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My first transmission line - 2008 Subaru WRX STI


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I like to work on my system every year when I go home to my family's house for the holidays. It's a great way to bond with my dad and younger brother and I get to use all the tools and space I don't have living in a big city. Last year I picked up a Sundown SD-2 10" so I could have bass for the first time in 7-8 years. With my dad and brother's help we built a fiberglass box to wrap around the rear wheel well. I loved that box for a year but it was time to try something different. I'm a huge nerd so I've been doing tons of research about transmission line theory and decided to give one a shot. So let's get started:

Woofer: Sundown SD-2 10" D4

Fs: 39.7 Hz (new, lowers a bit after break in)
Re: 8.0 ohms
Qms: 5.45
Qes: 0.56
Qts: 0.52
Cms: 0.09 mm/N
Mms: 178 g
BL: 24.7 NA
Vas: 13.8 L
Sens: 83.5 1w/1m
Le: 4.06 mH
RMS: 500 watts

Depending on what you read, this may or may not be a great woofer for a transmission line, but it's what I have so why not give it a shot. I started by reading up on Forevrbumpn's amazing Quarter Wave / T-line Tutorial (http://www.stevemeadedesigns.com/board/topic/1828-quarter-wave-t-line-tutorial-updated/) and got a pretty good idea of the basics of transmission lines (it's really not that complicated!). After that I nerded out and read everything I could find about transmission lines, well beyond the scope of what I actually needed. I found a pretty cool little transmission line modeling software from Leonard Audio I(http://www.leonardaudio.co.uk/software/publish.htm), it's kinda like a WinISD for Transmission lines. The version of WinISD I'm using also has an option to "Use 'transmission line' -model for port simulation" which matched up pretty nicely with the Leonard Audio program. After sufficiently nerding out I decided on a line length of 84" for an approximate tuning of ~38hz (near the woofer fs after break in). Is wanted to keep a lot of cargo space, so I decided to got with a quasi-floor sort of design. My "port" is 9in wide and 6in tall, for an overall box height of 7.5 in which takes up most of the cargo area. So lets get started with the pics:

Test fitting the "floor" piece which will form the bottom of the box. You can see the fiberglass box I made last year on the left.

ZSXgCjD.jpg

A little mockup of the line

hMLJlii.jpg

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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My pics are huge, so breaking this up so I don't lose anything.

I blow glass for fun, so I make my mom a christmas ornament every year:

bsySsik.jpg

I primarily make pipes, you can see some of my stuff at www.facebook.com/holymountainglass. I love custom orders and weird themes, especially stuff based on albums.

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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Back to the build:

Front, back, and sides glued and clamped

hr8shHw.jpg

Line pieces glued and clamped

cxVk49H.jpg

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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I fucking love STI hatches.. These and hawkeyes. Theres absolutely NO doubt that I'll be following this build.

On 5/8/2011 at 7:38 PM, Kranny said:
On 5/8/2011 at 7:35 PM, 'Maxim' said:

It hurts me inside when I read stuff like this and remember you're 15

LMFAO so true

:blush:

Mitsubishi 3000GT (Old Build)

Headunit: Pioneer 80PRS

Frontstage: (2) McLaren Audio MLT-2 Tweeters & (4) PRV Audio MR Series Neo 6.5" Mids

Substage: 4 15" Hybrid Subs - Tantric Motors & Sundown Softies

Amps: Banda 2.4D Amp (Tweets), American Bass VFL 350.4 (Mids), and (2) Ampere 3800s

Electrical :Singer 260A Alt & JY Power Lithium

 

2005 Chevy Colorado Ext Cab

Headunit: Pioneer 80PRS

Frontstage: 4 PRV 700Ti Tweets & 6 10" Delta Mids on 3000wrms

Substage: 6 Fi BTL 18s in a 4th Order Walkthrough on 3 Wolfram 4500s

Electrical: Singer "390" and JY Power

My Official Feedback Thread

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Here's where it gets a little complicated.

Mocking up woofer mounting

ZxbHQQB.jpg

As you can see, the line width is 9", the mounting hole on the woofer is 9 1/4", and the outer diameter is 10 1/2". The woofer fit tightly between the side and first line divider, giving me 3 solid mounting holes on the box side, front, and first line piece. Right by my foot you can see what I used for the rest of the mouting, I created an inner baffle/mouting piece that I secured to the sides of the box. I was a little worried about this at first,so I also glued it to the top baffle and it is very solid.

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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I fucking love STI hatches.. These and hawkeyes. Theres absolutely NO doubt that I'll be following this build.

Thanks man, I really love this car. The amount of space the hatch gives you is pretty impressive. I've moved couches, desks, TVs, and can even fit my bikes in the back fully assembled. I went with a floor style box so I could just throw shit on top of the box and not lose much space.

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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This was my first box build in a while so my cuts weren't quite perfect, used a little bit of weight to make sure the baffle glued tightly

jPCagI3.jpg

My cat wanted to help out

S09GBhx.jpg

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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I was running out of time, so I blasted a small cube heater through the port overnight. The sound and airflow coming out were pretty impressive. This is when I knew this thing was going to be loud! I had to leave early the next morning to drive back to Boston (~1000 miles in 16hrs, just me and the cat), so I didn't have time to wire it up and wanted to let the glue cure some more anyway, so the box made it in the car but I left it empty for the drive.

The next day I wired it up

QzeTM8F.jpg

Here you can better see the nice birch veneer plywood I used. I put a 1/2" roundover on the edges, but I didn't want to mess up the thin alreas near the woofer hole, so I left that alone for now.

cSs71oz.jpg

Mounted and wired.

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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Here's a closer shot

mOFVFYW.jpg

This is where I'm at right now. I plan on carefully finishing the roundovers, then staining the birch a darker color. Then I want to build a grill for the woofer and port and cover them with a vintage speaker cloth, like on old guitar amps and radios.

This box absolutely slams compared to the small sealed box I had before. On only 400W it makes my rear-view flap and rattle like crazy. The range is pretty good too, I can go down to about 30hz with pretty good authority and it can definitely get up to at least 80-100hz.

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

Link to comment
Share on other sites

For christmas I got myself a 3sixty.2 from a guy on car audio classified that I'm going to use to set subsonic and low-pass on the sub, as well as all the fancy stuff for my highs/mids. I'm just waiting on a "warm" day to wire it all up.

2008 Subaru WRX STI

K&N Typhoon Intake

Invidia Polished Stainless 3" turbo back with cat

Cobb Accessport

Dyno tune from Kaizen Tuning

320awhp 330ft-lb awtq

MTX 421D Sub amp

American Bass SQ900 Highs/Mids amp

Sundown Audio SD-2 10 D4

JL Audio XR653-CS 3-way Components

3sixty.2

Second Skin Damplifier Pro

Custom fiberglass wheel well enclosure

Transmission Line quasi-floor enclosure

http://www.stevemeadedesigns.com/board/forum/13-member-rides-builds-show-off-your-whip-show-off-your-system/

Bill Fitzmaurice TLAH line-array hifi towers

9 Goldwood 4" mids (each)

12 Goldwood 1/2" tweeters (each)

NAD 1020 Preamp

MiniDSP 2x4 Balanced processor

Thorens TD166mkII Turntable

Hafler DH-200 Amplifier

http://www.stevemeadedesigns.com/board/topic/192638-line-array-hifi-tower-build/

https://www.facebook.com/HolyMountainGlass

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