First impressions of SVS (1 Viewer)

Where to start... I got my first real sub yesterday. It's an SVS PB12/Ultra. My previous subs were just the dual 8" powered subs that are built into each of my Polk RT2000 speakers so this was to be a big step up, at least that's what I was thinking.

So I get home after a day of work and peek in the garage to see a really big box. I'm thinking, oh boy, this is going to be fun tonight. The sub is packaged well although there are some rather large holes in the side of the box that have been taped over. After a thorough inspection I find that the sub is in good condition with only a small scratch near where one of the holes in the box was. Now since this is a B stock sub it is possible it was there before it got shipped to me. I'll bring this to the attention of SVS Tom and Ron Temple from AGS.

The sub itself is impressively built. Very sturdy looking and the black finish is nice. I really like the way these things look. Although I knew the physical dimensions it's still a lot bigger then what I imagined but that's ok. I have room for it. I load it up on the hand truck and into the house it goes.

So I'm in the house now and it's time to wire this bad boy up and start on the calibration. Plug in the cable to the sub out on my HK receiver, in on the sub, power plugged in, power switch on, set the receiver to know it has a sub now and start up the tests. Hmmm... it doesn't seem to be very impressive at all. So after beating my head against the sub (it's sturdier then my walls) for a bit I figure out it must not be getting power. I check the fuse in the sub with an ohm meter and it checks out ok. Then it dawns on me that the outlet I plugged the sub into is a switched outlet. After smacking my hand to my forehead in a "Wow I shoulda had a v8" fashion, I turn on the switch. Oh nifty, there is a green led that I never noticed on the amp. Ok, now I know we have power. Back to the calibration tests.

I calibrate it via the Avia disc and notice that even though my sub level in the receiver is set at -5 I still only have to turn the sub gain up to the second hash mark. This seems pretty low to me but I'll roll with it cause the SPL meter says that's what it's supposed to be at. Now that we are calibrated, let's watch a few test clips. So I load up my favorite clip, Star Trek Insurrection, the scene where Picard blows up the Sona particle collector. Hmmm.. That was ok. Better then just the Polk's but not what I was expecting. I blow through a few different clips (Contact, The Matrix, Apollo 13) and the results are all the same. It's better then what I was used to but just not what I was expecting. At this point I decided to just watch a full movie and see what I thought.

I plop in SW:TPM, crank up the volume (I watched at 10db below reference) and away we go. One thing I did notice though that worried me before we even started the movie itself was the THX demo clip. The one with the exploding sphere, etc. When the sphere first explodes I noticed that the sub bottomed out. Now according to the meter I'm not running hot and I'm set volume wise at 10db below reference but this worries me a bit. I'll take note during the movie to make sure it doesn't happen again.

Well after the movie I come away with a mediocre reception to this sub so far. It's better then what I had before but not what I was expecting. I ask my wife what she thinks and she just says to me "I was expecting more." My expectations were mind numbing bass. Something that would just rattle the fillings out of my teeth. I had these expectations based upon the reviews I've seen here and the fact that I sized this sub 3 sizes higher then the minimum recommendation for my room. After conversing with SVS Tom we determined that my room size of 13x15 would only require a PB10. Now this was if I listened at -20 db below reference. Since my theater room opens up to the kitchen on one side of it I decided to step up to a PB12/Plus just for extra headroom but ended up getting a B stock PB12/Ultra as it was a good deal.

Tonight the plan is to try some different locations. I have a longer interconnect cable so I'm going to try placing the sub where I normally sit and walk around with the spl meter and see where is best to put it. Maybe location will make a difference.

Also, can phase cause an overall diminishment in bass output? I tried playing with the phase knob during the Avia phase tests but did not notice any difference.

I really want this sub to work and I know I still need to do some tests/tweaking to see if it will work for me. I'm overall impressed with the product, It's just not what I was hoping for. Just a little info on my setup for you folks so that if you have any hints and tips you can give you'll know what I have.

Harmon Kardon AVR 65
Polk Audio RT2000 fronts
Polk Audio CS400 Center
Polk Audio M1 surrounds

The HK is set to small all around and the sub output is turned on. The internal crossover is not adjustable and is set to forward everything below 100hz to the sub. I do not know what the crossover slope is. The sub gain is set to -5 in the receiver (can go all the way to -10) and the gain on the sub itself is set at the 2nd hash mark (I'm thinking this is 1/4 of the way) The phase is currently set at 0. PEQ is set to minimum (effectively off) and the internal crossover is disabled.

Tom

Phase only comes into play at the crossover point. That sub should really be blowing you away and be nowhere near bottoming out at those levels. What tune do you have it in?

It's set at the default of 20 hz.

As to the bottoming out, it only happened in the THX clip. I never heard it during the movie.

Not that this would make a whole lot of diffrence but did you cal it with the meter in the slow position?

Make sure the dvd player is set to bit stream or raw and make sure the dvd player and receiver don't have any dynamic range compression on. You are listening in DD/DTS right?

Where is the sub located in the room? Where are the ports facing? In that size room, you should be getting all the bass you can handle - bottoming shouldn't be an issue.

I calibrated with C weighting on slow response using Avia at as close to 83db as possible.

As for the DVD player and receiver, I have the DVD player set to pass a 96khz/24 bit PCM stream through and use the receiver to do the decoding. The receiver was in DD mode (as indicated by the DD symbol and the 3/2.1 on the display). I'm not sure what setting would effect Dynamic Range Compression on my receiver (my guess is "Night Mode" which was turned off.) I'll have to check the DVD player but if I understand it correctly when it's set to PCM mode it doesn't alter the signal at all. I'll double check tonight though.

