Passive or active subwoofer?

[Mike_S]

Vintage system here with no sub out, or sub anything. Have 2 powered subs hooked up directly from my main speakers. It goes, amp-speakers-subs. Any sub with speaker level imputs will do this. Set the crossover and gain on the subs, and you are done.

It sounds sublime! You have no idea what a pair of powered subs can do until you have them, it's a game changer! Weirdly, it sounds better everywhere, more then just bass, cleaner mids, better highs, everything sounds fuller, cleaner. Now I can get bass without turning my volume way up, or making things boomy with tone controls.

 

[Mr Boochie]

Hi there, I have a JBL control sb5 passive sub 40-120hz. They have a crossover of 120hz and the frequencies below this are taken from from attached Monitor Audio Bronze 2s.
They say having a powered sub takes the heavy lifting off the main speakers, but my Audiolab 6000aMk2 only has pre out (no bass management), so the main speakers would receive the low frequencies if I swapped for a powered sub.
What I want to know is, have I got this all right and is there any real point to swapping for a powered sub?

I know this is a weird question, but no-one I have spoken to seems to give me any reasons for their decision.

Any advice here would be greatley appreciated.

Thank you in advance.

I purposely make all DIY subs passive (home or autos) — to get the amp out of the cabinet. The amps tend to last a lot longer.

 

[Lux Man]

Active v.s Passive

Please tell me what I am missing. Isn't the only major difference determined by what you have driving and controlling the speaker itself. The speaker itself in the box can sound just so good based on it's qualities.

I think I have at least as much control over my passive sub as any active. Unless there is something out there in the active world that I am totally unaware of.

In the second screen shot you can see I sum the inputs into output 3, which goes ultimately goes to the amp and sub.

 

[OldJBL]

@Lux Man
For quality active subs, I think an argument can be made that the sub's amp has been designed to work well with the specs of the woofer and design of the cabinet. Maybe it is possible that an external sub amp, that is a later add-on, might not be an optimal design to get the best sonic performance. Then again, there might not be enough of a difference to matter? However, I can see where a lower quality active sub could perform worst than a passive sub with a higher quality add-on amp.

 

[C Hart]

Not sure if you are actually asking for an explanation of just making the case, but in the event of the former: There is no inherent difference in performance - good actives and good passives are both good. It is just a question of where you want to generate your biggest watts. For a passive that often means in an amp shared with other speakers, which then has to be designed to put out huge watts at hifi distortion levels. A plate amp with mediocre distortion is perfectly ok for below 80Hz - because of the complexities of bass waves humans don't hear distortion as easily down low, and again because of bass physics, you need a lot more watts for low frequencies than higher ones. So your main amp can be excellent and lower power, but your sub amp can be cheap as long as it's powerful. Or at least that is how I understand and practice the theory.

 

[Lux Man]

There is no inherent difference in performance - good actives and good passives are both good.

For me, you could’ve just ended your post right there. Regarding the rest of your post, I typically choose to use a high quality powerful amplifier no matter what I’m using it for.