Are walls always louder?

[shredder2]

Just narrowing the port will lower tuning I believe... that 90in2 of port I advised is 15" long... whats the port displacement now?... about 3.5ft3?.. just curious

 

[KilluminatiDre 10+ year member]

I cant remember, i threw all the measurements out weeks ago lol if it does lower tuning some i really dont mind. 32-35 is good for me. I didnt think narrowing the port would change tuning if the length of the port stays the same and the internal volume stays the same. The port has one bend in it thats 5.5", ill leave that bend how it is and just narrow the long portion of the port leaving the overall port length the same with just less port area. If i add thickness to that 5.5" bend to make it more narrow it would make the port longer at the same time. Internally the port opening will be the same and it will narrow down at the bend and have the same amount of area as it exits. I figure i might as well experiment since i can easily add and remove those pieces.

 

[KilluminatiDre 10+ year member]

I mentioned what i was thinking to one of my buddies whos been building boxes for awhile and he said i should be able to play around with the port area and also meter with different thickness and see where i get my best results at.

 

[Jski1990]

180 in2 of port area with 2 IDMAX 15's in a 8ft3 net box... wow

14,000 watts of signal to get it to 27 m/s?... That's a much too large port...

And it looks like you'll need 17K to get there... 14K

What is the m/s measuring and why is 27 the number you were trying to get? Sorry,I’m just starting to mess with winisd so I don’t know.

 

[hispls 5,000+ posts]

If any port is fine stick a single 8" with 180" of port...It will act like a infinite baffle that hasn't been sealed off and it will not get loud

It will also reach mechanical limits much faster than building a proper sized box and port

there is such thing as too much port

All of your statements are false. You do not understand what a port does and how it works and you do not understand what an infinite baffle is either. Please read that white paper I posted.

The only reason you couldn't have an 8" woofer with 180 square inches of port is that in the proper airspace for an 8" driver 180" of port area would not have enough depth to function properly.

 

[Jeffdachef 5,000+ posts]

I cant remember, i threw all the measurements out weeks ago lol if it does lower tuning some i really dont mind. 32-35 is good for me. I didnt think narrowing the port would change tuning if the length of the port stays the same and the internal volume stays the same. The port has one bend in it thats 5.5", ill leave that bend how it is and just narrow the long portion of the port leaving the overall port length the same with just less port area. If i add thickness to that 5.5" bend to make it more narrow it would make the port longer at the same time. Internally the port opening will be the same and it will narrow down at the bend and have the same amount of area as it exits. I figure i might as well experiment since i can easily add and remove those pieces.

less port area 100% lows the tuning if you keep the length the same. I'd highly recommend downloading torres box calculator (download link is on steve meade's forum from google searching) and playing around with numbers so you actually know what is what...

 

[Jeffdachef 5,000+ posts]

All of your statements are false. You do not understand what a port does and how it works and you do not understand what an infinite baffle is either. Please read that white paper I posted.
The only reason you couldn't have an 8" woofer with 180 square inches of port is that in the proper airspace for an 8" driver 180" of port area would not have enough depth to function properly.

Then in normal common sense terms, Its not doable. Plain and simple. Its better to keep noobs on the path with least margin of error compared to a more advanced path that they have no proper understanding of. Plus what you are saying would literally be a small 8 inch box with a giant external port which is more than likely a burp box if anything.

 

[shredder2]

What is the m/s measuring and why is 27 the number you were trying to get? Sorry,I’m just starting to mess with winisd so I don’t know.

Its rear port velocity... under 30 m/s is desirable to avoid port compression with a slot... rounds are higher and aeros are even higher.

 

[KilluminatiDre 10+ year member]

It's like people don't even understand how a port works.
http://jahonen.kapsi.fi/Audio/Papers/AES_PortPaper.pdf

Try reading what actual engineers who know what they're talking about have to say on the subject if you want to understand ports.

180"^2 port is probably overkill but it's not going to do any of the things these people say unless something is wrong with how you laid it out. If a port needed to have a minimum airspeed velocity in it they wouldn't work at low power which is simply not true.