The sub is located in the left corner of the room near the left front speaker. It is about 8 inches away from the wall to the left of it and 12 inches away from the wall behind it. The ports are facing the wall behind it. Below is a crude drawing of room layout.

..................|---------------|
..................|SS.................|
___________|....................|
.......................................|
.......................................|
...................cccccccccccc.|
----------------------------|

The SS is the location of the sub with the fronts and tv, etc to the right of the current sub location. The c's are the location of my theater seats.

I did think that I should be getting more bass then I could deal with but at this point it's not that way. I still have faith and am willing to try tweaking this setup to get what I'm looking for.

Most receiver's have seperate night modes and dynamic compression settings (although they do pretty much the same thing). I doubt that is the issue though. It would have been hard to bottom the sub out with DC turned on. It really should be extemely hard to bottom it with it off at those levels.

The same thing is happening to me too. I hooked up my 20-39pc Plus in my room and it keeps bottoming out. If it is calibrated right why would it keep doing it? Yes I used VE and the rat shack meter. I'm listening -10 below refernece. I'm going to try moving it around my room. For all the reviews i've read this sub has to be better than it is preforming. My Def Tech PF1500 rattles the room w/o bottoming out. I expected the SVS to be better than my 10 year old Def Tech.
The gain is only set to 9 oclock. I'll try more tonight, it also seems to be cutting in and out during heavey bass scenes. Weird

Matt.. your svs should knock your old one off its feet. You have something wrong going on. I would call one of the guys at the shop and talk to them ASAP... Good Luck

I'm just hoping that it's a setup issue. I know that even room construction can affect the bass you feel. Concrete floors absorb all of that ground pounding bass. In my case I have a 9 year old house built on a wood subfloor so no concrete there. I'll just have to check over all of my settings again and go from there.

Does anyone know what kind of testing the folks at SVS do to a sub before they sell it as B stock? Maybe there is something wrong with mine....

I have the 25_31 PC+ cylinder sub.

I have pushed it hard with some of the most serious scenes and yet I have never bottomed it out after hundreds of movies. I am suprised when I hear people bottom an SVS sub when calibrated correctly.



but an SVS is a different flavor of real bass that you have to get use to, its called real bass.

but you do sound like to have a problem. good luck fixing whatever it is.

Tom,

Please take a picture of the box and sub (scratch), send it to my email address [email protected].

As far as your sub output is concerned that's a question for Tom/SVS. However, I'm with the folks in the config camp. I'm sure with the proper placement/configuration you will find the sweetspot. I've pretty much looked at every post regarding SVS over the last few months on several forums and don't recall seeing any negatives. Most are blown away or get another to fill a monster room.

Hey if it was right just out of the box, it wouldn't be as much fun...

Ron, I'll get that pic to you probably tommorrow.

As for bottoming out, I can't stress enough that it was only once and only during the THX clip. Perhaps it is recorded hot on the SWTPM disc thus causing the bottoming. I did not hear it at all during the movie.

I'll let you all know more after some testing tonight.

Hey, I only have been coming over here for about a week and I've already met someone

1st, you bought a BStock and then are surprised to see a small scratch in the finish? What did you think a Bstock was?

2), it is def a config issue.
I have a 16-46pc+ and watching something like Constantine, BH down (Irene), Incredibles, Sin City the low extension si pretty amazing in my room. Never bottomed out, even on same THX demo. You won't get the boom boom type bnass, especially with music or crappy mixed movies, but watch something like Sin City or the Incredibles and be prepeared to be blown away when set up correctly.

Go rent BH down, wtach Irene and tell me you aren't blown away!

Tom,

Just out of curiosity, have you tried the subwoofer crossover test in the THX optimizer that comes on the Star Wars disc? It should give you a good sense of what the sub's doing from 200 Hz down to 20 Hz.

Ken

Do you any room behind your theater seating or is it flush against that back wall? If there is room, I would try putting the sub behind the seats near that back corner if possible.

If you do that, and it still bottoms, then there has to be something wrong with the sub.

I did play this and although I did not have the SPL conversion sheet for the rat shack meter handy I'm pretty sure it was right on par with what it's supposed to be. I have noticed that my room has a good peak around 38hz so I'm going to need to mess with the PEQ and try to tame that down.

One question I am curious about is the sub level adjustment in my receiver. The only output level adjustment I have is a sub trim level which is in the same settings area as the trims you would adjust when balancing all of the speakers in a tone test. Is this the correct trim I need to set at -5 for the sub?

Any other suggestions in helping tune and tweak this thing would be great.

Tom_T, if thats the place where you are cal'ing therest of the speakers then yes its the right place.

Unfortunately there is no room behind the theater seating for the sub. It sits right up against an outside wall and because the are big Lane recliners I would have to move them quite aways away from the wall if I were to try putting the sub there.

Any thoughts on room sizing? When SVS Tom sized the sub for my room he said that even though the room is open on one side it wouldn't affect the sizing. I can't help but wonder if maybe this is affecting my perception of the bass output. The kitchen area that adjoins this room is quite large, probably the same cubic feet area as the room itself thus changing my space from 1500 to about 3000 cubic feet. Would this make a single PB12/Ultra too small? How do you think a PB12/Plus 2 would perform?