Bass Management and LFE: NOT the same thing!

If you have a subwoofer in your system, you should always use bass management in the AVR.  Unfortunately this is not always the default setting and several manufacturers still insist on setting speakers to “Large” or “Full Range”.  Doing so will prevent bass from being redirected to your subwoofer from the satellite channels.  Audyssey recommends to manually change all speakers to “Small” (i.e. set a crossover frequency for each speaker in the manual settings menu) thus enabling proper bass management.  This has the additional benefit of much better low frequency correction because MultEQ uses filters with 8x more resolution in the subwoofer channel.  More information about this can be found on our blog post here.

The LFE signal and the bass management crossover are two different things.

The crossover is responsible for taking the bass from the speakers and sending it to the subwoofer.  That should be set at around the frequency where your speakers are no longer able to reproduce bass.  This is called the crossover frequency.

In 5.1 content, there is an additional bass-only track called the LFE track.  This is not played from the main speakers, but only from the subwoofer.  This track is authored to have content up to 120 Hz and so the filter in the AVR called LFE Lowpass should be set to 120 Hz. Always.  It is a mistake for AVR makers to even make this an option as it has nothing to do with bass management.

  I currently do not have a subwoofer.  Because of this I'm wondering if MultiEQ will still run or do I need to do manual settings.  Also, should I run my L & R mains as "large" or "full range" (not sure which term my AVR uses yet) to have the bass ran through them?  Any help is appreciated.

 Thanks,

John

MultEQ will run just fine if you don't have a subwoofer.  It is not in charge of redirecting the content to the sub.  It just measures whatever speakers and sub are in the system and creates a correction filter for each one to undo the effects of room acoustics.

If you don't have a subwoofer, then your front L and R speakers can only be Large.  You don't have a choice.  Small simply means: "send the bass to the sub".  If you don't have a sub, you can't set the front speakers to Small.  You can, however, set the other speakers to Small.  In that case, their bass will be redirected to the front L and R speakers.  This is a good choice if the woofers in the front speakers are larger than those in the center and surrounds.

I have a Onkyo TX-SR608 2010 AVR which has Audyssey 2eq. It automatically sets my fronts at 40hz frequencies and the center at 50hz. The subwoofer lpf is set to 120hz and subwoofer level is set at -04. Here's my issue, for movie playback, these settings sound optimal. I get rich thunderous bass from my Onkyo sub. The problem is that when I play music( any genre from Hip Hop to Metal, Latin or Classic just to name a few), I can hear all the bass through the front and center speakers but no bass from the subwoofer therefore I increment the sub level as far as +08 to avoid overexceeding it. At this point I hear a very minimal difference in sound and the sound at times is very distorted as if the sub was maxed out. I change the lpf to 80hz which also has very minimal effect. I've also manually reduced the front and center bass levels to -10 with no success and tried incrementing treble levels also with same negative results. I've also reduced the center speaker level output but same results. My sub is connected via monster sub cable to my receivers sub pre-out. I've also enabled my THX setting to double bass which according to my AVR manual, redirects all low frequencies from the front and and center channels to the sub for richer bass but does not help at all. My source output to the receiver is my HTPC(Home Theater PC) via Toslink or also known as optical cable. What is causing this and how can I solve it? as the receiver is new and it boasts great reviews. I know it's not faulty because most movies will output great lpe sound unlike my music whether it's Metal, Hip Hop, Latin or Techno or even Classic. Please Help.

I too have an Onkyo 608 and love the Blue Ray movie imaging but any CD stereo sound is very flat and plastic sounding.  My older Onkyo 602 has fantastic stereo sound.  Its rather frustrating when we buy newer equipment only to find out the old stuff is better (in some ways)

Victor,

Make sure that when you listen to music that your speakers are not set to Full Range.  This is a common issue.  AVRs switch speakers to Full Range which means that no bass will be sent to the subwoofer.  This also happens when you listen in Direct or Pure mode that turns off all digital processing including Audyssey, Bass Management, etc.

