Speaker placement - BJ70 JDM

[webbz47]

I am currently installing a stereo into my RHD 87' JDM BJ70. I've noticed from other posts that people have installed 6x9" speakers into the rear doors. After removing the back door panels on my truck I see there is only a large opening on the large door below the handle, there is also much re-enforcment for the tire carrier. This location is basically in the center of the vehicle. The smaller door has a speaker mounting location but it would be so close to the opening in the larger door that I can't possibly see any acoustic benefit from mounting speakers so close together.

Other people have mentioned the sides beside the rear seats, this area too is not great since there's a metal channel on the passenger side and a cubby hole on the drivers side (which could be removed easily). I also prefer the rear sound being projected to the front of the vehicle.

5 1/2" speakers can be easily be mounted in the lower front location of the front doors but I have not found a good spot for the 6x9" rear speakers. I am now thinking of purchasing speaker boxes and mounting them on the rear doors far apart from eachother. Has anyone else come across a solution for rear mounting speakers for these acoustically challenged JDM model BJ70's?

 

[roscoFJ73]

Has anyone else come across a solution for rear mounting speakers for these acoustically challenged JDM model BJ70's?

I think you have about covered it .They are turds for mounting speakers in

 

[crushers]

make special boxes and mount to the upper rear outside corners near the head liner...

 

[_Walker_]

Realistically speaking a set of high quality 5 1/2 are going to have much clearer sound than 6x9s the big thing you'll be loosing out on is low end, but even at that 6x9s don't really do bass much justice anyway... They kind of do everything mediocre.
IF your looking at putting a good sounding system in (and have at least a reasonable budget) Id look at putting in a set of 5 1/2s in the front doors (an optional additional set of 5 1/2s somewhere amidships) and a shallow mount 8 in the smaller of the two rear doors.
If you kill one of the hidey holes there is plenty of room for an amp for the 5s (spraying it with conformal coating may even let you get away with dunking it a few times.) The 8 will need a custom fiberglass box to fit flush, it will be tight BUT there IS enough room in there to get the required clearance. Pioneers shallow sub line is reasonably water resistant.
a roll or two of brown bread and presto a very nice sound, without all the flash and hassle of boxes strapped every which way...

 

[crushers]

please explain the "(spraying it with conformal coating may even let you get away with dunking it a few times.)" since i am at the same stage with my project and i thought amps had to be able to breath.

 

[jb BJ73]

theres definately enough room in the front doors for 6in speakers, which is what i've got in mine, but i reckon you could get 6.5in's in there. there's enough room in the side panels for 6x9s, i had to trim part of the plastic storage box to mount them just forward of the rear seats. you can't really feel the base in them when you're moving however, really need a decent sub for that i guess.

 

[_Walker_]

I did a fair bit of digging a few years back into "marine" amps when I was putting the system into my 74. Essentially when you buy a high quality marine unit its the exact same animal as their standard car decks except they did one of two things (they sealed the box with gaskets, and usually have a large heatsink.) OR in some of the more expensive units they dipped the PCB board in conformal coating, oh ya they also add $400 to the price tag.)

You are right that amps need to be able to breath as heat can become a serious factor in life span, conformal coating will decrease the thermal properties of the amp a bit, but talking to most of the electronics guys they seem to think the effect would be reasonably minimal, and while keeping a reasonably open design to still allow for airflow would still be light years better than sealing the amp in a box.

my 6x9s are running off of a clarion (300 something watt) amp. All I did was remove the board from the case (be sure its been depowered for a while and short out the caps just to be safe.) covered the inputs with tape and gave the whole thing a solid coating of a few mills, being sure to get into all the nooks and cranny's.
After a few coats and drying everything was reassembled and its been pounding away music for a little over a year and 1/2 now with no issues.

There are two types of conformal coating silicon or acrylic. Acrylic is tougher but is not a fan of vibration, where as silicone is recommended for any application vibration could be a factor (diesel.)
MG Chemicals 422A Silicone Conformal Coating

I also sprayed my glow screen relay and all the other little electronic boxes on the rig, so far so good no issues have arisen,
Iv got some pics of coating a board in one of the egt/pyro threads: (post #13)
https://forum.ih8mud.com/diesel-tech-24-volts-systems/261044-pyrometer-install-pics-wanted.html

 

[Stone]

When I had my BJ74 I installed a couple of 6x9's on the rear quarter panels...BUT obviously I had to cut holes in my panels. I didn't really care, they looked good there...but if you're one of those that don't like to cut holes in panels, you might not like the idea. Then again...you're cutting holes into your door panels anyway...

