Subwoofer, Active Vs. Passive


I recently saw in a thread that most powered subwoofers usually have crappy amplifiers.

Any thoughts on this?

Which is believed to be better? Active or Passive?

If most subwoofers have somewhat crappy amplifiers, would you be better off using an bridged stereo ADCOM to drive a passive subwoofer?

Thinking of that, I dont see many passive subwoofers out there. Are there any good reputable companys that specialize in passive subwoofers?

Ive been looking into building my own subwoofer, just for the experience. Who out there uses Passive Subwoofers, what do you use to drive them and why?
slappy
Thanks for all the responses. !!!

Im thinking of this for the 2ch setup im working on. If i build one, it will most likley it will end up being a party sub for rocking the house, i doubt i can build one near the quality of REL without alot of research, time, and lots and lots of cash. hahaha So i might just have to buy one for my serious listenin!
Slappy,

I think that you really need to consider whether you are doing a music/home theatre project vs. music alone. If it's music that you're after you may wish to consider the cost of a quality sub and look at the total cash outlay. Adding this amount to the main speakers/amps is what I would do. Understand though that my recommendation is based on what I believe is primary in my life. Yours may be different. I want the fewest components possible with as much good sound as I can afford. I'm willing to give up the lowest octave to rid myself of the clutter and associated problems with integration and maintenance. The definition of high end audio eludes me since I've heard many very expensive systems that are only a very small percentage better than my modest mid fi system. The last bit of improvement to be gained is too rich for my blood but I appreciate those that acheive it. By the way, I don't miss the last octave one bit and neither has anyone that has listened to my system. It's flat to 40 cycles.
I made the post on the amp quality. My post was in regard to subs with balanced inputs, I stated that most amp quality in active subs was about $80 and that many active subs have very short warranty on the sub amp. These statements are true in most cases but not all and were made in regards to the % of active subs on the market with high quality amps (not many). I won't get into which type (passive/active) sub is better because there is no real answer so the buyer must do their homework. Building a sub would be a great project for you Slappy, there are many kit's on the market and most can come with pre built cabinet if you have no woodworking skills...you will not need a crossover if you are going to use the one in your pre/pro. My sub is a large passive (Vmps) and can be orderd as a kit. I drive it with an Onkyo M-504 amp that puts out 325 watts into it's 4 ohm load. This sub is the bottom half of my Large Vmps Supertowers which I also sometimes use as subs for a three sub setup. Hope this is more clear, there are many good active subs on the market from high-end companys that use good amps...there are just many, many more who don't.

Dave
Well think about it. We try so hard to isolate our amps and preamps with cones and pucks. The worst place to put an amplifier is inside a sub enclosure. However, it sure is handy and it reduces the need for component space. The key to powered/passive subs is the ability to dial them in right. If you need bass extension a sub can work. I have difficulty matching subs with speakers that cut off 50hz and above. I just finished a passive sub project. I will let you know how it sounds.
Slappy, although I've made a comment or two about active and passive subs, I hope you don't think it was me who used the word crappy.

However, I wouldn't hesitate to use the word mediocre. As I don't believe there's one active speaker/subwoofer mfg'er yet who has received any special recognition for their beautiful amplification.

For that reason alone (there are other reasons), I would focus on the absolute best amplifier I could find and couple that with the best pair of full-range speakers that are capable of going down to the low 20Hz's or lower.

As for answering your question, the only passive sub I'm aware of is the German Physics sub which sells for about $13k.

On the other hand, the Von Schweikert VR-4 Gen III SE full-range speakers go down to 16Hz and retail for $6k and some reviewers claim this speaker to be the best speaker under $20k. If you believe them.

If the VR-4 is half of what others claim it to be, and you were able to find the right amp, You'd probably have a bottom end that no sub could approach.

-IMO
Actives are cheaper and are not necessarily worse than passives. If you want a passive you will need to buy a good amp and a crossover, plus more cables. When you plug in the price of a good amp & cross over, you'd probably find some fairly decent active subs.