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Tópico: Passive Subwoofers

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Hello everyone, I have never purchased passive subwoofers before. If i was to purchase one could i power it with a regular amp? Such as the crown micro tech 1200?
 
Mensajes Mon 25 Feb 13 @ 10:58 am
You would use a power amp for a passive sub. There are differences with running active tho. A passive sub will also require a crossover to get just the low freaks to the sub. I would also recommend a low pass filter to keep the sub from traveling out of range. Another thing to consider with passive is a limiter. The amp should be rated to allow plenty of headroom compared to the program wattage of the speakers.

It seams like a lot. I have these components as seperate units. There are a few amps out now with this processing built in, and presets that allow you to just enter the type of speaker, and your off and running.

Don't let this discourage you tho. I love passive gear. It allows more flexability. The speakers are generally lighter also, which is nice when putting them on stands.
 
Isnt a "low pass filter" a function of the crossover? The crossover separates the freqs. allowing only (in this case) the low freqs. to the sub......
 
I think he probably means a high pass filter (rumble filter) to prevent freqs below the capability of the sub from reaching the driver.

But yeah, if you pick the right x-over it may well have that onboard.

I'd never go back to passive kit. I find powered speakers just way more convenient (and when you're talking about subs, the weight difference isn't going to be that great as a good sub should be heavy anyway).
 
Makes sense....I asked that b/c I'm more familiar with high end car audio setups rather than live sound....Im a at home hobbyist "DJ"
 
So im guessing the "Crown Amp" wont work for this?
 
My mistake, I did mean high pass. My filters are on my EQ. 40hz high and 16khz low. My crossover did not have them.
 
hallabackkid101 wrote :
So im guessing the "Crown Amp" wont work for this?


the crown amp will work, but not alone. as mentioned, you will need a crossover to ensure only the low frequencies are directed to your sub.
 
Alright, So ill need a high pass filter. Does anyone have any recommendations?
 
Do you already have a crossover?
Are you planning on adding more passive components, or mixing passive with active?
To get the best sound you will have to match the crossover points between your tops and sub.
There are crossovers that have filters, or if your budget allows, a processor like a DBX Driverack.
 
I would recomend avoiding a Passive sub all together & buy a powered sub with crossover built in. You'll get way better sound & have an all in one compnent. The JBL's are my choice of Subs
 
TSLAMMINK wrote :
I would recomend avoiding a Passive sub all together & buy a powered sub with crossover built in. You'll get way better sound & have an all in one compnent. The JBL's are my choice of Subs


I agree with the ease of use because of the built in components.
I disagree with the better sound, especially if the tops are not matched or crossed over at the correct point.
Also, if the amp in the power sub fails, the whole thing is down. Passive you can usually swap some channels around to get sound again. It's lower cost over all, but there is more to deal with.

It's all about cost, time, and quality. You can't have all three.
 
blckjck wrote :
if the tops are not matched or crossed over at the correct point.

In most cases the top would be run from the high pass output of the sub, so they would cross over at whatever frequency that point is set to - which will 99% of the time be way higher than the low freq response of a typical full range top cab.

blckjck wrote :
if the amp in the power sub fails, the whole thing is down.

Can just as easily happen to an amp in a passive system. In fact, running a pair of powered subs gives you two amps, each with their own PSU. If one goes, you still have the other. If the PSU goes in a stereo power amp, both channels die.
 
Most power amps have filters built in so you may not need an external X over.
 
groovindj wrote :
If one goes, you still have the other. If the PSU goes in a stereo power amp, both channels die.


True, but I prefer taking a spare amp with me to a gig instead of a spare sub... ;)
 
Well there's the thing....

You wouldn't need a spare sub. If one of a pair died, you'd only lose a tiny bit of bass.

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djcity wrote :
Most power amps have filters built in.


Most? I'd say "some" would be more accurate.
 


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