Bass Management and LFE: NOT the same thing!

Hi Alex,

If you don't have a subwoofer then you have no choice.  Your speakers will be set to Full Range.  Setting the speakers to Small means: send the bass to the sub.  In your case that's not possible...

Hi Chris,

i ran an audissey auto set-up on a marantz processor AV8003 with Adam active speakers and as a result all the low frequencies were routed to the speakers with none reaching the sub: it remained switched off even in "action" scenes; I checked the settings and noticed that all speakers were on "Large". So according to your recommendation, I set all speakers to "Small" to have more LFE redirected to the sub. So far so good. I haven't changed the crossover that Audissey has set at 60Hz.

My question: I would love to have as much bass routed to my speakers as I had at the end of the calibration, when nothing was going to the sub; the sound was rich, full BUT I would also  like to have more bottom end and have the sub come into action more often as well.

1- So am I right in setting the speakers to SMALL?

2- Shall I also set the crossover to 80Hz?

3- And will this leave all the bass BUT the bottom end to be handled by my speakers?

Thanks

Chris I'm confused I ave a tx-nr709 and I can't find the bass management option. Is there one ? If so how do I reach it Thank you

@olivier: yes, leave all speakers as Small.  That sends bass to the sub.  If you set them to Large (Full Range) then no bass is sent to the sub.

80 Hz is a good choice for crossover.  Everything below that will be sent to the sub.

@Matthew: Bass management is engaged when you set your speakers to Small (i.e. set a crossover for them).  That's all you need to do.

Hi Matthew! I have the 709 as well, and I am not aware of an option to set them to small. You will as I did have to set them. I set the front, center & surrounds all to 80Hz as suggested in other posts. I set mine after I calibrated. Best of Luck!!!

hi chris, i have all my speakers bar the ffornts set to 80hz, my fronts audyssey set them as full, i have a 15" 300w rms sub and double bass selected. so the bas that the rears can cope with under 80hz will be sent to both the sub and fronts is that right.

Small means: set a crossover frequency and send the bass to the sub

Large (Full Range) means: don't send bass to the sub ever

Onkyo doesn't use the word "Small".  If you have a crossover set then you have designated the speakers as "Small" correctly.

Double Bass is a terrible setting because it sends bass to the speaker and the sub and results in muddy bass in the overlap region.

what even if my main speakers have 15" drivers.

It's up to you.  Sending bass to the sub has two benefits: (1) you get more headroom by using the sub amp for the low frequencies and more importantly (2) you get much higher MultEQ filter resolution in the sub channel so this will give you smoother bass.  Audyssey recommends against setting speakers to Large/Full Range if you have a sub in the system.

REL setup: I'm sure you know about the high input (fed from the main speaker terminals) and low input fed from the AVR sub out.

If I set the fronts to small and they are x-over'd in the AVR, then the REL High will only get a small range of front lows above the AVR x-over and below the REL x-over.  Seems nearly pointless or even troublesome. 

REL STONGLY recommend setting up with fronts set to large/full range and using these high inputs along with the low inputs (ostensibly with the AVR sending only LFE rather than LFE+main so that only center/surr lows are combined with LFE).  And there's the additional option of setting the AVR to LFE+Main and still picking an x-over point on the Large fronts to also combine front lows with LFE while also sending them to the fronts.

YIKES!   Boggles the mind.

The simplest thing seems to be using the low input on the REL and letting the rest go with the possible disadvantage of not making use of the separate volume control on the REL for the high inputs - I guess their idea is to give more independent control over the LFE level versus simply bass.  And some AVRs allow setting LFE level independent of the SUB level in surround modes.

Any suggestions for optimizing this array of choices?  Thanks.

@ chris Kyriakakis, Hi chris, been having problems with my 606 so bought an 875 lovely amp but when i set the audessey it sound totally different and not as dynamic as the 606 and to much treble, could there be a reason for this.

