Finally got to hear/setup a SVS sub

mantis

OK,
So I get a ticket with no sub.Yamaha rxv2400 receiver,Boston Accoustic Vri series speakers,Denon 2900 DVD player,Comcast Digital cable box,outdoors and inwalls for multiroom,volume controls etc but no sub.Ok they must have an exsisting Velodyne or older Polk/Mirage or something aleady at the house.There was an older system but the customer removed everything but the sub.There it was the insane sized SVS PB2-ISD,if you haven't seen it in person,its HUGE!!!.Well ok I'm very looking forward to setting this monster up and blowing my face off with it.The customer did alot of research to come to the SVS.They got rid of a few other subs and kept this one.Now with the new system going in,they where excited to here it with new gear.

So we install the rear Vri series rears on the wall,center into a custom cabnet,and the mains on top of the lower bookshelves all wired with Monster.A pair of outdoor speakers with an outdoor volumne control for music on the patio,a pair in the dinning room for dinner music.
Vri series Bostons are there high end line.they nice if your into Boston.I don't care for them and even less with a Yamaha receiver but It's hand selected by the customer and away we go with it.
So I started with 2 channel music setting up the sub by ear to play around with 2 channel.The sub was overly powerful and very boomy.I took out all the port plugs and found a slighty smoother response.But still it started to fitigue me.It sounded like the sub could only play one frequency.Just BOOM BOOM BOOM.Ok so I figured finding a better home for this monster would be the key.I walked around the room trying to find the sweet spot.It ended up in the back right corner a few feet out of it.When it was closer to the wall,it sounded terrible and super localized.Aweful at this point it was reminding me of the older BPS4000 sub Mirage made that sucked really bad but could shake the entire house.

Now I'm thinking this sub isn't all that it's juiced to be.So I setup the rest of the system after a few hours of 5 channel stereo to somewhat break in the systems new gear.The sub had many hours on it but I decided a few more might help.Yamaha has a auto calibration with a mic and I used it.I ran the Matrix and I just flat out sucked.the sub over powered the entire system and shook everything in the room.So I manually setup the system and come to find the levels being within 2db of correct.Some where right on but 2db was the average of flaw.

So back to chapter 29,30,31 and so forth trying to get this damn sub to blend in with the rest of the system.I put one plug in then 2 ,then tried them all out.Moved the damn heavy **** thing here and there and then realized something...............

This sub SUCKS!!! I don't like it at all.I got it to somewhat blend but it call attention to itself.I'm used to working with REL and Velodyne and I can get there subs to dissapear in any room in any system.After a few hours of placement ,trail and error,they for music and movies(more in favor of REL) they do a great job.I was going to push for a SPL1000 for this system but they didn't want to pack this **** sized sub back up and ship it back.They liked it as they where excited about the entire Install.

The Philips Pronto Pro topped the system off with nice control and they really loved the one remote one button action.

My final thoughts are dissapointing.I really thought these SVS subwoofers where ALOT better then they actually are.I feel this is a great sub for anyone who wants to shake there house.But Music it cannot do period.Even watching Movies sucked.It was so "I'M RIGHT HERE PEOPLE HERE ME GO" was so annoying.For the money you get what you pay for.A 900 dollar sub it is and a 900 sub of sound quality you get.You cannot compare it to higher end sub as in sound quality alone it gets crushed.The Velodyne SPL series can't pressurize like the SVS can.That I will say it excells at.But the overall sound quality in my honest opnion sucks.

For people who love them,I'm not here to bash you.If this kind of sub is what you like,then enjoy it and let my findings be my own.If your looking for a great sub with accurate bass and the ability to lose itself into the system and room, then look somewhere else.SVS gives you a really NON Livingroom size sub that can move air and play really loud.

Dan

scottvamp

If i remember you were a die hard REL fan to began with. This IS the first negative review I have ever read on SVS subs. My PB2+ I found the exact opposite of your findings. Of course, if $900 just pays for the power cord of the subs you may have heard than your talking a whole other league......

pjdami

Sorry to hear that you had a bad experience there Dan. Sounds like you tried pretty hard.

I took out all the port plugs and found a slighty smoother response

In my experience, I found the exact opposite to be true. By plugging ports and setting the subsonic filter at the appropriate setting you actually decrease the SPL output of the sub but get it to play lower. This is a good way to decrease big "bass" humps in the frequency response. My PB1+ has a parametric equalizer which also helps to tame big bass humps in response.

