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Discussion Starter · #1 ·

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Note it is a B4 and not a B4-Plus. Solid review with several good quotes for SVS.

Quote:
From my listening experiences with the B4, it is obviously the most powerful subwoofer ever constructed for consumer use.
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SVS has done it again. For anyone who wants to have the Darth Vader of subwoofers, the B4 is it. With almost unlimited power and low distortion, the B4 is definitely one of the Masters of the Universe.
 

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Quote:
Originally posted by cajunlab
Are those distortion numbers typical for a high-end sub?

Also, am I reading correctly that it is +/-10db from 80->15Hz?
Keep in mind he took those measurements outside.


"40 Hz at 100 dB produced only 1.2% THD. Maximum output was 122 dB, and the amp did not shut off."


I bet his neighbors thought the world was coming to an end. 122 db from 1 meter OUTSIDE. OMG.
 

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CB,


While that was a very very early sample (read shipping products have been improved in some key respects so I'd say Dr. Johnson's results are somewhat conservative), this was a "B4-Plus".


As noted he used "only" the K1 for power, and as noted tested outdoors -- which totally obviates any room gain which, depending on the room and the frequency would likely be anything like 8-14dB over outdoor ground plane measurements (keeping THD constant).


No port plugs (for lower tuning and enhanced response down low) or subsonic filters were used either as two other caveats to keep the context of the measurements straight. Not that we have any problem with the results.


Ron
 

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The B4+ was measured in 25hz extension mode. So once frequencies drop much below the tuning point...thd is going to rise very quickly. Hitting 100dBs outside with 3% thd at 20hz isn't too bad considering that is already 1/3octave below the tuning point of the enclosure. But you can see by 15hz the subwoofer isn't working optimally. One thing to remember, John Johnson measured the B4+ outside because he couldn't reach any type of output limits in his room...this is the first subwoofer that forced him to an entirely different measurement method.

In my experiences...going from ground plane to in room...You'll add about 4 to 4.5dB per boundary.(theory indicates 6dB per boundary...but in the real world everything is "lossy") So corner loading is going to add 8-9dBs...with another 1-3dBs for the ceiling depending on height and construction. So figure 10-12dBs just for the boundary effects. "Room gain'' is something entirely different. That is a phenomenon that boosts the deepest frequencies in an enclosed or semi-enclosed listening area. In a typical North American 2500 cu-ft living area with a couple openings to other room areas...you might see 2-4dB of *room gain* in the 16-25hz range. In smaller, well sealed rooms...you can see double that. In larger open rooms...nearly nothing. So going from ground planing to corner loaded in a typical 2500 cu-ft room...you might see something like 12-16dBs of additional output for the same input levels.


When I was using the K1, the B4+ stayed very linear (low distortion) until the K1 reached its output limits...than the odd order THD suddenly skyrocketed and the combination could only manage another dBish.(I remember John Kotches and I discussing this specifically a while back)


His maximum output readings do seem to parallel closely to what B4+ owners measure in thier rooms with the most bass intense DVDs. Until he measures a few other subwoofers outside(if he ever does), it will be tough to gauge just how well the B4+ numbers are in some regards though.


Tom V.

SVS
 

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Quote:
Originally posted by cajunlab
Are those distortion numbers typical for a high-end sub?
To see how those distortion numbers compare with other products, check out the current review in Home Theater Magazine by Keith Yates.


The numbers reported are quite good, with obvious exception of the 15Hz measurement which would have been more interesting if he had taken a couple measurements at 15Hz and 20Hz with different tunings.


Also note that the distortion is at the levels listed in the image, not what was observed as maximum levels.
 

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Any reason why you guys (SVS) weren't in the Home Theatre magazine subwoofer test? I couldn't believe that you guys (or Hsu) wasn't covered in the review.
 

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Quote:
Originally posted by Sevenfeet
Any reason why you guys (SVS) weren't in the Home Theatre magazine subwoofer test? I couldn't believe that you guys (or Hsu) wasn't covered in the review.
See the Hsu and SVS not in sub shootout? thread for the answer to your question.