 

[JAC83]

Around here people attach the speakers to the roof in the rear (right next to the door) by making a base out of mdf, if done by an skilled person they look almost stock.

That and the front door panels, that's what I plan to do in the future in my 71.

 

[crushers]

thanks Walker for the info...

 

[cicak]

I have pulled all the factory door panels (all 6 doors they where all geting tatty from the mud and the abuse ) of my LJ70 and replaced them with home made 1mm Alloy skins and stuck soundproofing on them - still looking for places to reinstall the speakers. Rear doors have 3mm 5 Bar Alloy plate next is the inside rear panels I will be doing this in the coming months. The panels are either attached with pop rivets or stainless steel PK screws for a slightly engineering look to them.

so thanks for the speaker tips as they are a pain to get speakers into them. I was looking at installing the speakers on the roof behind the passengers seats attached to the Milford Cargo barrier in a custom speaker box. I do not want to cut the alloy panels on the LJ70 as I do not want any water near the speakers ever unless there is serious flood inside the truck.

then I got an order to do another LJ70. the panels for this are stainless steel PK screwed on for a slightly more engineering look to them. All the panels were finish by sanding the panels with fine sandpaper in a circular pattern to produce a nice rugged finish.

Then did the complete inside of my TROOPY with 5 BAR 2.5 ALLOY (all soundproofed) and 1mm alloy again for the front doors so much cleaner than the factory panels. 1mm alloy panels were all then sanded with fine sandpaper in a circular pattern to rough them up a little.

 

[JAC83]

Any pictures?

 

[1985bj70]

I did up some door panels for my Bj70, made them out of 3/4" MDF, and did a second 3/4" ring to fit my RE Audio mids into the door (nearly 4" deep). My Dad did the vinyl work on them, I mounted the tweeters higher up on the door, and ran separate wires for the mid and tweet into each door. I have a Pioneer Premier deck that has the iPod input built in, and I am running a pair of Elemental Designs shallow 10" subs in a sealed box in the back. This is all run off of a Cadence 6 channel amp. If you deaden your doors and do a set of components up front run off of a decent quality amp, you will not miss the rear fill. In all of the systems I have done over the years I have never run rear speakers. My .02

Sorry for the blurry pics.....

 

[cicak]

I shall get some pics of the TROOPY interior up this week and the BJ70 when I get out to the workshop too see how the dead head gasket is going.

 

[cicak]

Nice job on the MDF panels - that would go off real quick here in the mud and the water which is why I went down the path of alloy panels - I could also go 5mm plastic but decided the alloy looked more rugged and jungle proof and would take the whacking and bashing from muddy boots and boxes and eveything else which gets tossed in covered in mud.

 

[cicak]

Wow looking at that nice BJ70 my TROOPY jungle basher looks quite pre-historic. My LJ70 is even worse.

As the TROOPY finished the 2008 Malasian International Rainforest Challenge and also celebrating its 21st birthday.

Left side passengers 1mm alloy panels with sound proofing behind the panel. Easy to clean and no maintenance required. No speakers either in the doors.

Drivers side. yup the truck was only half cleaned by the cleaners and still has mud on it from the 2008 RFC.

Left hand rear door with 5-BAR 3mm (1/8th for you imperial guys) checker plate alloy panels. Rear speakers removed as they were crushed already.

This wagon used to be owned by a CRANE company hence all the dents. It was only painted 2 years ago and looks like it needs a repaint already.

LEft Rear panel once again 3mm 5-BAR Alloy checker plate - cut from 1/2 a 8*4 sheet. D hooks been also added to tie down luggage. All these are pop riveted on and sound proofing or 3/8 inch plumbing insulation rubber put behind and compressed rubber glued to the inside of the outside panels to quieten down the TROOPY else the alloy resonates. The 6" speaker can be seen way down on the left we only have 1 speaker each side until we work out were to mount the front ones - maybe on the roof at the very front. YEs the box above the front window is a inverter.

Floor is 12mm marine ply with 3/8 plumbing rubber inslation glued under it to hide the dents and keep it a little quieter.

Right hand side panel same checker plate.

Roof lined with soundproofing after we pulled the headlining off as it had gone off. Very quiet you can talk and hear someone when it is raining now. Rear airconditioning unit can be seen just hanging down on top of door frame.

For bling we added led interior lights which also reflect of the soundproofing for even more light.

 

[1985bj70]

^^ Thanks. Yeah, MDF is not a good match for deep water crossings, for sure. My truck is a daily driver, and is not being used for the extreme wheeling that many others on here are doing...... I like the checkerplate look, very sharp.