Car Audio and Subs

Audio gurus please school me.
Mods please move if wrong forums.

I know about as much about car audio as I do about quantum physics. I know it exists and only have a rudimentary understanding of how it works.

So I have this collection of parts and need some help sorting it out. The Mustang currently has a system in it (came with it), the Frontier does not have a system, and I need to clear the extra system parts off my parts shelf. So please direct me what I need and what I should swap (if anything). Goal is to make room on my storage shelf and not spend any money, LOL. I also rarely (never) listen to music in the Mustang.

Mustang:
Pioneer DEH-P3100UB head unit https://www.crutchfield.ca/S-wSy8M5I...g&awug=9000829
Kenwood KAC-729S amp. https://www.crutchfield.com/S-bkQJLC...-KAC-729S.html
Kenwood KFC-W3003 12” sub. https://www.crutchfield.com/S-wHCtkt...KFC-W3003.html
OEM (?) speakers.

Frontier:
OEM head unit (no pre-amp outs)
OEM rear speakers and dash tweeters
Infiniti Reference 6x9 front speakers. https://www.crutchfield.ca/S-7rD5SAA...ce-9633cf.html

On the Shelf:
Alpine MRP-F200 amp. https://www.crutchfield.com/S-eocoAl...-MRP-F200.html
Sony XS-L101P5 10” sub. https://www.crutchfield.com/S-xFO11m...XS-L101P5.html

For the Frontier, I was thinking I could run a power line to one of the amps, use the speaker wire line in, build a box, and plug in one of the subs.

With the Alpine amp, would I then be able to power some better rear door speakers in addition to the sub?

https://photos.smugmug.com/Audio/i-t...1AC2768D-M.jpg

https://photos.smugmug.com/Audio/i-Z...6DA0C3B5-M.jpg

Sounds good,just run the Kenwwod amp "bridged"( it's marked on the amp) single channel,to get the full power,if the sub can handle it.

To do this setup a la cheap... If you don't listen to music in the Stang, pull out the amp and sub get rid of the extra unneeded weight. Remove the amp's wiring kit and re-use it in the Frontier. Tap the rear speaker wires at the back of the deck, run wires to the level inputs on the Kenwood amp. Use the 10" sub, smaller enclosure footprint, hook it up in bridge mode. Done...
Keep the rear OEM speakers as is. Don't bother upgrading or adding more juice especially in a small cabin, wont be noticeable.

Sell the Alpine Amp and 12" sub.

Thanks for the opinions and advice Reno and TB.

All the google advice I was finding involved installing a line-out-converter. But if I understand correctly now, both these amps have a built-in converter if I use the speaker wire inputs.

So I lighten up the Mustang, add bass to the Frontier, and make a few bucks in the process.
https://vignette3.wikia.nocookie.net...20121029194250

...any tips or links to building a box?
Was thinking something like this https://www.thesubboxshop.com/Nissan...ab05single.htm

Yes, both amps have speaker level inputs, no need for a line out converter.

Do you have any room behind the rear seats to fit a wedge style enclosure?

What are your overall audio goals for the Frontier? What types of music do you listen to, and what kind of volumes?

How much space are you willing to sacrifice for a box?

How much labour are you willing to put into this project?

Don’t really have a goal. Basically just trying to utilize and make the best of the bits and pieces I already have so I can clear off my shelf and sell the rest.
Listen to mostly old rock, 90’s alt., and some trip-hop.
Don’t want to sacrifice too much space as it’s at a premium in a king cab, but I don’t mind losing one of the jump-seats.
Willing to put in some labour building a good looking and good sounding box. But since I’ve never designed or built one, looking for some tutorials.

Don, I've used this site to help me calculate and build various enclosures over the years. You'll need to get the sub's specs, for the correct tuning and enclosure size.

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Originally Posted by RedSN

Don’t really have a goal. Basically just trying to utilize and make the best of the bits and pieces I already have so I can clear off my shelf and sell the rest.
Listen to mostly old rock, 90’s alt., and some trip-hop.
Don’t want to sacrifice too much space as it’s at a premium in a king cab, but I don’t mind losing one of the jump-seats.
Willing to put in some labour building a good looking and good sounding box. But since I’ve never designed or built one, looking for some tutorials.

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If you are content with the features of the Frontier's head unit then I would do the following with what you have

Take the Kenwood amp from the Mustang and use the 10" Sony sub in a sealed box. The Sony requires a much smaller volume sealed box, so generally speaking easier to install.
Also install the Alpine amp and run it bridged into the Infinity 6x9's. I would take the feed for the sub from the rear channels and the feed for the 6x9's from the front channels. This way you can have some control over the level of the sub in relation to the front stage.