This was Ron Stimpson's response with regards to whether or not SVS was invited to participate and declined:
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Originally posted by Ron Stimpson

Trust me, if anyone had had the balls to invite us, we'd have been there.


There are some bulls you don't invite into your china shop I guess.


Ron Stimpson

SVS
 

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Discussion Starter · #12 ·
quote:

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Originally posted by Ron Stimpson

Trust me, if anyone had had the balls to invite us, we'd have been there.


There are some bulls you don't invite into your china shop I guess.


Ron Stimpson

SVS

--------------------------------------------------------------------------------


I love that responce.:D
 

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As a B4+ owner, I can say that I am utterly amazed at not only the spl readings I have witnessed here in my 4500 CF room (122 uncorrected on the matrix heli scene for one) but how tight the bass is...accurate to a "T"...beautiful to boot!! Its good to see SVS spreading a bit more, as they make very good subs (I've had 2 myself..upgraditis ya know) and if ever I need another, It'll be with them...glad to see the review as positive as I have viewed it. 3C
 

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Blues In Thirds
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I for one am glad to see so many positive reviews of the B4. I'm debating getting 2 of them. Still trying to evaluate all the angles at this point...but I'm pretty close to taking the plunge.

Javry
 

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Yes, it is a great sub, and not that I don't want Tom and Ron to get a double sale..but try one first...I believe 2 gives you 6db max headroom...the bass is insane...and the product is wonderful...and ya need room....if you put one on each side you'll obviously loose some max ...these suckers are good size:) Check out my site for a few pics of them...3C
 

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One thing I didn't like about the review is when comparing it to other subs he's comparing it to low quality ones. I mean the sub with amp cost $3500 of course it's gonna sound better than a $500 sub that can't go to 20Hz it better for that price. I wish he would've compared it to say the HGS 18 or a REL sub or something more high end that also can go to 20hz and below so you could get a better reference as to how good it was.


Daniel Smith
 

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took a look at your site. Man..is that nice, or what? Thanks for the advise. At this stage in the game, I'll take all of it I can get. I assume you're satisfied with your purchase? Have you tried it on U-571 and LOTR TT? BTW, how does the unit perform during 2 channel?

Javry
 

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If you read the conclusions...and I'm sure Johnson has seen his fair share of subs...I don't think he is leaving out the big guns...as TV said above, "One thing to remember, John Johnson measured the B4+ outside because he couldn't reach any type of output limits in his room...this is the first subwoofer that forced him to an entirely different measurement method.


Could mean they were measureable inside? On the flip side, maybe he hasn't measured them all yet? dunno, but at 2499 its one helluva sub, and its one upgrade I won't be looking at doing for a long ass time:)
 

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Jav...thanks....yes, I am far more than satisfied...I have cranked up the ring drop, battle scenes from lotr, and all the major "bombs" in dvd...I was very impressed with the helicopter scene as it is about 6 seconds of pure sub destroying bass...with 6 seconds at 122 uncorrected (~ 130 corrected) things start moving around the room. We have vaulted ceilings upstairs with a light fixture hanging from it...my sub sits downstairs(cement/carpet below it), and at one point the light was swinging from the ceiling lol...now this is 20' ABOVE the sub..... in LOTR I ran it at 12 below reference, and couldn't take much more as window treatments, and my TV screen were wavering pretty bad...its intense! As for music...bass is easy to get in many forms...boomy or not, its present and some people love that boom ****...not me... Its this part, not the spls, that amaze me..it is VERY tight, accurate to a "T"...its blends very well with my system, and I actually find myself using it for all my 2 channel listening...Using the Lexicon mc-8, I use the L7 more...sounds great...you won't be disappointed! 2 of these would be overkill in my 4500 CF room...My crown K1 will give out before the sub...long before..and I, nor my house, could take 140 db's ...My wife said one day we'll have a big crack in our wall upstairs lol...then again..I believe her..that's the power it has. 3C
 

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Jav, how big is your room? I have 2 big openings, 1 going up and one going down a hallway...If my room were smaller, I'd be in big trouble....I'd be buying new windows...and I'm serious.
 
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