Ill definitely be reading this. thanks

 

[KilluminatiDre 10+ year member]

ok so i have enough spare wood around the house to combine 3 pieces of 5/8 mdf which would narrow the port by 1.875, ill start there and see how it goes then if needed i have a spare piece of 3/4 which will narrow it by 2.625. if my tuning goes down ill be fine anywhere between 28-35hz. even if the port area is still slightly big it wont be as big as before.

my first box was 32hz with 128 sq in of port area and i was able to do 146 on music with 2 soundqubed hds315s on 2100rms and pretty much stock electrical. it was almost enough for me daily. just want alittle more output than that had. ill have twice the power, much better subs, and a good electrical this time around so ill see how it works out.

 

[shredder2]

ok so i have enough spare wood around the house to combine 3 pieces of 5/8 mdf which would narrow the port by 1.875, ill start there and see how it goes then if needed i have a spare piece of 3/4 which will narrow it by 2.625. if my tuning goes down ill be fine anywhere between 28-35hz. even if the port area is still slightly big it wont be as big as before.
my first box was 32hz with 128 sq in of port area and i was able to do 146 on music with 2 soundqubed hds315s on 2100rms and pretty much stock electrical. it was almost enough for me daily. just want alittle more output than that had. ill have twice the power, much better subs, and a good electrical this time around so ill see how it works out.

You do understand box rise don't you?.. if that 2100 rms you stated was an amp tested at a certain load... it's gonna be quite a bit less when driving a speaker in an enclosure... box size and other factors will affect it quite a bit... I wouldn't be surprised if that "2100 rms" was actually around 1500 or less... just sayin'

 

[KilluminatiDre 10+ year member]

You do understand box rise don't you?.. if that 2100 rms you stated was an amp tested at a certain load... it's gonna be quite a bit less when driving a speaker in an enclosure... box size and other factors will affect it quite a bit... I wouldn't be surprised if that "2100 rms" was actually around 1500 or less... just sayin'

yep, been doing alot of reading on box rise. thats why im going with the 4k to have more than enough. i was going to get the orion xtr2500 which has dynod at 2900 @ 1 ohm i think. my buddy suggested i wire it to .5 to compensate for box rise but i dont feel comfortable with .5 on a daily box so im just gonna get the 4k and a beefy electrical.

and im sure that would explain why i never got voltage drop with a 160a alternator, probably didnt see anything near 2100 lol

at first i had the hifonics brx2400 then i "upgraded" to the sounbdqubed 2200 then years later after selling everything i found out they both have the exact same board which would explain why it never got louder after the "upgrade"

 

[Jeffdachef 5,000+ posts]

ok so i have enough spare wood around the house to combine 3 pieces of 5/8 mdf which would narrow the port by 1.875, ill start there and see how it goes then if needed i have a spare piece of 3/4 which will narrow it by 2.625. if my tuning goes down ill be fine anywhere between 28-35hz. even if the port area is still slightly big it wont be as big as before.
my first box was 32hz with 128 sq in of port area and i was able to do 146 on music with 2 soundqubed hds315s on 2100rms and pretty much stock electrical. it was almost enough for me daily. just want alittle more output than that had. ill have twice the power, much better subs, and a good electrical this time around so ill see how it works out.

For efficiency sake, When you cut the port area, you want it to make it more like a square rather than a long rectangle. A square port is always better than a long skinny port.

yep, been doing alot of reading on box rise. thats why im going with the 4k to have more than enough. i was going to get the orion xtr2500 which has dynod at 2900 @ 1 ohm i think. my buddy suggested i wire it to .5 to compensate for box rise but i dont feel comfortable with .5 on a daily box so im just gonna get the 4k and a beefy electrical.
and im sure that would explain why i never got voltage drop with a 160a alternator, probably didnt see anything near 2100 lol

at first i had the hifonics brx2400 then i "upgraded" to the sounbdqubed 2200 then years later after selling everything i found out they both have the exact same board which would explain why it never got louder after the "upgrade"

brz 2400 is the same board. BRX is a cheap chinese board, definitely not the same.

 

[KilluminatiDre 10+ year member]

Yea brz is what i had then. Its been awhile, i get those mixed up. I just always remembered it had a korean board. This was 2014 lol

I see what you mean. It will take alot to make this port skinny. Its 9.25" wide now. Even using all of the spare wood i have it would still be over 6.5"

 

[Cassix]

I have my daily drivers wired down to .05 ohm and i havent regretted a second of it.

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