Stereo system build thread

[magicmike]

DISCLAIMER- Well folks for those who don't know I used to be an installer back in the day when I was just a young lad. Well after installing systems in my previous cars that "never seemed to be finished" (those of you who are installers know what I mean), I decided that I would cut some corners on things that weren't as technically important in the system install but are normally considered to be "good work" or "friggin sweet". Normally I would gut an interior of car completely short of pulling the dashboard. In this case I want to get this done as fast as possible so I'm cutting some steps. The steps that I'm cutting are in my opinion not a big deal for what I'm doing with this car and for "MY" plan for this car.

Thanks for reading



Well I'm keeping the wagon for a little while longer due to my financial woes. It makes more sense to sell the g35 and drive the suby with a practically brand new engine in it. So that being said I figured I'd take the approximately 5+ grand worth of stereo equipment under my stairs in the closet and throw some stuff in the car.

Its old stuff but some of you will recognize some of the stuff.

Heres the planned system:

Head unit: Sony CDXC910 - this is by far the finest sounding stereo I've ever owned.
Front stage (Doors): A/D/S 336is - 6.5 inch separates - also one of the finest sounding separates I've heard.
Rear stage (shock towers): A6im's if they fit and I have a set of 4inch ims as a back up.

Midbass: 3 A/D/S AL8 8" subs
Subs: 2 12" kicker comp VR's

Amps
2 A/D/S P840 (40 watts X 8 channel at 4 ohm)
1 A/D/S P4100 (100 watts X 4 channel at 4 ohm)

System layout:

One of the P840's will be bridged to 4 channel and run only the front speakers. Basically these bridge to 120 times 4 at 4 ohms.
The other P840 will be bridged into 5 channel mode running 120 watts X 3 into each 8" midbass and then 40 watts X 2 for the rear speakers for rear fill.
The P4100 will be bridged into 2 channel mode with is roughly 250 X 2 at 4 ohms for the subs.

I will be using 2 A/D/S AC502's to control the mid bass and sub bass levels remotely.

I will be building a pretty cool motorized amp rack that I'm thinking about and intend to have full functionality of the spare tire well.

Pics to come!

[Legacy777]

Sounds pretty damn nice!

I miss doing some of the stereo stuff I did when I was younger.

[magicmike]

Update : 12/04/10

OK so I wanted to do a little creative designing and playing around with the space I had available so I took some basic measurements of the available hatch area and my equipment and I starting messing around with some ideas.

I'm basically going to have a small box for the 3 8"s and the amp rack will be "permanently" mounted in the car. I'm not going to be able to have much functionality of the hatch area if I try to incorporate the 2 12" without getting into some ridiculous fiberglassing pods on each side and quite honestly I haven't heard a good sounding fiberglass box to date IMO.

So I decided to do a removable box for the 12's that I can just pull out and store if I need to use the cargo area.

Here are my preliminary designs.

Heres the rough layout of the cargo area:


Heres the box for the 3 8's:


Subs installed :


Heres the very rough draft of the future motorized amp rack:


Heres the 3 a/d/s amps installed on rack:


I know there are two pieces that look like they are coming out of the space, dont worry about that. Like I said these are rough drafts.

Your opinions, comments and suggestions are welcomed

[Legacy777]

You'll blow your ear drums up

Looks good.

[magicmike]

You'll blow your ear drums up

I'm going for SQ so it will be tuned pretty flat.

[Legacy777]

That may be so, but two 12's and three 8's will still be pretty loud!

[magicmike]

yeah, my intent is to mainly have the 8's running and the 12's tuned so low they only give the very low freq's. But yeah, should be pretty friggin loud with 120 watts going to each midrange and tweeter in each door.

As for an update, I got the front door adapter plates made and installed over the weekend. Ran some 16/4 into each door (thats 16awg times 4 conductor in one sheath for those who dont know).

Ran the monster 4 channel twisted pair rca's and the midbass and sub level controls to the back.

Instaled the New deck

Ran the 4awg.

Pics to come when I get home.

[Legacy777]

Very cool! Looking forward to the pics.

I didn't know they made a 4 conductor speaker wire in one sheath....pretty sweet.

[magicmike]

ok, busy weekend working on the car and freezing my jingle balls off!

