fabulousfrankie Posted September 23, 2003 Share Posted September 23, 2003 Just browsing at www.hometheaterhifi.com and noticed they have a reviw on the B4 Plus. I thought the bass heads here would enjoy it. The most interesting thing in there is the mention that SVS may be available at dealers soon. http://www.hometheaterhifi.com/volume_10_3/svs-b4-subwoofer-9-2003.html EDIT: Sorry about the title, I forgot to finish typing, I guess that means it's time for bed. Quote Link to comment Share on other sites More sharing options...
pinipig523 Posted September 23, 2003 Share Posted September 23, 2003 WOW. Quote Link to comment Share on other sites More sharing options...
danechristian Posted September 23, 2003 Share Posted September 23, 2003 i am impressed. WOW!! but.. can some body elaborate more.. about its total harmic distortion. look at the results Quote Link to comment Share on other sites More sharing options...
Hardhead Posted September 23, 2003 Share Posted September 23, 2003 The results? First you've got to put the results in context. All the tests were done OUTSIDE; as noted in the review, a room would have given another 10 dB gain. That means more than 8 times the power had to be used outside than inside and the sub had to work more than 8 times as hard. Consequently, the distortion figure of 31.4% undoubtably would have been 1/8 or less of what it was outside. Also, notice that the 15 Hz test was below the sub's design frequency of 20 Hz, and the test was made without the port plugs which would have lowered the design response frequency to 16 Hz. Also note that the amp shut down a few times during the various tests, but the sub never did. Truthfully, how many times are you going to drag your sub outside and expect it to perfom at high SPL's at frequencies below its design point? If you do that, prepare yourself for disappointment. No sub does well under those conditions, none ever will, and it's unreasonable to expect one to do so. In context, the results are extremely impressive. No, I don't have any connection or affiliation with SVS--dammit. Quote Link to comment Share on other sites More sharing options...
fabulousfrankie Posted September 23, 2003 Author Share Posted September 23, 2003 I don't think John Johnson should have included the 15Hz distortion level. This is below the tuning frequency of 25hz(w/all ports open) and excursion wildly increases so this is the reason for the higher distortion. The B4 Plus was built with variable tuning points for a reason, if one wants lower extension they can plug the ports and that will "control" the woofers excursion down to the tuning frequency. If you were to plug two ports and tune it to 16Hz, the distortion at 15Hz would be substantially lower. It also seems to me like SVS should have sent a K2, but it's still impressive review. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted September 23, 2003 Share Posted September 23, 2003 I guess there is no need to wait for an Ultra version. It sounds like the B4-Plus will be enought. Thanks for the heads up on the review. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted September 23, 2003 Share Posted September 23, 2003 Well one thing is SURE,I am ordering a B4-Plus and a PB2-Ultra in a few months.ANd no I will not order a weak K1,at l;east a K2 will have to feed the monster. Now the sub was tested OUTDORS!!!And still gave 110dB at 20Hz,factor room gain and you have a solid 120dB at 20Hz inside/corner loaded.At the sweet spot 31.5Hz the SVS B4-Plus PPOUNDED 120dB outdors!! This should translate into a foundation anihalating 130dB indors! Yes thank you SVS,you will make a happy sub human happy. You bet your horns I will get both the B4-Plus and the PB2-Ultra.For my small theater!!! In the large room I will have to wait for a confirmation review and get one or two Everest subs. All day I was distracted because of the B4-Plus,this is bad.And a clear sign Quote Link to comment Share on other sites More sharing options...
kenratboy Posted September 23, 2003 Share Posted September 23, 2003 10,000 WATTS PEAK!!! OMG!!! Quote Link to comment Share on other sites More sharing options...
fabulousfrankie Posted September 23, 2003 Author Share Posted September 23, 2003 ---------------- On 9/23/2003 7:21:03 PM TheEAR wrote: Now the sub was tested OUTDORS!!!And still gave 110dB at 20Hz,factor room gain and you have a solid 120dB at 20Hz inside/corner loaded.At the sweet spot 31.5Hz the SVS B4-Plus PPOUNDED 120dB outdors!! This should translate into a foundation anihalating 130dB indors! ---------------- Here's something TV wrote on what you can expect in translating the numbers from outdoors to in room: 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 Quote Link to comment Share on other sites More sharing options...
formica Posted September 23, 2003 Share Posted September 23, 2003 Thanks for the link.... I usually enjoy reading "secrets of hifi" reviews but I have to admit that their analysis of the B4 seems to simply glaze over this sub. Maybe it's the lack of a consistent benchmark (as SVS mentions) or maybe the lack of any serious music tests... I'm not sure. I'm not saying that this sub is unimpressive, as it is truly a FLAGSHIP sub. I guess I was expecting more from the review.... as it left me hoping Tom Nousaine will get around to testing it. Am I the only one? Rob Quote Link to comment Share on other sites More sharing options...