FWIW, I like my SVS sub (PB1+) and it blends in perfectly with my system. There are people that own REL and SVS (same owners) over at Home Theater Forum and they talk highly about both subs.

I don't know man. The Yamaha receivers are also known (at least my RX-V1300 did) to put out some thunderous bass due to the 4 V preout instead of the normal 1 V preout that most receivers have. But this should be compensated for at the gain on the sub amp or by decreasing the LFE level on the amp to -5 db or so.

Sounds like your heart is set on a REL or Velodyne and there's nothing wrong with that.

Paul

gatemplin

Maybe the problem is not the sub. They have a ruler flat anechoic frequency response for each tuning frequency. They are also very low distortion with two woofers sharing the load. Maybe it's the room that is bad. I also have a bad room with a 20 dB hump at 40 Hz and the sub only sounds good after hours of working on the EQ, placement doesn't help. Also, maybe the floor is vibrating. The SVS has deep extension which many people dont like for music. Also they have very low harmonic distortion which some people like, they say it sounds musical or warm or fuller. I am not an SVS owner but I have heard them before.

pjdami

Maybe it's the room that is bad.

The room is critical. I had the same problem in my living room. I can post two totally different FR curves for the same sub (corner located vs. along the wall). It took me over 2 weeks and 30 plus frequency sweeps to get the SVS right in my living room. Some people have it lucky the first place they put it is the right place. In the corner in my living room I had a huge +30 db hump from about 40 hz down which overpowered the room. I tried everything in this position even the PEQ and could not tame it. I finally settled on an along the wall position and got a decent flat response with no big humps. Much better there.

I firmly believe in using Frequency Response sweeps to look at how the sub is interacting with the room and then listening to see if it matches what one should be hearing (i.e. does it sound good there).

I do respect Dan's experience with setting up subs but the SVS is so powerful that sometimes setting up by ear can be very very difficult without doing some FR sweeps.

Paul

mantis

Yes,
a EQ could have helped greatly.A nice Rane EQ would have got the job done.

The room was on the larger size and SVS said this sub should work great in the room.It was around 16 x 20 or so I didn't meaure it.I spend more time with it then I usually do in a customers system unless they pay for the extra tuning.

Overall quality of the sub I feel the SPL Velodynes do a better job.They don't have the output but sound quality is better and smoother.

Even so I 'm happy to at least experience one.

Dr. Spec

I also respect Dan's ear, but also concur with others here. The SVS really IS almost ruler flat in an anechoic chamber and has very low distortion. A flat FR, low THD, and high dynamic compression limits are the hallmarks of great bass. Famous sub reviewer Tom Nousaine says make a sub flat, deep, clean, and loud and pretty much everything falls into place. SVS faithfully follows that formula to a tee.

I don't doubt for a second the sub sounded boomy and one-note-ish; Dan has heard almost every major make of sub and I'm sure he has decent ears. I also don't doubt the room is responsible for what he is hearing, and all suggestions and possibilities above are totally correct; a booming floor, hot calibration, and a ragged FR with a huge peak around 40 Hz are all very possibly the culprits here.

An accurate FR sweep is really the only way to tell what's happening in the room. It's been said many times that above 300 Hz you are listening to the speakers, and below 300 Hz you are listening to the room. There is nothing special or magical about good bass, and the best subwoofer in the world can be made to sound absolutely terrible in the wrong room.

Here are two reviews of the PB2-ISD that aren't shy about touting its music performance.

http://www.thebigpicturedvd.com/bigequipment19.shtml

http://www.audioholics.com/productreviews/loudspeakers/SVS_subsPB2-ISD_OutlawLFM-1_1.php

And here's before/after screen shots of typical FR irregularities I encountered and tamed while setting up the PB2-Ultra. And I have what are considered to be GOOD basic room acoustics. I can't imagine working with a BAD room.

Dan, if you want to hear a properly set-up SVS, you are always welcome to stop by. It's among the best bass you will ever hear.

Doc

pjdami

I firmly believe in using Frequency Response sweeps to look at how the sub is interacting with the room and then listening to see if it matches what one should be hearing (i.e. does it sound good there).

