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JBL 4645
03-10-2010, 09:19 AM
I’m wondering would this idea work or have some trail and error difficulties?

The idea is to use box loaded with sub, and tube port extending around the room with the tube going vertical upwards then bending around going along the front of the room then bending around and travelling along the length of the room and once again bending around along the rear wall.

The rear part will have open cuttings to allow airflow out.

Now would this be tight flabby :barf: unsuccessful :dont-know or an epic hit?:D

If port low notes are reproduced from the openings would this not create an even low pitched frequency within several low pitched notes?

Just curious to know what you think?

Cheers:)

Ruediger
03-10-2010, 09:27 AM
I’m wondering would this idea work or have some trail and error difficulties?

The idea is to use box loaded with sub, and tube port extending around the room with the tube going vertical upwards then bending around going along the front of the room then bending around and travelling along the length of the room and once again bending around along the rear wall.

The rear part will have open cuttings to allow airflow out.

Now would this be tight flabby :barf: unsuccessful :dont-know or an epic hit?:D

If port low notes are reproduced from the openings would this not create an even low pitched frequency within several low pitched notes?

Just curious to know what you think?

Cheers:)

The air in the tube shall behave like a mass. That requires the tube to be small compared to the relevant wavelengths, l < lambda/12.

The sketched configuration would behave like a transmission line coupled to a box, a resonating something.

Ruediger

loach71
03-10-2010, 09:43 AM
Adrian -- if you want to build something like this try the Basset. It is a huge coffin-like enclosure that appeared in a U. K. audio magazine in the 1960s.

tim

JBL 4645
03-10-2010, 09:54 AM
Okay so the, idea will kinder work.


Adrian -- if you want to build something like this try the Basset. It is a huge coffin-like enclosure that appeared in a U. K. audio magazine in the 1960s.

tim

hmm creatures of the night huh.:D

I’ll have look around for something made around 1960’s wow the 60’s man.:p

loach71
03-12-2010, 09:54 AM
Okay so the, idea will kinder work.



hmm creatures of the night huh.:D

I’ll have look around for something made around 1960’s wow the 60’s man.:p

Hey --- I built one in the late 1960s.
I used two KEF B139 woofers in it.
The box is about 7 feet long by 2 feet square.
When placed on its side it is a good seat -- hence the name Bass -- seat..
Thoroughly dry British humour...heh heh heh:hate-pc:

JBL 4645
03-12-2010, 12:47 PM
Hey --- I built one in the late 1960s.
I used two KEF B139 woofers in it.
The box is about 7 feet long by 2 feet square.
When placed on its side it is a good seat -- hence the name Bass -- seat..
Thoroughly dry British humour...heh heh heh:hate-pc:

I like that. That’s not a bad idea sub bass seat. :D

Only downer is when you stand up you don’t notice as much.

So the only way is to rise a sub flooring over the existing floor and make the depth handle the depth of a, 12” 15” or 18” mounted in the flooring placed around the back wall and each sidewall and front wall spaced apart evenly.

Balance the frequency out over comfortable SPL db so it doesn’t curse structural damage or damage you’re hearing. This should vibrate the floor kinder like sitting on bus where you feel vibrations in your feet legs, as well as vibrations travelling up the seat itself!


One thing I’ve come to notice is the solid floors are good so you minimize vibrations buzzing sounds as the lows under different SPL db excite different parts of the uneven wooden floor that might need screwing tightening up a bit.

Most lows below 40Hz tend to have uniform frequency coverage over the seating area and beyond it, well (slightly) until it drops off on the SPL db or RTA display.

Lows above or starting around 50Hz tend to wonder all over the place with uneven non-uniform frequency coverage. This is the reason why we need so many subs to tackle the issue.

I know the upper lows around 50Hz don’t really tend to push a lot of air out the ports it seems its coming mostly from the sub bass driver itself.

Unless you can filter off the lower end of the with steep crossover filter then bump-up the output within the 50Hz to 80Hz or what ever?

The box I have in mind is keep the sub housed within sealed with only the port to allow the frequencies to pass though it.

The box may have to be so thick with MDF to muffle the loud sound pressure within it down to what ever SPL db from the outside?

Would the tones within a 50Hz to 80Hz region be even out of each port hole that is laid out at the back or would it be random levels of frequency or close enough?

Its when you hear tone say at 70Hz and its peaking more on one side of you’re head say right ear and less in-between and even on the left ear...until you move to the other side of the sofa or seat the frequency starts to balance out more evenly on both ears.