# PB13-ultra 20hz vs 15hz - how loud ?



## Thomasdk1405 (Jun 23, 2008)

Hi again !
Need to ask here again. I've switched countless of times between the 20 hz and the 15 hz modes on this great subwoofer. When in 20 hz - I get the feeling of much more power, hair moving experience in certain movies - eg live free and die hard - bridge collapsing from harrier rockets - also war of worlds where huge truck goes down along with bridge. 
When in 15 hz mode - I do get another feeling - not as powerfull - but here do get a strange feeling in the lightning scene - which I dont get in 20 hz.

And that made we wonder - how loud should one play to get the benefit of the sub 20 hz effects ?
Read something about an AV mag that tested a huge 21" subwoofer (think it was called bag end ?) - but here they noted that to get something out of the black hawk down - Irene scene you should play it at 90 db or more !!! - That is way more than I'll ever play - my HT got 75 db at 0 level on the receiver - and I think that's very loud.

Also tried to test the sub with 15 hz and 20 hz sinus tunes. 20 hz tune - here both modes did shake the room although the 20 hz mode was much more violent - but the 15 hz sin tune in 20 hz mode did only move the woofer in and out fast - no sound and no real feeling in couch or anything. In the 15 hz mode - here my door rattled and I did get a little couch shaking.

Also played the exorcism of Emily Rose scenes - out of body experience and decide to stay - back and forth between modes - 15 hz yes - do get the couch shaking - but 20 hz - I simply get more scared :sweat:

Cloverfield with monster walking down the street where they hide in the store - 20 hz - its like monster is right outside the window - 15 hz mode - not so huge a monster outside window....

Maybe I need to boost the volume more and then I'll have the night and day experince (and wear ear protection  )

I'm not aiming at starting the huge debate here - just some kind of hz decibel fact info - if such exists.

/Thomas


----------



## GoNoles (Jul 7, 2012)

I've done a lot of looking at subs lately, 20hz mode performs slightly better from 20 and up, which is all that matters to me 



















http://www.audioholics.com/reviews/...5HZCEA2010CHARTPASS.png/image_view_fullscreen

Many of the comments Ive read if folks prefer 20hz to 15hz mode.


----------



## steve1616 (Apr 6, 2009)

I prefer the 20 Hz mode. I have tried all the modes and the 20 Hz just seems to give me a lot more clean output. For some reason I am bottoming my PB13 Ultra on some scenes even when I don't have it super loud so I definitely wouldn't want to give up any headroom with the 15 Hz mode.


----------



## GoNoles (Jul 7, 2012)

Someone on another forum just bought one, and after going back and forth he preferred 20hz as well.


----------



## drdoan (Aug 30, 2006)

20 would be my choice. Have fun. Dennis


----------



## Sycraft (May 21, 2009)

One thing to make sure to look at is if you don't use some sort of room EQ, 15Hz mode may be better because it may counter room gain. I have a PC20-39+, one of their older 12" subs, and I have it set to 16Hz tuning for that reason. In 20Hz tuning I had a HUGE spike in volume at the low end, and then a fast rolloff. In 16Hz mode it tamed the spike down to almost totally flat down to 13Hz with a gradual rolloff.

I probably should change it, now that I do have an Audyssey system, but I haven't bothered yet (a case of "it works so why bother").


----------



## jdent02 (Jan 13, 2012)

Sycraft said:


> One thing to make sure to look at is if you don't use some sort of room EQ, 15Hz mode may be better because it may counter room gain. I have a PC20-39+, one of their older 12" subs, and I have it set to 16Hz tuning for that reason. In 20Hz tuning I had a HUGE spike in volume at the low end, and then a fast rolloff. In 16Hz mode it tamed the spike down to almost totally flat down to 13Hz with a gradual rolloff.
> 
> I probably should change it, now that I do have an Audyssey system, but I haven't bothered yet (a case of "it works so why bother").


Similar result here, my PC12-Plus in 20Hz was far too boomy in the 20-30Hz region. Made a great impact, but some ugly overtones. 16Hz mode is much smoother and noticeably 'deeper'. It may not shake things as hard but it's more pleasing to me.


----------



## beyond 1000 (Aug 28, 2008)

jdent02 said:


> Similar result here, my PC12-Plus in 20Hz was far too boomy in the 20-30Hz region. Made a great impact, but some ugly overtones. 16Hz mode is much smoother and noticeably 'deeper'. It may not shake things as hard but it's more pleasing to me.



I have a PB13 Ultra with Sledge and I do prefer the 15hz setting. My room isn't that huge and in WOTW the bottom end is definitely deeper in the 15hz setting. With 15hz in the scene where the bridge gets destroyed in NYC I hit 116db with plenty of headroom to spare in power. In 20hz I imagine I would have nailed about 118db. True the sub would potentially have more output in 20hz but there go your ears. In 15hz you keep your hearing at the cost of your body's structural integrity. :wave:


----------



## jdent02 (Jan 13, 2012)

Although the funny thing is the 20 Hz mode would probably be more authentic to the theaterical experience: loud bass that doesn't go very deep and sounds a bit bloated......


----------



## Mike P. (Apr 6, 2007)

jdent02 said:


> Although the funny thing is the 20 Hz mode would probably be more authentic to the theaterical experience: loud bass that doesn't go very deep and sounds a bit bloated......


A theater would be closer to 30 hz.


----------