Oh yeah Doc, thanks for sharing this method with us here at Club Polk. This method, although crude as you once said with the Radio Shack decibel meter, turned out to be very beneficial for me as I don't work with subwoofers all of the time.

The PB1+ with the PEQ turned out to be the saving grace for me in my living room. Without it I would have gone Behringer FBD for sure.

One of these days that corner of mine will be attempted again. It certainly is a challenge for me there but I like challenges....

dorokusai

Dan has a Rel tattoo on his shoulder, waste of time guys

Rel....all day

mantis

Doc,
I know and thanks for the offer.One of these days I will take you up on it.Even in a bad room,I can surely tell a good sub from a bad one.Remember I only spend the day with this sub.I was at the home for 10 hours.4 of which was setup and playback.The sub using auto cal/my ears and an SPL meter didn't do much justice.

The comment about the Yamaha running hot out of LFE is true.They always push the sub harder then most.

I will be returning to this home next week.I'm gonna tweak the system again,bring some other cd's to test music,and a few other DVD's to give it another workout.

The sub is in the best place for this room.I like to sit the sub in the listening area and walk around the room looking for the strongest output.

This room is not very bad for acoustics,actually it's ok.The room has a quiet to it and a mix of hard and soft everywhere.Plush carpet and furniture with a hard cabnet/wall unit and some windows in the back of the room.but soft curtians covering this window.Fireplace off to the left which is reflective.The sub lives on the back wall on the fireplace side.It has 2 feet from the back wall and 3 feet from the side wall.caddy cornering the sub was also tried for the sheer hell of it.

Now that I'm thinking of it,the sub also sounded forced.Not natural and soft but forced out the notes or note in this case.I don't know the actual playing tiime of this sub,but they sure are using the hell out of it as they bought a bunch of new movies to run this weekend.Maybe also the sub needs more break in time.I will find that out next week when we return.

One thing is really cool is the fact that Velodyne has a built in EQ and comes with a mic to set it up with.Very cool as you can notch peaks and flatin out the in room response.Rel is now getting into this area with there new Strata sub.I'm really juiced to get my hands on one.

SVS.........man We shall see,
Stay tuned,
Dan

dave shepard

If it's ok with Doc as soon as I get a free weekend I would like to go to Doc's and spend a little time there meeting him and getting pointers and would be willing to take you (Dan) with me if you would like.

Dave

Dr. Spec

You guys are welcome any time. A few Club Polkers have graced my home and it's always been a positive experience.

In addition to poor room acoustics, there is also the possibility the bass management circuit was set up improperly (e.g., LFE + mains or w/e), or the phase could be set wrong, or the low pass could be enabled, or a DSP mode is enabled, ad nauseum.

Again, no one doubts what Dan is hearing; we just know it's not a bad subwoofer. A trip through the Reviews section on the SVS website will tell you that at a glance.

Dan, don't judge this sub until a thorough and exhaustive analysis of the entire set-up has been conducted, and an accurate FR sweep of the room is performed; something is wrong if that sub sounds rotten.

PolkWannabie

Dr,

I'd like to get an idea of where in New York you are and maybe stop by sometime to hear your SVS and the rest of your set up ... You can PM your reply if you like.

mantis

DOC,

In addition to poor room acoustics, there is also the possibility the bass management circuit was set up improperly (e.g., LFE + mains or w/e), or the phase could be set wrong, or the low pass could be enabled, or a DSP mode is enabled, ad nauseum.

The system was set up as follows...
Mains,center,rears all small and crossed at 80hz(tried 90 and 60)
No DSP modes and no Mains + sub was used.

In 2 channel it was in stereo,theater it was in Dolby Digital with no DSP of any kind.

SPL was check 3 ways,SPL,System auto calibration ,and my own ears.I always tweak even after a calibration with SPL or a Auto Cal.Sometimes the system needs a bit here and there.Depending on all the seating.

The sub maybe liked by alot of people but I have high standards for subs.Hince why I don't like most of them.

Again I am going back to the house next week sometime,depending on when it gets back on the schedule.I will do a full recalibration and give my final thoughts on the SVS.FOr now my first Impressions stand.

Thanks again for all the comments and offers.Dave that would be a cool trip.

Dan

pjdami

Another thing that happened to me in one of the positions I tried with my sub was that I went from a big null to a big hump in frequency response.