@Stephen: I have never understood the reason for connecting high and low to the REL sub.  The LFE level is set by the bass management in the AVR and should not be changed if you are interested in reference listening.  The subwoofer level (different from the LFE) is also set in the AVR.  

The LFE+Main selection is a bad idea because it ends up doubling the bass in the overlap region and this can cause muddy bass.  So my suggestion is to connect the sub to the Sub Out (line level) and set the mode to LFE.  Then both Audyssey and the AVR bass management can work as intended.

@Scott: The 875 has MultEQ XT so you should be getting much better bass performance due to the higher resolution filters than 2EQ that was in the 606.  Are you sure Onkyo is not setting your speakers to Full Range?  

Thanks Chris - re-ran the 3808CI setup following those suggestions and it worked perfectly without me having to "post" tweak anything.  Speakers were set small, x-overs were good, eq is good - well, maybe I had to bump the LFE filter point back up to 120 - can't remember if setup put it there or 80 this time.  At any rate, sounds much better this way leaving the "high-input" stuff out of it.  Much more straightforward as well.

@ Chris it has indeed set the fronts at full range. So will adjust then to 80 they say the go down to me 25. Also i find the dsp modes sound different like dpl 2x sounded great on the 606 but it sounds to to centerd on tv stuff so does neo 6 and find neural thx the best sounding. At the moment i have audessey off and prefer the sound . Do you recommend the full 8 steps set up i only used 3 the first time.x

Full Range is the wrong setting if you have a subwoofer.  The AVR is doing this based on their own rules.  We recommend against it.  

You must absolutely use all the available measurement positions to give the algorithm the room information it needs.  The mic pattern should be as shown here: http://www.audyssey.com/audio-technology/multeq/how-to

I can't comment on the surround up mixing modes.  They each have pros and cons.

Hi Chris,

Thank you for the excellent tips.

When I run Audyssey it sets my mains and centre to 'Large'.

In my Denon manual it says, "LFE: Play low range and LFE signal of channels set to 'Small'" and "LFE+Main: Play low range and LFE signal of all channels" and "Select LFE+Main if you want the bass signals to always be produced from the subwoofer".

So, it seems to me that if my speakers are set to Large, the low range and LFE signals will still go to the subwoofer provided I select LFE+Main.

Is this correct of should I just select Small for everything and select LFE? 

Thanks in advance.

Rob

Audyssey is not in charge of the Large/Small setting. That's up to the AVR maker.  They use 40 Hz as the decision point, so if Audyssey reports a roll off below 40 Hz the AVR sets the speakers to Large.  It's a bad idea to do this if you have a sub.  The sub is better equipped to handle the lower octave and you also get higher resolution filters in the sub channel with MultEQ and MultEQ XT.  So you should change the setting to Small after the calibration is finished.

LFE+Main is another bad idea.  It doubles the bass by sending it to the speaker and sub even if the speaker is set to Large.  That can cause boomy bass in the overlap region.  You should only use LFE mode.

Thank you very much Chris.  This is very helpful.

By the way, Audyssey in general has greatly improved the sound in my room.  Thank you for this excellent product.  I will not buy a receiver without Audyssey.

Rob

@Chris. I have set my onkyo 875 up using the audessey 8 positions but it still sound better with out audessey on which is weird because the onkyo 606 with audessey sounded awesome.
I have been told that my leather sofas could be the problem and to place the Mic in the center of the room instead and enter the distances and levels manually after.
I understand the that i can do the distances but how would i enter the levels, should i just enter the levels it has set this time that doesn't sound right or get a meter and do it that way.

Scott

Scott, levels and delays are an insignificantly small part of what Audyssey does. There is no rocket science there. Anybody with a tape measure and an SPL meter can do it.  The trick is in the acoustical correction.  In the 875 you have much higher resolution filters than the 606 so you should be getting much closer to reference.  But, maybe your own preference is different. Audyssey can't really help with that... 

