AV123 or SVS?

[mike c]

are you getting close to concluding your "new" PB12NSD tests?

 

[craigsub]

are you getting close to concluding your "new" PB12NSD tests?

Yes - In fact, one could almost substitute the NEW PB12 into the original PB12-Ultra's tests.

It is a bit awkward, as SVS is, in theory, a competitor to my new subwoofers, for me to go too much in depth about it.

Plus, the usual panel of listeners I have had in the past no longer is participating in the listening tests, so I am pretty much on my own here.

That being said, I have been flipping back and forth between the PB12-Ultra and the NEW PB12-NSD - and they are REALLY close.

 

[mazersteven]

a competitor to my new subwoofers,

.

See what happens when you take time off away from the forums. You miss everything.

 

[craigsub]

See what happens when you take time off away from the forums. You miss everything.

Google Scamp-10 subwoofer. You will find us ...

 

[mazersteven]

Google Scamp-10 subwoofer. You will find us ...

You "Rule Breaker".

 

[craigsub]

You "Rule Breaker".

Next thing, I will be in bars having martinis.

 

[mazersteven]

Next thing, I will be in bars having martinis.

I have plenty of bail money set aside, so don't worry.

 

[Ilkka]

Having been involved in about 500 of these so called "objective" tests in the past 10 years, I always find it rather humurous when guys opine how "accurate" they are.

Here, for example, is one graph of the response curve of the New PB12-NSD:

And here is another response curve of the same subwoofer:

They are not exactly close, are they ?

Hello,

Old thread but had to bump it up to correct some false claims.

I naturally agree with Craig that a properly constructed GP session should yield very similar results. But here's the important part - the subwoofer needs to be the same unit, not just the same model. Believe me or not, but there are quite a lot of variances between different units of the same model. Driver T/S parameters differ, amplifier components have tolerances etc. So when someone is testing two different units of the same model, don't expect them to be identical. Also notice that the frequency response curve on SVS' site isn't for the updated version of PB12-NSD. It dates back to August 2006 which tells that it is the older version.

Having said that, the SVS PB12-NSD (new) I tested shows a larger than typical difference to SVS' own results (frequency response only, maximum output is the same). Prior publishing the results, I forwarded them to SVS and let them know about the transparency. For more information, I suggest you to ping Ed Mullen at edm@svsound.com

-Ilkka

 

[gus6464]

So if I am reading that graph correctly you get about 85dB @~16Hz without even taking the room into consideration for $600? That sub would kill in a small room

 

[mike c]

So if I am reading that graph correctly you get about 85dB @~16Hz without even taking the room into consideration for $600? That sub would kill in a small room

that's a frequency response graph, and is not representative of what the subwoofer can do ... basically a token spl just to check the frequency response.

if you want to see what it can actually do, this will be more of help:

but then, it will be doing those SPL's at the cost of the following THD

if you want a SECOND third party ground plane test, AVTALK just finished testing the PB12NSD as well ... but have not posted results yet, i'll post it in the subwoofer section as soon as they do.

 

[gus6464]

that's a frequency response graph, and is not representative of what the subwoofer can do ... basically a token spl just to check the frequency response.

if you want to see what it can actually do, this will be more of help:

but then, it will be doing those SPL's at the cost of the following THD

if you want a SECOND third party ground plane test, AVTALK just finished testing the PB12NSD as well ... but have not posted results yet, i'll post it in the subwoofer section as soon as they do.

So all those separate sweeps are tied to the gain knob on the amp? For example if you set it to max you will get the most THD at a certain SPL right?

 

[mike c]

So all those separate sweeps are tied to the gain knob on the amp? For example if you set it to max you will get the most THD at a certain SPL right?

actually, the gain knob is relative to two other things (among others):
-receiver master volume
-subwoofer channel level

but yes, when the subwoofer is playing X SPL at Y frequency, you can check the graph how much THD it produces. people generally consider 10% THD and below inaudible for bass frequencies ...

so if you look at the THD graph, you can see the PB12NSD can do 100db at around 17-18hz ground plane. so indoors, since it will be easier for the sub to produce the same 100db, there will be less THD.

 

[gus6464]

actually, the gain knob is relative to two other things (among others):
-receiver master volume
-subwoofer channel level

but yes, when the subwoofer is playing X SPL at Y frequency, you can check the graph how much THD it produces. people generally consider 10% THD and below inaudible for bass frequencies ...

so if you look at the THD graph, you can see the PB12NSD can do 100db at around 17-18hz ground plane. so indoors, since it will be easier for the sub to produce the same 100db, there will be less THD.

Ahh I see now. So from those graphs one could say 100dB @~18Hz is the magic number for this sub? So in a small to medium size room this sub would be all you needed unless you wanted <18Hz extension right?

 

[mike c]

Ahh I see now. So from those graphs one could say 100dB @~18Hz is the magic number for this sub? So in a small to medium size room this sub would be all you needed unless you wanted <18Hz extension right?

i must correct myself, instead of 100db at 18hz, it should be 98db at 18hz

but yes, if all you need is 98-100db of SPL, then that's all you need.

but then, it is not rare for movies to have peaks that exceed that 98-100db, i would agree though that for music, it should be very sufficient.

 

[gus6464]

i must correct myself, instead of 100db at 18hz, it should be 98db at 18hz

but yes, if all you need is 98-100db of SPL, then that's all you need.

but then, it is not rare for movies to have peaks that exceed that 98-100db, i would agree though that for music, it should be very sufficient.

Are there tests that measure the perceived "tightness" of a sub? I have heard subs that extend low and hit hard for movies but if you play a song they get pretty sloppy. I know some drivers can move faster than others and that it's not necessarily the size of the driver that affects that. Any type of measurements like that exist?

 

[mike c]

Are there tests that measure the perceived "tightness" of a sub? I have heard subs that extend low and hit hard for movies but if you play a song they get pretty sloppy. I know some drivers can move faster than others and that it's not necessarily the size of the driver that affects that. Any type of measurements like that exist?

i believe "speed" falls under the group delay test (check out the last two graphs)

http://www.hometheatershack.com/forums/subwoofer-tests/8151-svs-pb12-nsd-new.html

and btw, AVTALK has completed their test of the PB12NSD

http://www.avtalk.co.uk/forum/index.php?t=msg&th=24671&start=0&rid=7164&SQ=1216247853

and here's a FAQ on the ground plane tests done:
http://www.avtalk.co.uk/forum/index.php?t=msg&th=13417&start=0&rid=7164&SQ=1216247853

 

[croseiv]

For the price, the PB12-NSD is one heck of a sub!

(Currently I'm watching Eragon. The PB13-Ultra is incredible...)

 

[zhimbo]

Also notice that the frequency response curve on SVS' site isn't for the updated version of PB12-NSD. It dates back to August 2006 which tells that it is the older version.

From a thread posted by mike c, I came across these measurements of the PB12-NSD.

These independent measurements look very much like Ilkka's.