SVS B4-Plus more than measures up (1 Viewer)

[Reginald Trent]

The ONLY negative I see is the lack of some sort of grill/protection for the speakers. That should be the first thing they address. Can you imagine how upset you'll be if your cat scratched and damaged your sub's driver? How about your young child damaging it by punching it with their fist or a toy?

 

[Eric Hargrove]

I think SVS said the production versions would have grills to protect the woofers. As far as I know, this was a beta test version. Brian's glowing review has me considering opening my wallet and replacing my Ultra with a B4. Shame on SVS...

 

[Tim Morton]

That driver look an awful lot like the eclipse subs i ran in my car....absolutely the BEST sub on the car audio scene when i was in it.

 

[BrianKR]

Since you also mentioned you normally listen at 10 db below reference it would have seemed that two CS+ subs would have given you the slam.
I was also wondering (maybe wear some earplugs) if you could document the Toy Story 2 Logo db intro like you did the other movies? This is the only DVD I have in my possesion at the moment.
One last question. When you recorded the SPL from 4M away did you have all other speakers playing?

Zack_R,
Sorry for the delay in my response.
Yes, I did calibrate the CS+ subs using Avia.
With Toy Story II are you referring to the opening scene "Game Over"? When I measure that scene @ -5dB under reference I hit highs of: @1m 113dB & @ 4m 108dB
I am assuming most of the numbers I recorded would be significantly higher (especially the Pod Race and Game Over scenes) using RS correction table:
16hz/11dB
20hz/7.5dB
25hz/5.5dB
31hz/3.5dB
40hz/2dB
50hz/1.5dB
I did have all the speakers on when taking the SPL readings @ 4m. The only speaker I turned off was the left front channel when I would check for port noise or distortion.
Reginald,
SVS will have grille covers for the drivers on the B4+.

 

[Edward J M]

I went back and played most of the same scenes over again with C-weighted fast and I got an average increase of 1.5 to 2.5 a scene. I also increased my overall output by placing the B4 in the corner.

So, if we add an average of 4 dB for the RS Correction Factor, and an average of 2 dB for the Fast setting, we're looking at a staggering 6 dB increase over your initial listings as the true SPL.

I would dare say with a professional-grade SPL meter on C-Weighted Fast, you would have recorded 130 dB on the Arizona explosion. Staggering - and right in line with Tom's predictions.

I have taken the liberty of adding the 6 dB in to your readings just to get an overall flavor of how it looks with all the corrected values.

Star Wars AOTC Ch 1 "Return to Corusant" / Time 0: 02:01 & 0:02:08
@1m 124dB @1m 123dB
@4m 118dB @4m 118dB

Star Wars AOTC Ch 1 "Return to Corusant" / Time 0:03:24
@1m 127dB @1m 126dB
@4m 119dB @4m 118dB

Titan AE Ch16 "In the Ice Ring" / Time 1:03:47
@1m 122dB @1m 120dB
@4m 117dB @4m 115dB

The Matrix Ch32 "Rooftop Rescue" / Time 1:51:16
@1m 121dB @1m 119dB
@4m 1114db @4m 113dB

Jurassic Park III Ch5 "The Spinosaurus" / Time 0:24:05
@1m 122dB @1m 120dB
@4m 117dB @4m 116dB

Pearl Harbor "Attack" Ch22 / Time 1:29:58
@1m 130dB! @1m 129dB
@4m 123dB! @4m 122dB

 

[Mark Seaton]

I would dare say with a professional-grade SPL meter on C-Weighted Fast, you would have recorded 130 dB on the Arizona explosion.

Realize that this correction is from the C-Weighted curve. With the weighting engaged you are just guessing as to what the low bass output really is, yet it is obvious the readings will all be conservative relative to real levels at various frequencies. Likewise, it should be understood that merely balancing the level read on an SPL meter via noise tests will typically leave a subwoofer calibrated a good deal hot, and the meter essentially averages the energy from any peaks and dips, but only after passing it through the weighting filter. A spectrum analyzer, a high resolution RTA, or a higher resolution measurement system is really needed to asses deep bass output.

In no way am I discounting the high output observed, but rather want to clarify what the numbers are and are not telling us.

Regards,

 

[Edward J M]

A spectrum analyzer, a high resolution RTA, or a higher resolution measurement system is really needed to asses deep bass output.

Definitely, Mark. The average Joe just doesn't have access to that stuff.

My goal was simply to point out that Brian's initial measurements were conservative from the standpoint that the RS meter typically reads several dB low in the 25-30 Hz region, and any SPL meter will typically give higher readings on Fast vs. Slow.

Will Brian ever know the "true" SPL in his basement on the Arizona explosion as measured with that type of gear? I doubt it.

With that said, I think consistency of methodology is more important here than the actual "true" SPL. The vast majority of HT enthusiasts own the RS meter and use it on C-Weighted Fast and add the approximate Correction Factor when they are monitoring SPL from their systems.

I simply wanted Brian's readings to reflect the same methodology so that valid comparisons can be made by enthusiasts taking the same measurements on their owns systems.

It's like using a scale that is probably inaccurate but precise. It doesn't tell you how much you actually weigh, but it will accurately reflect differences in weight between two people.

