The Official LFE Technobabble Thread!!!

[Kal Rubinson]

The Enterprise just sounds so wimpy without its ominpresent rumble, even when just relaxing in Ten Forward while Whoopi serves you your ice-filled Altairian-whatever.

I was actually looking for info about the Super Furry Animals' 5.1 dvd version of their Rings Around The World album and stumbled on this article explaining how they put together the surround mix - following is the part that fits into this discussion:Hmm.....

I get your point although neither of those are in my collection.

 

[quadtrade]

So those that are using "full size" speakers. What are you using and in what configuration?

JBL L65s Jubals 4 of them and in 4 corners plus the tactile sound driver

center is a JBL Century 100

Nothing better than those old JBLs

 

[DaneelOlivaw]

I get your point although neither of those are in my collection.

Oops better clear up what I meant by my post above:

a) I agree with you that music mixes don't need the LFE channel

b) I also agree with you that movies & TV shows DO benefit from the use of the LFE channel, Star Trek being one of them.

c) I included the Super Furry quote and my "Hmm" because I had never heard of a band using the LFE channel to specifically include such extremely low frequencies in their music (and if more bands started doing that, it may be a good idea to keep one's sub activated until they know the mix they are listening to doesn't include such sonic elements!).

BTW for anybody reading: here's the Furry's page, with videos, for that album: Rings Around The World.

 

[ssully]

My front speakers are Canadian Energy Connoisseur C-9s with 3 x 6.5 drivers. They are flat (+- 3 db) to about 30 hz and they claim to have usable bass to about 25 hz. Rear speakers are the bookshelf version with the same drivers, only 1 x 6.5 though - they're listed flat to 46 hz. I think that when you tell the players that you don't have a sub they send the LFE to the fronts. For digital sources that's what I have my receiver set to do in bass management. I've never noticed any bass roll off as sounds move around to the rears with either 6 ch direct or any of the bass managed digital sources.

They're excellent loudspeakers for sure (as loudspeakers tend to be when adhering to FLoyd Toole's performance goals), but as these measurements show, (and as Toole notes in his book) the standard '+/- 3dB ' criterion leaves a lot to desired in terms of descriptiveness. The Energy C9 is actually quite flat in the upper bass range to about 100 Hz; below that the amplitude drops off steadily, such that the -3dB point is at what looks to be about 35 Hz...and then plunges downward from there.

http://www.soundstagemagazine.com/measurements/energy_connoisseur_c9/



Now this may or may not make an important subjective difference when there is true LFE content; it depends on how much bang you require for your buck and whether you 'need' to hear that lowest two octaves or so at comparable level to the rest of the spectrum . But it appears that a good sub could be useful to achieve objectively flat response from at least 30 to 100 Hz (or even 20 Hz, all the while assuming some excellent room acoustics or modal taming here).

 

[Kal Rubinson]

They're excellent loudspeakers for sure (as loudspeakers tend to be when adhering to FLoyd Toole's performance goals), but as these measurements show, (and as Toole notes in his book) the standard '+/- 3dB ' criterion leaves a lot to desired in terms of descriptiveness. The Energy C9 is actually quite flat in the upper bass range to about 100 Hz; below that the amplitude drops off steadily, such that the -3dB point is at what looks to be about 35 Hz...and then plunges downward from there.

Now this may or may not make an important subjective difference when there is true LFE content; it depends on how much bang you require for your buck and whether you 'need' to hear that lowest two octaves or so at comparable level to the rest of the spectrum . But it appears that a good sub could be useful to achieve objectively flat response from at least 30 to 100 Hz (or even 20 Hz, all the while assuming some excellent room acoustics or modal taming here).

An additional point is that the FR is not necessarily rated at a high output level. It is in the sub-100Hz where great dynamic demands are placed on speakers and many, that have a reasonably flat FR at 1watt input, do not have the dynamic range to sustain such a FR at 100w.

 

[BananaSlug]

Before I bought the Energy speakers I had bookshelfs. So from my perspective they have great bass. But, you people have to stop trying to convince me I need to spend more money Actually, I'm happy enough. The danger will come if I hear someone else's system that has better bass.

 

[Kal Rubinson]

Before I bought the Energy speakers I had bookshelfs. So from my perspective they have great bass. But, you people have to stop trying to convince me I need to spend more money

Not trying to sell you new speakers. Just championing bass management.

 

[Ge Someone]

My front speakers [..] They are flat (+- 3 db) to about 30 hz and they claim to have usable bass to about 25 hz. [..]
Now, I've never used a sub with this setup so I can't say that it wouldn't improve the sound.

My situation is similar to BananaSlug's. Only difference is my front speakers would originally go down to 52 Hz (-3dB) but the manufacturer makes these add-on modules matching their speakers that have to be placed somewhere in the signal path before the end stage. Those compensate for the low-end roll-off every speaker has. (See graph all info is unfortunately in German ) In my case that means 29 Hz @-3dB. It does that by letting the amp work a bit harder (must have some extra power there).
I have to set my rears to small (80 Hz) as they're not nearly as big, so it's a compromise for (old) quad stuff. I'm lucky with my receiver as it can do bass management on all inputs, even the analog 5.1 (rare).

Even for movies this sound quite impressive(, at least in our living room).

All that said, I'm in the camp that thinks surround music doesn't realy need a pre-defined sub channel. Actually, when there is one it is often very low in the mix. I guess that's because the mixers are trying to mix in a way it would sound OK either with or without LFE channel.