I need help with my PB-10 ISD! (1 Viewer)

[Vaughan Odendaal]

Hello Victor,

I'll answer your questions as soon as I can (I'm still at work). And thank you very much for the feedback (that goes for everyone too)!

--Sincerely,

 

[Garrett Lundy]

Until you ge an SPL meter and a test disk, you're only making precision guesswork happen.

 

[Vaughan Odendaal]

Hi Victor,

Is the subfloor of the room concrete?

Yes.

Have you checked phase?

Well, not 100%, really. I've moved the control from 0 to 180 degrees, but I don't detect any differences in output or quality. But then again, I don't have a steady tone to play with, I'm just using movie material.

Perhaps I need someone to change the phase control while I sit in my seating position, because at present, I have to do both at the same time, which isn't good.

If the sub is trying to work against the mains the whole time your bass response is not going to be right.

How would I know if my subwoofer was working against the mains? Thanks.

--Sincerely,

 

[MichaelPR]

Much of this advice is useless until you can get a copy of Avia and an SPL meter. I had similar issues at first and until I properly calibrated it the subwoofer never sounded right to me. THe PB10 deffinately has some power to it that you should be feeling.

 

[Vaughan Odendaal]

Alright. I might be getting an SPL meter tommorrow (not the Radio Shack). It is analog.

I'm wondering, do different SPL meters vary at all, or will they produce more or less the same results?

I also just wanted to know, what kind of a difference would there be if I use my recievers test tones compared to Avia? Is it noticeable? Thanks.

Just for interest sake, I put in Master and Commander yesterday, and the bass was quite deep. Very deep. But I was unable to feel any bass.

Gain at 50%, with subwoofer level at -5. I have a feeling that the subwoofer might not be in the best location. In my room, when the cannons fire, the bass drones on a bit (it's not deep and tight).

I'm going to have to experiment.

PS I tried setting the gain to 60%, but then it really gets boomy when the cannons fire. Don't the cannon blasts in MAC have subsonic bass in them?

--Sincerely,

 

[Robert Hoffman]

With a concrete floor and over 4000 cu ft of space you might need a larger sub.

 

[Vaughan Odendaal]

Well, I don't have over 4000 cubic feet of space to fill. It's more like 3400 cubic feet (the listening area is around 2500 cubic feet which opens up to the kitchen, hence the additional 700 cubic feet of space).

--Sincerely,

 

[Edward J M]

Poor sounding bass (droning, booming, etc.) from the PB10-ISD is a result of either improper set-up or (more likely) poor room acoustics.

Poor room acoustics can result in a very ragged and uneven FR in the 35-150 Hz region. Peak-to-null differentials of 30-40 dB are not uncommon.

Reverberant bass energy can bounce around untreated rooms for over 1000 ms at some frequencies. This can obscure detail and lend a sense of boom and overhang.

At least you've got concrete floors going for you, that's a big plus. But a concrete floor will not transmit tactile vibration in the same manner that a wooden floor will. I'll take concrete over wood any day, but it does require more SPL to provide a sensation of slam or felt impact in the room.

I'm not surprised at all by your impressions of the PB10-ISD in a 4000 ft3 room with a concrete floor. That is a very big room and most enthusiasts who want to "feel" the bass would be looking at a minimum of dual 12" woofers in a space that large. Personally I would be using a minimum of four 12" woofers in a room that large. This goes back to our discussion about the difference between clean (distortion limited) output and maximum output (with distortion disregarded) before the onset of power compression.

My eval room is less than 1/2 the size of your room. My SPL peaks were obtained with the PB10-ISD about 10-11 feet away. I would rate the PB10-ISD as being comfortable up to about 105-106 dBC SPL peaks at the listening position in my own eval room. Above that, and it can be driven into compression (as my review noted). In a room 2X the size of mine, you might only be seeing 101-102 dBC peaks before the onset of power compression.

The PB10-ISD has class-leading THD and bandwidth linearity figures, but it's still a single 10" woofer with a single 3" vent - it has maximum output limits that can be exceeded if you overdrive it in a 4000 ft3 room. While its limiters are very good and it won't bottom out or make overt signs of distress, anyone with a trained ear can tell when a subwoofer is being driven into compression.

You simply can't expect a single 10" subwoofer (even one as potent as the PB10-ISD) to provide a high level of "slam" in a 4000 ft3 room with a concrete floor. When people start reporting "wow" levels of pants-waffling chest-pounding slam from a subwoofer, you are talking clean, uncompressed SPL peaks of about 113-115 dB or higher in the 25-40 Hz region. That would be 110-112 dBC on a good quality sound level meter set to c-weighted fast.

Since doubling your subwoofer results in a 6 dB increase in sound pressure, going from (for example) clean uncompressed peaks of 102 dBC up to 112 dBC would require a total of 3-4 PB10-ISDs.

Bottom line the PB10-ISD will not rearrange your hairstyle in a 4000 ft3 room nor should anyone expect it to. This subwoofer is perfect for moderately loud playback levels in mid-size rooms of 2000 ft3 or less. Dual PB10-ISD in a 1500 ft3 room might get you up close to reference level but as noted above, dual 12" Plus subwoofers are not uncommon in smaller (1200-1500 ft3) rooms where high impact with clean headroom is desired.

