# 93 Lexus SC400



## DATCAT (Aug 3, 2009)

Thanks to so many here at DIYMA my knowledge of quality car audio has been able to "evolve." I purchased this car about 8 months ago and installed some gear which had been in storage for a couple years. I installed a Pioneer premier 860 - Phoenix Gold Ti 475 and 400.2 (each had a burned up channel due to getting wet)- Diamond Audio up front and rear fill - 2- Kicker L5 in sealed MDF box. Some of this equipment is ok quality and defiantly an improvement over the 17 year old factory system. I didn’t take any pictures of that install. I decided to start upgrading my system a piece at a time. I purchased fully working PG Ti 475 and 600.2 swapped them out and then got 2 DIYMA R12s from a member here. I decided to build a FG box for the DIYMAs. As I am sure that many of you here understand it is exciting and a bit nerve racking when you decide to build something and document it for others (way more qualified) to view and critique. I want to improve my fabrication and installation skills so please feel free to offer any suggestions and wisdom you may have.


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## DATCAT (Aug 3, 2009)

I had originally planned to build 2 small enclosures in the trunck. However, the day before I started to build the enclosures I decided to listen to the subs up front. They sounded much better in the back seat so I decided to change plans and buil the enclosure in place of the back seat. I used blue painters tape to mask off the seat well. I wanted a straight front to the bottem of the enclosure so I kerffed a 1x3 to follow the conture of the hump. I used Pam as the release agent as suggested by several FG tutorials. I must not have used enough because the tape stuck to the enclosure. At first I was freaking out but thn I figured most of the tape came off and once installed no one will be able to see it.


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## DATCAT (Aug 3, 2009)

Fabricating speaker rings without a jig is quite a pain on the arse. Fabricating speaker rings with a jasper jig is a piece of cake provided one has the correct mesurement. I purchase a jasper jig a few months ago and bought a bosch router off Craigslist, but the jasper jig did not line up with my cheap router. Solution trip to Lowes (new tool day). Found out why ryobi router bits are so cheap. I got what I paid for. This resulted in another trip to Lowes for a quality bit.


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## deesz (Feb 1, 2010)

nice ride to be doing a build on. when putting the tape down make sure its as flat as possible. some of the reason the tape is sticking is because some of the sticky side of the tape isnt pushed down all the way then the resin goes inside then and grabs to this. keep up the good work cant wait to see the progress.


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## DATCAT (Aug 3, 2009)

I am suprised at how long it takes to create a FG sub box. I have gotten the rings postioned. Most tutorials suggested gluing small dowles to suspend the rings. I decided to use MDF which I glued and screwed to the rings and then used construction adheasive to hold them in place while I glassed them in. Due to the size of this box I wanted to help reduce the box flex. Another problem I am running into is this box is way too much air space. I used some floural foam then glassed it in to use up a good bit of air volume. Thanks to some feed back I learned how to post larger pics.


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## johnmasters (Mar 30, 2009)

I am glad I found your thread as I am in the middle of a very similar build for two DIYMAs sealed in the exact same area of my convertible and I have a few questions...

What amount of airspace are you trying to achieve?

What internal space do you estimate that you would have now WITHOUT the foam and including driver displacement?

Is your box going to be chambered. If so, are you going to run them in stereo or mono?

In what direction are you going to point the subs? 

Did you consider using a common baffle instead of two different rings for strength?

Can you explain a bit more about the difference in sound when going from the trunk to the cabin?

Were you using both diymas before or will this be the first time you've heard them both together?

Will there be any kind of seat panel covering the subs or will they be totally exposed to the cabin

-What you can do if you dont want the tape to stick is hit the tape with some spray adhesive, put on a nice coat of tin foil and then coat the tin foil in pam then NO tape and the tin peels rite off.

-I think your project would go along quicker if you use FG mat instead of cloth. Although the mat looks harder to deal with because of all of the strands, its actually easier and quicker.

-The kirfs sure are a good way to get that shape looking good.

Can wait to see your progress!


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## DATCAT (Aug 3, 2009)

Here are some better pics of how I secured the speaker rings in the FG box. I screwed and glued 2- 4" feet to the rings then used construction adhesive to glue them into position. After allowing the construction adhesive to cure for a couple days I glassed the feet in for a solid contact to the base of the enclosure. I also glassed in the floral foam as well.