My first course of action was to tackle the door speakers. My 6.5" midranges were around .75 inches deeper than the already aftermarket pioneer coaxials I had in there so I went with 3/4 inch birch plywood for a material to make the adapters.

ok, so after taking a peek at the door I came up with a template out of cardboard and tranferred the design to the 3/4 inch stock to make the plates.

I'm using birch plywood for the entire system including the speaker boxes. (THIS IS NOT AN OPEN DISCUSSION OR A HOW TO SO DON'T COMMENT ON HOW I "SHOULD" BE USING MDF INSTEAD. I KNOW WHAT I'M DOING AND DON'T WANT THIS THREAD TO BE A PISSING MATCH ABOUT HOW YOU READ SOMEWHERE THAT MDF IS THE BEST ETC ETC) lol ok rant over Thanks



As you can see I added an area to flush mount the tweeters in the plates as well. Now to cut the holes:
Grab tools, what is in this box cost me a lot of money!


Heres the 6" (I think) hole saw used:


Tweeter holes cut:


Angled slush mount cups used to angle the tweeters back and up at a 45 degree angle in the door:


Heres a little trick I'll share with you for cutting large holes with a hole saw.
1. Get the hole started to give an outline of where the hole is exatly and then use a flat style bit to slam 4 holes quickly at the quadrants on the onside edge. This gives the sawdust a place to evacuate while you are cutting the large hole and the bit wont overheat and burn the wood (as much). Works pretty good:


Holes cut:


Heres another tip- Do all the cutting and drilling while the plates are still in one big piece of wood. Its a lot easier to handle the work and drill holes etch as well as clamp.

Speaker fits:


Now for some goodies (Brass thread-serts):


Threatsert holes drilled where the speaker mounting holes line up:


More on that later......

Now I cut the shapes out:


Test fit in the door and check for some clearances:


Window down at a point where it would hit:


Speaker in (no hittie):


A little sanding for paint prep:


More sanding to clean up outer edge:


Now to protect the plates from moisture, a good coat of ruberized undercoating. Yes this is what installers use although Wurth makes some really nice shit and this stuff sucked but will still do the trick


Now for the threadserts after they dried of course:

Threadsert "installation" tool :


Threadserts installed:


Tweeter pods were just hot clued in place, there was no room for anything else. Would have used epoxy but I dont really care and I think it will hold just fine.


Screwed in the door:


I'll skip to the wiring (I was doing that while they were drying )

About 10 years of installing yields you one of these boxes lol:


Now to get the wire into the door:
Pull the car end of the rubber grommet out.
I made a slit in the grommet and pulled it through the "quick" way:




I just wiretied it to the main harness:
Disclaimer - Normally I would have run the cable through the factory harness and not cut into the boot but I dont really give a shit anymore lol.


Now for connecting it to the speakers:
Tools:


Tweeters:


Mids:


Done:


Door panel on:


Got the harness wired for the sony deck:
Threw in some extra wiring there for the illumination on the volume pots used by the ads amps:


Next project:
I need a holder for my circuit breaker thats going in front of the battery:

[Legacy777]

Dude.....why aren't you using MDF, that stuff is totally the shit! hahahaha....j/k


VERY NICE WORK! I love the idea with the brass Threadserts! Very good method to keep those screws from backing out or stripping the wooden holes over time.....like what has happened to the spacers I made.

[gijonas]

Nice shit man.When looking at threads like this I picture totally hacky ricer stereo B.S. but this is good.

[evolutionmovement]

Looks good. That fits really well in there. Didn't realize there was so much room under the speaker cover.

What's so great about MDF that you think people would attack you over not choosing it? Density? F-that junk. I rate it one step above particle board, which I rate lower than cardboard (because cardboard can be used to make composites). The dust when working on it is terrible and the material is heavy and less elastic than ply. I'd also trust the inserts in the ply better. Hell, try to make a boat out of MDF. I'll be building one out of plywood. Is it a resonance thing? I imagine in theory it could be superior with a more consistent density, but ply comes in all grades, which can be had without knots or spaces. Either way, the installation is an old station wagon with unoptimized acoustics filled with a collection of various extraneous noises of variable frequency. I'd pick the superior building material any day.