The null there's not much one can do about except move the sub. The null was in the 45 - 60 hz range where I believe the test tone for calibration of the sub on a S&V or Avia disk resides ( in those frequencies). The null was large, -15 db at one point. This caused overcalibration of the sub albeit inadvertantly and unknowingly. This is another reason for the frequency sweep importance; to make sure that one is not in a big null or hump at the calibration frequency for the sub.

Dan do you have a frequency sweep disk? I have the files I can email you and you can burn a disk. I think a frequency response profile (like Doc showed above) is almost mandatory here.

Not doubting your judgement or ears here at all; but the FR may reveal some things. It could very well be that you just don't like the sub like you say but I'm sure that Doc would like to see the FR sweep too.

The Yamaha AVR too can be very hot with the LFE preout as mentioned. I would try to reduce the LFE signal to -5 db maybe even more. This is something Doc has suggested many times to reduce the signal from the receiver. I remember when I owned the Yamaha and I had an Onkyo Integra for a week on demo the difference in the bass was huge with the adjustments needed on my PSW-350 sub at the time.

How much gain on the plate amp on the sub did you have it set at? More than 12:00 o'clock?

pjdami

Here at two examples of the same sub but different positions. Two totally different sounds here from this sub. Note the huge room gain here in the first one. I couldn't find the file I had with the big null at 45 - 60 hz. It wasn't even worth keeping if I remember correctly.

Dr. Spec

Dan:

Sounds like you nailed the set-up pretty well.

As for SPL calibration, I refer you to this interesting thread over at HTF and in specific a quote from Mark Seaton (highly regarded owner of Sound Physics Labs and the famous Contrabass Servo-Drive subwoofer):

"Calibrating" an un-equalized subwoofer without knowing the (frequency) response is more of a best guess than any sort of calibration. Any peak above 40Hz in the response will radically throw off the level of the rest of the frequencies.

This thread (ironically enough) was started by a PB2+ owner who had the same exact impressions you did on that PB2-ISD. Some very knowledgeable enthusiasts (and BFD/PEQ experts) all basically said the same thing - the room-induced FR undoubtedly looks like a roller coaster and the sub will never sound good until that is corrected. One look at some of the before/after FR curves will convince anyone the best of subs can sound terrible in a bad room.

http://www.hometheaterforum.com/htforum/showthread.php?s=&threadid=206716

Also interesting in this thread is the concept of the "house curve". Basically it's an ever rising response curve that compensates for the human ear's insensitivity to lower bass frequencies. While I haven't (yet) tried a "house curve", many experienced enthusiasts swear by it.

Until you are willing to run an accurate FR sweep of the room and correct for room induced anomalies, you are listening to the room and not the sub, and unfortunately you'll walk away with the wrong impression of the PB2-ISD.

Poor Paul had to suffer through nearly 30 sweeps over two weeks trying to tame a 30 dB (!!) hump below 40 Hz. I'm sure that sub sounded like **** at first too.

This is really a perfect example of why subwoofers get SO much attention for both music and HT applications; the room has far more of an effect on the SQ of bass than many people realize, so there is a huge disparity of opinions on the same exact subwoofer. What sounds musical, accurate, well defined and seamlessly blended in one room, sounds like an absolute boomy mess in another. It's sad but totally true.

pjdami

The above plot was in the corner about 1 foot from one wall and the sub pulled out with the ports about 5 inches from the back wall.

The below graph is where I am now. Much flatter and more relaxed sounding for me. I found it sounded totally different here:

Dr. Spec

Even so, Paul - I'd dump $140 into a BFD and start fine tweaking. There's still a lot of unrealized potential in that PB1+. I do agree though that this curve is the best of your options.

gatemplin

Yep, a BFD would do you good Paul. Here is my frequency response without a BFD, the second graph.

http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=15226&highlight=tempest

Here is the frequency response after the BFD, a totally different sub.

http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=19711&highlight=tempest

Dr. Spec

Here is the frequency response after the BFD, a totally different sub.

'nuff said.

Your EBS Tempest had the potential all along (well after you fixed the cabinet volume ). The room was just holding you back. A perfect example of a house curve.

Also interesting in that HTF thread is the concept of boosting dips in the response, which may or MAY NOT be nulls. The only way to tell if you have a true null is to attempt to boost it. Wayne P really knows his stuff and his posts/ threads are always worth reading.

gatemplin

Originally posted by Dr. Spec

(well after you fixed the cabinet volume ).