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## DATCAT (Aug 3, 2009)

After installing the rings it was time to move onto the stretchy fabric to create a sexy curvy shape to the top of the enclosure. Reading tutorials on FG fabrication it seemed this was as easy as stretching the fabric and stapling around the outside edge. I had a grand ole' time because the staples would just bounce off the FG. I visited Home Depot to buy heavier duty staples. The best I could get was about 2mm penetration with a crumpled up staple. Someone on here suggested I use CA glue. After the resin was cured on the fabric I pulled all the staples out due to them being in the way. I think next time I will try CA glue. Sorry I forgot to take any pics of the fabric stretched over the box before I resined it.


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## DATCAT (Aug 3, 2009)

After several layers of FG chopped mat - fabric - knytex I think it is thick and strong enough. I cut the material from over the speaker rings and use a router to cut the FG flush with the ring. I dropped it in the car for a test fit. I think it looks pretty good. I will apply Rage Gold and then tan carpet when I get the exact shape I want. I will build a false shelf above the sub enclosure and try to mimic the original seat to help with stealth.


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## DATCAT (Aug 3, 2009)

johnmasters said:


> I am glad I found your thread as I am in the middle of a very similar build for two DIYMAs sealed in the exact same area of my convertible and I have a few questions...
> 
> What amount of airspace are you trying to achieve?
> 
> ...



I am trying to have .8 ft^3. I currently have approx 1.8 ft^3. I did not plan that well size wise. I originally planned to fabricate 2 small FG boxes in the trunk. However, the night before I began to build I changed my mind and decided to put them up front. I had been using both of them in 2 separate sealed MDF boxes for the last couple months and decided to try listening to them sitting in the back seat. They sounded considerably better in the cabin with me. I have had several others here on this forum tell me they should sound the same as in the trunk but to me they sounded more "live" or "real" while up front. In the trunk they sounded good but in the trunk they sounded more muffled, sort of more like a conversation going on in another room. 

I intend to build a shelf aprox 6" above the subs that will be open in the front but will be intended to look somewhat like a back seat to keep some level of stelthiness. This shelf will also give me somewhere to toss my crap without damaging the fragile cones these have. 

You asked if I intended to have my box chambered. I am not sure what you are asking. If you are asking will the subs share a common air space then the answer is no. They are 2 separate sealed spaces. I had originally intended to point the subs at about a 45 degree angle towards the back. As I was figuring out the placement it became clear with these weighing 38 lbs each and the fact that I had WAY too much air space I decided to mount them flat pointing towards the roof.

Thanks for the tinfoil tip. I had that same suggestion from others as well. This really was a learning experience. I think this box is turning out fairly well and I will incorporate what I have learned into the next one.


Good luck - I hope this helps a bit. If you haven't listened to the DIYMAs yet you are in for a treat. Just like so many have stated before they are very accurate but not a SPL sub. I would love to see your progress as well......


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## johnmasters (Mar 30, 2009)

Thanks for the reply,

Your box is looking good. BTW, are you using fiberglassforums.com?

I have finished my FG base but have not yet decided which way to go. For the last few months I have used one Diyma in.8 sealed and it sounds great but I am in a convertible and would like a bit more output so the choice is either two DIYMAs sealed or one ported.

I built a 1.2cf box for the DIYMA this weekend tuned to 29hz and and put it in the car for the short drive to work. After little tuning, although it does seem louder, it does not seem as impactful. I will eq more this afternoon and start a test box for two DIYMAs.

How close are you to taking a listen?


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## DATCAT (Aug 3, 2009)

I am hoping to take a listen before vacation which starts Friday. I would have been able to listen to it by now but I am half stupid and did not calculate internal volume correctly. I stated before that I thought I had aprox 1.8ft^3. Well I really have about .8ft^3. I don't know where I went wrong on my calculations but when I poured in packing peanuts then measured them I was way less that thought. What set me back is I went ahead and used spray foam then used the packing peanuts. Well I have spent the last couple evenings pulling out the foam. Trust me pulling the spray foam back out really sucks! I am done with the foam and should be able to start Rage Gold tonight after work and have it in the car on Wednesday (provided I don’t do something else stupid).