Sorry, I just passionately hate MDF and particle board. I think their usage should be severely restricted. People argue that it's a form of recycling otherwise unusable wood to make things like furniture, but that furniture is garbage and ends up in land fills in short time and isn't recycled at that point because of the glues and plastic veneers that keep it together and attempt to make it look passably attractive. Those wood chips are better used as mulch or paper pulp (I'm not sure why they don't go to paper pulp, but I'm not that familiar with paper production. Perhaps the pieces are too small, so the fibers won't hold together well when made to papers' thickness? Whatever. Who cares? This is what happens when I get started on something.).

[gijonas]

Looks good. That fits really well in there. Didn't realize there was so much room under the speaker cover.

What's so great about MDF that you think people would attack you over not choosing it? Density? F-that junk. I rate it one step above particle board, which I rate lower than cardboard (because cardboard can be used to make composites). The dust when working on it is terrible and the material is heavy and less elastic than ply. I'd also trust the inserts in the ply better. Hell, try to make a boat out of MDF. I'll be building one out of plywood. Is it a resonance thing? I imagine in theory it could be superior with a more consistent density, but ply comes in all grades, which can be had without knots or spaces. Either way, the installation is an old station wagon with unoptimized acoustics filled with a collection of various extraneous noises of variable frequency. I'd pick the superior building material any day.

Sorry, I just passionately hate MDF and particle board. I think their usage should be severely restricted. People argue that it's a form of recycling otherwise unusable wood to make things like furniture, but that furniture is garbage and ends up in land fills in short time and isn't recycled at that point because of the glues and plastic veneers that keep it together and attempt to make it look passably attractive. Those wood chips are better used as mulch or paper pulp (I'm not sure why they don't go to paper pulp, but I'm not that familiar with paper production. Perhaps the pieces are too small, so the fibers won't hold together well when made to papers' thickness? Whatever. Who cares? This is what happens when I get started on something.).

Dude seriously

[Legacy777]

Steve,

You mentioned one of the reasons it's used for stereo boxes,

The dust when working on it is terrible and the material is heavy and less elastic than ply.

Less compliance or flex is desired for sub boxes.

I'm sure Mike has his reasons for using the wood he is using. So I'll let him share why. I'd be curious to know.

[speedmaxx]

sickkkk project! should sound sweet...

Im gonna have to borrow that tweeter mounting idea, those mounts turned out sweet

[magicmike]

Thanks for the kind words! And here I was thinking my shit was totally hacked! Remind me NOT to show you guys any of the "real" stereo systems I worked on before lol.

I should probably get my scanner hooked up and scan in some of the pictures of systems I did for a couple of the patriots back in the day when I worked at a shop down the street from Gillet stadium lol.

I used to do really really nice work. I worked at a place in boston called Rich's car tunes for a while. The owner "Rich" was a total douche bag but I did some of my nicest work there. We'd have a car for 2 days to do a deck and 4 plus an amp. In other places I'd have about 4 hours to bang that shit out lol.

Anyway, thanks for the props, in all honesty I'm doing a really really horrible job but at this point I just dont care anymore lol, like my boy says: "I'm too old for this shit!"

Been way too cold to work in the garage but will have more pics soon...

[magicmike]

Steve,

You mentioned one of the reasons it's used for stereo boxes,

The dust when working on it is terrible and the material is heavy and less elastic than ply.

Less compliance or flex is desired for sub boxes.

I'm sure Mike has his reasons for using the wood he is using. So I'll let him share why. I'd be curious to know.

Well heres why they use it for speaker boxes in shops:

1. Its cheap
2. Its solid or the same consistancy through the whole piece like if you had to champfer the edges or something it wont fall apart or be jagged like a piece of plywood would be (see above photos lol)
3. Its heavy as shit! This is based on the whole reasoning that a sub woofer enclosure needs to be extreamly dense or neutral such that it does not ADD to or DISTORT the output of the speaker. For example, if the speaker is playing at a certain frequency it is vibrating and the the box is absorbing the back waves of this frequency and flexing and vibrating itself thus "spoiling" for lack of a better word or introdicing new resonant frequencies that would them counter act or fight the speaker. The "theory" is that the more or better a speaker enclusre can absorb the sound the "better" the speaker response will be.

OK sit down for this one folks...... Although this is ABSOLUTELY true in home theatre speaker enclosures design this may not be "and from my experience" as crucial in an auto sound woofer enclosure where running frequencies from about 20htz to 80htz and loss of accuracy would not be audible to the average joe.

