Do I need a second subwoofer? (4800 cubic feet basement)

[prometheusdt]

Below is a rough drawing of my basement with dimensions. The drawing is not to scale. The ceiling is 8'8", so if my math is right, the basement is about 4800 cubic feet. The stairs are open (no door). I currently have a 5.1.4 setup with the HSU VTF-3 MK5 HP. After I run Audyssey, it sets my sub trim to -11.5. I would raise it to -3.5, but the bass still feels underwhelming when watching a movie or listening to music (volume is at -18 dB reference). I barely get any vibration in my chest. Speakers are all set to small with crossover at 80 hz. I've moved around to the other seating positions to confirm that the MLP isn't a null spot. Do I need to get a second subwoofer or is there some settings on my receiver/subwoofer that I need to look into?

http://imgur.com/a/8GVK9kI

 

[nbk13nw]

You can always try moving the sub nearfield for a quick test. Place it a few inches behing the chair or sofa and give it a whirl. My basement is around 7000cuft and even running 4 18" subs at different locations the tactile response was lacking. The overall response was great in the room, pretty flat at all positions. But i ended up moving two nearfiled to get feeling i had with the original subs running nearfield.

 

[lovinthehd]

It's a big space, hard to know what your expectations are from where I am, tho an 8dB bump is among the highest I've heard post-Audyssey. Nearfield may improve things. More subs might be a consideration. Even tactile transducers might be a consideration.

 

[ryanosaur]

Rule #1: If you have to ask: YES.
Rule #2: If you think about asking: YES.
Rule #3: Why haven't you ordered a second Sub already?!?!!
Rule #4: If you are still interested, you are one of us; get a measurement mic and download REW. Learn how to use them, and dial your rig in!
Rule #5: Have Fun!

 

[Danzilla31]

Rule #1: If you have to ask: YES.
Rule #2: If you think about asking: YES.
Rule #3: Why haven't you ordered a second Sub already?!?!!
Rule #4: If you are still interested, you are one of us; get a measurement mic and download REW. Learn how to use them, and dial your rig in!
Rule #5: Have Fun!

Totally agree with rule 1 and 2!

I'm moving to a new house new room for the theater only 3100 cubic feet. Do I need to bring both my SVS PB 4000's?
no.

Am I going to?

HELL YEAH I AM!

 

[William Lemmerhirt]

Totally agree with rule 1 and 2!

I'm moving to a new house new room for the theater only 3100 cubic feet. Do I need to bring both my SVS PB 4000's?
no.

Am I going to?

HELL YEAH I AM!

No. You need to ship them up to me!!!

 

[Danzilla31]

No. You need to ship them up to me!!!

Nah I'll just ship you down to listen to it!

 

[William Lemmerhirt]

Nah I'll just ship you down to listen to it!

I can live with that!

 

[prometheusdt]

I purchased the UMIK-1 as everyone recommended and below are the results. I attached the picture as well as REW's mdat file within the zip. Measurements were done with Audyssey off. What's the difference between the top line versus the bottom line? Where should I go from here?