Post area Help

[J-MurdR]

So I build my first ported box. Everything is sounding pretty good. I built it to the manufacturers recommended volume and port area for two SKAR SVR 12 D4s on a taramps smart 3 set to 1600watts. Skar recommended 2-4 cubes. I built the box to 4 cubes Net at 34hz. The port area skar says 21.87 inches squared per sub and I doubled that for two subs coming out to 43.75 inches squared. I know alot of people say 16 inches squared per cubic foot and I'm about to build another box and dont want to leave anything on the table. Does anyone have any experience on the subs and the best port area size? Thanks

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[Bobbytwonames 5,000+ posts]

So I build my first ported box. Everything is sounding pretty good. I built it to the manufacturers recommended volume and port area for two SKAR SVR 12 D4s on a taramps smart 3 set to 1600watts. Skar recommended 2-4 cubes. I built the box to 4 cubes Net at 34hz. The port area skar says 21.87 inches squared per sub and I doubled that for two subs coming out to 43.75 inches squared. I know alot of people say 16 inches squared per cubic foot and I'm about to build another box and dont want to leave anything on the table. Does anyone have any experience on the subs and the best port area size? Thanks

Why are you limiting your amp to 1,600 watts? Do you have a bass knob with a clipping light? What amp are you running?

 

[Buck 5,000+ posts]

I've designed skar svr boxes. I rarely pay attention to recommend manufacturer port area. Port area changes depending on the goals and tuning, so I always do port area based on actual port speeds and how I want the port speed for any given situation. Lmk if you need help or a design for these subs.

 

[Bobbytwonames 5,000+ posts]

I've designed skar svr boxes. I rarely pay attention to recommend manufacturer port area. Port area changes depending on the goals and tuning, so I always do port area based on actual port speeds and how I want the port speed for any given situation. Lmk if you need help or a design for these subs.

Port speed is a fukking joke. What speed are you shooting for? 50 m.p.h. or more. Port speed would depend on the type of bass being played. This port speed talk is a joke. I've talked to multiple people about it and they laugh at me.

 

[Buck 5,000+ posts]

Port speed is a fukking joke. What speed are you shooting for? 50 m.p.h. or more. Port speed would depend on the type of bass being played. This port speed talk is a joke. I've talked to multiple people about it and they laugh at me.

Well, port speed is very important to know. I don't know what you mean by this post, but port speed is very important to know. Too high of port speed, then you can have woofer cooling issues and port noise, and too low of port speed can cause unloading issues and too narrow of a bandwidth for the overall system. Port area can affect voltage spikes in the amp, because port area can change how the subwoofer moves. Port area is an impedance/resistance factor. Of course it matters.

 

[Bobbytwonames 5,000+ posts]

Well, port speed is very important to know. I don't know what you mean by this post, but port speed is very important to know. Too high of port speed, then you can have woofer cooling issues and port noise, and too low of port speed can cause unloading issues and too narrow of a bandwidth for the overall system. Port area can affect voltage spikes in the amp, because port area can change how the subwoofer moves. Port area is an impedance/resistance factor. Of course it matters.

How do you know port speed if you don't know which song is playing and at what frequency? I can understand if you would say a range of port speed, but you make it sound like a particular m.p.h.

 

[Bobbytwonames 5,000+ posts]

Well, port speed is very important to know. I don't know what you mean by this post, but port speed is very important to know. Too high of port speed, then you can have woofer cooling issues and port noise, and too low of port speed can cause unloading issues and too narrow of a bandwidth for the overall system. Port area can affect voltage spikes in the amp, because port area can change how the subwoofer moves. Port area is an impedance/resistance factor. Of course it matters.

You said port speed not port area. Don't change the subject.

 

[Buck 5,000+ posts]

How do you know port speed if you don't know which song is playing and at what frequency? I can understand if you would say a range of port speed, but you make it sound like a particular m.p.h.

The unit is usually meters/sec or mach. I know port speeds at every frequency. There's peak port speeds at specific frequencies that you have to know, as well, usually mostly influenced by port tuning and somewhat by woofer Fs.

 

[Buck 5,000+ posts]

You said port speed not port area. Don't change the subject.

Port area is how you change port speed.....

 

[Bobbytwonames 5,000+ posts]

Well, port speed is very important to know. I don't know what you mean by this post, but port speed is very important to know. Too high of port speed, then you can have woofer cooling issues and port noise, and too low of port speed can cause unloading issues and too narrow of a bandwidth for the overall system. Port area can affect voltage spikes in the amp, because port area can change how the subwoofer moves. Port area is an impedance/resistance factor. Of course it matters.

Please tell me how you figure port speed in a 4 cube net box with a single 15" 1500 wat rms sub on a 3,000 watt amp @1 ohm on the Metallica song "Enter Sandman". 2007 Cadillac Escalade with an AGM battery and a 270 amp alternator upgrade.

 

[Bobbytwonames 5,000+ posts]

The unit is usually meters/sec or mach. I know port speeds at every frequency. There's peak port speeds at specific frequencies that you have to know, as well, usually mostly influenced by port tuning and somewhat by woofer Fs.

You can't trust Fs from the manufacturers, you know that. 40% of Fi's specs were proven wrong.

 

[Bobbytwonames 5,000+ posts]

The unit is usually meters/sec or mach. I know port speeds at every frequency. There's peak port speeds at specific frequencies that you have to know, as well, usually mostly influenced by port tuning and somewhat by woofer Fs.

BUCKO, the Fs on my 8's says 50 point something. So, should they be able to play low? Just curious.

 

[Buck 5,000+ posts]

Please tell me how you figure port speed in a 4 cube net box with a single 15" 1500 wat rms sub on a 3,000 watt amp @1 ohm on the Metallica song "Enter Sandman". 2007 Cadillac Escalade with an AGM battery and a 270 amp alternator upgrade.

It matters more what the port speed is under full RMS power into the woofer. Look man, I'm a long time designer. I design a lot of complicated enclosures. People who know how to design know how to design. Port speed matters relative to how much power the woofer has. Port area depends on how the system is being used, as well. There's a ton of factors that go into determining the best port area for any situation. That's what people pay me to figure out. Port area is very important and can really change how a woofer plays.

 

[Buck 5,000+ posts]

BUCKO, the Fs on my 8's says 50 point something. So, should they be able to play low? Just curious.

Depends on the rest of the t/s parameters. There's a lot of factors that come into how low a woofer will play. A lot of times you can tune low and make many woofers play low. Woofers with higher Fs's are going to typically want to play higher notes more so than lower notes, but it really depends on the overall woofer design and how the entire system is setup. I've made woofers with 40 hz+ Fs's play subsonic before, but those were woofers with pretty substantial xmax.

 

[Buck 5,000+ posts]

A woofer with a lower Fs is typically going to play low notes better. But, it depends on the rest of the t/s that shows how the woofer is designed. In some woofers, Fs is less relevant than other woofers.