For HT, how important is extension south of 20 Hz?

I use two Martin Logan Decents. I think they go down to 18Hz. I've spoken with you a bunch of times over the phone but we have never met. You gave me advice about Mcintosh monoblock, MC1000s with the Soundlabs. I think we spoke last a month or so after the hurricane.

My current subwoofer system is based upon (4)15" Adire Tumults.They are sealed.Two per cabinet in separate chambers.

I use (4) QSC 1450's, bridged mono to each Tumult.They have a relative high F3 (around 38hz in a 3.0 cu. ft. enclosure).To counter that rolloff I use a Marchand BASSIS to extend the bass down into the 5-8hz range.My Behringer 1124p is used for one bad room mode.

WTS, deep bass really fills the frequency response.There is information down into 8hz that needs to be felt not heard.There is an energized feel when the room pressurizes.It's almost like surround bass.In WOTW the lightning strikes are around 8-10hz and at 90db it hits home and gives you that feel that a 20hz high pass does not.

Make no mistake getting down that low is a DIY job if you don't want to go broke.I don't know of many subs capable on the commercial market that can get that low without a mortgage attached, if at all. I'm not sure the return is there for you unless you feel it for yourself.it's a personal thing.If I'm going to buy a DVD I want all the sound....even down to single digits.

Enjoy..hope this helps KG

I recently completed building (2) sonosubs using a design found over on AVSforum with TCsounds TC-2000 15" drivers in each sub. They are flat to 14hz, am driving them with 1000 watts to each sub. This is my first experience with bass of this type for HT. It is just plain fun watching the expressions on my friend's faces when they are over watching a movie or even some concert DVD's (like PF Pulse). Some movies are just plain scary. Like Dave said above, room pressurization is awesome. My recliner feels like one of those electric massage chairs. Supposedly, there is a fair amount of LFE info in the 6-10hz range.

I think it is important for the sub to go below 20, especially for movies, you can't hear it, but you can feel it. Sometimes it feels like my couch is shaking. As Bulldogger said: "The bass down that low causes your clothing to move " totally agree with that.

Thanks for the responses. And Bulldogger, do I know you? When I was in New Orleans there was at least one active audio club member from Gretna...

Just curious, Bulldogger - what subwoofer(s) do you use for movies now?

Thanks,

Duke

02-19-07: Drubin
"And then there is legendary Brown Note, the frequency reportedly somewhere between 5Hz and 20Hz that invokes involuntary gastrointestinal motility. Wouldn't want to miss out on that. Great for parties and family gatherings"

HeHe....they busted that one on the Myth Busters TV show.

Dave

And then there is legendary Brown Note, the frequency reportedly somewhere between 5Hz and 20Hz that invokes involuntary gastrointestinal motility. Wouldn't want to miss out on that. Great for parties and family gatherings.

Good question and I don't know the answer. I've never measured the low freq output in any movie I've watched so I'm not sure how low they go?

I'd guess that the lower the sub will go...the less problems it may have out putting the freq's above at high SPL's?

My room is 4600 cubic ft.... 3 VMPS subs (17hz)...each has an active 15" and 12" driver, and a 15" passive,...nearly bone crushing bite when called for, extended low freq harmonics in SiFi and Horror type movies are amazing in their ability to pressurize the room.

That said...what freq's are these? I'm not sure.

Dave

I too think it's a personal choice. I have a pair of subs that measure below 20Hz (due to in room gain) and it's nice, but they are actually only rated to 20 Hz.

My opinion is that 20 Hz is fine.

Though, I just read a Dolby Digital White Paper that says the Sound Engineers will send LFE info from 3 to 120 Hz to the .1 channel.

I think it is more for bragging rights than anything. Although I have heard some systems with huge twin subs and it FEELS great to have such super low bass. But I personally wouldn't bother trying to be flat below 20Hz.

I think that is is necessary for movies. The bass down that low causes your clothing to move and you really feel like you are witnessing the event. A few subs that I have used for music worked well but ran out of gas with movie soundtracks. By the way, I'm in Gretna.