Custom speaker box build (no subs)

[D Von]

Hey whats up guys, thanks for checkin this out.

For awhile now I've been designing an enclosure to hold (4) 6x9 speakers. I'll be installing the box in the extended cab of my 03 GMC Sonoma pickup.

The box will span the width of the cab and stand signifigantly high, I'm thinking to the bottom of the rear window. The speakers will run across the top of the box and fire up. I've done some research on the speakers and appearently this is how they sound best.

I'll post measurements, diagrams, and pictures in the next week or so, but until then I have a question:

Should i port the box and if so, where?

[PSPookie]

WinISD
http://www.linearteam.dk/

[hbarcat]

Originally Posted by D Von

Hey whats up guys, thanks for checkin this out.

For awhile now I've been designing an enclosure to hold (4) 6x9 speakers. I'll be installing the box in the extended cab of my 03 GMC Sonoma pickup.

The box will span the width of the cab and stand signifigantly high, I'm thinking to the bottom of the rear window. The speakers will run across the top of the box and fire up. I've done some research on the speakers and appearently this is how they sound best.

I'll post measurements, diagrams, and pictures in the next week or so, but until then I have a question:

Should i port the box and if so, where?

Go with a sealed box. Ported boxes are a huge hassle (if you're designing and building it yourself) and the tiny amount of benefit you might get from a ported box is far outweighed by the negatives. IMO.

In general, porting speaker boxes for vehicle use is not worthwhile like it is with speaker cabinets you'd use for in a home or for a club. The small space inside the vehicle vastly alters the bass response and boosts it to higher levels. With a sealed box, the response is smoother and flatter and more accurate. Porting will increase bass response but often results in boomy or unpleasant bass that is difficult to control within the vehicle. Ported boxes also require larger volume than sealed boxes, and usually you don't have lots of space to waste in a vehicle.

Also, you may or may not be able to find the necessary T/S parameters for your 6x9's in order to properly design the ported box, and an improperly designed ported box is just going to sound bad.

A sealed box generally handles more power than a ported box.

Check this out:

http://www.polkaudio.com/caraudio/su...eting_data.php

[D Von]

thats great man thanks a lot. i will make it a sealed box because i listen to mostly metal and tight bass is what im looking for. plus its a lot easier lol. should i seperate the speakers with mdf as i would with a regular sub enclosure?

[iamlowsound]

Originally Posted by D Von

thats great man thanks a lot. i will make it a sealed box because i listen to mostly metal and tight bass is what im looking for. plus its a lot easier lol. should i seperate the speakers with mdf as i would with a regular sub enclosure?

Yes.

lowsound

[hbarcat]

Originally Posted by D Von

should i seperate the speakers with mdf as i would with a regular sub enclosure?

Depends on how the speakers are wired. I assume that the two on the left are for the left channel and the two on the right are for the right channel?

If so, then I would separate the left pair from the right pair. There is no need to separate speakers that share a signal.

By the way, it's important to make sure to not have the total impedence of the speakers less than that recommended by the amp manufacturer or damage to the amp may result. Usually amps should not run with speaker loads less than 4 ohms per channel. If your speakers are each 4 ohm (most 6x9's are) then this results in 8 ohms per channel if you wire them in series and 2 ohms per channel if you wire them in paralell.

[D Von]

Originally Posted by hbarcat

Depends on how the speakers are wired. I assume that the two on the left are for the left channel and the two on the right are for the right channel?

i was considering a 4 channel amp... but once again, i find myself questioning my intellegence...

http://www.mtx.com/caraudio/products...ers/TE1004.cfm

this amp is like 600.00 and if i could get away with something cheaper that would put out enough power, that would be sweet.

[Joe Gress]

Look's like keith will have some competition with his unce-unce fail truck.

[hbarcat]

Originally Posted by D Von

i was considering a 4 channel amp... but once again, i find myself questioning my intellegence...

http://www.mtx.com/caraudio/products...ers/TE1004.cfm

this amp is like 600.00 and if i could get away with something cheaper that would put out enough power, that would be sweet.

Do you already have the speakers? If so, you should match the amp to the capabilities of the speakers. What speakers are you going to use?

[D Von]

Originally Posted by hbarcat

Do you already have the speakers? If so, you should match the amp to the capabilities of the speakers. What speakers are you going to use?

i have a liking for mtx stuff, and these are moderately priced and seem to be pretty powerful.

http://www.mtx.com/caraudio/products...exXThunder.cfm

i might change my mind and go with something similar, these seem to be hard to find since circuit city went under...

