No sub signal in Stereo mode

Mikejo

I haven't had any luck from Onkyo on this problem, so I was hoping someone might offer a solution.
I have an Onkyo TX-SR502 with a Polk PSW350 sub. The sub works fine in all listening modes, except Stereo (the Onkyo manual indicates that the sub should work in Stereo mode). I've tried changing the crossover frequency and the sub speaker level on the receiver. I've also tried increasing the volume and low pass adjustments on the sub. There just doesn't appear to be a signal to the sub in the Stereo mode.
Has anyone had similar experiences with this Onkyo receiver? I use to have a Sony 830 unit that worked fine in the Stereo mode. Other than taking the receiver in for service, does anyone have any suggestions.

Thanks.

adam2434

I've never owned one, but I have heard about these types of issues.

Are your front L/R speakers set to small in the Onkyo?

If not, they will need to be set to small.

If they are already set to small and you're not getting bass to the sub, then the Onkyo has a design flaw in my opinion.

Mikejo

Thanks, Adam 2434! I'm guessing that your suggestion to set the speaker size on the fronts to Small is a standard setting for system with subs, but it did not appear in the Onkyo receiver manual (simply indicated that for front speaker cones larger than 6.5", which mine are, the setting should be Large). I switched the speakers to Small and the sub works fine in the Stereo mode. I'm not a stereo enthusiast per se. But I find it odd that the sub works in all Listening Modes when the fronts are set to Large, but not in the Stereo mode.

Anyway, thanks for your help.

polrbehr

I had a similar problem with a Denon AVR-2106. There is a setting in the subwoofer mngmt. setup which can be either "Normal" or "LFE + Main". Since setting the Denon to the latter, the sub (a PSW450) performs as expected,
with fronts set to either large or small. Hope that helps.

adam2434

Mikejo wrote:

Thanks, Adam 2434! I'm guessing that your suggestion to set the speaker size on the fronts to Small is a standard setting for system with subs, but it did not appear in the Onkyo receiver manual (simply indicated that for front speaker cones larger than 6.5", which mine are, the setting should be Large). I switched the speakers to Small and the sub works fine in the Stereo mode. I'm not a stereo enthusiast per se. But I find it odd that the sub works in all Listening Modes when the fronts are set to Large, but not in the Stereo mode.

Anyway, thanks for your help.

The likely reason that the sub worked with other modes is because you probably had your center and/or surrounds set to small, so the receiver was directing bass from those channels to the sub. The sub is only going to get bass from the channels set to small.

As polrbehr mentioned, some receivers allow you to run the fronts as large and get bass from the fronts to the sub. This is can be called "LFE + Main" or "Plus" etc. The issue with this is that you will get a lot of overlap of the mains and sub unless you dial in the sub's crossover to blend where your fronts roll off. If you do this, the bass from your other channels and LFE channel will see 2 crossovers, which is not desirable and defeats the benefits of the receiver's bass management.

If I were using truley large mains (primarily floorstanders) and I wanted to use my sub for stereo, I would just pick a lower crossover in the receiver that was closer to the natural roll of the mains - say something in the 50-60 Hz range and keep the fronts set to small. Then for surround sound, I would set the receiver's crossover higher to accommodate the smaller center and surrounds - say 80-100 Hz if they are decent size speakers.

Some other set-up tips and things to consider:
1) Make sure you use the unfiltered LFE input on the sub. This disables the sub's crossover, which is what you want when you're using a receiver's bass management.
2) What speakers do you have? This will help determine the best crossover frequency to select in the receiver. Most folks with medium sized speakers like to use a crossover setting in the 60-100 Hz range and set all speakers to small.
3) If you haven't already, calibrate your speaker and sub levels with a spl meter.

Mikejo

This information has been vastly helpful. It's too bad the audio industry doesn't use folks like yourselves who really understand audio systems to write the manuals. I've gotten more out of reading these responses that an hour or two of pouring over the Onkyo manual and websites.

By the way, I'm still using a pair of Polk Monitor 7s that I bought in the 80's. They have 6.5" mids and 10" woofers, hence the reason I set the speaker size to Large. I would prefer to buy a pair of tower speakers (like the RTi8), buy I hate to part with the Monitor 7 (and the $850).

