HT 5.1 bass management

[stanlee]

Hi guys

How do I set up the bass in my receiver/processor so the LFE is sent to all speakers including the sub while watching movies? When I set all speakers to large, the sub barely moves.

My gear:
anthem MRX700 into XPR 5 powering:

B&W's
803d's L/R
CMC2 center
804s surrounds
ASW 855 sub

Thanks for your help.

[vneal]

Set speakers to small. Cross over at 80hz

[stanlee]

All speakers to small? Will that take away the bass from the other 5 speakers?

[knucklehead]

May 19, 2015 21:34:30 GMT -5 stanlee said:

All speakers to small? Will that take away the bass from the other 5 speakers?

Yes - and thats what you want it to do. Bass frequencies below 120hz or so are omni-directional - you will have a tough time locating your subwoofer by following the sound. An additional benefit is moving all that low frequency 'work' to the sub makes for a lighter load on the rest of your speakers. THX recommends setting the crossover at 80hz - I get great results following that advice. You should too.

[stanlee]

I will. Thank you.

[stanlee]

Like this?

Attachments:

[knucklehead]

Yep - give it a try and see if you like it. For music you may not but for movies it should give you the best results.

Did ARC set your speakers to large?

[stanlee]

No I set it to large. I believe arc set it to small 60Hz if indeed it did.

[stanlee]

Good thing I listen to music using a separate pre-amp. It might be complicated if the MRX was involved.

[brand]

Honestly the 80 hz is not set in stone and it depends on the speaker (L/R) you have. I like to have it lower on my L/R simply because my RF 7s produce tighter/punchier bass (if it's due to the speaker or the speaker location I don't know) than my PB13 so feel free to experiment.

Edit: And for music I don't even use a sub because no sub compares to the bass SQ of the RF-7 in my room due to several room issues.

[stanlee]

Yeah I tried listening to music with the sub, it was a disaster. I just relegated it to HT use only.

[dudeisms7]

Drivers noticeably physically moving a lot is not a good thing. Properly balanced systems can still thump your body with bass without much visibly noticeable movement

[stanlee]

question:

What does it exactly mean when you set your speakers to small 60 or 80 Hz?

Does it mean any frequencies below 60 or 80 will be handled by the sub?

[Boomzilla]

It DOES. However...

The "audio clues" as to where a sound is coming from are NOT in the "below 80 Hz" range. They are higher in the frequency spectrum. In other words, It's the crack of the lightning, not the rumble of the thunder, that directs your attention to where the storm is coming.

This is true in the HT world also - Even if the crack of the explosion is in the right rear speaker, the lower frequency impact will come from the subwoofer (wherever it may be). But your ears will "assign" that sound to the right rear because that's where the higher-frequency "clue" was.

Cheers - Boom

[qdtjni]

For HT, I would cut the 803Ds at 30-40 Hz, the 804s at 40 Hz and the CMC2 at 60 Hz.

EDIT: Obviously, I would try something higher if it doesn't sound good with the above settings.

[stanlee]

Goshhh now I'm confused!

[Boomzilla]

If your processor allows you to set different crossovers for different speakers, then set them as you see fit. The "rule of thumb" for crossover settings is that the sub should cut in at least one octave above the main speakers' 3dB down points. In other words, if I have a speaker that rolls off at 40 Hz, then the sub crossover should be set to 80 Hz If I have a speaker that extends to 30 Hz, then the sub crossover should be set to 60 Hz., etc.

This allows the acoustic roll-off of the speaker to NOT interfere with the electronic slope of the actual crossover filter. This maintains phase at the crossover point, preventing dips or peaks in the frequency response.

Boom

[vneal]

I understand your confusion. Your thinking I have these great sounding expensive 803Ds that go down to 30Hz. If you are listening to 2 channel that is great. There is strong argument that for stereo this is plenty without a sub, Enter a subwoofer. Many spend big bucks on their main speakers only to purchase a lesser quality subwoofer with mixed results. Boomzilla above is correct in that if I have a speaker rolls off at 40 Hz, then the sub crossover should be set to 80 Hz and if a speaker extends to 30 Hz, then the sub crossover should be set to 60 Hz., etc. So for HT and most audio using a sub with a 803D it should be set to small and crossed between 60-80Hz. It cost nothing to experiment. My CM10s sound best crossed at 70Hz and I use the VARIABLE setting on the sub and to my ears I set the low pass filter at 12db and the phase at 0 degrees. Though bass heavy music sounds tighter with the low pass set to 24 db on my sub. I reread my JL Audio manual and they recommend you start at 80Hz also. The lower you set your Hz crossover in other words if you set it at 30Hz--the muddier your bass will sound. You will have more of it but it will sound poor. I realize many subs are not as variable as a JL Audio unit, well sometimes you get what you paid for

[Boomzilla]

JL makes excellent subs. Yes, experimentation in sub positioning, in crossover slope, in sub levels vs. the mains all have effects on the sound.

I might disagree with your statement that implies (if I understand you correctly?) that the lower the crossover, the muddier the bass sound. There are too many variables, IMHO to make such a blanket statement.

In fact, many run their main speakers full-range and then cut in the subs below the main speakers. I've not heard muddier bass from such setups.

Many subwoofers offer a phase adjustment pot, but some offer only a zero-180-degree switch; others offer no phase adjustment at all. My Oppo has an elegant solution - In its setup menu, the user measures the distance from the listening position to all 5.1 (or 7.1) speakers, and the Oppo phase-corrects them all. For this to work, the subwoofer's local phase must be set to zero.

Cheers - Boom

[stanlee]

Thanks guys. I'll try the 80 Hz first and go down to 60 Hz if needed. Now should I set 80 Hz for all 5 speakers or just the mains? What about the surrounds and center?