LFE vs Diverted Bass - Is your processor WRONG? (Updated with custom test tones) (2 Viewers)

[Sebastian]

TX-DS484's bass management was inevitable. With no sub, full-range material goes to each of the speakers and any LFE .1 channel material is discarded. If you have a sub, it gets the LFE and any bass below 80Hz if the main speakers are set to "Large," rolled off at 12dB/octave. Speakers designated "Small" are crossed over at 120Hz instead, with a 6dB/octave slope. While far from comprehensive, I suspect the configuration options available here are sufficient for a typical surround buyer. If you have either a set of mostly full-range speakers all around or a subwoofer and a set of smaller satellites, like most smaller home-theater speaker systems, one of these modes should suit you fine. The main group that's shortchanged here are people who have large front speakers and smaller rears but no subwoofer

Even called Onkyo to confirm this
Actual website
The tones are 40 Hz so I should be getting nothing if the bass management is correct. The only time I should have any signal on the main speakers is if I have the sub option set to no.
I will test again to make sure i did not screw anything up and will test with sub set to no and see if that changes anything.
What would suggest setting my speakers for HT use? Large or small. I have HTD level II 5.1 set. 5 1/4 drivers I think on the mains.

 

[Vince Maskeeper]

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Well given your receiver's wacky decision of changing the rules completely on what large/small settings mean from the dolby standard- I would suggest you go with large (sub set to ON) and have the 80hz crossover point (IMHO that 120 x-over point is WAY too high!). If this works as they say it works- the tone in question should be produced essentially exclusively by the subwoofer.
Take particular note of which tone you are listening to (the fist is Left, then center, right, left surround, right surround and then LFE). If this is rerouting bass properly and everything is configured as you say it is configured- you should get resonably even output, all coming from the sub no matter which tone you play.
-Vince

 

[Dan Hine]

Sebastian,

IMO an 80hz crossover would be ideal for you so I would set your speakers to large. I also feel that most subs just don't sound as good up around the 100hz and up range...another reason to set your speakers to large. Let us know what you decide.

Dan

 

[Sebastian]

These two statements seem to directly conflict one another. All sound on these tones should come from the sub, and not from the other speakers. Originally you said that you get "no output" with speakers set to small- now that second quote seems to contridict this.

Sorry about that, what I should have said is that there is no sound coming from the 5 surround speakers, only the sub is producing sound.
I believe it is pretty obvious I am doing this test wrong. All sound is supposed to come from the sub only and at each test tone, the SPL reading should be noted on the RS SPL meter right?
If that is the case, like a moron I was taking the reading from each surround speaker and noting that SPL level.
So my next question is, why is the sound panning across all 6 speakers when the speakers are set to large? Just does not make sense to me.
The LF, C, and RF definitely have a good level of sound coming from them with speakers set to large. I would say more sound than the sub, is this normal?
Thanks for your patience

 

[Sebastian]

Okay, Played tones again. With sub set to yes and speakers set to small. All test tones are coming from the sub and nothing from the other speakers except for a hissing sound. I did not take any readings with the SPL meter but by ear the test tones sounded even except the last tone that has the LFE +10 boost on it. (sound was even on the all six speakers with the LFE compensated for)

Sub yes and speakers set to large sound pans across all six speakers just like the receiver test tones and Avia test tones when calibrating the level.

When the sound is panning across the 5 surround speakers there is no sound coming from the sub except on the last test tone.

Is this how it is supposed to work? Or is my bass management on my receiver messed up?

With this given info, do you still recommend the large setting?

 

[Vince Maskeeper]

Well- this means your manual and their website are lying.

The way Dolby bass management is SUPPOSED to work is this:

If you set to large, all bass from the main channels are sent to the proper main speaker, and all LFE bass signal sent to the sub. In a config with LARGE setting, the only material sent to the sub is the dedicated LFE track.