If you are placing the mic at ear level in the positions specified (all of them--not just 2 or 3) then you should be getting the correct acoustical calibration.  The leather sofas are not an issue.

Ok thanks Chris. As i said i used all 8 points and after listening watching a couple of movies the difference is little more bass in some areas not really heard before. With music is the biggest difference. Should it really be used with music.

Scott

Hi Scott, the acoustical problems of your room don't really care if you are playing music or movies.  They need to be fixed so you can listen to the content they way they heard it in a calibrated studio.  If you have personal preferences beyond that, these are not something that Audyssey deals with.  It's not a content EQ method, but rather a room acoustics (and psychoacoustics) correction method.

Hi Chris.

Audyssey calibration starts by asking to set the sub's level at 75db.  After calibration, it sets my sub's trim to +2.  Preferred level though has me increasing the trim by 6db to around +8.  I read though that it's best to leave the trim value between 3 and 4db so as to save the amp's power for the other channels, while utilising the sub's amp to handle the increase in power.   To achieve this, can I start Audyssey with the starting gain higher than 75db, so if I increase the trim later on by the same amount of 6db, it would fall w/in the trim value of 3-4?

Two follow-up questions:

1.  I've ran calibration with only 3 positions, since my space allows for only 3 persons, ideally (w/ 1 on each side beside the main listening position).  Is this enough for Multi-eqXT (on an Onkyo NR809) or should I run the full 8 positions?

2.  After running calibration, if I feel the need for increasing the gain of my sub, to maintain the avr's sub trim to 3 and 4db, can I just re-run calibration at the main listening position only, or the whole setup (3 or 8 positions, w/c ever is the answer to #1)?  If 1 is enough, how do I cancel and save it after the 1st position (since it asks to move the mic to position 2)?

Thanks.

Hi Joel, is your sub self-powered? If so, the AVR is not using any amp power for the sub.  If you are indeed using the AVR amp for the sub then you also don't really need to worry.  Each AVR channel is separate.  Yes, they share a power supply but it's not really a big issue.

In any case, if you want to start with a higher level it's fine to do so.  Audyssey will set a trim that brings it down to reference 75 dB and the trim setting will be smaller than what you have now.  I don't expect this to make any audible difference whatsoever.

1. You should always always always run all available positions.  The algorithm needs to collect as much information from the room as possible.  The mic placement should follow the guidelines shown here.

2. There is no need to re-run the calibration if you change the level.  Audyssey is setting it to film reference.  If you have a personal preference for a different sub level then you can change it after the calibration is finished.  All AVR settings prior to running the calibration are ignored.  

Hi Chris,

I have an Onkyo 609 and have been very impressed with Audyssey 2EQ.

I calibrated my speakers by running Audyssey Quick Start continously adjusting the gain on my sub (Paradigm) until I got a channel to 0dB (+/-3dB) so the centre is now -3db.  This put the sub gain at about 9 o'clock and a reading of -3dB.  I then ran a Full Audyssey setup and saved it.

Crossovers are front (floorstanders) 40Hz, centre 40Hz and rears 90Hz as set by Audyssey and so I have left them alone.

I only tend to turn the sub on (at the mains, always shown on, on the 609) for movies as there is ample bass for music but for movies the sub is lacking.

Have I setup my speakers correctly, adjusting to get a speaker channel as near 0db as possible?

Am I better tweaking the sub level by changing the db setting towards 0 or adjusting the gain on the sub?  It feels at the moment that the Fronts are dealing withg the bass.

Many thanks!

Hi Andy,

There is no need to worry about getting the speakers to have 0 dB level adjustment.  The whole point of calibrating is to let Audyssey measure and automatically set the levels.  As long as the sub level is not out of the range that the AVR can handle (–12 dB for most AVRs) then you are fine.  This "need" to get the sub close to 0 dB is one of those silly internet myths that have no basis (imagine that!).