Small Truck, Big Woofer, Need a New Box???

[SDMorris]

Hey everyone. I have a 1997 Ford Ranger Extended Cab. As im sure you all can imagine, even being an extended cab its still quite a small truck. Currently I am running a single 15" DC Level 4. It is hooked up to a MTX Thunder 1501D amp. This subwoofer was bought locally by a friend of mine from a guy that he said was running it in an extended cab Chevy Silverado. I have the gain and EQ both about halfway up on the amp, so im not feeding a WHOLE lot of power to it, considering the Level 4 could probably take the entire force of that amp. Although, even at the settings its at, after playing for a little while I can start to smell coil and the sub starts to heat up, so much that the dust cap is warm to the touch. Im trying to pin-point my problem here, but im not quite sure what it is.

Using the RE box calculator, I figured out that the box is tuned at almost exactly 50hz and about 3.8c/f... first off im not sure if I used the program correctly, but here are my dimensions:

(The MDF is .75" thick)

Box:

W: 32"

H: 20"

L: 16.5"

The Port dimensions are:

W: 5.5"

H: 13.5

L: 15"

Speaking to Rusty, he said that the box is about 1-1.5c/f too big, and I have too much sq/in of port. Ok, I have already drawn up plans for a new box, but money is an issue.

Do you guys think the box size/tuning compared to the size of the cab could be a problem? Im kinda stuck as to why this thing heats up the way it does.

Also, could it be my electrical? I know... im probably gonna catch a couple "What the hell are you thinking" remarks off this, but I really haven't done much to the electrical yet. Pretty much the only thing "Electrical" different about my truck is 6 gauge (Yes, 6) power wire and ground wire for the amp. I was running a cheap flea market Lanzar audio amp before this amp that got some water damage.. (leaky back window seal :censored:) so I bought this amp, knowing it was a much better amp, atleast then what I had. Musically the amp is MUCH cleaner, the bass sounds WAY cleaner and a good bit louder even considering the amp is turned down.

I know this amp wants more power, I get light dim after 10 or so minutes with the lights on and the battery meter on the dash drops when the bass hits, so I dont bump at night usually. I have about 8ft of 4 gauge on hand that I am planning on using to do a big 3 soon with, as in tomorrow or the next day.

So, why do you guys think the sub gets hot and the coil starts smelling? It's obvious the sub isn't at FULL power handling, I mean it moves pretty dang good but I know for a fact its got more in it, but it just gets too damn hot. Please help!! Thanks

Sean

[dwright27]

probably playing wayyyy below that 50 hz tuning for an extended period of time. may even be clipping it a bit to much.

edit: expos cal says 4 cubes after displacement @ 48 hz with 75 square inches of port.

so around 18 or 19 square inches per cube.

that tuning is too high for daily imo though.

Edited January 26, 2010 by dwright27

[SDMorris]

That is a good possibility now that I think about it. So you think a new box will solve the problem?

[matt402]

tuning = too hi.

tune to lo-mid 30s & upgrade electrical

i have heard a pure spl system on music tuned to 70hz tho... :01nocomment8so: .

[Torres]

yes imo the tuning is way too high for a daily box. also...just because the gain is 'turned halfway up' does not mean that it has more power to give. the gain matches the head units preout voltage. so if it has a high voltage, it could be turned a quarter of the way for full output, or if if has low voltage, it could be turned 3/4 of the way for full output. so it's possible you have too much gain turned and sending a very clipped signal to your sub causing it to heat up like it is.

redoing the box will definitely help. afterwards i'd reset the amp properly

EDIT: wow and DEFINITELY DEFINITELY upgrade your power wire. i use bigger wire for speaker wire. let alone power wire your amp is trying to suck a milkshake through a coffee straw right now

Edited January 26, 2010 by Torres

[Beanz]

DUDE that mtx has 0/1 gauge inputs for a reason.that thing is gonna blow somday if you dont upgrade soon.

[SDMorris]

Edit: BTW can someone throw the numbers of my box who really knows what their doing with a box calculator together, and tell me if I got my numbers right? Please and thank you

Ok thanks guys, then im definitely going to build a new box ASAP. I was thinking tuning around 35hz? You think that will still hit the lows nice and give good highs in the small cab of my truck? The amp was tuned by a professional. Petey is a local guy here on the DC Street Team and I believe the other DC team (the really serious team) him and rusty are good friends, and im pretty good friends with Petey. He tuned the amp for me the day I got it. My head unit has 4v preout.

Actually I think my amp only has 4 gauge imputs. I have the MTX Thunder 1501D, not the Thunder Elite 1501D. But I do agree either way, I need some bigger damn power wire and need to stop being a cheap kid doing whatever I can for some boom boom.

Also, im curious, as I've never experienced listening to a system after a major box change like im planning to do. I do listen to lots of rap, and I really like them low notes. I'd say most of my favorite songs to bang dont go past 40hz mostly. How much of a difference in loudness do you think I'll get? I was told my system is probably only mid 30s right now on the db meter, which I think is pretty pathetic for what I have. When the lows come out, you can hear them, but I knowww it should be WAY louder. With my windows halfway down, they move like crazy in the doors and my dash moves up and down along with my steering wheel, and the outside of my cab on the backside by the bed flexes like hell, as does the window. But it needs to be louderr

Also, I DO listen to a gooood amount of Country music and Rock. Usually I just turn down the sub to like -15 -20 on my deck. Same deal when I change the box?

Edited January 26, 2010 by SDMorris

[SDMorris]

[matt402]

yes imo the tuning is way too high for a daily box. also...just because the gain is 'turned halfway up' does not mean that it has more power to give. the gain matches the head units preout voltage. so if it has a high voltage, it could be turned a quarter of the way for full output, or if if has low voltage, it could be turned 3/4 of the way for full output. so it's possible you have too much gain turned and sending a very clipped signal to your sub causing it to heat up like it is.

redoing the box will definitely help. afterwards i'd reset the amp properly

EDIT: wow and DEFINITELY DEFINITELY upgrade your power wire. i use bigger wire for speaker wire. let alone power wire your amp is trying to suck a milkshake through a coffee straw right now

use this guys calculator .

[SDMorris]

use this guys calculator .

Hmm, thanks. I worry myself sometimes, that was right in front of my nose and I didnt see it. lol. So according to THAT one, I am at about 40hz before displacement and 4.22sq/ft of airspace. This worries me now, I mean is playing low to mid 30hz notes in a 40hz box really going to heat up that Level 4 that much? I have a feeling the box isnt the culprit now with the heating issue. Now, with the sub not being as loud as it should... I believe its the problem.

Anyone know where I can get a good 40hz test tone?