Mounting Subs in supra's trunk

TomFraser

New Member
Just got 2 subs, one amp... will be about a 1200 peak watt system (400 RMS)

I am worried about the wood covering the spare tire, It will shake and not be a stable base for a sub enclosure.

How do you guys mount a sub enclosure in your supra's? I don't want to cut the wood, but have no issues adding brackets etc.

Any ideas are appreciated, thanks!

EDIT: also I have an extra battery that will be in the trunk to hook up to the subs, what is the best way to hook up both the main battery/alternator, and the extra to the subs? Thanks
 

pbasil1

Fully built 1JZ project
Jan 30, 2008
402
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Huntsville,AL
U need 0 gauge wire to run to the alternator from the battery in the back as well as a battery isolator. The isolator will prevent one battery charging more than the other, and then the weak one pulling its charge from the good batter, thus making both batteries weak.

And to stiffent the board in the back, i would just make a few more stand offs for the wood piece to rest on. Or you could cut a whole new piece of wood from like 3/4" MDF. But that would start to get heavy back there...
 

TomFraser

New Member
pbasil1;1065859 said:
U need 0 gauge wire to run to the alternator from the battery in the back as well as a battery isolator. The isolator will prevent one battery charging more than the other, and then the weak one pulling its charge from the good batter, thus making both batteries weak.

And to stiffent the board in the back, i would just make a few more stand offs for the wood piece to rest on. Or you could cut a whole new piece of wood from like 3/4" MDF. But that would start to get heavy back there...

Sounds good... the previous owner did all the wiring and had a similar setup, just took it with him when selling the car. Will check over it to ensure it does as you say.

Also open to creative ideas others have about ensuring the wood stays in place, and pics of where you mounted your subs and to what

Thanks

EDIT: Did supra trunk setup change through the years? I have an 1988, thanks
 

ValgeKotkas

Supramania Contributor
Apr 14, 2006
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You can see my sub mounting in a day I hope (if I remember to take the camera with me....usually I forget.).
But I can say, that it'll be heavy, really heavy. PROBABLY targa option will be left intact.

Buuut...why you need an extra battery? 400rms isn't much....?
 

Pernilongo

LADA is my daily
Jul 15, 2007
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Extra battery is a great idea. I sometimes even like to put 1 or 2 crates of bricks in my supra to compensate for lightweght weels, s smaller sub, and so on. :evil2:
 

TomFraser

New Member
ValgeKotkas;1066003 said:
You can see my sub mounting in a day I hope (if I remember to take the camera with me....usually I forget.).
But I can say, that it'll be heavy, really heavy. PROBABLY targa option will be left intact.

Buuut...why you need an extra battery? 400rms isn't much....?

because I know if my mom borrows my car she will listen to the radio with the engine off regardless of what I tell her... that should help a little bit.
 

OfnaRcR4

Shea!
Oct 2, 2006
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TomFraser;1066084 said:
because I know if my mom borrows my car she will listen to the radio with the engine off regardless of what I tell her... that should help a little bit.

Lol, for more than like 15 mins?
 

TomFraser

New Member
OfnaRcR4;1066310 said:
Lol, for more than like 15 mins?

if she is picking up one of my brothers she'll sit in a parking lot for up to an hour waiting for baseball/football/soccer/etc. to be over.

My dad made it so her radio only works if the engine is running on her ford windstar.

shes not stupid or anything, just doesn't care about things like this :icon_evil

The other problem is that she loves standard cars, and her minivan, my dad's truck, and my dad's mercedes are all autos, she always fills my tank, so i always let her drive, wouldn't anyone? ;)
 

annoyingrob

Boosted member
Jul 5, 2006
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If you want to mount a panel to the bottom of the trunk WELL, remove the gas tank, drill some holes through the bottom, and bolt it down with some lag bolts. Then, silicone over the bolt heads underneath the car to prevent leaks.
 

ValgeKotkas

Supramania Contributor
Apr 14, 2006
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Promised some pics. But I lied about the targa, till the last second I though we could make it, but our last decision was to put the condensers like this, cause there's no room :(.
We'll see what happens with the targa.
p1068562_1.jpg

p1068562_2.jpg

p1068562_3.jpg

What you don't see now, is spare tire well that's used aswell. I'll make pics as I pull it out to make some repairs.
 

Pernilongo

LADA is my daily
Jul 15, 2007
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Electrical condenser is a cap by another name. Probably a regional peculiarity. In eastern Europe caps are called "buffering condensers".
 
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pbasil1

Fully built 1JZ project
Jan 30, 2008
402
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0
Huntsville,AL
annoyingrob;1068780 said:
Do I even want to know how big that port is?

Ya . Just the right size by the looks of it?


So thats a 15" L7... If i were to guess ^ cu/ft... And hopefully tuned around 25-33hz? Unless your tying for spl... Then a good 40-55hz should blow the supra to bits! Am i close?
 

ValgeKotkas

Supramania Contributor
Apr 14, 2006
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We call them condensers (word from the dictionary) :). But yeah, capacitors in your language then :D

Well, I don't know the exact Hz's, bu I took the numbers from the manual. I chose from the 3 vented options the middle one, ''Street Bass'' :D 4,5cu.ft + 3x16,25'' 14,75'' long port. That makes about 5cu.ft then I guess?
It isn't actually ''tuned'' (port isn't straight and we are no professionals ;), so don't know the Hz again, but it's sure a nice kick when the song is good. Sometimes though it's too much....but looking at the back - the membrane almost isn't moving at all.
 

TomFraser

New Member
I have a wire coming from the battery, and powering my amp/radio, and it is blowing 30 amp fuses that are on the wire from the battery, doing some math, my amp can handle 500 watts RMS (1000 peak) which is 41.6 amps @ 12v. If I take peak into consideration then it is 83.3 amps @ 12v. (5 speed 1988 N/A) so I am wondering, how many amps would my car be using if I had all my lights on, A/C blasting etc.

I think a 50 amp fuse should be enough, this allows for 600 watts which it shouldn't hit very often. but I don't want it to draw too much, so what do you guys think?
 

Cravin Boost

MMMM Smells like coolant
Nov 8, 2005
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Ita all good just making sure I was not confused :)

you tune the box with a wave generator and changing the length of the port. the port in my enclosure is not straight either it has a 90 degree bend in it. we tuned it to 37 Hz. we found a wave generate program on the Internet and ran that from the audio output on my laptop to the input on my base amp and adjusted it until the speaker looked like it wasn't moving( it is it just doesn't look like it). you would be amazed at how much air it moves from a speaker that appears to not be moving at all.

Pernilongo;1069015 said:
Electrical condenser is a cap by another name. Probably a regional peculiarity. In eastern Europe caps are called "buffering condensers".
 

pbasil1

Fully built 1JZ project
Jan 30, 2008
402
0
0
Huntsville,AL
TomFraser;1069257 said:
I have a wire coming from the battery, and powering my amp/radio, and it is blowing 30 amp fuses that are on the wire from the battery, doing some math, my amp can handle 500 watts RMS (1000 peak) which is 41.6 amps @ 12v. If I take peak into consideration then it is 83.3 amps @ 12v. (5 speed 1988 N/A) so I am wondering, how many amps would my car be using if I had all my lights on, A/C blasting etc.

I think a 50 amp fuse should be enough, this allows for 600 watts which it shouldn't hit very often. but I don't want it to draw too much, so what do you guys think?
You left out the amps inefficiency... So add about 40% to the power draw you calculated because most class D amps are 60-75% efficient. They draw a bit more power than they put out. I would use an 80 amp fuse in line with the battery.