I wouldn't run rear fill speakers at all. It throws off the sound stage. I know it sounds odd, but when done properly having a front stage only provides a much richer, complete sound. Also, make sure the 6x9's are installed properly. That means solid base, and having the back of the speaker as isolated as possible from the front of the speaker. Also having some sort of a seal between the front of the speaker and the back of the door panel makes a massive difference in performance.

Installation is 75% of the end product in car audio.

Building a sealed sub box is very simple, and are much more tolerant to being a bit off of premium size as compared with a vented box. A vented box is also much larger in size. The two main things that need to be kept in mind about a sealed box is that it needs to be sturdy, and all the seams tight and sealed.

Your Sony requires a 0.75 cubic foot box according to Crutchfield. There are lots of websites and online calculators to help work out box details.

Check out www.diymobileaudio.com It's the sister site to the one @True Blue linked, but it is dedicated to car audio rather than home audio. Lots of information on there from the very basic, to the very advanced. There are some threads stickied at the top of most of the forums that outline the basics and lead from there.

If you want to change out the head unit in the Frontier I have one that's collecting dust on my shelf that is a couple steps up the line from the Pioneer that you have in the Mustang that I would be happy to donate to the cause. I should have thrown it out long ago, but it still works.. you know how that goes.

Hhhmmm, interesting idea Vic. What about just using the single Alpine 4-channel amp? Using channels 1-2 to drive the 6x9 door 3-ways, and bridge channels 3-4 to drive the 8” sub?

Obviously this project is going to be a learning experience. Really appreciate all the help and suggestions so far.

Ripped out the passenger side jump seat.

https://photos.smugmug.com/Audio/i-v...7067CA7B-L.jpg

Mocked up the amp and sub location, and marked up the proposed box.

https://photos.smugmug.com/Audio/i-C...15943DF4-L.jpg

Thoughts? Ideas?
Going to mock up a cardboard box next to nail down the final dimensions. Initial volume calc is about .8 cu.ft.

LOL, my cardboard sub box

https://photos.smugmug.com/Audio/i-6...6B688D36-L.jpg

Any reason why everybody seems to use MDF? Is there a reason not to use plywood?

Quote:

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Originally Posted by RedSN

LOL, my cardboard sub box



Any reason why everybody seems to use MDF? Is there a reason not to use plywood?

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Plywood flexes, MDF will not, less vibration

Quote:

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Originally Posted by RedSN

Hhhmmm, interesting idea Vic. What about just using the single Alpine 4-channel amp? Using channels 1-2 to drive the 6x9 door 3-ways, and bridge channels 3-4 to drive the 8” sub?

Obviously this project is going to be a learning experience. Really appreciate all the help and suggestions so far.

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No your going to want two separate amps, especially if your running tri-ax 6x9's unless that amp has a dual cross over for separate channels, otherwise your going to have highs running through your sub or just low pass running through your 6x9's which won't be very effective...

MDF is much denser of a material making it preferable for speaker box construction as the sound is less likely to “leak” out of the enclosure.
It is also a more stable material, not prone to shrinkage/ expansion and is perfectly flat.
You want to ensure you pre drill all holes into the ends of the material to prevent splitting of the board. Use a quality wood glue on all joints
For mounting of the subwoofer itself, use “T-Nuts” and bolts to allow the speaker to be taken in and out as many times as needed, screwing into the MDF will only hold up for one or two installations

Quote:

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Originally Posted by Gabe

MDF is much denser of a material making it preferable for speaker box construction as the sound is less likely to “leak” out of the enclosure.
It is also a more stable material, not prone to shrinkage/ expansion and is perfectly flat.
You want to ensure you pre drill all holes into the ends of the material to prevent splitting of the board. Use a quality wood glue on all joints
For mounting of the subwoofer itself, use “T-Nuts” and bolts to allow the speaker to be taken in and out as many times as needed, screwing into the MDF will only hold up for one or two installations

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Unless it gets wet...then you can watch expand... expand... and expand some more! LOL :)

You can use that 4 channel Alpine in a 3 way setup. It has the cross over abilities to make that happen. It's going to be light on the power for both the 6x9's and the sub, but it will work. Might as well give it a go and see how you like it. I've got a Alpine Mrv-f300 which is the slightly bigger brother to that amp collecting dust on a shelf may work a little better for you.

MDF is used for boxes because it's cheap, sturdy and easy to work with. For high end light weight boxes people use furniture grade Baltic Birch plywood but it's like 3x the cost of MDF.

Box design is looking good. Can't wait to watch it take shape.

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Originally Posted by Ghost Rider

Unless it gets wet...then you can watch expand... expand... and expand some more! LOL :)

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fair point

I've had a couple of those Alpine amps over the years, really good performers.

If you've got the line level input plug, should be a nice easy clean install.

I hate it when people ask for advice, and then do the exact opposite anyway, but this is an exercise of using surplus materials and installing a system on the cheap and cleaning off parts on the shelf. So I built the box out of 3/4” plywood left over from the basement reno. Glued, screwed, and biscuited, then all the internal seams sealed. Hopefully it sounds okay and holds together.

