Sealed subwoofer system

[kelticwizard]

Some woofers may get a boost in SPL rating by using tighter suspension, not more flux on the voice coil.

I always kind of suspected that. PA speakers have a short voice coil, but not that short, and they sometimes have sensitivities over 100 dB @ 1W/1M. They have very stiff suspensions.

 

[pinkmouse]

I always kind of suspected that. PA speakers have a short voice coil, but not that short, and they sometimes have sensitivities over 100 dB @ 1W/1M. They have very stiff suspensions.

It is also very rare to see PA drivers with anything but paper cones...

 

[Brett D.]

Navin,

The better question would be: Just how big of a tranny does a
350 to 500 watt monoral amp need?

The plate amp I run is 500 watts RMS Mono and runs a larger
toroid than most class A two channel amps. Alternately most of
these sub amps run in Class A/B or G and D I believe and they are
all certainly more efficient than a pure class A amp though some
would argue not as "musical" but for sub frequency use what is
exactly audible? Drivers can make as much as 40% distorsion and
I don't think the human ears can even pick up on this, a measurement
mic can.


I guess it's all in what you want.. I am into HT and 2Channel and
because of this I need a large excursion driver to produce lower
than 20Hz info in movies... For music you never see much below
the 30's unless it's Pipe Organs. A high sensitivity modest excursion
driver certainly "can" work given the right enclosure and tunning.

In the end, like everything else it all boils down to preference or
design philosophy.

 

[navin]

given that your plate amp might cost more than some class A amps.

 

[Brett D.]

If I told you what I paid for my Carver Sunfire plate amp you
would smack me It's from an OEM'd sub and the company (AR)
was selling off thier parts replacement stock to a surplus company.

Believe it or not.. I paid a whopping $54.00 for a brand new
sealed 500 Watt RMS Bob Carver Sunfire TDC Sub Amp with a
Variable 40-120Hz XO and a Audio/Video Selector (Video adds
Bass Boost, Audio is Flat) Plus Gain Control. It was meant for
the European Models (240V) but luckily I have a 220V Receptacle
in my Living Room.

But I agree my luck is not the standard.. But you can still buy
QSC or Crown Pro Amps cheaply and add a Behringer Feedback
Destroyer for EQing...

 

[7V]

Believe it or not.. I paid a whopping $54.00 for a brand new
sealed 500 Watt RMS Bob Carver Sunfire TDC Sub Amp with a
Variable 40-120Hz XO and a Audio/Video Selector (Video adds
Bass Boost, Audio is Flat) Plus Gain Control.

You've been robbed, Brett. If the company won't refund your hard-earned money, I am prepared to reimburse your original stake - only because I feel strongly for the victims of this sort of scam.

 

[Brett D.]

Steve,

I know, I know! I was a victim... It happens! But through years
of counsuling perhaps I will recover?


I wish I would have bought a pair! Since when I run dual stereo
sealed AV-12's I need another amp.. Chances are I won't find
another one of these when I need one.. *Shrugs* I guess I will
just go with a QSC Amp and a Behringer FBD

 

[navin]

Believe it or not.. I paid a whopping $54.00 for a brand new
sealed 500 Watt RMS Bob Carver Sunfire TDC Sub Amp
...

You lucky ........ I'd say more but then dave'd dump me in the sin bin.

 

[smithsonga]

Guys

Here is the graph from WinISD...ORANGE line is with two lambda SB15 drivers, 390 liter box. (smaller box increased loss at 20hz and raised a peak in the 40-50Hz range and if I got even smaller, I lost more at 20Hz...go larger didnt do too much.

Thoughts on this graph? Figured between room gain and equalization, I can raise the 20 Hz -6dB loss. But I keep my sealed system with low group delay.

The GREEN line is a ported system using Lambda PB15, same size enclosure, tuned to 22Hz. I prefer the sealed.

 

[navin]

you ever consdiered what you gonna do when all your room stuff resonates? bass traps and diffusers will be order of the day.