HELP with VTF-2 Positioning

[spoonfed]

Having recently purchased a HSU VTF-2, im having big dramas making it work well in my room.

The attached BMP shows the rooms layout and dimentions. I cannot really move seating position as this is optium for the Projector.

My issue is that bass from the sub just seems horrible. Lacking kick, very very droney/boomy, to the point makes one sick after extented listening/viewing.

Im not to concerned about music as im pretty satisfied with the mains (Quads) without a sub.

I've tried every position i can think of.

Front left corner (a bit off each wall). Front right corner, rear corners, rear centre, front centre, centre room left wall, left and right wall in front of mains. I can reduce the "boomyness" in some positions but the result is reduction in everything.

At present there is very little "feel" from the sub, plenty of "ear presure" and "heard" tones (even with crossover very low).

I want ot acheive what other ppl i know have. 1 has an MX350 (M&K) which you never would know was there bar from the hairs standing up on ones neck and kick in the guts from explosions and rumbles, no lingering booming, resonance or anything. His room is approx 4200l x 4500mmwide.
While yes the VTF-2 is not quite in the same league im expecting better than currently getting, especially when comparing to the pretty average sub previously.

Any ideas would be great. Im going to borrow the MX350 before the "30 day return" period is up and see if the same issues occur. If not, or if substanially reduced i'll know its not 100% the room, in which case i'll return the VTF-2, do without a sub (or use my old one) as it is very frustrating at present.

Thanks

Danny

[tdekany]

Did you say that you had it right behind the "couch" seating position? Also, take your sub to your friend's house to see what it can do in a different room.

[Lwang]

Given your room length of 4.2M, the first room mode would be at 41hz. Any corner loading or placement along the front/rear wall will excite that freq to the max.

To minimize that freq, place your sub midway along the left wall. That would eliminate odd order modes. Also, play around with your seating position, possibly moving back and forth up to 500m to see at which spot you would minimize that 40hz peak. You would also lose that corner loading effect that HT people wants, which is to maximize SPL.

[Ddavidson]

You will find its your room not the sub. The room is forcing it's signature on the low bass.

Have you measured your room response? If so what are your corrected measurements? It looks like 41hz is very strong mode (along with the followup 82hz, 123Hz. Subwoofer set-up takes time and you need to understand that equipment can sound very different at a friends house because of the acoustics.

If you seriously can not change your acoustics something like the BFD is very cheap (worldwide) and this will be of help in solving your room mode (peaks).

Behringer BFD web site.
http://www.behringer.com/02_products/prodindex.cfm?id=DSP1124P&lang=eng
Set-up how to for HT:
http://www.snapbug.ws/bfd.htm


Ddavidson

[spoonfed]

Once again, thanks for everyones input.

Im taking the Sub this arvo to mates house (he has an MX350) so i'll see what its like there.

Sooooooooo frustrating when its something like the room causing the issue.

I have tried it on the left wall mid way, but output was very low, and it couldn't really be felt at all there.

[Ddavidson]

Do not forget the M&K settings in the processor / receiver will need to be different for the VTF-2 so balance it with warble tones and pink noise so they are the same level.

NOUSAINE's 10% distortion cut-off results are listed here so you should find that output and depth are of little problem especially at this price point. It also pays to remember that the mx350 retails for about $1,800 vs $499 so if your in the market for a sub that cost that sort of money you probable should look at getting two new upcoming VTF-3's which retail at $999.
http://members.cox.net/frankcarter/Tom%20Nousaine%20Sub%20Data.htm


Ddavidson

[spoonfed]

Just got back from the VTF-2 vs MX350 "comparo"

The VTF-2 is better in my mates room. It still has a small "boom" too it, not really a "boom" sort of feel it in ones ears at a certain frequency, hard to explain but the MX350 didn't have it.

setting the two sub to the same level (ie matched to his listening volume) using SPL Meter we were away.

Given the triple price difference the VTF in this room didn't do too bad. Using We Were Soldiers as one of the test DVD's. The close M16 fire the two sounded very very close in the kick. The main area where the MX350 was noticed more was in larger explosions, ie aerial bombing scene for example, the extra depth, and more punch of the MX350 was noticed here. The VTF did hold its own (given the price difference) i'd like to chuck a VTF-3 in the comparo and see how it goes. Of note i think we were pushing the VTF-2 pretty hard, not to 100% but i think the MX still had reasonable amounts in reserve.

For music, we managed to "blend" the VTF in with his Quad 22L's a bit better than the M&K, which seemed a little slower than the HSU in this instance.

SPL tests found both subs true to their "advertised" specs, with the M&K easily flat to 20hz, and the VTF flat to 25. The roll off to 15 in the M&K was a similar Db drop as the VTF to 20.

Seeing as i've just got home and are now armed with a SPL meter, i'll being doing some more playing

[Ddavidson]

For music, we managed to "blend" the VTF in with his Quad 22L's a bit better than the M&K, which seemed a little slower than the HSU in this instance.
That doesn't surprise me. I have had most decent subwoofers inc: several M&K's (even the 5000) in my good rooms. I have directly compared them all to both my VTF-2 and VTF-3. Needless to mention the end result as I have owned both VTF's since they almost first came out. It took me almost 30 days trying to find a sub to topple them, but it was always a no brainer after directly comparing the price vs performance. Even blending with my friends Maggies in my bestroom was a pleasure compared to the Velodyne we could not make work. SPL tests found both subs true to their "advertised" specs, with the M&K easily flat to 20hz, and the VTF flat to 25. The roll off to 15 in the M&K was a similar Db drop as the VTF to 20.The RS meter is not accurate for low bass so you really need to be careful and do the "frequency corrections" one by one.
Here is the web address for the Radio Shack 2050 meter mods: http://www.gti.net/wallin/audio/rsmeter/33-2050/33-2050.html

