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Quarter Wave / T-Line tutorial-UPDATED


Forevrbumpn

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Fun with t-lines... :)

well, there's no sub I guess.. but yeah

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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After reading this thread for 3 days I think I got it! How am I looking?

2 12" woofers, 30Hz tuning

1130 / 30 = 37.66

37.66 / 4 = 9.41'

9.41' X 12" = 112.92" round up to 113"

SD = 150

internal port dimensions 15.75" X 9.5" = 149.625"

I am needing a 15.75" X 9.5" port that is 113" long right?

I can make the line it any way i want as long as i keep the internal port dimensions constant correct?

The port length goes from wall next to subs to port opening right?

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9.41 feet long (~113"), not 150"

Also two twelves have an SD of about 226", well 200 ish if you measure it from center to 1/2 of surround is more correct.

So your port would be 12.7x15.75 (=~200) and 113" long.

Port length is from center rear of sub to end.

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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Thanks! now can anyone show me how to draw 45 degree angles on sketch up i cant figure it out.

box-1.jpg

just measure a distance from the corners in each direction to a length determined by you. you can then simply use the push/pull tool and lift it up.

If you dont want them to look solid, then simply do the same as above again but with shorter lines, then pull up what you will have which will essentially look like a strip of wood. I can do some quick tutorial pics if you need or cant find anything on youtube. there are a lot of tutorials about sketch up

PSN: Rcp_soundz

Good rule of thump is go by what fuse size is being used in these amps. The higher the more amperage it pulls, this is what I look at.

I'll stick a 300 amp fuse in a potato and sell it to you for $2k.

1991 Mazda 323VERY small build thread here: http://www.stevemead...23-small-build/

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Also two twelves have an SD of about 226", well 200 ish if you measure it from center to 1/2 of surround is more correct.

Should I go by the average or the specs from the site?

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pull out a tape measure or ruler if you want the "correct" measurement.

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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I'm only asking questions because I don't know the answers to them.

why do the manufacturer put incorrect specs on a sub?

You obv know what you are talking about and I am going with your suggestions but 200 to 150 is a big jump

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200 to 150? Depending on manufacturer each 12 will be roughly 100-110 square inches each. You combine the drivers to get your SD figure to create the internal width and height measurement.

Read this, but realize the measurements in this guide are based on outer rim measurements and not center to 1/2 surround: http://www.stevemeadedesigns.com/board/topic/6819-cone-area-of-a-subwoofer/

Manufacturers give you measurements that "work" for the sub. They are not often perfect and when you want to build an enclosure that is "correct" you need to do some actual math. Its not something they are doing with intent to give incorrect information, but rather they can only give so much information before they start writing books...

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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