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Port ratio and port area questions


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I know it's been asked before but let's pretend I'm dumb ( prolly ain't hard ).  Between Torres and triticums port calculator I am questioning some numbers . The port calculator says I need 83sqin port ( 4 hds2.108 on 3k, giving them almost .75 each ) closest I can get with my space ( 53wx16hx13d) is 65sqin @ 34.7hz. port ratio is 1:2.6 ( no clue if that's good or not honestly) . Long story short that's a MASSIVE port! 13x5@44" long! This is my first attempt at a Hugh power small box and it's driving me nuts trying to crunch number to get this pretty close to right the first time. Only have 2 sheets  of mdf (one 3/4 and one 1/2, which I'm gonna use for port to reduce displacement) and where I'm at it's almost $60 a sheet. 

Am I in the ballpark if a decent sounding setup or am I gonna get a bunk ass box out of this? This is a "semi-temporary" box because my ultimate goal is to put these under my rear seat but I gotta have a box to use between my trying to find the optimal box under the seat.

Anyone else's designs are welcome. I have access to 8" sonotube also if that's a better choice for a port. 

2009 Silverado 1500, 7.5" lift, 37x12.50r17s, Built Gen 4 5.3L ( 4.8l flat pistons, decked 243s, SS2 Cam, Pac 1218 springs, ported intake, 120mm TB, Long tubes, 3" duals HP tuner software tuned by me), 4l80e swapped and 4.56 gears. All done by me. stereo is Pioneer avh 600ex, all stinger rca, jp23 v1.5, skar rp150.4, and hertz hpd4. 2 SHCA 6.5 8ohm, 1 SHCA 3.5", and 1 DS18 tw120pro in each door. The 3.5 mid and 3.5" tweeters are powered by the skar rp150.4, the 6.5s are powered by the hertz bridged @4 ohms. Dual runs   of 3/0 welding cable, 300a alternator, 2 Vmax AGMs up front. current sub is a AB XR 12 ( dual 2 ohm) with bottom spider cut out in 2.25 cubes at 32hz

 

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I don't agree with triticums port calculator. He's very helpful and knowledgeable and I don't discount his experience 1iota but... I build 2-3 boxes a week and my boxes always perform. I use Torres and I keep spot ports at or under 18in per ft³ ( usually 15-17) regardless of people saying that rule of thumb isn't good. It's ALWAYS WORKED FOR ME. We use term lab and SSD meters and I know what my enclosures do and numbers don't lie. They never disappoint. I keep port ratio under 1:8 (usually around 1:2-1:6 if possible). Rules of thumb are generally guidelines but they didn't find their way into common practice for nothing. I keep specs around MFG recommendations. I go slightly larger on Port area for some and slightly smaller on others depending on what type of tuning I'm looking for. Smaller makes tuning lower easier without having a port a half mile long ( total exaggeration). Just food for thought. If you are running 10 inch drivers you don't need anywhere near 80 in of Port area. Jmo

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Triticum has done lots of testing, don’t be afraid to trust his calculator. I know of just a couple other people I trust equally to him when it comes to enclosures.

I would ask him if what you want to do will work, his calculator is not the one single option. What you want to do might still work.

 

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1 hour ago, DiBo said:

I don't agree with triticums port calculator. He's very helpful and knowledgeable and I don't discount his experience 1iota but... I build 2-3 boxes a week and my boxes always perform. I use Torres and I keep spot ports at or under 18in per ft³ ( usually 15-17) regardless of people saying that rule of thumb isn't good. It's ALWAYS WORKED FOR ME. We use term lab and SSD meters and I know what my enclosures do and numbers don't lie. They never disappoint. I keep port ratio under 1:8 (usually around 1:2-1:6 if possible). Rules of thumb are generally guidelines but they didn't find their way into common practice for nothing. I keep specs around MFG recommendations. I go slightly larger on Port area for some and slightly smaller on others depending on what type of tuning I'm looking for. Smaller makes tuning lower easier without having a port a half mile long ( total exaggeration). Just food for thought. If you are running 10 inch drivers you don't need anywhere near 80 in of Port area. Jmo

I'm using 4 8"s , I've built probably hundreds of enclosures in my lifetime , most of which were back in early 90s and sealed. Build a few dozen slot ports but usually for bigger woofers where as these small box/high power combos are new to me and just make everything I have learned ( wether right or wrong) come into question.  I guess only way to find out is build it and see what it does , worse case I reface it and use it for different woofers right?