To improve SQ, look at some simple DIY room treatments and bass traps to reduce nulls, and try an inexpensive PEQ like the BFD to tame peaks. For "slam" playback levels in that size room though, you are looking at multiple subwoofers. It's not the fault of the PB10-ISD; this is more a case of your expectations being out-of-line with the maximum output capabilities of this subwoofer in that size room.

 

[Clinton McClure]

No boominess at all Vaughan. I no longer have the one-note bass problem I once did. I was running an underpowered small sub in a big room (3500 ft³) and that's about all I would hear. After switching to a larger more powerful sub (in addition to proper equalizing) that problem went away.

As others have stated and I cannot stress enough, the only way to see what is really going on is to wait for the SPL meter and perform a proper calibration. For the more advanced, I cannot recommend enough the use of a good parametric equalizer.

I also agree with Edward. In a large room with a concrete floor the sub is going to need to work really hard to provide tactile vibration. Perhaps you might read up on tactile transducers (bass shakers) if you really wish to feel the LFE in your listening position.

 

[ErnieGplus]

This sounds Like A Job For An IB(if you wiiling to cutt holes in your walls) Or DIY Aproach. I had The exact same problem Going from an svs pb2-plus(dunno what its called now) To A DIY Single sealed Avalanche 18. Im pretty Picky And I had Room Similar Size comparrible to yours with concrete floors too. And The avalanche 18 barely cuts it to my standerds(im a bass head) I heard it struggle alittle so Im cosidering buying another one. But for now I moved it into my tiny Bedroom from the living room.(And I still crave more bass) Anyways best of luck to finding great bass

 

[Clinton McClure]

A few days ago I checked out Mike Knapp's HT in the equipment page. His sub set up is just...

That IB closet setup is awesome!!!

 

[Vaughan Odendaal]

Hi Edward,

Those are excellent points you brought up. Thank you. At the moment, the bass, in my room, is not particularly tight.

Would it be advisable to decouple the subwoofer from the floor? Would that improve the response at all?

Poor room acoustics can result in a very ragged and uneven FR in the 35-150 Hz region. Peak-to-null differentials of 30-40 dB are not uncommon.

Exactly. I might have a 10db (if not more) peak between 50-70hz or lower. I can't measure my room response, unfortunately, so I can't give you any more information on that. I wish I could, though.

Reverberant bass energy can bounce around untreated rooms for over 1000 ms at some frequencies. This can obscure detail and lend a sense of boom and overhang.

It seems like there is a lot of overhang. Sometimes it's less depending on the material, but I haven't heard really tight, clean bass, or felt infrasonic bass yet. I just watched Eric Clapton, Live at Hyde Park, and, for instance, on Chapter 9, the bass drones on and on at certain parts.

I watched the Day after Tommorrow, at a medium volume, and the bass scenes were deep, but not tight or clean sounding. There seemed to be a boom quality to it that I didn't like.

I wish I knew why this was the case, though.

I'm not surprised at all by your impressions of the PB10-ISD in a 4000 ft3 room with a concrete floor.

My room size (including kitchen area) is around 3400 cubic feet, perhaps a little smaller.

Personally I would be using a minimum of four 12" woofers in a room that large.

Well, I've heard TN use less powerful subwoofers in his 7000 odd ft3 room, and according to him, the subwoofers shake his room, and his room is like almost twice the size of mine.

I don't know. But again, thank you for the nice and insightful post.

--Sincerely,

 

[Vaughan Odendaal]

Clinton, I would like to know, prior to using the BFD to tame the in-room response, did you ever feel that the bass was boomy?

I know you said no, but you also said that you used a BFD, so I just wanted to know what kind of quality you got (running the subwoofer 25 dB's hot with sub-standard room response.)

Thanks.

--Sincerely,

 

[Edward J M]

I saw that you revised the volume of the room as I was making my first post above. Nevertheless, it's still a larger room (with open connected spaces), and I would rather see dual 12" woofers minimum in that room (with concrete floor) for a "bass head" looking for good slam and room pressurization.

Remember, everyone has different tastes in bass. The PB10-ISD has been perfectly adequate (output wise) for many enthusiasts in that size room. OTOH, I have a friend who uses four sealed 15" Adire Tumults and 2500 watts in a very small (maybe 1000 ft3) dedicated HT room.

Reading into your posts, I think I have a good idea of what you want/crave from a subwoofer system, and I don't believe a single 10" woofer will satisfy your needs in that size room.

You can certainly work to improve SQ, though, and it could turn out you are sitting in a huge null and you find the PB10-ISD performs much better in a different spot as you map out the in-room FR in other sub locations and listening positions.

Regards,

Ed

 

[Vaughan Odendaal]

Hi Ed,

In your primary room, do you have any special treatments (bass traps, acoustic panels etc?), and, I also just wanted to know, did you have to use a parametric EQ to get the results you speak of (with your PB-10 in the primary room)?

