I am awaiting FedEx delivery today of a 2nd HSU VTF-3 MK3 and I plan to co-locate them in order to get a +6db gain in dynamic headroom which I could really use in my open room (totals approx. 7000 cu.ft). When I run my 3.3 in max extension mode I do not have quite enough dynamic range for demanding DVD movie scenes so I am hoping the duals will solve this (max output mode gives me plenty of headroom, but I really like the additional sub-20hz rumble in extension mode). I know another option is to place the subs in different locations to potentially give a smoother overall bass response from multiple listening positions, but that would typically provide only a +3db output gain and I want all I can get so will likely stick with co-location.

Other than max output, can some of you experienced in dual sub use tell me about other benefits you have realized from running two subs in a home theater or for music? Should I expect a greater sense of ease, lower distortion levels, increased pressurization of air? How did your sound change when you doubled your subs?

I have dual 3.3s with turbos. I split them up which evened out the bass in my room considerably. It was quite a pain getting them calibrated. I had no idea how many cancellation issues I would encounter. Due to room configuration, having them colocated did nothing for the localization issues I had. There is a definate increase in pressurization and lower distortion but I also upgraded from a single 2.3 so I'm sure that had something to do with it. It's mostly used for HT but music sounds great as well!

Hi

I have been using dual subwoofers for about 3 years. I like the sound of a "wall of bass". I prefer to have them in the front two corners of my room. You might like to try them both co-located, and spaced farther apart. I am using a pair of HSU VTF-3HO's with Turbos. People shake their heads in appreciation of my subwoofers.

All the Best

I am awaiting FedEx delivery today of a 2nd HSU VTF-3 MK3 and I plan to co-locate them in order to get a +6db gain in dynamic headroom which I could really use in my open room (totals approx. 7000 cu.ft). When I run my 3.3 in max extension mode I do not have quite enough dynamic range for demanding DVD movie scenes so I am hoping the duals will solve this (max output mode gives me plenty of headroom, but I really like the additional sub-20hz rumble in extension mode). I know another option is to place the subs in different locations to potentially give a smoother overall bass response from multiple listening positions, but that would typically provide only a +3db output gain and I want all I can get so will likely stick with co-location.

Other than max output, can some of you experienced in dual sub use tell me about other benefits you have realized from running two subs in a home theater or for music? Should I expect a greater sense of ease, lower distortion levels, increased pressurization of air? How did your sound change when you doubled your subs?

Can you try sitting them side by side with turbo? That might be pretty sweet.

I too am going down this road. I am debating a second sub. Any coments or ideas are appreciated.

It's not whether you want dual subs or not -- you do -- it's where you place them.
Co-locating IF your first sub is generating unpleasantly uneven bass at your listening position will just make things worse -- you'll have to move the subs or your LP, and/or get EQ and/or traps. In some cases non-colocated subs can end up giving more useful non-boomy output than colocating them.

Where dual subs get more difficult to set up is if your room is asymmetrical -- like one side open to a hallway. Non-colocated dual subs work best if each sub's location is acoustically similar -- in a corner, by a wall, etc. -- not one sub in a corner and the other in open space, for example. Keeping the subs roughly equidistant form your listening position, and roughly the same distance from you as your main speakers, helps keep eveything 'timed' correctly.

Man, some would say this sounds complicated, but I think it's gonna be FUN!!

I am really close to pulling the trigger on sub #2!

Thanks everyone for the input. In my current large room I really need the full +6db gain that co-location provides and the frequency response in the current placement has been pretty good to my ears so I think that will work. In August I will be moving the home theater to a room of less than half the current size that can be sealed, so I expect a big performance gain there and will then have the freedom to experiment with the subs placed apart to smooth out the response over a larger listening area and will be able to live with the +3db gain.

So yesterday the 2nd 3.3 arrived. I stacked it on my current unit, used a Y cable to split out from my receiver, then used Y's for each sub to connect to both L and R inputs because that gave a measured increase of +3db in signal strength compared to only using one of the inputs. I then turned on only one sub, calibrated using Avia to 79db, 6db less than my speakers calibrated to 85db, then switched to the other sub and also calibrated it at 6db less than reference, then when I turned on both I grinned to see the +6db gain I had read about so that I was now at 85db reference, equal to the mains. In reality I believe this makes the bass 2-3db hot due to the RS meter error. The stacked subs were run in the max extension mode (18hz tune) with one port on each plugged (no Turbo), still leaving a total of two 4" ports open which is more than enough.

HOLY CRAP!!! :eek: My jaw hit the floor and stayed there yesterday after listening to selected scenes from Master & Commander, War of the Worlds, Jurassic Park III, Polar Express, Finding Nemo, and Star Wars Phantom Menace. The overall improvement in sound from adding the 2nd co-located sub is astounding. Maybe many of you already experience this from just one sub if you are in a sealed room that is not too large, but for me this was a revelation and the kind of movie experience I had always hoped to experience in my home. Dynamic bass passages were so much more powerful and visceral, the bass more textured and detailed, and my whole room was moved in a way I've never felt before thanks to two 12" woofers. The LFE effects in every scene had an uncanny realism, drawing me into the films in a much greater way.

