot of tuning to get it just right with the rest of your system... you're trying to match two separate amplifiers.


Your observation that All Channel Stereo may be sending more bass because it's sending the bass from all channels could be correct. However, on my 901, I don't see any difference, in terms of sub output, between Stereo and All Channel Stereo. I am running 7 actual speakers plus the sub. In either mode, the sub sounds the same to me.


Honestly, if you're just running 2.1, and if you're out of your warranty period, I'd set the Onkyo to Stereo, tune your sub, and forget about it. If you're still in warranty, it might be worth spending some time to troubleshoot to find out if something is actually wrong. But I suspesct you will need more speakers to do this properly.


Have you correctly configured the Hardware Setup area with the proper number of speakers? In other words, does the Onkyo itself know that it has only 2 speakers and a sub attached?

 

[Oliver Deplace]

By any chance, do you have the surround speakers activated in setup?

Your situation could be explained if the surrounds were activated (and high passed), though not physically there. The bass info they would receive would be diverted to the sub. Since the surround speakers would not be delivering the higher frequency content in "All Channel Stereo", the spectral balance would be skewed toward the bass.

When listening in stereo, the processor would not be sending the surround info to the sub. So, it would sound leaner.

If you don't have the surrounds activated, then I dunno.


And about where you should make the level change, it should be the receiver.

If you raise the gain at the sub, it could make any noise (collected between the receiver and sub) easier to amplify. Usually a non-issue with subs, especially if it's used for the very low frequencies, say, 40Hz and down.

 

[CUclimber]

Quote:

By any chance, do you have the surround speakers activated in setup?

Wow. Just, wow.


I usually consider myself a pretty smart guy and can generally troubleshoot stuff pretty well but I'll be honest here-- I never even considered turning the surround speakers off in the reciever!


By doing that of course the reciever won't even let me change to a surround mode, so my whole original question is moot. I upped the gain for the sub to +7dB, tweaked its position a bit more, and all is well in my setup.


Really, thanks for all the suggestions!