If you set to small- then all bass info below the specified crossover level (sometimes adjustable, sometimes fixed) is rerouted from the main channels into the sub. The sub also is sent the LFE material from the dedicated LFE track

Now, this is the way every dolby bass management system I have ever seen works. However your manual suggested it worked otherwise.

But when you played the tones, it seems like it is operating exactly as a normal Dolby management circuit functions. When set to small, bass tone from the mains was rerouted to the sub. When set to large- the tone was NOT rerouted to the sub, and instead was sent to the main speakers.

This is how it is supposed to work- and how it works on every other system I've seen. So the bottom line is- you system works like it is supposed to, which is completely different from how the manual suggests it should work.

In that case, I would suggest the SMALL speaker setting- which will cause all super low bass info to be rerouted from the mains to the sub.

I would suggest double checking the tones with a meter- just for the heck of it- so we can see how close you system is on rerouting from the main channels. Also, make sure that 10db boost you get on LFE only happens with tone #1 and does not happen with tone #2.

-Vince

 

[Vince Maskeeper]

To anyone who runs their speakers as Large,

I just thought of an interesting side effect of these tones. If someone chose to run their speakers as "large" these tones could also be useful to that person as well.

If you calibrate your speakers and sub to be even using a test disc like Video Essentials (which features a dedicated LFE test track, a must for calibrating if you have large speakers since AVIA has not dedicated LFE tones)- then they should be at an even level in output.

If you have them even in output and set to large- try these tones (specifically the second tone). This will produce an even 40hz tone in every channel, and then the sub. If your main speakers are capible of handling 40hz properly, the tone should not significantly change in volume as it makes its way around the room (some variables such as room design will have some influence with a 40hz sine).

IF it seems like your speakers set to large produce this tone at a much lower volume than the LFE sub tone using test #2- then you should reconsider running your mains as large!

-V

 

[Sebastian]

Finally ran the test tones with sub set to yes and speakers to small where sound was coming only from the sub using the RS SPL meter.
L: 0
C: -0.5dB
R: -0.5dB
LS: -1dB
LS: -1dB
LFE: -0.5dB and +10.05 Db on the other test tone.
So I would take it that the receiver is doing a good job routing the bass?
I am still a little confused about what is going on with my rec bass management.
One of two things are happening here:
1. Vince is right the website that reviewed the receiver and Onkyo's phone customer service don't know what they are talking about. If this is the case how can I know what the crossover is set at?
By Dolby standards is the crossover supposed to be at 80Hz or 120Hz?
By ear and listening to music and movies I would say the receiver with speakers set to small is set at 120Hz.
Anyone know where I can get some test tones to see for sure where the sub rolls off at? I have the Ultimate DVD platinum disc and I will see if anything is on that.
I recall that other Onkyo owners were told the same thing about crossover points.
2. The website and Onkyo is right and my receiver for some reason does not work properly when the speakers are set to large.
Anyone else with an Onkyo receiver with these results?
Thanks again Vince for your help and patience!

 

[Vince Maskeeper]