2009 Silverado 1500, 7.5" lift, 37x12.50r17s, Built Gen 4 5.3L ( 4.8l flat pistons, decked 243s, SS2 Cam, Pac 1218 springs, ported intake, 120mm TB, Long tubes, 3" duals HP tuner software tuned by me), 4l80e swapped and 4.56 gears. All done by me. stereo is Pioneer avh 600ex, all stinger rca, jp23 v1.5, skar rp150.4, and hertz hpd4. 2 SHCA 6.5 8ohm, 1 SHCA 3.5", and 1 DS18 tw120pro in each door. The 3.5 mid and 3.5" tweeters are powered by the skar rp150.4, the 6.5s are powered by the hertz bridged @4 ohms. Dual runs   of 3/0 welding cable, 300a alternator, 2 Vmax AGMs up front. current sub is a AB XR 12 ( dual 2 ohm) with bottom spider cut out in 2.25 cubes at 32hz

 

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41 minutes ago, ehall8702 said:

I'm using 4 8"s , I've built probably hundreds of enclosures in my lifetime , most of which were back in early 90s and sealed. Build a few dozen slot ports but usually for bigger woofers where as these small box/high power combos are new to me and just make everything I have learned ( wether right or wrong) come into question.  I guess only way to find out is build it and see what it does , worse case I reface it and use it for different woofers right?

I don't know why TF I thought 2-10's... Lol. 4-8's is a different story. You're using the heavy duty street soundqubed drivers?

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Yeah got 4 of em on the way I'll have em in a day or two. Eventually I want to fit them under the back seat of my Sierra but for now I'm just gonna build a box to put on the rear seat

2009 Silverado 1500, 7.5" lift, 37x12.50r17s, Built Gen 4 5.3L ( 4.8l flat pistons, decked 243s, SS2 Cam, Pac 1218 springs, ported intake, 120mm TB, Long tubes, 3" duals HP tuner software tuned by me), 4l80e swapped and 4.56 gears. All done by me. stereo is Pioneer avh 600ex, all stinger rca, jp23 v1.5, skar rp150.4, and hertz hpd4. 2 SHCA 6.5 8ohm, 1 SHCA 3.5", and 1 DS18 tw120pro in each door. The 3.5 mid and 3.5" tweeters are powered by the skar rp150.4, the 6.5s are powered by the hertz bridged @4 ohms. Dual runs   of 3/0 welding cable, 300a alternator, 2 Vmax AGMs up front. current sub is a AB XR 12 ( dual 2 ohm) with bottom spider cut out in 2.25 cubes at 32hz

 

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want a "high power, small box" to build, that's what most of my customers want. you're going to need to do it like I build them. decrease the port area to increase the port velocity. Tune low, like 28 or 30hz. get the velocity between 25-28m/s. you'll have a drastically smaller port with really good output and bandwidth.

if nothing changes, nothing changes

You don't know what you don't know, till you don't know

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2 minutes ago, mothra said:

want a "high power, small box" to build, that's what most of my customers want. you're going to need to do it like I build them. decrease the port area to increase the port velocity. Tune low, like 28 or 30hz. get the velocity between 25-28m/s. you'll have a drastically smaller port with really good output and bandwidth.

This is what I usually do. I don't make the port that small but I do make it a tad smaller than recommended sometimes. For instance I just made an enclosure for 2 zv5 18's with 200 in of Port area. They called for 224

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13 minutes ago, mothra said:

want a "high power, small box" to build, that's what most of my customers want. you're going to need to do it like I build them. decrease the port area to increase the port velocity. Tune low, like 28 or 30hz. get the velocity between 25-28m/s. you'll have a drastically smaller port with really good output and bandwidth.

What are you using to get port velocity numbers? I have Torres but have not really messed with winisd . And basically you are saying smaller port tuned lower will give me better output than a bigger port tuned at 34hz?

2009 Silverado 1500, 7.5" lift, 37x12.50r17s, Built Gen 4 5.3L ( 4.8l flat pistons, decked 243s, SS2 Cam, Pac 1218 springs, ported intake, 120mm TB, Long tubes, 3" duals HP tuner software tuned by me), 4l80e swapped and 4.56 gears. All done by me. stereo is Pioneer avh 600ex, all stinger rca, jp23 v1.5, skar rp150.4, and hertz hpd4. 2 SHCA 6.5 8ohm, 1 SHCA 3.5", and 1 DS18 tw120pro in each door. The 3.5 mid and 3.5" tweeters are powered by the skar rp150.4, the 6.5s are powered by the hertz bridged @4 ohms. Dual runs   of 3/0 welding cable, 300a alternator, 2 Vmax AGMs up front. current sub is a AB XR 12 ( dual 2 ohm) with bottom spider cut out in 2.25 cubes at 32hz

 

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14 minutes ago, ehall8702 said:

What are you using to get port velocity numbers? I have Torres but have not really messed with winisd . And basically you are saying smaller port tuned lower will give me better output than a bigger port tuned at 34hz?

I go for sound. I don't build for numbers. I should've clarified that. Four numbers I Tune higher. In that case I make the port larger and shorter. For sound I usually make the port recommended +/- 10% or so and longer. I like to peak around 32-36hz if possible. Obviously vehicle resonant frequency is going to vary from vehicle to vehicle. You will get more output with a larger port but you won't get any lows. With those 8's I'd tune around 35 and I'd go with about 18in² of Port area for 72in² total. Length will determine tuning. Triticum calculator wasn't far off in my opinion for those 8's. And when I say off I mean off in terms of my preferences. So I stand corrected about my first statement. Honest mistake

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