I really don't know how to fully put into words what I heard. For me it is a quantum leap in impact over the sound of a single VTF-3.3 which was already great! I am going to run through some more DVD scenes today but am trying not to ruin my relationship with our very nice next door neighbors :)

Glad to hear that you got what you were looking for with the stacked subs. One thing, you are currently running your subs 2db hot, not low, due to the spl meter being less sensitive in the bass area. But, since your jaw is probably still on the floor, you may want to leave them the way they are. :D

Good luck

RossandWendy, I have bookmarked your post to refer folks to in the future, when they ask "What good will dual subs do me?" :)

When using variable tune ported subs, one of the nicest advantages of dual subs is that they allow you to run in a lower tune with greater extension, and still have plenty of output.

So yesterday the 2nd 3.3 arrived. I stacked it on my current unit,
Do provide pics please. :D

Glad to hear that you got what you were looking for with the stacked subs. One thing, you are currently running your subs 2db hot, not low, due to the spl meter being less sensitive in the bass area. But, since your jaw is probably still on the floor, you may want to leave them the way they are. :D

Good luck

Yes, they are about 2db hot due to the RS meter. It seems from forum reading that a lot of folks are running their sub around 3db hot and that seems good for me on movies, although for tv and music I often turn it down a couple of db.

Have you tried running only one of your 3HO's to compare the sound?

RossandWendy, I have bookmarked your post to refer folks to in the future, when they ask "What good will dual subs do me?" :) :cool:


When using variable tune ported subs, one of the nicest advantages of dual subs is that they allow you to run in a lower tune with greater extension, and still have plenty of output.

It is nice to be able to change tunings, but after further listening with the duals I still find that I prefer the max output mode for it's better sound quality (fuller, more natural mid-bass) and greatly increased dynamics. I lose most of the output below 20hz compared to extension mode but from 20hz on up it again takes the sound to another level. I tried the depth charge scene in U-571 and the duals in extension mode seemed to not quite offer what I had hoped on the extremely dynamic peak levels of this track, and when I switched to max output mode and ran it again I was literally scared, such was the impact of the wall of bass plummeting me :eek: :D

My preference for modes may be due to my room being open so totals near 7000 cu.ft., and in August when I move things to the sealed 2800 cu. ft. room I may find max extension mode with the duals is way more dynamic than now.

Do provide pics please. :D

First time posting pics, hope this works...

Nice. I have just one VTF-3 MKIII in a 4,800ft3 space and it performs incredible in max extension mode. Question, how did you mount your center channel speaker? It looks like you have a flat panel TV and the speaker is on top of it.

Gordon

First time posting pics, hope this works...

Nice pics. Here's some minor things I'd do to improve your setup, IMO of course.

1) Get a good universal remote. Too many remotes and that HK one is not that great.
2) Run the wiring through the speaker stands if possible, maybe even go white or tan for across the carpet.
3) I noticed the subs help keep the glare off the TV, but they appear to block your walkway and w/ a new power outlet they could be pushed up against the wall.

I have a laptop at my table too. It makes for a more interactive setup.

Nice setup. I bet you have enough bass to make sure everyone in the house knows it ;).

Nice. I have just one VTF-3 MKIII in a 4,800ft3 space and it performs incredible in max extension mode. Question, how did you mount your center channel speaker? It looks like you have a flat panel TV and the speaker is on top of it.

Gordon

Hi Gordon,

It's comments like yours about the performance of your 3.3 that have me really excited to see how much improvement I will gain from mine when I move the HT out of this big open non-sealed room :)

For my center channel (Ascend Acoustics 340SE) I use an OmniMount 300 A/H speaker stand that has a unique angle which allows it slide underneath the plasma tv stand and puts the speaker stand's top plate in a perfect position right behind the top of the plasma (stand height is adjustable). Most of the speaker's weight rests on the stand so no problem with the front resting a bit on the plasma, and it sits atop an Auralex MoPAD for sound isolation and proper downward angling towards the listening position.

Here are pics:

Nice pics. Here's some minor things I'd do to improve your setup, IMO of course.

1) Get a good universal remote. Too many remotes and that HK one is not that great.
2) Run the wiring through the speaker stands if possible, maybe even go white or tan for across the carpet.
3) I noticed the subs help keep the glare off the TV, but they appear to block your walkway and w/ a new power outlet they could be pushed up against the wall.

I have a laptop at my table too. It makes for a more interactive setup.

Nice setup. I bet you have enough bass to make sure everyone in the house knows it ;).

AdilM, all good suggestions and thanks for the nice words. The profusion of remotes is indeed ridiculous and drives my wife crazy :p I've heard the Logitec Harmony remotes are pretty good and need to get one. Yes, the speaker wire will be run through the stands when we move in August, I know it looks pretty messy right now :o The sub position is crazy as it makes getting in and out of the patio door more trouble than it should be, but they actually measure best there - I have tried every placement variation (with the single 3.3) you can imagine using the RS meter and various test tones and that exact spot and angle of the sub gave the smoothest response in my room.

First time posting pics, hope this works...
Nice. You got me thinking now. I already have one 3.3... :rolleyes: :cool:

Nice. You got me thinking now. I already have one 3.3... :rolleyes: :cool:

Thinking is dangerous my friend, very dangerous, just look what trouble it got me into... :rolleyes: :cool: :D

Thinking is dangerous my friend, very dangerous, just look what trouble it got me into... :rolleyes: :cool: :D
I know, thinking is bad. :D What makes it worse is HSU is only about an hour and a half away. :o

Maybe you should get the turbo for the top vtf3 and try running it in max extension and running the one on the bottom in max output, The turbo does increase the headroom in max extension mode. I have a large open floor plan and would have liked a second sub but instead added the MBM12 to my HO and that has really added to my viewing and listening experience.