RickB Posted September 24, 2003 Share Posted September 24, 2003 ---------------- On 9/23/2003 12:01:03 AM fabulousfrankie wrote: http://www.hometheaterhifi.com/" target=_blank>www.hometheaterhifi.com and noticed they have a reviw on the B4 Plus. I thought the bass heads here would enjoy it.] The most interesting thing in there is the mention that SVS may be available at dealers soon. <[A href=" http://www.hometheaterhifi.com/volume_10_3/svs-b4-subwoofer-9-2003.html "'> http://www.hometheaterhifi.com/volume_10_3/svs-b4-subwoofer-9-2003.html " target=_blank> http://www.hometheaterhifi.com/volume_10_3/svs-b4-subwoofer-9-2003.html ] <[sTRONG>EDIT: Sorry about the title, I forgot to finish typing , I guess that means it's time for bed.] ---------------- Has anyone heard anything about SVS being sold through dealers? I hav'nt seen anything about it. Quote Link to comment Share on other sites More sharing options...
Bruinsrme Posted September 24, 2003 Share Posted September 24, 2003 I do not understand why he tested the sub outside, was he afraid of structual damage if it was tested inside? Ron from SVS briefly mentioned that topic but there are not any at this time. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted September 24, 2003 Share Posted September 24, 2003 Yes strange,unless the reviewer was afraid to get evicted or cause his wooden shack to collapse. To have real numbers you always test all your subs in ONE master spot where bass quantity and quality is best(to the ears of the listener sitting in the sweet spot). I find the review lacks max SPL numbers measured inside,the same reviewer tested SUnfire,Velodyne and other subs,I know none as potent as the B4-Plus but the best should be done INSIDE. Quote Link to comment Share on other sites More sharing options...
InnovaZero Posted September 25, 2003 Share Posted September 25, 2003 If I remember right, I guess he had trouble finding the limits of the sub in his testing room. Which I don't know honestly, cause those otehr subs you talked about already do 115-120db at 31.5hz. Quote Link to comment Share on other sites More sharing options...
xcjago Posted September 25, 2003 Share Posted September 25, 2003 Considering that outdoors does not involve any distinguishing factors, such as the difference in room size and room harmonics, wouldn't testing outdoors be the most objective and accurate way of testing a subwoofer? Quote Link to comment Share on other sites More sharing options...
fabulousfrankie Posted September 25, 2003 Author Share Posted September 25, 2003 ---------------- On 9/25/2003 3:30:44 PM xcjago wrote: Considering that outdoors does not involve any distinguishing factors, such as the difference in room size and room harmonics, wouldn't testing outdoors be the most objective and accurate way of testing a subwoofer? ---------------- Short of building your own anechoic chamber, I think so. If there are no reflective boudaries(besides the ground) within 50-60ft then you won't have to worry about reflected energy influencing your measurements. Each reflective boundary adds 6dB, if you move the mic 2M away from the sub this reduces the level by 6dB and gives you quasi-anechoic results. This technique for measuring is called ground plane. Quote Link to comment Share on other sites More sharing options...
skonopa Posted September 26, 2003 Share Posted September 26, 2003 ---------------- On 9/25/2003 4:06:56 PM fabulousfrankie wrote: Short of building your own anechoic chamber, I think so . If there are no reflective boudaries(besides the ground) within 50-60ft then you won't have to worry about reflected energy influencing your measurements. Each reflective boundary adds 6dB, if you move the mic 2M away from the sub this reduces the level by 6dB and gives you quasi-anechoic results. This technique for measuring is called ground plane. ---------------- And that is exactly what Klipsch does. They can only accurately test down to (if I recall correctly) around 80hz in thier anechoic chamber. Below that, they use the ground plane testing. They just simply go out to the rear parking lot. They have marks painted on the ground to mark off 1 meter and 2 meters and another mark to indicate where to place the speaker. This is from what I saw during the "Klipsch Trip" this past summer. Quote Link to comment Share on other sites More sharing options...
fabulousfrankie Posted September 26, 2003 Author Share Posted September 26, 2003 ---------------- On 9/26/2003 4:02:47 PM skonopa wrote: ---------------- On 9/25/2003 4:06:56 PM fabulousfrankie wrote: Short of building your own anechoic chamber, I think so . If there are no reflective boudaries(besides the ground) within 50-60ft then you won't have to worry about reflected energy influencing your measurements. Each reflective boundary adds 6dB, if you move the mic 2M away from the sub this reduces the level by 6dB and gives you quasi-anechoic results. This technique for measuring is called ground plane. ---------------- And that is exactly what Klipsch does. They can only accurately test down to (if I recall correctly) around 80hz in thier anechoic chamber. Below that, they use the ground plane testing. They just simply go out to the rear parking lot. They have marks painted on the ground to mark off 1 meter and 2 meters and another mark to indicate where to place the speaker. This is from what I saw during the "Klipsch Trip" this past summer. ---------------- And SVS too...that's actually where I learned what ground planing was. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.