Oddly, while helping someone else on the forum in this thread:
http://www.hometheaterforum.com/htfo...threadid=81777
I downloaded the manual for the Onkyo TX-ds484 and the crossover point or specifics of the bass management processing is not outlined at all in the manual. It is obviously a fixed x-over point (since no control is mentioned or offered)-- but again it appears to me like the reviewer above was incorrect- or at some point in the production run they switche to a different decoder chipset which operated within dolby specs. I think the magazine just got wrong info from Onkyo and published it without actually testing.
I checked some other products in that line and found that the manual for the DS-989 model (the top of that production line) did mention the crossover point, and said that when setting to small, all freq below 80hz were sent to the sub (See pdf file tx-ds989_us.pdf page 30, lower left). It seems the 989 works exactly as a normal dolby decoder should.
I also looked over the manual for the 494, which also alluded to this function, while not directly stating:
"When subwoofer mode is set to mode 2 (mode two is all speaker are large) and audio is reproduced in the stereo mode, the subwoofer may not output audio from certain sources."
It's basically saying that if you set to large, the only material ever going to the sub is LFE... so if you listen to anything other than 6 channel soundtracks, you won't get sound from the sub (since they have no LFE track).
So, since there are 2 products in the line that show they work exactly as dolby spec, I'd guess you could at least lean in the direction that the 484 is doing so as well!
If the crossover worked as outlined in that review you quoted above- your system would have bass tones sent to the sub with speakers set to large and sub set to on- however you have shown this to be false.
You could prove this again using a music CD. Find some bassy music, Set the receiver to stereo mode (don't use any DSP like pro logic), and toggle the receiver back and forth from Large to Small speaker settings.
Do you get bass coming from the sub with the speakers at large? How about with them at small. To make it really obvious, disconnect all speakers EXCEPT the subwoofer, the try this experiment. It should be immediately obvious what is going to the sub in large/small mode.
-V

 

[Sebastian]

Just Called Onkyo and spoke with two different people and informed them about these tests. The first person was product support and he informed me that with the sub set to yes, speakers to small the crossover is 120Hz and with the sub set to yes and speakers set to large, the crossover is 80Hz. Then I spoke with engineering and he said everything is working properly and that is how it is supposed to work. Just when the crossover is at 120Hz by the time it gets to 40 Hz the sub is the only speaker producing sound because it was rolled off at a higher frequency.

When they are set to large and the crossover is at 80Hz the receiver, since it started at lower frequency the receiver is still dividing the frequency between the main speakers and the sub; to avoid any frequency gaps. Basically there is still some life in them in the 40 Hz range. This is what I thought before about what was going on but as Vince stated at 40Hz should be 10-12 dB down no matter what the speakers are set to, according to Onkyo and that website that reviewed the receiver. Man! I wish I knew for sure what slope they were rolled off at!

What do you think Vince? You understand this stuff a lot better than I do.

Come to think of it, there still should more sound coming from my sub than my main speakers with the speakers set to large. When I get some time, I will run these test again with the speakers set to large and see if there is any sound coming from the sub. The only thing I will have to get a ladder to get to my sub (located on top of a plant shelf above my entertainment center).

Or maybe I will adjust my subwoofer level to +12 dB and see if I hear anything with the test tones playing.

This really should not matter because the sub should be producing the vast majority of the test tone and should have worked the first time, but who knows maybe I screwed the first test up

 

[Boris]

Hi.

Thank you Vince, it's very handy to know your own gear's working correctly.

Here's my systems results. (Calibrated using Avia, reference level 00dB on master volume, Denon 3801 all speakers set to small).

At 5dB under reference I measure-

80dB

80dB

80dB

79dB

79dB

91dB

Then-

80dB

80dB

80dB

79dB

79dB

81dB

And just out of interest, the individual channel volume settings have no effect on the rerouted bass info.

Thanks again.

Boris.

 

[Arnel]

Vince, I have tried your test tones and get the correct/expected results on my Yamaha RX-V800. This only proves that that specific test tone on AVIA is wrong, I hope they would do something about it. Anyway, I'm now trying to checked if my sub is in-phase with my speakers. Using again test tones from AVIA, I found that my Main speakers are in-phase while the rest (C, LS and RS) are out of phase with my sub. Is this possible or I'm just doing it wrong?

 

[Casey H]

Vince, All,
Saw this on a search. Found it to be very helpful and just wanted to bump it back to the top for those who didn't catch it the first time!
Casey

 

[Vince Maskeeper]

Figured I'd bump this old thread for anyone who would find these tones helpful.

_V

 

[Edward J M]

Much thanks, Vince. I'm going to try these files.

I have the Avia disc and it consistently reads 10 dB low on the six channel pan when it hits the LFE channel on my Denon 3803. This led me on a wild goose chase wondering if my set-up or the BM circuit in my 3803 was defective, neither of which I now think are true.