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## DATCAT (Aug 3, 2009)

I was able to break out the Rage Gold and go to town on smoothing out the FG. I found out that Rage Gold is a great product if you work with small batches. Defiantly work with this when it is in the peanut butter stage and the hard cheese stage or there will be lots of sanding in your future. I think it is good enough for carpet. I will need to improve my skills to make one ready to vinyl or paint. Haven’t found the right carpet yet, so I will put it in the car tomorrow until the swatches show up from Your Auto Trim Store .


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## DATCAT (Aug 3, 2009)

I got a chance to put the subs in and listen for about 5 minutes before vacation started and we drove to the midwest. It sounded really good.


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## DATCAT (Aug 3, 2009)

I finally picked out a carpet color and got a chance to put the carpet on. It turned out looking pretty good. I will need to improve my skills with the Rage Gold if I want to use vinyl or paint. The color is a better match than this picture shows.


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## DATCAT (Aug 3, 2009)

Tonight when I got home from work I was able to remove most of my interior. I was plesently surprised there was asphalt vibration dampener on most of the sheet metal under the carpet. This car is a relatively low noise car. My plan is to install damplifyer and MLV where needed. I got 40sq ft of damplifyer and 100sq ft of 1lbs/ sq ft MLV. I will dampen the doors and sheet metal around the sub and supplement the factory installed dampener. I plan to use double layer of MLV in the doors and a double layer where the back seat used to be and a single layer under the carpet.


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## DATCAT (Aug 3, 2009)

Finished putting damplifyer on the door skins. I will build FG covers for the access ports on the doors and deaden the inside as well. I also applied damplifyer the the back wall and all the sheet metal I could see. I got the back deck tore out and covered with MLV as well as the back and quarter panel walls. Tomorrow I will finish the MLV and put the interior back in. With a bit of luck Monday I will get to the doors and start installing the Hybrid Audio L6 and L1s.


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## e36bumpin (Mar 20, 2008)

love how you put subs in the back seat, cant wait to see this done


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## DATCAT (Aug 3, 2009)

e36bumpin said:


> love how you put subs in the back seat, cant wait to see this done


Thanks - I think they sounded better in the cabin. I spent many hours today finishing up the MLV and the interior will go back in tomorrow. Then I am going to build a shelf about 6 inches above the subs to mimic a back seat to keep them stealth.


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## johnmasters (Mar 30, 2009)

That box is looking great.

Were you able to solve your internal volume issues?


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## DATCAT (Aug 3, 2009)

johnmasters said:


> That box is looking great.
> 
> Were you able to solve your internal volume issues?


Yes I have about 0.8^ft. The subs sound really good in this size enclosure.


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## DATCAT (Aug 3, 2009)

Got more completed today. I finished installing the MLV. The engine control computer is being repaired so the car won't run. I should get it back this week and I am looking forward to testing the sound deadning products I have installed. I put the interior back in today and did not have any real issues with the MLV causing any fitment issues. I got the carpeted subs back in and built the shelf (false seat). I fabricated the back deck and seat back using hardboard and a swimming pool toy.


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## ssmith100 (Jun 28, 2007)

Interested to see how you'll do the doors. This is my install thread on my car.

http://www.diymobileaudio.com/forum/diyma-build-logs/49945-1992-lexus-sc-300-build-stealth.html

I've kind of taken a break from it for a while. Summer is getting here so I'll probably start finishing the trunk and possible upgrade for the doors.

Shane


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## DATCAT (Aug 3, 2009)

Tonight after work I got the tweeters ready to pop in. I am trying to keep stealth or factory look so I used the factory tweeter covers to mount a pair or HAT L1s. The factory tweet covers needed to be shaved from the back and many more holes needed to be drilled to allow the tweets to play through the factory mounts. I wanted to keep the original grill cloth so I carefully peeled the original off and re-glued it back on afterwards.


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## DATCAT (Aug 3, 2009)

I taped off the giant opening in my doors (2 door) and applied the first layer of fiberglass. I will apply another layer tomorrow then pull them out and build them up until they are stiff enough and mount them back in my doors with screws to help seal off the doors. Then mount the HAT L6s in the factory door speaker position and deaden the rest of the door and install MLV. The end of this phase of this project is within sight. A few more days and then on to re-working the trunk. I don’t like how I mounted the amps and (I know it is a sin here but I have caps).



















After first layer of chop strand


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## arw01 (Nov 24, 2010)

Any updates since then?

Can the photos of the tweeter work be re-freshed so they load again?


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