Tried everything at least 5 times, hours and hours of tweaking, swapping and comparing the 608 against the 602.  The 608 can't reproduce CD stereo sound nearly as well as the older 602.  The 602 although rated slightly lower in watts weighs about 10 pounds more than its upgraded 608 brother, perhaps a change in amplifier design is behind the weight/sound changes.  Front speakers are set to 85 and speakers are flat but sub works.  Tried full range and speakers improve slightly but sub is gone.

I have just (finally) installed my TX-SR 608 (2EQ System). I'm using on wall spekaers from Axiom

M22's and the VP150 centre channel. My 4 surrounds are QS4 Bipolars. If you look them up, you will find a pretty decent spec.

Anyhow, like Victor, when I ran the 2EQ on my system, I got some rather surprising results. 2EQ reported back centre at 50hz (lower than expected), Fronts at 60hz (lower than expected) and surrounds at 100hz (as expected.)

Now it was my distinct understanding that on the Onko 608, the o/p from the 2EQ does indeed get used to set the X/over frequency for bass management of the sub.

So, these values being different than expected, and assuming the bass management of the AVR is set as per the settings on the 2EQ, then can I "trust" them ?? 

The reason I ask, is that so often, you see forum posts where the correct setting is to start with is 80hz across the range with the subs higher. I've no problem whatsoever doing this as I understand how bass management works.

I just need a sanity check.

Thanks

Steve

Steve, that's why we need to measure.  Speaker specs don't know about your room or where the speakers are placed relative to the walls.  If you move the fronts and center out from the wall you will see the measured roll off change to a higher frequency.

So, do I leave them as the AVR (based on 2EQ) sets them ? Or.... should I opt for another more standard (i.e. 80hz setting).

I raised a more detailed request outside this thread, so perhaps it might make sense to answer that rather than hijack this thread.

Many thanks

Steve

My suggestion would be to leave them. Why not try both and see?

Hi Chris,

 I have Definitive Mythos ST - Floor Standing speakers and it comes with built-in subwoofer and I dont have a separate subwoofer. Definitive suggests that the sepaker setting should be large/full band and subwoofer setting to be set as Yes in the receiver. I updated this and once I finish running the Audyssey calibration, it updates the Subwoofer setting as "No". Can I turn them back on. Whats your advise.

Also, during movie watching, I wanted to hear the dialogue louder from the center speaker. Can these be tweaked once the setup is completed. 

Please advice.

Thanks,

Danny

Hi Danny,

If your product has MultEQ or MultEQ XT then we recommend connecting all the subwoofers (the ones in the speaker cabinets and any external ones) to the line level Sub Out of the AVR.  You will need to use y-cords for this.  The benefit of doing that is that the subwoofer channel filters in MultEQ and MultEQ XT have much higher resolution and so you will get smoother bass response.

You will have to make sure that all speakers are set to Small for this to work correctly.  Audyssey is not allowed to make this determination.  The AVR manufacturer makes it based on the info it receives from the Audyssey measurements. 

Chris, 

Definitive advises to set speakers to Large/Fullband for MYTHOS ST. Is it Ok to set them as small.

Small only has meaning if you have a subwoofer in the system.  If you have a system with MultEQ or MultEQ XT then we strongly advise to connect the woofers as subwoofers.  In other words, connect them with a y cord to the Sub Out of the AVR and make sure that the speakers are set to Small once the calibration is finished.

Thanks a lot Chris. One more question. 

Does this hold true also when I am using MultEQ XT32. After the calibration, can I set them to small. I am asking this because I m planning to upgrade my AVR to Denon 4311 and it comes with XT32. 

Yes, this recommendation is for any version of MultEQ.

Hello, i have on my avr MultEQ XT32 . After the auto setup my subwoofer has less punch. Is this because of the flat frequnecy response audyssey makes to my system?

When i disable the Audyssey EQ the bass punch is back again.

This is most interesting... perhaps this ought to be on an Onkyo thread and not Audyssey ?  With my Onkyo 608, then as reported elsewhere, via BR / DVD the sound is superb. however, with any CD 2 channel source, the sound is rubbish.

It's so incomparable that it cannot be the AV player but something else in the Onkyo that affects how the music is managed.

I've tried it all- except forgetting that I have an AVR and trying to set it up as 2.0 channel.

