Marantz AV10 AV Processor Review

[TimoJ]

But in most cases, if the frequencies involved are below 80Hz - we cannot distinguish the direction from which they come.... making it all a bit pointless?

Maybe in theory but in a real listening room you can easily locate a subwoofer that is crossed at 80Hz.

 

[TimoJ]

In mastering I would say that's a technical mistake to have frequencies <80Hz separated on one channel ... I never experienced the case that the woofers of one speaker are moving but not the others.

 

[dlaloum]

Maybe in theory but in a real listening room you can easily locate a subwoofer that is crossed at 80Hz.

Which points to the 80Hz LFE crossover, being one driven by marketing/sales, rather than the actual margin of audibility for directional bass...

And really, the main channel speakers need to go down to at least the limit of directional bass.... so a 60Hz or 50Hz bass extension is what is needed in the mains .... Full range mains are the real solution, with subs suplementing the bottom 2 or 3 octaves only... say 15Hz to 60Hz... also subs designed for the lowest frequencies, tend to not do so well at the higher end of the bass range... so limiting them to the range they do best is optimal that way too!

And once you have them down at that low end - is there a point to directional bass?

But if you have a bunch of satelite speakers, as many do, with bass extension limited to somewhere between 60Hz and 120Hz ... and the subs have to fill in the gap up into the range where bass is directional - then Directional bass with subs is very useful.... but it seems a fundamentally flawed paradigm.

 

[Oddball]

From my experience, in smaller room I was definitively able to locate 1 sub that I had rolling off steep at 100 hz and was crossed at 80hz or even 60hz. Even when I had another smaller sub in the same room, it was still obvious where is the big one (was temporary setup so did not let the little one drag the big one). With 2 same subs located symmetrically by FWs, it was no longer possible to locate subs. In big loft with 4 subs, can't locate anything either. This is not using directional bass, as it has its own shortcomings.

While it would be hard (impossible?) to tell direction of 80hz sound itself, the pressure it creates (especially if you run your subs +15db hot) is what IMO I felt in that setup. Once you have equal pressure coming from at least different sides, the localization goes away.