My 3803 performs fine on DVD DD/DTS movies and I certainly have no shortage of bass after proper calibration.

I know Ovation recorded the LFE channel 10 dB low on the 6 channel pan, but my 3803 apparently refuses to automatically boost that channel 10 dB to achieve parity with the other low passed channels.

I sent Ovation an e-mail about this and they never responded. Does anyone know why my 3803 reads 10 dB low on the 6 channel pan on the LFE channel?

To muddy the waters further, it does not read 10 dB low on the LFE channel reverse sweep.

I'll post my results here using Vince's tones - thanks again.

Regards,

Ed

 

[Edward J M]

Update:
Well that didn't take long. The files downloaded and burned perfectly and flagged DD with no problems in my DVD2900 and AVR3803.
I set the SPL meter near the sub at 1 meter and ran both files after adjusting the volume to 80 dB.
File one read 80 dB +/- 0.5 dB for all six tones.
File two read 80 dB +/- 0.5 dB for all five low passed tones and 90 dB for the LFE tone.
Looks like there is nothing wrong with the BM circuit of my 3803 and the Avia six channel pan has a problem with the LFE track.
A thousand thanks, Vince - this really lays to rest any niggling doubts I had about the 3803 BM circuit functioning properly. I REALLY appreciate you taking the time to create these wav files.
Regards,
Ed

 

[Kevin C Brown]

Have another question for y'all concerning Avia and the sub test tones.

I have noticed this on 3 pre/pro's now, and wondered if anyone else had seen it.

On Avia, in one section, you set the level of the mains. And then in the sub section, there's Left Front/Sub, Center/Sub, Right Front/Sub, etc, test tones. I have *always* gotten a low sub output with the Center/sub test tone combination. I had assumed a problem with Avia, but anyone else ever spot this?

 

[Zack_R]

I have *always* gotten a low sub output with the Center/sub test tone combination. I had assumed a problem with Avia, but anyone else ever spot this?

I have. Since it's not an LFE signal, I'm assuming it's because my center doesn't produce near the bass that the my mains produce. So there is no coupling effect when the sub portion sweeps with the center. Even though the bass portion is 70 Hz and below, the crossover setting on your receiver will allow the sub and speaker to go above and below at the cross over.

Generally speaking most center speakers are not full range and they are not near a side wall (such as more common with mains) couple that with anemic bass and I think you get a lower sub output.

FWIW, I just use the first one to three left/sub phase bursts for calibration purposes on the front.

 

[Kevin C Brown]

Zack, not the sweep, just the test tones that toggle between the main speaker and the center. (But I *also* do notice it during the sweeps too!) That's just it. I had a center channel that went down to 40 Hz or so, and I *still* had the effect. Now, I have a center I crossover at 120 hz (very accurate though), and does it about the same. But yeah, like yourself, I just use the left channel. (That's the corner my sub is in anyway.)

 

[Edward J M]

Since Avia is a true DD disc, the test tones are not discrete and the surround speaker in question will also play part of the subwoofer tone.

It's actually amazing how much of the sub tone it plays with the crossover set to 80 Hz. Power down the sub on the sub test tone and see how much SPL you are still getting from the surround speaker - I'm getting anywhere from 78 to 82 dB depending on the speaker and/or its room position.

This "surround speaker contribution" phenomenon often leads to a weak sub calibration with Avia, and I now resort to my discrete AVR test tones to double check just how hot the sub is running. Many enthusiasts calibrating the sub with just Avia for HT find that they need to be 6-8 dB hot in order to get the proper effect for HT.

I think Zack hit the coupling concept well. My left main is right next to my sub and that particular sub level test is louder than any of the others.

If your center channel is now high passed at 120, I would expect the sub level test for this channel to read lower since you are not allowing the center channel to contribute any bass to the sub level tone.

Regards,

Ed