Sealed, Ported, or Passive Radiators?

So, you have what, 19 subwoofers in your system? I would think you'd be better served by selling all of those woofers and getting a nice Velodyne 15" or 18" DD Series or Optimum Series subwoofer.

Not to mention how much floor space you're gonna re-claim...

-RW-

Just curious, have you ever heard of wave cancellation?

:-)

My first choice would be transmission line. Yah, they can take up some space but if done properly, they'll give you the most realistic bass(midrange too) and won't require much power.

My second choice would be sealed. You still get good clean sound with plenty of extension and weight to the music but you'll need more power to drive them. No problem, you can get that from good plate amps like those available from Rythmik Audio. They're reasonably priced, give you tons of flexibility and are, in my opinion, the best plate amps available.

Other than a few REL's, like the old Stadium or Stentor, I hate ported bass. To my ears, it always sounds flabby and ill-defined. Solid state current will tighten things up a bit but you never get realistic pitch or tone. I know, many will disagree but if you haven't heard bass done right, you don't know what you're talking about.

01-04-13: Mapman, I used to religiously use ported subs as well and for a long time couldn't be talked out of it. Then I was shown an extremely large transmission line system and liked that even better. But as far as performance in a variety of situations, I found, that a properly built passive radiator system had deeper extension and smoother response.

I kept going back to a ported setup though simply for it's ease of use and design. I also don't run my sub amps down to 1 ohm or any thing like that. I use three Audio Source 200 watt amps for the subs. They are bridged down to mono but never see less than 4 ohms worth of a load on any one of them, they usually stay at 8 Ohms bridged. So even though the amps aren't any thing special, they do alright.

I was also under the impression that giving the largest ported box it's own amp would help keep them under control...... is that right???

In any case, thanks for the comments, I hadn't given much thought about actually building/using a transmission line box yet. And I've got plenty of space.......
Andrew

01-04-13: Jafant, Of course I'd have to agree with that, however it's the time and energy I'm a bit short on. I'd have to build up with some more prototypes before I could fully integrate them into my system, I am looking toward changing my system around again one day soon.
Andrew

01-04-13: Rlwainwright, I would most certainly agree with you if, we were referring to say, my living room. I usually try to follow the K.I.S.S. (keep it simple, stupid) philosophy, however in this case we are talking about what is in my sound room. Which I built specifically to explore some extreme setups.
Andrew

01-05-13: Geoffkait, Yes of course I have heard of wave cancellation. If you re-read my post you'll see that I have split up my subs into frequency specific "task masters" if you will. I also use a Pioneer Elite SC-61 that comes with a mic and tunes itself, adjusting for Standing Waves, Phase Control, Speaker distance from listener, and so on. I also keep all my sub boxes up front and on the same plane as the L/C/R channels.

01-05-13: Rfogel8, Again I agree that Transmission line subs are performers...... and that sealed boxes can do well also.

It is perhaps my fault I didn't make my question(s) clear enough.

Does the simple concept of using task specific subs & woofers, split among the frequency ranges like mids & highs, in order to handle specific areas of low end frequencies, have it's advantages?

And more specifically, I am wondering if combining the best setups into "Frequency or task specific" groups can be beneficial? As far as I can tell it is, but my setup is huge and made up of a lot of left overs. So......has anyone else done this before? With what kind of results?

I feel like I've finally got a system that never says no, regardless of my constant poking and prodding. It has the authority of a hard hitting car stereo and the best clarity I can afford.

A passive radiator is the same as a port, but it can just be tuned by the mass of the radiator verses a HUGE column of air or a port so small it would chuff. BOTH systems will show the maximum port velocity or passive radiator excursion when the active driver moves the least. This is the theory of the critical damping frequency system. The active driver hands off more and more of the work to the port or passive radiator the lower you go. That's good as it minimizes cone excursions at the very low-end improving disortion numbers. It's bad in that the port / radiator can take control of the active driver as it has a lot of acoustic leverage on the active driver the lower you go. New driver integration and suspension allow much better control than past systems (ever hear a JBL L36?).

Ports are tough to do well, because they have two resonance design frequencies, though. One is high enough to give the classic mid bass "hump" many ported speakers are noted for. Air suspension has one resonance hump to manage but needs LOTS of cone excursion to go deep, or BIG woofer area, or both. CAD has allowed a HUGE improvement in ported speakers such that sealed enclosures are almost a lost art. Amazing what a few decades do to design.

Still, each has pluses and minuses. I don't really have room for HUGE ported subs or do home theater so that I need infinitely loud explosions. How loud is too loud on a movie sound track? If the blast didn't turn your guts into paste, it wasn't realistic enough. Music doesn't need to do that, it's enjoyable. Dying standing beside a bomb isn't.

There is a lot of good info on the web on speaker design and when you read about the complexity of ported speaker design, you think, "no way!" Well, amazingly, there is a way today. But, ported or passive radiator cabinet volume is bigger all things being the same (low-end frequency reach). Physics can't be denied just used to perfection in modern ported or passive radiator speakers.