What is a "Passive Speaker Box"

rijndael · 07-14-2007, 08:02 PM

i have been searching on google and here for the past half hour...i cant find anything...

the reason I would like to know is because the TC-9 sub that i am planning on getting said something about a small passive enclosure...

heres from the site: http://www.tcsounds.com/tc9.htm
Recommended enclosures

The TC-9 subwoofers are engineered for small sealed, ported, passive or horn loaded systems and designed for high power capabilities. We recommend an amplifier between 500 and 2000 watts RMS per driver.

There is no single perfect box. Much of what we offer is merely a general guideline to get you started. All of our system recommendations are geared for flat response but it is important to note that we do not show the recommended EQ necessarily for true in room liner frequency response. At a minimum, we strongly encourage the use of a high pass filter to prevent over excursion and potential mechanical damage to the driver in any given system design.

i know what the others are (sealed and ported)...but what is passive?

thanks....its probably a simple answer and im a retard...lol

XC-C30 · 07-14-2007, 08:09 PM

I'm not sure, but I think they mean using a passive radiator or variovent.

pancit175 · 07-14-2007, 08:22 PM

And thats a huge range for recommended RMS power, its almost unheard of.

rijndael · 07-14-2007, 08:35 PM

Quote: Originally Posted by pancit175

And thats a huge range for recommended RMS power, its almost unheard of.

ill be purchasing the DLS A6 amplifier....so power is not an issue...1200W RMS...

i thought the same thing about the passive radiator....but that doesnt make any sense...why would you need a radiator in your speaker box?

XC-C30 · 07-14-2007, 08:50 PM

Do you even know what a passive radiator is or what it is for? A passive radiator is always enclosed together with the driver....

rijndael · 07-14-2007, 08:53 PM

Quote: Originally Posted by XC-C30

Do you even know what a passive radiator is? A passive radiator is always enclosed together with the driver....

my previous response should have given you that answer...lol...the answer is no.

I dont know much about subwoofers.

but either way, what would something that has to do specifically with the driver have to do with the enclosure?

EDIT: I only know what is good by the pretty colors.

rijndael · 07-14-2007, 09:01 PM

hey...i think i found a partial answer to another question i raised in here...

read from the part it says about "for passive systems"....

Tuning Fq: The tuning frequencies specifying the actual tuning frequency of the system. For ported systems, this only depends on the port length, port area and volume of the box. For passive systems this only depends on the compliance, mass and surface area of the radiator(s) and the volume of the box. Increasing the number or size of the passive radiator(s) is like increasing the size of the port(s) and will allow for more output at tuning frequency.

XC-C30 · 07-14-2007, 09:01 PM

A passive radiator changes the parameters of said driver dramaticaly, giving you more options. Like a sealed or vented box would have certain volume, certain volume is needed when using a radiator. I'll give you an example of the setup I'm building: The sub is a peerless XXLS 12", the Fs lays at 17.7Hz. Now, with the matching passive radiator, the Fs changes to 10.4Hz, allowing the sub to go even lower, if possible, in the right environment.

rijndael · 07-14-2007, 09:12 PM

Quote: Originally Posted by XC-C30

A passive radiator changes the parameters of said driver dramaticaly, giving you more options. Like a sealed or vented box would have certain volume, certain volume is needed when using a radiator. I'll give you an example of the setup I'm building: The sub is a peerless XXLS 12", the Fs lays at 17.7Hz. Now, with the matching passive radiator, the Fs changes to 10.4Hz, allowing the sub to go even lower, if possible, in the right environment.

ok...and "F" meaning Frequency, right? got it.

but im still confused how you can manually tune it? is it a turn of a knob or is it just by the environment you put it in?

XC-C30 · 07-14-2007, 09:21 PM

Fs = free-air resonance. Tuning it: that's where the x-over comes in, just like with a sealed enclosure.

edit: actually I have to correct myself here. Yes it is by the turn of a knob, BUT, you may want to set the x-over point as low as possible... If the environment, doesn't allow it, you won't be able to hit certain frequencies. Like in my car, I won't be able to go below 25Hz or something, unless I open the trunk or doors, to get more pressure.

rijndael · 07-14-2007, 09:24 PM

got ya...now i understand...

but i still dont know what a passive enclosure is...

the only thing i can think of is thats the speaker box with a horn...cause i cant find anything else on it...and horn isnt mentioned anywhere on the others, and you cant consider a horn a port...

XC-C30 · 07-14-2007, 09:38 PM

I wouldn't know what a horn enclosure is either. What I do know is that some enclosures have a cone shaped port instead of a straight one. If you do it right, a cone shaped port can be equal to several straight ports, again giving you more options in enclosure building. But I'm not sure about this one, so don't shoot me for it if I'm wrong.

A passive enclosure I think, is an enclosure that makes use of a passive radiator, as I said before. A passive radiator is, as the name may imply, a driver without a motor (no magnet, pole piece, backplate and cylinder)... It makes use of the pressure and airflow coming forth from the actual "active" driver.

rijndael · 07-14-2007, 09:42 PM

Quote: Originally Posted by XC-C30

I wouldn't know what a horn enclosure is either. What I do know is that some enclosures have a cone shaped port instead of a straight one. If you do it right, a cone shaped port can be equal to several straight ports, again giving you more options in enclosure building. But I'm not sure about this one, so don't shoot me for it if I'm wrong.

A passive enclosure I think, is an enclosure that makes use of a passive radiator, as I said before. A passive radiator is, as the name may imply, a driver without a motor (no magnet, pole piece, backplate and cylinder)... It makes use of the pressure and airflow coming forth from the actual "active" driver.

ohh Jesus God....lol....now i completely understand...i definately misunderstood what you were saying before..

thanks XC

XC-C30 · 07-14-2007, 09:49 PM

Unless you have a big 18-wheeler, I wouldn't consider using a passive radiator. You're just not able to use it in the car environment. I'd stick with sealed or vented.

XC-C30 · 07-14-2007, 09:54 PM

Hmmmmm, I see this very topic was actually pretty useless, given the fact that it's all explained at the TC website. Look at accessories...

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