[D Von]

here's my half assed idea:



There is a bump in the bottom of back of the cab that I'll have to build the box around. Plus, there's a bracket used to attach the jack to that I'll have to notch out of the back.

That black space in the bottom of the side is what I'm concerned about, if that will ubstruct the sound quality. But I was considering just filling in that space with whatever, maybe framing it in and putting a piece of mdf right on top to make it flush. This would definitly make it easier to seperate the speakers too.

The grey square in the back is for the bracket I'll have to build around. And no I can't take that stupid thing off, it's attached to the frame!

This stuff is easy for me, I've been in the construction/ cabinetry field for four years. It's just the whole... speaker.... thing... that I'm oblivious too.

[D Von]

I found this about the speakers too:

Thunder 6" x 9" 3-way Speakers
Peak: 320 watts
RMS: 80 watts
Impedance: 4 ohms
Injected polypropylene cones
Rubber surround
High temperature aluminum voice coil with kapton former
13mm Mylar tweeter
2 1/4" Midrange
Oversized magnet
Grilles included
Frequency Response: 36 Hz - 22,000 Hz
Sensitivity: 93 dB

but like i said, anything similar that you can recommend?

[D Von]

i decided to go with kenwood 5 ways, really awesome speakers for 100 a set. and the dude at the local speaker shop is hooking me up with a 2 channel 600 watt orion (eek) amp for 200 bones.

the box is mostly built, all i have to do now is cut the holes for the speakers and attach the top. i went with 3/4 osb board, i wanted to use mdf but they were going to charge me like 60 bucks for a sheet and wouldn't cut it for me.

i did add a solid center support/ seperater. i wasn't sure if i was supposed to cut holes in it but i can always go back and drill a ton of holes if you think i should.

i'll post pictures once i get back from vacation and this bad girl is finished.

[Spector_Ray]

Originally Posted by D Von

i decided to go with kenwood 5 ways, really awesome speakers for 100 a set. and the dude at the local speaker shop is hooking me up with a 2 channel 600 watt orion (eek) amp for 200 bones.

the box is mostly built, all i have to do now is cut the holes for the speakers and attach the top. i went with 3/4 osb board, i wanted to use mdf but they were going to charge me like 60 bucks for a sheet and wouldn't cut it for me.

i did add a solid center support/ seperater. i wasn't sure if i was supposed to cut holes in it but i can always go back and drill a ton of holes if you think i should.

i'll post pictures once i get back from vacation and this bad girl is finished.

That's a lot of amp for 6x9's.

[D Von]

Originally Posted by Spector_Ray

That's a lot of amp for 6x9's.

for four 6x9's?

[yosemitesamiam]

Great thread! May I join in? I'm going to be building a bass cab as well...I have a JBL D130F (15" speaker made for the guitar famous showman amp). I'm sure it can handle bass as well. I am in search of the perfect head unit for it, of course...any ideas for me?

I too plan on a sealed enclosure, (thought the D130 loves its air, it will easily fill a 24,000 cubic foot room and over-drive front of house with 150 watts), just to keep the mud out, and keep my hearing and sanity! I know the big speaker sounds like overkill, but right now I'm from the "why buy something else if you already have that?" mentality.

[D Von]

Originally Posted by yosemitesamiam

Great thread!

yea right lol, people stopped helping me because i have almost no clue what i'm talking about. (even though i do appreciate everything hbarcat said.)

well, it really comes down to making something for yourself, and that sence of occomplishment you get. good luck on your box as well!

[Stanley Design]

Just put a plug adapter in the cigarette lighter and plug in some cheap and big bass combo that you find on craigslist. Then you'll have a jam amp at all times in your car and it'll be louder than balls. 300w bass amp will blow out 3000w car amp for sure.

[yosemitesamiam]

Originally Posted by D Von

yea right lol, people stopped helping me because i have almost no clue what i'm talking about. (even though i do appreciate everything hbarcat said.)

well, it really comes down to making something for yourself, and that sence of occomplishment you get. good luck on your box as well!

I know how to pick through BS...keep doing what you are doing!

[hbarcat]

Originally Posted by yosemitesamiam

I have a JBL D130F (15" speaker made for the guitar famous showman amp). I'm sure it can handle bass as well. I am in search of the perfect head unit for it, of course...any ideas for me?

That speaker is either 8 ohms or 16 ohms. Just so you know.

And you don't want to drive it with the head unit - you want to use a dedicated amp to drive a 15".