oh tee,,,, outdoor theater bass

[Phil-G]

so after going thru my "lucy pulls the football moment" with the indoor movies, I've decided to go outdoor.
after going over in my head head how I would handle the sub bass. I went and asked the kid next door how he setup his car. this thing has the lowest most powerful bass I have ever heard and can't hear. so he gives me a phone number and say's "he's got what you need."

[mah]

Small outdoors or huge car??

[Phil-G]

2015 monte carlo with who knows what in it. he might be a "pharmacist"
I just want to know how they get as much house shaking bass as they do from such a small space.
from 250' away it can make every window in my house rattle.

[Elitopus1]

"Street pharmacist" lol.

I dont know the science behind it but it is crazy how much bass you can get out of a car. When I was in high school I had a few 15" woofers with a few amps powering them in my truck. I think its a mix of the large wattage, large xmax woofers, and the car acting as sort of a bandpass box. I mean its like a speaker box within a bigger box. I know that helps the bass.

I was never this serious but I knew people who were in SPL competitions. They would do things like put dynomat all around the car and even pour concrete in the car doors so they wouldn't vibrate. There was a guy with a Escort station wagon that weighed close to 6,000 lbs because of all the gear and concrete.

I had another friend with a competiton truck. 6 15" woofers with an amp on each VC (12 amps total). This thing had such loud sound pressure it would blow stuff out the windows. It was like a bass breeze.

It seems like growing up in small town FL kids had nothing better to do than mod their cars and smoke dope. Probably like a lot of other places in the country

[bowtie427ss]

Measure them. I can almost guarantee they're not "musical" or anything remotely resembling smooth in terms of response. Generally, car subs tend to play well around the resonant frequency of the car's passenger cabin, and increasingly poorly as the frequency moves above or below that resonance.

Build a real sub, or four. A horn sub. Tapped horns. Lab horns. EAW "super sub" clones. Fitzmaurice Tuba horns. Something like that

[Phil-G]

i talked to the guy today and he suggested a folded horn. but he wanted to look at the specs on what I have first. i'll talk to him tomorrow at his shop. see what he has to say

[GM]

I just want to know how they get as much house shaking bass as they do from such a small space.

Because it's a small, rigid [well sealed] space. 'Cabin' [room] gain rises at up to 12 dB/octave below its 1st eigenmode depending on how well it can contain the increasing pressure, so the lower [or much higher] its Fs, the greater the potential gain BW.

Modern cars are much more rigid [relatively high Fs] now for a variety of performance related reasons, but still pretty low and why once its Fs is excited, the whole car acts as a radiator, creating the obnoxious high amplitude 'one note' bass that rattles windows, etc., down in the low bass BW.

Anyway, historically, 'thundering' bass in theaters, large and/or open venues had 'thundering' mid-bass with 60 Hz typically ~ -12 dB and 40 Hz -24 dB, so if 'x' woofers at 'y' power suffices at 80 Hz/channel/2 pi space where PA 'woofers' excel, then up to [128x] each is required to get to 60 Hz and twice that to get to 40 Hz and why large horn stacks with high excursion woofers capable of mega-watt power handling is required to go low outdoors. This is where tapped horns are preferred since both sides of the driver[s] are utilized over a ~two octave BW.

GM

[mah]

Subwoofer


If your outdoor theatre is for family/friends then maybe a number of 'bucket subs' near the listeners would work for the smaller area.

Limitation could be amp power required.

[GM]

Ran out of time to post........yes, multiple small subs located around the LP is ideally the way to go even with/without surround sound in HIFI//HT apps: http://www.harman.com/sites/default/...s/multsubs.pdf

GM