Oops:D Well, I gave sub designing a try. Didn't quite work out, but alls well that ends well. Thanks for the help along the way:)

pjdami

Also interesting in that HTF thread is the concept of boosting dips in the response, which may or MAY NOT be nulls. The only way to tell if you have a true null is to attempt to boost it. Wayne P really knows his stuff and his posts/ threads are always worth reading.

Thanks for pointing that out Doc. I have thought about the BFD for the corner as the PEQ didn't have enough "cut" to tame the room gain there even at the 20 hz tune.

Only reason I have not purchased the BFD was because I had read that trying to boost nulls was fruitless. However, looks like I'm continuing to learn something all the time here. I did try to boost the nulls with the equalizer in my B&K AVR but that didn't help much.

Regardless, I'd rather live with the nulls than the big humps and a BFD is certainly an interesting project which poses its challenges.

Graham, nice looking curve after with the BFD. Un-effin-believable. If I need any help with the BFD, I'll know who to ask!

Paul

gatemplin

Thanks Paul, it took many, many hours as you know but I love it. I also asked Sonnie Parker a few questions and he was a big help. That curve is a combination of phase adjustments, crossover and filters. There are 4 filters of EQ and one for the house curve. It is a fun project if you get around to it.

Dr. Spec

I just finished dialing in the PB2-Ultra with the LSi7's. The 7's behaved differently that the RT800i's, and the sub control settings were a bit different.

Think this might sound halfway decent? :cool:

HBombToo

All the curves are way cool and right up my ally! That said, I appreciate what Dan has to say also but am a bit dissappointed.

Doc helped me purchase my twin svs a while back and for the room I was in he made the right call from a far. I relocated and stuck the twins in a room 1/3 the size of my original and all I heard was booooom.... booooom....... booooom!

The elephant needed tamed and I went to work and followed the fundamentals. Yes my processor and gain controls helped but position was also a key. I continue to play with gain and don't use a meter:(

A new neighbor whome I learned has been trained in classical music and pretty cool ta boot said my system was a good reference. I nearly fell over!!!! Prior to that though, he faced away from my system as we listened and informed me that is the way he was trained to MAKE music. While he was doing that I thought he was nuts but drank my beer and just waited.

I think that was a way cool compliment and now I have to wonder if a preconceived notion on Dans part has prevented an honest experience here on Polk. I hope thats not the case and I'm all ears.

1/2Twin

gatemplin

Nicely done Doc. She digs nice and low and it looks to me like you've got some wicked room gain. Are you using the PEQ on the Ultra?

Henry,
Maybe some frequency sweeps will help locate the problem in the new room.

Dr. Spec

Yes, I used the PEQ to nail a peak at 60 Hz. I know it was the sub because I disconnected the 7's and just swept the sub through an analog input on my AVR.

Sweeping through the AVR is the only way to include the BM circuit and the mains. The equivalent is you guys using a CD with burned test tones.

Yeah, I've got tons of room gain, but it's all below about 30-35 Hz and you can't really hear it at all on music (except 32' pipe organ). The essentially flat curve from 35-100 is what makes the sub sound so good on music. I'll take free room gain below that anyday.

If I disable the infrasonic filter and EQ circuit (Bypass on the tune switch), the sub alignment becomes considerably overdamped and the curve with two ports plugged is literally a flat line (with room gain included) from 100-12 Hz. While technically this may be the most accurate curve, it sounds weak - hence the concept of a house curve (which I approximate pretty well in the standard 20 Hz tune even without a BFD).

Dr. Spec

I relocated and stuck the twins in a room 1/3 the size of my original and all I heard was booooom.... booooom....... booooom!

Henry, my guess is that due to the small size of the room, you are experiencing room gain too early (i.e., at too high of a frequency).

Room gain starts to occur when the wavelength is longer than the wall-wall boundary distance. It's "about" a 2nd order transfer (12 dB/octave).

You'll see from my graph that I "just" start to see room gain around 35-40 Hz, and the 20 Hz level (one octave deeper) is indeed about 12 dB higher.

In a smaller room, you might start to see room gain at even higher frequencies, where it can affect the sound of bass guitar and kick drum, etc. I think you should sweep the room at the listening position and see what's happening in there. Too much room gain can actually be a bad thing (witness the car audio subwoofer phenomenon).