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View Full Version : Big port vs. Small port?



18lexusowner
05-20-2009, 11:21 AM
Which would be better for SPL?
The sub is in my sig.

The recommended is 20sqin and 15" deep. But I was big SPL outta this sub. (window flexing stuff)

What kind of port would be best for that? Also, big enclosure with a big port?

LGK
05-20-2009, 11:23 AM
why do you have a picture of a jag in your signature mr lexus ?

BASSINMYSUBS
05-20-2009, 11:25 AM
Which would be better for SPL?
The sub is in my sig.

The recommended is 20sqin and 15" deep. But I was big SPL outta this sub. (window flexing stuff)

What kind of port would be best for that? Also, big enclosure with a big port?

i say tune around 30-32 hz in about 4 cubes

mazdakid
05-20-2009, 12:52 PM
i say tune around 30-32 hz in about 4 cubes

Why would you tune so low for spl? You should probably have more than 20" of port area for that sub.

18lexusowner
05-20-2009, 02:46 PM
why do you have a picture of a jag in your signature mr lexus ?

Because I'm not too great with pic editing and that was the best looking luxury sig i could find. And I know that its a jag, not a lexus :/

18lexusowner
05-20-2009, 02:46 PM
High frequency is window shaking spl?

I thought it'd be the other way around

93dakota
05-20-2009, 03:55 PM
Go with a low tuning if you want a lot of flex. as for port a bigger port to a point will give you better SPl but it does have its draw backs. If i were you i would use about 16-18 inches squared per of port per 1 cubic ft of net box volume.

DNick454
05-20-2009, 05:01 PM
Which would be better for SPL?
The sub is in my sig.

The recommended is 20sqin and 15" deep. But I was big SPL outta this sub. (window flexing stuff)

What kind of port would be best for that? Also, big enclosure with a big port?


Hmm this is the second instance I've noted that people who own RD subs were recommended by the manufacturer to use grossly small ports. For something along the 4 cubic foot volume with a SPL 15" woofer, I would say 50-60 sq. in of port. I don't understand why RD recommends such itty bitty ports, that's gotta choke the sub down like no other.

DNick454
05-20-2009, 05:02 PM
High frequency is window shaking spl?

I thought it'd be the other way around

Generally, tuning higher gets you more SPL, on pure loudness scale. But if you're looking to get loud in general on music and flex the hell out of your car on the lows in rap music, then yes, tune lower, around 32-35Hz.

18lexusowner
05-21-2009, 12:31 AM
I'm going low than with a large port.

Both MisterGrubbs and Steve from RD audio said that the Sonance series likes small boxes/ports for some reason. I dunno why, don't know enough about soundwaves and building enclosures to understand that. Right now my box is tuned at 32hz and it flexes my windows on 1 song, but it has a very small port and I would like more umph out of my sub.

thegreatestpenn
05-21-2009, 12:35 AM
rule of thumb is 16sq. inches of port per cubic ft iirc. remember you port to volume, not to sub size. me i slap the biggest port I can in/on and tune at either 33Hz, 35Hz, or 38Hz (38Hz for SPL)

adas
05-21-2009, 12:37 AM
Just try it! worst case your out the $25 cost of a sheet of mdf :)

DNick454
05-21-2009, 12:54 AM
Just try it! worst case your out the $25 cost of a sheet of mdf :)


That's always a good attitude to have :laugh:

Maybe you stumble upon something ground breaking:crazy:

dappa5
05-21-2009, 07:59 AM
Just try it! worst case your out the $25 cost of a sheet of mdf :)
**** right! :D
try :crap:try :crying:try:furious: try :verymad:then give up and settle for your fifth attempt :D

adas
05-21-2009, 02:52 PM
**** right! :D
try :crap:try :crying:try:furious: try :verymad:then give up and settle for your fifth attempt :Dthere you go-point is to keep the box from every try and use which one is best :laugh:

Mike465
05-21-2009, 03:01 PM
Hmm this is the second instance I've noted that people who own RD subs were recommended by the manufacturer to use grossly small ports. For something along the 4 cubic foot volume with a SPL 15" woofer, I would say 50-60 sq. in of port. I don't understand why RD recommends such itty bitty ports, that's gotta choke the sub down like no other.

If you are using a 15" Sonance then your box needs to be 3.75 cubic feet with 30 square inches of port tuned to 35Hz. Having that small of a port does not choke RD subs. Me and Steve test again and agina on enclosures for his subs. I built a box for 2 HW 15's that had only 80 square inches of port and we can do 155's in the kiack all day long.

Mike465
05-21-2009, 03:07 PM
rule of thumb is 16sq. inches of port per cubic ft iirc. remember you port to volume, not to sub size. me i slap the biggest port I can in/on and tune at either 33Hz, 35Hz, or 38Hz (38Hz for SPL)

Well if you try to have a huge port tuned to 33Hz when the sub plays that low you are going to loose controll of the cone and blow your sub. Plus, the larger the port you have you are going to have steaper and steaper roll offs above and below tuning. Yes, if you are making a burp box then it will not matter but far a daily box it will not work.

Mike465
05-21-2009, 03:10 PM
I'm going low than with a large port.

Both MisterGrubbs and Steve from RD audio said that the Sonance series likes small boxes/ports for some reason. I dunno why, don't know enough about soundwaves and building enclosures to understand that. Right now my box is tuned at 32hz and it flexes my windows on 1 song, but it has a very small port and I would like more umph out of my sub.




Build the box to 3.75 cubic feet with 30 square inches of port tuned to 35Hz. You will not be disapointed:D

DNick454
05-21-2009, 09:42 PM
Mike, you never answered my PM :p: and you're going against my "moar port = moar betta" theory. I dunno man, I'm losing faith I tell ya :rolleyes:

Lakota
05-22-2009, 12:03 AM
I normally say big port...

kush-divinity
05-24-2009, 09:42 AM
I have had decent sounding boxes with smallish ports. Like Mike said, you have a flatter response with a port on the smaller side. But you WILL lose max SPL. Nothing to care about if it is in a daily.

I'd prefer a flat box with exaggerated response around 25-40hz than a 50hz 1 note wonder fartbox anyday.