Thanks for the great advise.

adam2434

With your 7's, for stereo, I'd try a crossover in the 60 Hz range in your Onkyo (if it has an option in that range) and set them to small. I'd also try 80 Hz, and switch back and forth to see which one you like better for stereo listening.

Then, for surround sound, I would keep all speakers set to small and set the crossover to 80 Hz in the Onkyo, assuming you have typical/normal sized center and surround speakers (say something with at least 5.25" woofers).

Good luck and glad we could help.

polrbehr

If, as you say, your mains are producing good low frequency response, then your subwoofer should only be "filling in" as needed anyway, as mine does. In fact, the only speaker I have set to small is my CSi30 center. My surrounds, while only R15s, are actually wired as satellites of an Advent powered sub (yes, I love bass), enabling a large setting in the speaker management of the AVR. I am not sure how other receivers are set up, but the Denon allows a full range signal to be sent to any speaker set to large, while directing any low frequencies, as set in the crossover, to the LFE channel, provided you use the LFE + Main setting I alluded to earlier. So, my settings are as follows > fronts,large - center,small - surround, large - subwoofer,yes (LFE+Main).
This seems to yield a good combination for almost any listening choice.
By the way, an SPL meter is a must. Adam is absolutely right on that.
You won't believe how "off" most speakers are, but the meter doesn't lie.
My sub was about 7dB louder than the rest of the speakers before I adjusted
it.

adam2434

Polrbehr, this reply is not to start a debate, but rather to check my own understanding.

If you set your speakers large and use the LFE + Main setting (I believe this is called "Plus" on my Pioneer Elite and "Double Bass" on some other receivers), you are not really using the sub to fill in the bass. Rather, you are running your speakers full range and sending the bass below the crossover to the sub. You're not getting a blend between your speakers and sub, but rather you are having some bass frequencies being played my both the speakers and sub.

For example, say your front speakers are capable of playing flat to 40 Hz and your sub plays flat to 20 Hz. You set the fronts to large, sub to "LFE + Main", and crossover to 80 Hz. You are using the LFE input on the sub, or have the sub's crossover turned all the way up, which are the 2 preferred ways for HT bass.

In this example, both your fronts and sub are playing 40-80 Hz content from the front channels Sure, that will possibly give you more bass, but will not be blended or calibrated bass.

If you want to blend your fronts and sub for more calibrated/even bass, you would set the speakers to small so that the fronts play from the crossover point up and the sub plays from the crossover point down. If your speaker and sub levels are calibrated properly, this should provide a decent blend (of course, the speakers themselves, their placement, and the room will determine the quality of the blend).

If you prefer the extra bass you get with LFE + Main, then cool, we all have our personal preferences. However, I believe this would "technically" stray from a properly calibrated set-up.

The above assumes that I properly understand what the receiver is doing in the LFE + Main setting. The description of "Plus" in my manual is so vague that I can't tell what that setting does.

polrbehr

Your understanding is correct, adam2434. The bass was being played by fronts and sub alike. I try to keep an open mind on all of this, and welcome any comments and suggestions. The Denon I purchased (one month ago) replaced a Technics SA-DX930 HT receiver, and I am still trying to decipher the manual. For a while there my sub wasn't working at all, it seemed, which is why I changed the setting in bass management in the first place. It turned out that the crossover was set to 40Hz, which I have subsequently set to 80Hz. So, if I set my fronts to small, then anything below 80Hz would be sent to the sub only, and anything above will be handled by the fronts themselves?
I will certainly give that a shot, as R50s, which I do like a lot, are not nearly as effective at reproducing bass as a sub. Thanks for the comments.

adam2434

polrbehr wrote:

So, if I set my fronts to small, then anything below 80Hz would be sent to the sub only, and anything above will be handled by the fronts themselves?
I will certainly give that a shot, as R50s, which I do like a lot, are not nearly as effective at reproducing bass as a sub.

Yes, that should be the case. The bass management would direct any sub 80 Hz content from channels set to small to the sub, freeing the speakers from playing those frequencies.

If you ever listen in stereo with your R50s, you might want to try 60 and 80 Hz (depending on what options the Denon has), and determine which sounds better for music. The R50s should dig deep enough for a 60 Hz setting. For surround though, I would go with a higher setting, probably 80 Hz, given the rest of your speakers.