TragicMagic

Hey guys,

The two speakers that came out of my fiancee's 2008 Accent are a couple of 6.5" 20WRMS speakers.

I want to build two separate enclosures for them. Ported, and tuned to 120Hz. I'm thinking it might enhance the mid-bass frequencies, and therefore have a "fuller" sound. I'm going to use them for my garage, once I get a used stereo receiver from a garage sale or something.

So, at http://www.carstereo.com/help/Articles.cfm?id=31, if I fill in the parameters: one 6.5" driver, with a 4mm XMAX, with a 120Hz tuning frequency, it states that the minimum port diameter should be 2.8", to avoid port noise.

Now, I've been taking 3" ID cardboard tubes, that would normally end up in the garbage, from work. They're the inner tube of plastic wrap or wax paper rolls.

I want each box to be an 8" cube. With .5" MDF, Rockford Fosgate's BoxWizard states that I'll have an internal volume of .2cu.ft.

A 6" length of cardboard tube with an O.D of 3.375", has a volume of .031cu.ft ( You can double-check if you'd like. ) Subtract .03 from .2, and you have .17cuft.

According to the Port Calculator site, a .17cu.ft box with a 6" long by 3" diameter port, will be tuned to about 116Hz.

Just wanted a second opinion on this. Am I wasting my time porting a low output speaker like this? The port material, and the labour is free, so I might as well try it out.

Now, while figuring out the number/calculations, I noticed that if I were to make a bigger box, the length of the port needed to tune to 116Hz decreases. At .3cu.ft, it says I'd only need a port 2.5" long. My question is whether or not the length of the port effects how well a port will sound. Does that make any sense?

I should find out, how exactly a port works...

Thanks guys.

jalat

iTrader: (6)

i would say that is it were like a bookself speaker, one with a seperate mid, and tweeter setup it would sound like a great idea to port the mid and seal the tweeter, but if its just the speakers itself, i say sealed them up.

i'm not too good with things like this though, its just athought

TragicMagic

I've actually been hitting up the Value Village in town. They sometimes have speakers from older Stereo/CD players, without the player. Most of what I've pulled out of these boxes are little 3" woofers. One box had a 4", and a tweeter. On the positive wire going to the tweeter there was a little black cylindrical thing, the wire being soldered to either end. This is the "filter" right? Does anyone know where I can go to buy a handful of these?
Upon a brief search, I see there called capacitors and come in many variations.

I'm thinking I might turn these 3" paper cone speakers into tweeters, by using one of these capacitors.

Is there a way to use these to band-pass the frequencies going to the tweeter? Can I put one in that only allows frequencies higher than 2500Hz through, and then a second one that removes the frequencies around 16000Hz? I'm only using these number to form the question, not actually suggesting these are what I'd use.

What about the rate of the cut-off? Are there capacitors that have the same x-over frequency, but varying degrees of slope? Can I find one that does 2500Hz at 6db/Octave, and another one that does it at 12 or 24db/Octave?

I'm not looking to make beautiful sounding speakers. I just want to send frequencies to these speakers that allows them to play well...

Does anyone know a sight/forum that I can get good info on this sort of thing?

aussie1978

Tragic, if theres a specific site for home audio you want i would go to diyAudio.com - audio projects by fanatics, for fanatics and see if you can find more info on there (and they're friendly too) - on that note, i know theres quite a few guys here that would be able to answer your questions too. If it were me i would not make the box a cube shape, for mids it seems to make the sound very muddy (due to internal reflections). Have you ever seen a good home speaker in a cube? me either...

TragicMagic

Thanks Aussie. I'll check that site out.

I was hoping to port these boxes to simply allow the relatively weak speakers to still produce some mid-bass with some volume, as opposed to prosition. I can definitely change the depth of the boxes, they don't have to be 8". It was more of an attempt to keep things simple for myself.
I want to have as much of the frequency range being produced by these speakers, and the port, as they can physical handle...

codtripwire

aawwww.... heck i've played with this type o crappola, some good.some bad ontairo? e-bay, buddy...someting like ssmb8 full range, then a cheap set of components for top fill/ that way tweet is protected from internal sonic waves(by construction) and by crossover,build the inclosure with the back pannell tapered wide at the base to much narrower at the top,and to cheap out,carpet underlay line the inside of the box. just try to make the box narrow on the face & deep from face to back. ceck, even any cheap sub driver single 4 ohm bass driver will more than fill the void. final imp after comp/sub per box will be 8 ohms....

codtripwire

easy for me to say i realise,i've got a massive stockpile of new crap that i'm never gonna use....for this type o' thing.(shameless plug....tons of kicker + other stuff gonna be for sale CHEAP pm)