svs subwoofer pb12

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GM

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Joined 2003
While I have loads of experience with various high SQ 'sub' alignments, AFAIK I've never been exposed to any of their products, but consider this, typically the best recorded music available to the general public has been, and still are, movie soundtracks, so would be very surprised if they didn't do other music formats with equal aplomb. Then again, after looking at its measured response, my SWAG is that the 20 Hz tuning with the vents damped to 'taste' will prove the highest SQ in-room.

Since increased system efficiency always increases its in-room SQ potential, BIB (bigger is better) rules, so obviously their largest, lowest tuned sub has the most potential for personalized vent tuning and/or EQ. Based on its measured response, the driver has a < 0.5 Qts, so has enough damping on its own to be critically damped in a large enough net Vb, though not low enough to mate to a low Qts driver or compression horn system.

All this assumes a XO <80 Hz and of course only one way to know for sure............



GM
 
I have the PB12-Plus/2 which is also the last version of this sub SVS made. Since SQ always comes first with my system, I have it tuned as such.

I have it located directly in the middle of the front wall with my center channel sitting on top of it, right under my 100" screen and 50" plasma. Because it's a tall enclosure, I have it laying on its side with the woofers facing the wall. I found that tuning it to 16Hz provides the flattest, smoothest response in my room with extreme detail with all music. It's very quick and dynamic and extends down to 12Hz quite easily according to SynRTA and TrueRTA.

It still doesn't match the 15" dipoles I had years ago, but it's the next best thing to them in a much more compact size. I'm listening to Radiohead's OK Computer right now and the sub is doing its job quite well, blending in perfectly with my mains and delivering the goods the way a good subwoofer should. Very natural and realistic.

I'm happy! :D
 
While I have loads of experience with various high SQ 'sub' alignments, AFAIK I've never been exposed to any of their products, but consider this, typically the best recorded music available to the general public has been, and still are, movie soundtracks, so would be very surprised if they didn't do other music formats with equal aplomb. Then again, after looking at its measured response, my SWAG is that the 20 Hz tuning with the vents damped to 'taste' will prove the highest SQ in-room.

Since increased system efficiency always increases its in-room SQ potential, BIB (bigger is better) rules, so obviously their largest, lowest tuned sub has the most potential for personalized vent tuning and/or EQ. Based on its measured response, the driver has a < 0.5 Qts, so has enough damping on its own to be critically damped in a large enough net Vb, though not low enough to mate to a low Qts driver or compression horn system.

All this assumes a XO <80 Hz and of course only one way to know for sure............



GM

Did you have a look at this? Svs: Pb12-nsd - AV Talk - AV Forums and Hi-Fi Forums

That gives us some real life outdoor measurements to go by. Can you deduce the sound quality from looking at that? Again i am wanting something which works well for music rather than for a home theatre setup.

What do you make of the measurements of low frequency extension, distortion and the rest of it?

thanks.
 

GM

Member
Joined 2003
I have now........ ;)

Well, not surprisingly due to its relatively small size and modest venting, it suffers from vent compression at higher SPLs as nearly all vented alignments do (the abrupt wide band notch down low) along with some thermal power compression due to VC heating (a bowing of its mid band as system Q (sysQ) rises) that again, virtually all speakers do when driven hard. The former will be muted/abated somewhat due to room loading and the latter will typically only occur if played at high average SPL. Note that some of the vent compression could be due to the amp clipping. Maybe Chops can shed some light on this.

With the vent flared at both ends and grill in place, any 'chuffing' is likely to be lost in the raised noise floor of high SPL. Worst case, you may need to add a bit a damping to the vent for highest perceived SQ same as virtually all simple reflex alignments.

Its overall performance reminded me of the reference Genelec that won a fairly recent measured/subjective SQ shootout, so something to compare to: UltimateAVmag.com: Way Down Deep Part One

On paper it looks to me like SVS came up with a poor man's 1/4 size HT S6 at < 1/4 the price (based on $9950/4), so I amend my initial 'off the cuff' good bang/buck assessment to great bang/buck WRT this particular model.

All that said, Chops confirmed what I surmised, but we all hear the same, yet not so much and each room/speaker location is different, yet dominates perceived sub SQ and just as importantly, how well it mates to the mains where bass 'speed' is reproduced.

Bottom line, if your peak SPL needs fall within its low distortion window, then vent tuning alone should be sufficient to get you the desired in-room sysQ and though some thought has been put into isolation mounting, it's been my experience that virtually all speakers < ~150 lbs can subjectively be 'tightened up' by mass loading, so consider experimenting with setting heavy weights on it and if it helps, then replace it with a heavy potted plant or so some other WAF compliant weight.

WRT how much peak SPL is required, IME folks tend to underestimate what they need and the clean power required to achieve it, so overdrive the system into deep distortion, then proclaim it's due to a vented alignment, 'slow' sub, you-name-it.

The tone of your PM implies that all this info/opinion will just trigger a 'this is all well and good, but would YOU buy one without an audition' sort of response, so the unsolicited answer is only if I wanted a modest amount of 'fill' for the mains and if XO'd < 40-50 Hz/4th order primarily due to keeping the bulk of its high SPL distortion out of the >60 Hz BW where perceived bass EQ resides and to a lessor extent its plate amp. Then again, if I lived in a multiple family dwelling, I wouldn't be able to play it loud enough for either of these to be an issue.

You're welcome! Hope it or whatever you choose works out well for you.

GM
 
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