RE: Powered Subs

["Qua Veda" <qua@oregon.com>]

Hi Kris,
I think the danger you refer to  would not be from the frequency itself, 
but
from overdriving gain in an attempt to hear the low frequency better.  This
could result in clipping the amp that would cause serious damage to the
speaker driver (not to mention your eardrums)  

If my understanding and experience are correct, the 10hz signal simply 
would
not be reproduced by the 1x12, since the circuitry probably rolls off
considerably below ~70hz   I imagine the EV's (great speakers!) may have
clip protection designed in.   

A rule of thumb is to have power amp that is 1.5 -2X the rating of the
speaker you are driving.    A speaker/cabinet rated at 150w/channel would
benefit from an amp rated at 200-300w/chnl.  This is to ensure plenty of
headroom for the amp so it doesn't clip.   

Another point to keep in mind is that the reproduction of low frequencies
requires a lot more amplifier power.  That's why the subs often come with
400w power amps. 

BagEnd www.bagend.com  makes a powered sub with integrated ELF processing,
capable of reproducing 8hz.   Click on Tech Library in the left menu, then
read about InfraSub  if you'd like a better explanation.    One of the
advantages of their design is that the cabinets are surprisingly small.    
I
have some of their PA speakers, including an ELF sub, and can attest to the
very high quality audio - both for studio/home theater, and sound
reinforcement (which is the type I have).
-Qua


-----Original Message-----
From: Krispen Hartung [mailto:khartung@cableone.net] 
Sent: Tuesday, January 01, 2008 3:40 PM
To: Loopers-Delight@loopers-delight.com
Subject: Re: Powered Subs

True, they won't damage my 1X12 cabs provided I keep the level stable. I 
could hook up my laptop to one of my cabs and blast 10hz into it with the 
volume on ten, and my laptop level all the way up...it would pop the cone 
right out. So, whether they can handle it, depends on what you mean by 
"it".

For what I want to do at an experimental music concent, they won't cut it.

Kris


----- Original Message ----- 


> With Max etc,  you can produce sounds below 50hz that some subs can
> reproduce.
>
> But don't fear, I believe the low frequencies won't damage the 12" mains.
> the mains will reproduce only harmonics of the fundamental low notes, 
> rather
> than the fundamentals themselves.   That's why you can 'hear' low end 
>even
> on a car radio without sub woofers.  The harmonics kind of fool your 
>brain
> into perceiving the fundamental sound.  You just don't get the full 
> impact.
> Besides subs, you need room acoustics that will support low frequencies.
> This is where room dimensions , shape, and acoustical treatments can 
> really
> make a huge difference.
>
> -Qua
>
> -----Original Message-----
> From: Krispen Hartung [mailto:khartung@cableone.net]
> Sent: Tuesday, January 01, 2008 12:05 PM
> To: Loopers-Delight@loopers-delight.com
> Subject: Re: Powered Subs
>
> ----- Original Message ----- 
> From: "Rick Walker"
> [snip]
>
> Rick - let's use BEMF as an example. You remember how huge that sounded 
> last
>
> year, right? We could not have produced that with just the 15" mains that
> were next to the stage. We had subs on each side and they were pumping 
>out
> the sounds in a major way.  When you have electronic musicians (guys 
>using
> max/msp, Reaktor, etc) producing giant, almost movie soundtrack sounds in
> the 50-100hz range, two powered 12 inch cabs, or even an inexpensive home
> theater sub isn't going to do the trick in my opinion.  What I will buy, 
>I
> will use at BEMF this year. I'll have my two 1X12 powered ElectroVoice
> SxA100s for mids/highs, but I will definitely need some low end. I'm 
> afraid
> I would blow those speakers with the low end that I heard at last year's
> festival. So, the single Mackie powered sub I listed seemed like a good
> choice in this case. Sure, I would love to save myself some money and buy
> two lower end powered subs for $300 each, but then I am already at $600,
> only $250 short of the big daddy Mackie sub which is a nice piece of gear
> that will deliver low end for years and years.
>
> Kris
>
>
>