Thoughts welcome

Steve

Hi Martin, 

Audyssey sets the level for Reference. That means: 

1. the speaker and sub levels are set so that they all play at the same level 

2. the speaker and sub levels are set so that when the master volume of the AVR is at 0 dB you are listening at film reference level (same as what was heard in the studio during the mix).

I'm not really sure what "punch" means, but if you want more bass than reference then you can set the level of the sub to your own preference. It's no problem. The room correction filters will continue to operate. The only difference will be louder than reference bass.  Some people call that "punch", but it's nothing more than "loud bass".  Not a problem, but it's "preference" not "reference".

Also, please make sure that the settings in your sub are not interfering with proper measurement and bass management: 

http://ask.audyssey.com/forums/84181/entries/76175.html

Hi Steve,

Could it be that you are listening to stereo content in "direct" mode? That turns off all digital processing including bass management and Audyssey.  So the benefits of room correction are lost.

In setting up my subwoofer (Acoustech PL-200) and running MultEQ XT, I had the polarity set to 0, as I had read in several locations.  After running MultEQ XT, the bass was underwhelming.  If I change the polarity to 180 (which significantly changed the bass output when I was testing the subwoofer), do I need to re-run MultEQ XT?

Similarly, I had neglected to change the crossover on the subwoofer to "Out," and instead left it on "In."  Should I run MultEQ XT again after switching it?

Thanks for your help.

George

Hi George, there is no need to rerun MultEQ after changing the subwoofer polarity.  It will have no effect on the filters calculated for the sub.  However, if the crossover was set to In when you ran the measurements then you may want to re-run in case the filter was interfering with the measurements.

Hi Chris,

I'm running the Denon 1911 and like my bass.  I have the level set past the 12 o'clock position, maybe around 9 o'clock and my reading is a -9.5.  Is that ok, or do I need to turn it down and redo Audyssey.

You are fine.  This is still in the range that the AVR can compensate.  You only need to turn down the sub level (and run MultEQ again) if the reported level is –12 dB.  Then you are at the limit of the AVR range and don't know if more adjustment may be needed.

So if I wanted, I could actually turn it up a bit more and run Audyssey again?

It will make no difference whatsoever.  If you turn it up on the back of the sub and run Audyssey again then it will turn it down in the AVR for you.  No matter where you set the volume on the sub Audyssey will always give you the same bass level.  That's what Reference means!  It's the level they were using in the studio where the content was mixed.  If you want more bass than reference then you have to turn up the sub level after Audyssey is finished.  I suggest doing that in the AVR menu so that you can always go back to the reference level any time.

Hi Chris,

I recently purchased a Denon AVR 3312CI and everytime I run the Audyssey auto setup it has my front speakers set to "Large".   These speakers are capable of going as low 40hz.  However, I believe I remember reading that you guys recommend setting all speakers to small if there is a subwoofer involved, which I do have.   Will it matter if I left the front speakers set at "Large" since Audyssey did pick up that the crossover for the fronts should be at 40hz?  Thanks so much for your help!

Mark

Hi Mark,

Audyssey doesn't set Large and Small.  Denon does.  They use 40 Hz as the decision point and so if the speaker was measured to roll off there (or a little below due to wall proximity) then Denon sets it to Large.  We disagree because then no signal goes to the subwoofer. So, yes, after the calibration is finished go ahead and set it to Small.  That way the content below the crossover point will be sent to the sub where the MultEQ filters have 8x higher resolution.

Chris, I have a question about one of your comments from 2010:

Victor,

Make sure that when you listen to music that your speakers are not set to Full Range.  This is a common issue.  AVRs switch speakers to Full Range which means that no bass will be sent to the subwoofer.  This also happens when you listen in Direct or Pure mode that turns off all digital processing including Audyssey, Bass Management, etc.

I do not have a subwoofer, my front speakers are full band floor standing Cerwin Vega speakers (AVR Onkyo SR608, Musical Fidelity V-DAC Mkii). Does your above comment apply in my case? If yes, how can I make sure that my speakers are not set to Full Range when I play 24-bit 96Khz music? Thanks, Alex