Birch plywoood
1. Damn expensive! $50 for a 4x8 sheet
2. Its relatively solid and extremely well fit together layer wise. Its a higher grade plywood and has a clean veneered surface that looks really nice!
3. Its light (er)
I personally have used both to build boxes and I have NEVER heard any difference quite honestly (besides the weight!)

So for me I'm going mainly on the weight factor since I'm going to have 2 boxes back there and some trim panels etc.

I'm actually going to make my amp rack out of thin walled steel box tubing to reduce the weight only because I can weld it easily and not use so much wood. I cant weld aluminum myself so don't chime in Steve about using that instead lol. Although I'd love to but I've used aluminum in the past and had to rivet or screw and tap all the joints and it was a bitch so I'd rather weld

[evolutionmovement]

? Sounds like we agree. I probably shouldn't rant so long so people would read my whole posts, but I mentioned that I don't think you'd notice any difference in resonance between the two materials in an automobile, particularly one where I had to put in ear plugs to reduce hearing loss from tire noise while driving over that horrendous concrete they use for highways in the South West. I doubt it will razz like a ghetto Honda anyway!

As a guy working out the designs for 3 human powered vehicles (sail trike, tilting trike, handicapped transport/mobile elliptical machine) and a car I'll build in a garage, I'd also love to use aluminum, but recognize my limitations in cost and skill (even though I'm farming out the car chassis). So steel it is. It's also easier to bend as getting the right alloys in tempers that can be bent is difficult. Plus in your case, I don't think you need thick steel so the weight penalty is minimal.

[gijonas]

+1 on the birch plywood,great stuff.When i was doing custom carpentry work we had to make a few high end home theater setups that used the same stuff for enclosures.I am not a sound specialist but im not retarded on the topic either ,but despite the fact that its probably not ideal in the music world to do it that way I think it sounds great.Or at least i highly doubt that i would ever notice the theoretical superiority of the MDF.

[magicmike]

? Sounds like we agree. I probably shouldn't rant so long so people would read my whole posts, but I mentioned that I don't think you'd notice any difference in resonance between the two materials in an automobile, particularly one where I had to put in ear plugs to reduce hearing loss from tire noise while driving over that horrendous concrete they use for highways in the South West. I doubt it will razz like a ghetto Honda anyway!

As a guy working out the designs for 3 human powered vehicles (sail trike, tilting trike, handicapped transport/mobile elliptical machine) and a car I'll build in a garage, I'd also love to use aluminum, but recognize my limitations in cost and skill (even though I'm farming out the car chassis). So steel it is. It's also easier to bend as getting the right alloys in tempers that can be bent is difficult. Plus in your case, I don't think you need thick steel so the weight penalty is minimal.

I concur lol

[magicmike]

t i highly doubt that i would ever notice the theoretical superiority of the MDF.

Thats the thing, look at any high end home audio speaker designer and show me one that uses mdf to build speaker enclosures. There isn't one.

[evolutionmovement]

Honestly, as a high end stereo designer, would you use something so cheap and ugly? Even if there's a theoretical improvement someone with golden ear could hear with the room dark and mind clear of distractions, I contend that the average person would not and someone paying the kind of money those people do would likely be displeased to see those materials being used. Hearing is as much subject to perception as anything and knowing something's built of quality materials or not is likely to sway the user's opinion of the tonal quality. If perception meant nothing, there'd be no VW (or plenty of other "premium" brands of any kind).

[magicmike]

OK Day .....mmm 12 I think lol

ok Time to make up the breaker holder for the power wire:
Tools and 16awg steel sheet metal:


Put some tape on the sheet metal to draw out the lines for what I wanted to cut:


It will take shape leter (ha ha pun intended) Marking for 2 mounting holes for breaker:


Fine tooth metal cutting blade in the ol jig saw and some wd40 for lube:


First cut:


Second Cut:


Third Cut:


Drill out the holes for the mouting hardware:


I filed the edges down with a file then touched them up with the belt sander:


Hit both front and back surfaces with the palm sander:



Now for some bending:
Heres my little sheet metal break I bought from Harbor Freight a while ago, works pretty good for light metal.


