Originally Posted by BassThatHz
I would not use the PA-460 in a bandpass box.
In fact I wouldn't use bandpass at all... they tend to have horrible sound quality.
Just stick with ported, the PA-460 can be ran up to 300hz.
Mid-bass is 50-300hz, which is the frequencies you "feel in your chest".
<30hz is for earthquake simulations, which won't be very possible on dirt or concrete (2nd-story floors made of plywood is a different story.)
99% of music and movies is >30hz. Rock/Metal/Pop/Dance/Country/Classical/Techno/Explosions/Cat Scares/etc
A 30hz ported box should be plenty...
I really feel like 40hz would be just fine. Right now I am using a pair of Elac UB5's in my family room without a sub and get a disturbing rumble from them and they only go down to 46hz.
I cannot stress enough how much I DO NOT want a sub cabinet on the patio, or under a chair, or under/as table, or under couch.
I intend to have three speakers mounted to the retaining wall and two mounted to the house.
All of them will be white (not wildly intrusive or clashing) with 6.5" drivers in sealed cabinets.
100db is cop-calling levels for most people (and 115db definitely would be....)
I cannot say I have ever spent time with a DB meter while listening to music, so I will take your word for it. I believe everyone here gets what I desire, some reasonable low end for music or movies.
That said, SPL drops 6db per doubling of distance, so you lose about ~10db in the first ~10ft, and you'd be down -16db at 20ft etc. That's why you want the subs to be as close to your seat as reasonably-possible, same for the LCR's but you must maintain some of that "big screen" sound which only happens with distance and big/efficient speakers.
Inverse square law, same applies to light; I spent years as a professional photographer.
I have been using my Elacs on the patio for movies, placing them about 12 feet away from us and slightly in front of the screen. Saturday I placed them about 20" away from the retaining wall, about 2' behind the screen, and it was much better; seemed much more integrated with film instead of just squawking at us.
A normal cinema that seats 200 people often has 10-50kW and all the speakers are big PA floorstanders, obviously that is overkill for your situation.
50k/200=250watts per viewer. If I expect no more than 6 viewers I should have a 1500 watt system, right? <-- THAT IS A JOKE
As I said before, the crawl space used to be vented, each vent was roughly 8"x10". A total of three across the addition directly at the patio.
I had two ideas prior to bandpass, maybe they were better?
1. IB manifold, as shown below, leveraging those penetrations by opening them back up. My concerns:
- if IB, how will those wave in the crawlspace affect the family room; rattle it to pieces?
- is the opening required to be equal to the radiating surface of the cone? If so, that would be very limiting.
2. I then thought about a pair of ported cabinets as a manifold. Imagine the image below with each driver in an enclosed cabinet and the ports also feeding the manifold. Concerns:
- the wall penetration, I assume having the ports and drivers feeding a manifold would really jack up the math.
As I write this I wonder if this would be reasonable.
Have two ported boxes feeding a manifold to the patio and redirecting the ports directly outside?
If I have two 12" drivers feeding a manifold, how large an opening to I need? I have ABSOLUTELY no idea.