Regards,

Ed

 

[Jonathan T]

BrianKR, I hate you!!
Just kidding
Your review of the B4-plus is exellent. It's makin me want to build a sub that can perform on par with it, even though the room that will end up with the HT system is 10X16X9, a lot smaller than your toom. But hey, it's never too much.

 

[Michael R Price]

Jonathan,
Two Tumults and you're in! Or maybe even one LAB horn.

 

[Eric Hargrove]

Brian,

Maybe you've said it before but I'm kind of curious how big your home theater room is. My room is appoximately 5500 cu ft and I can hit 116-119db with my Ultra on some bass heavy movies. I don't typically listen that loud probably about 10db below reference normally. It looks as though Tom V' performance numbers on the B4 are a tad conservative as could be expected.

 

[seng]

"Hi Seng,

Two corrections...

First, as for actual low end production, a ContraBass will out woof a pair of HGS-18s at low frequencies without too much trouble. I wouldn't hesitate to say the perception of the ContraBass with most DVD soundtracks would be like that of 2-4 HGS-18s, but 4 could certainly achieve higher total SPL over some bandwidth.

Secondly, the ContraBass is a good deal more than $2500. The ContraBass as sold through professional sound contractors for Church, theme park, studio, and organ reproduction use list and sell for $3,600 as of Jan. 31st, 2003, $3000 was the price before that date. The new, and as of yet un-publicized, Theater Calibrated ContraBass gets some additional circuitry to further flatten out the top end of the sub, and most significantly gets a hand selected motor for quieter operation, along with overall tigher QC. This variant is sold through custom home theater installers at a suggested retail of $5,500. If sold directly from us online, I would guess it might be a bit closer in price to the B4-Plus.

As for the comparison, from what I can tell from the details posted thus far, the B4-Plus and the ContraBass are rather different beasts. The ContraBass is optimized for unequalized, free field response to ~16Hz and relatively high efficiency at those frequencies. In my estimation the B4 looks to be an interesting solution to providing full level playback from a single enclosure when used with all 4 ports open. Much above 20Hz, I would expect the B4 to exceed the ContraBass in continuous output, mostly due to the huge power handling, where the ContraBass would be reasonably close dynamically. With most reference scale systems, a pair of ContraBasses are typically specified by consultants who have used them before, mostly in the name of reducing the continuous power required and increasing headroom, particularly below 20Hz. I *suspect* (as I haven't seen associated specs) to acheive a low enough tuning to support 16Hz output you would need to plug two of the ports. It will be interesting to see what sort of output and distortion is available with two of the ports plugged.

While the B4 strays from some of my personal goals, I expect is will be a great solution for many bass hungry customers and in it's trade offs it should acheive the noteable goal of full level playback without being overdriven.

Regards,"



Hi Mark,

Are you implying that the B4-Plus is more ideal to use for a mid-size theater than the ContraBass? Because most of the explosions, gun shot sounds, and ect... have frequencies above the 20Hz? Also can you send your new prototype contraBass sub (when its ready)to one of us to have it evaluate and compare to the B4-plus? thanks

ps. how do you use the quote function here?

Seng

 

[TimForman]

Well, I think this looks perfect. I'm gonna get one as soon as I move my HT into my bomb shelter.

 

[Jonathan T]

I don't have enough money to build a 2 tumult sub, maybe in a couple years.

 

[John Cain]

Hmmmmm..

I wonder if this sub would out woof my two Ultras ???

Hmmmmm....

Thanks for the review.

-- John

 

[Frank Carter]

John,

Tom V. said the B4 Plus is equal to about 4 CS Ultras!

 

[John Cain]

Tom V. said the B4 Plus is equal to about 4 CS Ultras!

OMG!! I need to look into this puppy a little bit more!!

-- John

 

[Tom Vodhanel]

>>>OMG!! I need to look into this puppy a little bit more!

 

[Adam_Reiter]

Yeah, I am ordering this bad boy tomorrow!! Sucky thing is waiting prolly 3 weeks for it to show up. SVS-Ron, if you see this, can you verify that the B4 Plus I will order tomorrow, can come with grills? I have a 2 year old and a 5 year old and would like it if I didn't have to send them to an early grave had they kicked in one of my woofers.
Just have to decide which amp I want to go with. hmmmmmmm. How many here on this board have this Sub? Just John and Brian? Your duo is about to turn into a Tres Amigos!!

 

[John Doran]

adam,
sweet...the more the merrier.
i have the B4 without grills and turned the ports toward the wall - i have a baby on the way and i could just imagine it jamming peanut butter sandwiches and milk into the sub... :frowning:
as for the other exposed woofer, if no retrofittable grill appears by the time the little tyke is mobile enough to do damage, i'm gonna jury-rig something to keep the little-one at bay...
good luck.
- jd

 

[Ron Stimpson]

Adam,

No grills on the B4's at this point. We're still investigating but that's it.

Sunfire got by for many years (and still does) with exposed woofers and I'm sure a few were exposed to kids too.

FWIW the woofers are VERY tough items. Aluminum cone, rubber surrounds. Unless they take a knife and hammer to them you'll be fine.

Having had all manner of speakers, glass tables, amps and other items exposed to children (mine now 12 and 14) I can assure you they CAN be trained to not trash your gear ;^)

Ron