One Bend:


Clamp:


Two bend:


Basic shape finished:




Primer:


Satin Black paint:


Painted 2:


Breaker mounted:


Mounting location before:


After (The bracket just gets clamped on by the battery holder clamp. My design yes, and the breaker brackt moves out of the way easy to change a headlight bulb):


Connection to Battery clamp:


Oh yes, made up the 4awg ring terminals with this bad boy that cost me a few hundred bucks lol !


Fin:







Also tackled the rear speakers.

I did not think the massive A61m's would fit in the stock locations or even with a trim ring but I threw them in for a laugh:

Pioneer 6.5"


ADS 6.5"


lol I was hoping they wouldn't fit so I could use these
These are 4 inch im's but of the same higher top level quality of the front speakers. The A6im's are a little lower quality (which isn't saying too much because they dont make low quality speakers lol)


Check out the side view of these beasts!


Picking up some 1/4 inch plywood to make the plates for those tonight:

Heres a few shots of the 3 amps lined up for measurements:






Also some thoughts on my x-over settings for the system

The amps have rediculous x-over capabilities, you can basically do what ever you want at any channel practically so I plan to do the following:

Front Doors:
Mids - Bandpass from ~120 to 2k
Tweeters highpass 2k up

Rear Speakers:
Mids - Bandpass from 160-200 to 2k
Tweeters highpass 2k up

The 3 8" mid basses:
Bandpass ~80 to 120

The 2 12" subs:
Lowpass 0-80

The x-overs are infinitely variable so I will have to play with everything once its installed.

I'm betting on the 8's providing mostly all the bass output and the 12's just being there for the rumble. Like I stated originally I might not even have the box with the 12's in the car all the time. Also, I'm going for a loud clean sound quality system not a bass rattle your car system

[Legacy777]

Very nice Mike! I like the circuit breaker design. I usually bend the metal in my vice with hammer....works alright....haha I need to get one of those breaks. The last time I went, they didn't have them in stock. I know to make them work correctly, you need to do what you did & clamp the brake down next to the metal.

Some comments on your crossovers.....not sure what the attenuation octive is on them, but I'd suggest maybe having a little bit of crossover between frequencies. Depending on the subs and how they respond in the boxes, you may have some high or low notes as a result, so yeah....you'll have to see how it sounds and probably tweak them a little.

[magicmike]

Some comments on your crossovers.....not sure what the attenuation octive is on them, but I'd suggest maybe having a little bit of crossover between frequencies. Depending on the subs and how they respond in the boxes, you may have some high or low notes as a result, so yeah....you'll have to see how it sounds and probably tweak them a little.

I was reading the manual for the separates and for the amps. I've been on the fence a little on which way to go with the x-overs as far as active vs passive. I've done both and certainly passive is a lot easier and safer but ultimately for better flexibility and fine tuning active is the way to go. I need to make up my mind before I install the amps and do the wiring obviously but I'm leaning towards my first thought of going active.

As for the active slopes in the amp x-overs they are 12db/octave. I was not able to find any data on what the slopes are in the passive x-overs although they are extremely nice I have no clue. When I used these separates before they were used with the passive x-overs at that time and sounded pretty damn good to me.

The amp manual recommends a good starting point to cut off the midrange to be at 2500Hz and to start the tweeter at 3500Hz using low pass and high pass filters respectively. At a 12db slope that should "blend" for lack of a better word pretty well and if they are suggesting it in the amp manual then they most likely are doing something similar in the passives.

I might try some different tests to see how both setups sound.

Also, been thinking that the separates are rated at 150 watts max per pair so maybe 120 watts to each speaker might be excessive. It might make more sense to bridge the 8 channel amp down to 4 channel and put 120 watts into each corner or maybe use non bridged channels for only the tweeters so they get 40 watts but then bridge channels for the midranges.... ARRRRG too many possibilities lol

I don't know I'll let it percolate some more...

As for the rear speakers (I tackled those last night) holy crap even 4 inch speakers dont fit I had a nice 1/2 inch adapter plate made when I noticed that the damn tweeter was considerably higher than the factory cover and would never go in so after some looking at it for a while and 2 beers later I realized that if I mounted the speaker from underneath it would clear the grill but on the right side I had some sheet metal shit that was getting in the way lol

After beating the ever living shit out of this sheetmetal I was able to get the clearance I needed I'm still not sure what this was but it looks like some metal surround for the gas filler tube, thats all I can ascertain without taking all the plastic trim off.

I'll have the speakers installed tonight, more pics to come.