The electronics of the stock analog RS SPL meter rolls off the bass by

20HZ =6.2DB
25HZ =4.4DB
31.5HZ =3DB
40HZ =2DB
50 =1.3DB
63HZ =.8DB
80 HZ =.5DB
100HZ =.3DB
125HZ =.2DB
160 =.1DB

200HZ to 1250HZ Flat

The electronics of the stock analog RS SPL meter rolls off the treble by

1600HZ = .1DB
2000HZ =.2DB
2500HZ =.3DB
3150HZ =.5DB
4KHZ =.8DB
5KHZ =1.3DB
6.3KHZ =2DB
8KHZ =3DB
10KHZ =4.4DB
12.5KHZ =6.2DB
16KHZ =8.5DB
20KHZ =11.2DB
i'd like to chuck a VTF-3 in the comparo and see how it goes.
I have both and find them pretty much evenon most fronts. However if you are a big organ music fan or have a very big room then the VTF-3 offers some good advantges. If not then the VTF-2 is more than enough for most people.

Of course if your one of these who will "only" ever playback a movie at at full reference level (115dB) then the VTF-3 will deliver a few more dB below 25Hz that could be of use. I use my big system for playing back my low (16Hz type) organ music and the smaller VTF-2 system for just about everything else.
The VTF-3 is quite a lot bigger in physical size than the VTF-2, so that extra 5Hz by going flat to 20Hz rather than flat to 25Hz means a much bigger heavier box that might give you WAF problems. My wife caused me much grief over the size difference between my existing VTF-2 when I first got the VTF-3. The VTF-2 was an easier sell to the wife and was nearly 1/2 the price. (($500 vs $850) Yet it has 90% of the performance of the VTF-3. Even with it's flat to 25Hz rating it still had much more output at 20Hz with less distortion than either the 300w 15" Velodyne CHT-15 or the M&K MX125Mk2.

I think it comes down to how loud you listen because most people have small rooms. I just do not see many people playing back that loud so I think a lot of people waste money on buying a biggers sub when the fact is they do not use it. Sure if you have the money who cares, but the reality is that except for some rare organ music and a few effects 99% of you sources only have frequencies above 25Hz.

The Hsu subs are a little different because they actually are "rated acurately" and when its flat to 25Hz, 32Hz or even flat to 20Hz it actually measures that way (unless you stick it in a room that forces it's own sonic signature onto the subs reproduction)
Not even a Hsu sub can change the room acoustics.http://www.hsuresearch.com/forum/images/icons/icon10.gifhttp://www.hsuresearch.com/forum/images/icons/icon10.gif
sort of feel it in ones ears at a certain frequency
Because we can not hear it you need to work out what you are hearing by locating the actual frequency where it occurs. One thing is the VTF-2 plays very loud down low, so you will get movement,vibration and no definite sound. Your hearing can not hear such low notes (so you can only feel pressure not hear notes). the first time I ever got a Hsu subwoofer I thought it was not playing very loud so I kept play the song and walked out of the room to get my RS meter. I could not believe it all I could hear was vibrations and things rattling. My old subs could never do this low stuff and could never sound so balanced. Trouble was I perceived the Hsu as playing at a lower Spl level than my older subs, but it was playing much louder and totally flat all the way down to its 25Hz bottom end rating. My other subwoofer was 20Hz rated, but the Hsu proved that not all specs are the same.

Ddavidson

[spoonfed]

Ddavidson,

I wont post an "epic" this time as no doubt you'll read the AVS topic :)

I posted in both so see the "variation" of ideas/input, but it seem most ppl on here are also on AVS (which is not a bad thing) ie you, Sorny etc etc ;)

The SPL Meter is a Radio Shack 33-2055 digital. Whats the difference between teh 33-2050? I can't really modifity it as it not mine, but im guessing it has the same "acuracy" as the model on the link given (unless this one is improved or something) so cant at least calculate based on that.

As i stated on AVS, i've moved it back to directly behind listening (centre of room (left/right)). This seems give give the best "feel" relative to the percieved "heard" volume level, the 40hz hump seems around the same DB higher in all positions, so i've given up eliminating that until i look into a bass trap or something.

D

[Ddavidson]

The SPL Meter is a Radio Shack 33-2055 digital. I can't really modifity it as it not mine
You should buy yourself one as you really need to balance all your speakers and this unit helps. perhaps your friend might like to mod his meter as well and at least then WYSIWYG instead of using the correction chart. It helps to locate room modes and make system improvements.
Buy the analog for yourself as the analog is easier to read at a glance and average.

Here is the web address for the Radio Shack 2055 Digital meter mods:
http://www.gti.net/wallin/audio/rsmeter/33-2055/33-2055.html

As i stated on AVS, i've moved it back to directly behind listening (centre of room (left/right)). This seems give give the best "feel" relative to the percieved "heard" volume level, the 40hz hump seems around the same DB higher in all positions, so i've given up eliminating that until i look into a bass trap or something.
Yes that gives you the close crotch impact, and by positioning in the middle of the room you might cancel a little of the 41Hz hump. But if you add a 40Hz bass trap you will find you can move the sub to one of the corners (or at least closer) and gain the headroom back that you should be getting. At that position the couch should move with impacts on some of dvds. The VTF-2 is amazing once you have the room/system balanced. Especially located as you have it behind the couch. You can not do this with most other ported subs because all you hear is port noise. The high flow port on the VTF-2 really is invisible to locate unless its a sustained high output 16Hz note which only really happens with my organ music.

I will go read what you said on AVS where no doubt the Spl junkies are flooding the board.


Ddavidson