I'm not like one of those bass heads who crave the loudest bass. The SVS PB-10 ISD is my first subwoofer. I'm not used to feeling bass, really. If I put the subwoofer directly behind the seating position, perhaps then there would be more of a tactile feeling?

One position I haven't tried is putting the sub in the front right corner (I'll try the left front corner too). Perhaps then I will get an improved response.

Again, thank you very much for the suggestions, Ed, I really appreciate it.

--Sincerely,

 

[Edward J M]

Yes, I have two tube style bass traps in the rear corners and twelve panel (2'x4'x2") style traps (about 100 square feet total) on the ceiling and corners. In addition, the floor is concrete, most of the walls are partial concrete block or brick, and the drywall is reinforced to the studs with screws and additional insulation has been placed between the stud cavities.

My room exhibits a typical mild peak around 70 Hz due to the dissimilar high pass and low pass slopes in the bass management circuit, and the vertical floor-ceiling axial mode.

I do now use a parametric EQ (Rane PE-17) to reduce this peak (before/after FR is shown in some of my sub reviews), but I didn't for the PB10-ISD review - I adopted this practice after that review.

You can see this peak in the in-room FR graph, although the scale is quite compressed. I've since switched to a more expanded scale to better show in-room FR anomalies.

Even with the mild upper bass peak, you can see the in-room FR of the PB10-ISD is quite good, with no major/sharp peaks/nulls - and that's with 1/24 octave resolution. The room gain starting below 33 Hz is consistent with my room dimensions. I do not find room gain objectionable as it doesn't negatively impact the SQ of music, and it helps to provide more felt impact on HT effects.

If you have critical ears, you will eventually become very picky about sound quality - soundstage, imaging, detail, ambience, etc., and the quality of your bass is no exception. Some people are not terribly finicky and place the sub in the corner, do basic calibration, and enjoy. Other enthusiasts are very concerned with room acoustics and the listening environment, and spend a lot of time and energy optimizing the room.

Once you hear what a system is capable of in a properly treated room, it's pretty hard to go back. There is no floor boom, no droning, no suck-outs, no overhang, and no muddiness - just clean, detailed, smooth, tight bass.

Room treatments and bass traps are still considered lunatic fringe by many, but they are steadily becoming more mainstream. I try not to ram room treatments and EQ down anyone's throat - it's not for everyone. I just suggest treatments and EQ as possible fixes when I hear people complaining about boomy, droning, loose, muddy bass. I can tell you unequivocally that in your particular case your SQ problems are not being caused by the subwoofer. Even the very best subwoofers can sound rotten in the wrong room - I see it (or rather hear it) all the time.

 

[Vaughan Odendaal]

Ed,

If I place the subwoofer directly behind me, do you think that would give me more of a tactice feeling?

--Sincerely,

 

[Edward J M]

Sound pressure varies inversely with the square of the distance, so moving the sub closer to the listening position should increase SPL considerably.

With an 80 Hz XO, you might be able to localize the subwoofer directly behind you, though. I prefer the subwoofers on the front stage, between the mains. That way they blend the best and present more of a coherent point source in the crossover transition bandwidth.

I've tried the subs in other locations (than the front stage), and I don't like it. It's generally fine for HT but less than optimal for music applications.

 

[Brian L]

I have a room with cement floors, and was never happy with the "feel" of the bass with the sub in the front corner. I never got that "my room shook" response that so many comment on. It measured fine, but there was no "seat of the pants" feeling.

So, I moved my HSU 1225 behind the couch (its not quite to the back wall, but close), as suggested in some of the paper work from HSU research.

HOLY CRAP. I sometime thing that the couch is actually going to move around the room. I can't imagine what a bass shaker would add to the party. Cue up "The Incredibles" or the opening scene of "Attack of the Clones" and get ready to jump.

I would agree 100% with Edward's comment about the crossover and localization. In my case, I actually cascaded the crossover in my AVR with the crossover in the sub amp (both 80 Hertz), which helped address the localization issue.

You won't usually notice it with movies (other than the fact that you will swear that the couch is a left over prop from "The Exorcist"), but it can be distracting for music.

Brian

 

[Eric Burg]

I got my pb10 isd about 2 months ago and can tell you that I definitely can "feel" the bass from it. When playing the pod race scene, you can feel the leather seats vibrate and I even had to add sound damping material onto the back of my Matrix movie poster, because it was vibrating against the wall. My room is about 14' x 24', concrete floor with just carpet over the top, no carpet pad. My ceilings vary from 8-10' depending on what part of the room you are standing in. I have the sub placed about 3 feet from the left front corner, facinging the opposite wall that is about 10 feet away. It is about 9 feet from my seating position. It took me a long time to determine the right spot for the sub. Tried the crawling method, random placement, moving it a few inches at a time and measuring with the spl meter. I even had to move my seats slightly to get into the sweet spot. There is a huge null area just 1-2 feet behind where the seats are now. I have the gain not quite to 50% on the sub and the level on my reciever is set to -3.0. I also had to do quite a bit of tweaking with the phase control. I used Avia to initially set the phase, but didn't like the response I was getting when listening to music, so did some adjusting while listening to bass tracks that I was very familiar with. After all that, I have the bass I am looking for.