Next up: sanding and cleaning up my rough carpentry, and then adhering some automotive carpet to it. Then onto the wiring component of this project.

https://photos.smugmug.com/Audio/i-B...CA0FFAC2-S.jpg

https://photos.smugmug.com/Audio/i-4...574BF1B1-S.jpg

https://photos.smugmug.com/Audio/i-X...3AA081C3-S.jpg

Since we’re on the subject, I wanted to switch my stock headunit with a Bluetooth one. If I do this will I lose the power of my speakers ? The stock system is really loud and I want to keep it that way


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LOL! For this size of enclosure you should be OK. You may want to throw in some polyester fiberfill just to kill some standing waves. The other consideration is to consider a new amp as they are a lot more efficient and much more compact. (It's just something to consider not a must :D )

Quote:

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Originally Posted by RedSN

I hate it when people ask for advice, and then do the exact opposite anyway, but this is an exercise of using surplus materials and installing a system on the cheap and cleaning off parts on the shelf. So I built the box out of 3/4” plywood left over from the basement reno. Glued, screwed, and biscuited, then all the internal seams sealed. Hopefully it sounds okay and holds together.

Next up: sanding and cleaning up my rough carpentry, and then adhering some automotive carpet to it. Then onto the wiring component of this project.

https://photos.smugmug.com/Audio/i-B...CA0FFAC2-S.jpg

https://photos.smugmug.com/Audio/i-4...574BF1B1-S.jpg

https://photos.smugmug.com/Audio/i-X...3AA081C3-S.jpg

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You just need to buy a headunit that has a built in amplifier assuming that your existing headunit has built in power.

Quote:

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Originally Posted by Zutz2v

Since we’re on the subject, I wanted to switch my stock headunit with a Bluetooth one. If I do this will I lose the power of my speakers ? The stock system is really loud and I want to keep it that way


Sent from my iPhone using Tapatalk

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Quote:

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Originally Posted by Scrape

The other consideration is to consider a new amp as they are a lot more efficient and much more compact. (It's just something to consider not a must :D )

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The whole point of this exercise is to get rid of stuff, not buy more stuff. I don’t even need a sub in my truck! LOL

So far I have cleared out:

• A pair of 6x9 speakers
• A 10” sub speaker
• Some plywood scraps
• A handful of screws
• Half a tube of silicone
• An old amplifier
• some speaker wire

Carpet is going to be the one and only purchase for this project. And even that I contemplated just using some old paint I have lying around.

It’s more of just a low budget learning experience. Maybe my next audio project will include a new amp.

Quote:

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Originally Posted by Scrape

You just need to buy a headunit that has a built in amplifier assuming that your existing headunit has built in power.

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It’s the stock head that came with the 03 GT


Sent from my iPhone using Tapatalk

Quote:

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Originally Posted by RedSN

Carpet is going to be the one and only purchase for this project. And even that I contemplated just using some old paint I have lying around.

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Why not? Profile the edges, skim coat with bondo or drywall mud, sand and paint.

I made this enclosure for a buddy about 15 years ago, no carpet.
https://i.postimg.cc/TPMQ5q2X/box.jpg

I had this setup in my Dakota, built around early 2000.
https://i.postimg.cc/h4fZX0Vf/finishedbox.jpg

Oz Subs! I have an entire set sitting here at home. Beautiful sound from them. I knew the designer of those speakers.

Quote:

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Originally Posted by True Blue

Why not? Profile the edges, skim coat with bondo or drywall mud, sand and paint.

I made this enclosure for a buddy about 15 years ago, no carpet.
https://i.postimg.cc/TPMQ5q2X/box.jpg

I had this setup in my Dakota, built around early 2000.
https://i.postimg.cc/h4fZX0Vf/finishedbox.jpg

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Those subs were fantastic. Had them with me for 17 years in 3 vehicles and 4 different enclosures, sadly they went with the Dakota when I sold it in 2012.

Quote:

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Originally Posted by RedSN

The whole point of this exercise is to get rid of stuff, not buy more stuff. I don’t even need a sub in my truck! LOL

So far I have cleared out:

• A pair of 6x9 speakers
• A 10” sub speaker
• Some plywood scraps
• A handful of screws
• Half a tube of silicone
• An old amplifier
• some speaker wire

Carpet is going to be the one and only purchase for this project. And even that I contemplated just using some old paint I have lying around.

It’s more of just a low budget learning experience. Maybe my next audio project will include a new amp.

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I've got a roll of carpet from my horde I'd be willing to donate to the cause. I actually 2 rolls leftover and just can't throw them away.

Much appreciated, but I stopped at Princess Auto on my way home last night and picked up a couple of yards.
*now searches YouTube for “how to wrap a speaker box”