07 Honda Fit - Bangin on a Budget

[Polish 9]

Update time, I got a bit of work done today. See pics for progress.

 

 

New amp next to old amp. MB quart ONX1.1600D on the left MB Quart FX1.400 on the right.

 

 

OEM ground spot next to battery. Sanded to bare metal.

 

 

4 gauge engine block to battery ground. You can see the OEM wiring which grounds the engine block. I left it and added this 4 gauge to an empty bolt hole on the head. This is as close as I can get to grounding the alternator. I will be doing the positive feed from the alternator once I get some 0/1 and adding 0/1 grounds as well.

 

 

New 4 gauge battery to chassis ground added in conjunction with the OEM ground. It will be 0/1 eventually but I only had the 4 gauge to use for now.

 

 

2 gauge wire to amp connected to battery. I mistakenly had it on the lug to the right before this, I didn't realize it had an 80 amp fuse there. As you can see it's connected right to the battery now.

 

 

OEM battery (replacing with AGM soon) with new 2 gauge wire to amp and 2 new 4 gauge grounds.

 

 

Dirty engine bay with new 2g wiring to amp and new fuse holder. Also the 2 new 4 gauge grounds.  

Edited February 24, 2013 by Polish

[edouble101 314]

What you are measuring with your DVM is DCR. DCR is the speakers impedance at rest. The advertised impedance of a speaker (ie 4 ohms) is an average over a range of frequencies.  You measured 0.8 ohms which is accurate for a 0.5-1.0 ohm load at the amp. Based on t/s specs of the drivers you purchased and the wiring configuration you are using, 0.5 ohms should be the minimum impedance at your amplifier. 

 

A quick test for a DVM is to touch both probes together when in resistance mode. The display should be 0.00 (or to whatever decimal place it is).

[altoncustomtech 773]

I think it's coming together nicely.  You should be fine on that ground on the block, that's a plenty substantial piece of metal to ground to, lol.

[Polish 9]

What you are measuring with your DVM is DCR. DCR is the speakers impedance at rest. The advertised impedance of a speaker (ie 4 ohms) is an average over a range of frequencies.  You measured 0.8 ohms which is accurate for a 0.5-1.0 ohm load at the amp. Based on t/s specs of the drivers you purchased and the wiring configuration you are using, 0.5 ohms should be the minimum impedance at your amplifier. 

 

A quick test for a DVM is to touch both probes together when in resistance mode. The display should be 0.00 (or to whatever decimal place it is).

 

Thanks for the info, your post prompted me to do more research and I learned basically that a multimeter is not going to give an accurate reading of the speakers actual impedance like you said. I guess I assumed resistance and impedance were the same thing and assumed wrong. Thanks for posting this. 

 

I think it's coming together nicely.  You should be fine on that ground on the block, that's a plenty substantial piece of metal to ground to, lol.

 

Thanks Alton. I wasn't quite sure on the block thing, I see a lot of people saying to ground right to the alternator but mine doesn't have a grounding point that I can see. So I figured this would suffice since the alternator is bolted on right next to this spot. 

[Polish 9]

Well, I am a dumbass. I don't know what I was doing wrong the other day to get 7.9 ohms per coil but it wasn't right. I metered my box again and got the same .8 ohms but when I touch the probes together, I still get .3 ohms. So there is a little resistance in them. I loved how much power the amp was making at .5 but I didn't want to leave it like that due to it not being stable that low. So I pulled all 4 subs once again and checked each coil directly at the tinsel leads which got me about 4 ohms per coil, so the subs are correct. I wired each sub in series as I had it before and got about 8 ohms per sub, then paralleled them all and ended up at 2 ohms final load. So the amp won't make as much power but I'd rather play it safe. I'll eventually be upgrading anyway and will buy subs that give me a 1 ohm final load. Just finishing up the 2 gauge install today as well as some more sound deadening. More pics to come later.

[Polish 9]

I went ahead and pulled the back seats since I never use them anyway. I need more MDF to make a proper amp rack so it's just on basic amp board for now. I didn't bother making the wires pretty since I'll be getting MDF within the next week or two. This is what it's looking like for now. 

 

 

MB Quart ONX1.1600D plus a Scosche Distribution block which I am merely using to monitor the amps voltage for now. It only has 100 amp fuses in it  at the moment so I bypassed it for the time being. I did run some small wire direct from the amp power terminals though so I can watch voltage. 

 

 

The subs now centered in the back. I can't tell if it made any difference yet really since I made a lot of other changes at the same time.

 

 

What is left after the rear view mirror falls off. I have remounted it for now but I may need to modify the way it mounts if it keeps falling off. 

 

So that is the update for now.

[Polish 9]

New Vid for your viewing pleasure...

 

[Dictator 39]

looks good lanzar makes some good budget subs should try out the opti 15's next

[Polish 9]

Yea I am pretty impressed with them considering the price. I am not sure what I'll do next for the sub stage, thanks for the suggestion though. I need new batteries among other things first though.

[Polish 9]

Well I am a big giant fail. I was dinking around in WinIsd today (software I designed my box with for those unfamiliar with the name) and noticed a tragic error. I enter the Vas as L instead of Ft^3. It is still tuned to 33hz but the response plot changed drastically when I corrected the error. I thought I was getting a pretty decent gain at tuning frequency but it turns out, I don't get one at all. The peak is actually in the mid 50's, although it's not a huge peak. Needless to say, I want to build a new box now. I am thinking a 4th order is in order but we shall see. I may change woofers or just add 4 more as cheap as they are in order to get the amp down to 1 ohm. Having 8 10's certainly sounds like a fun time to me. 

[altoncustomtech 773]

Eight tens would definitely be some fun to play with.  Still tuned in for whatever direction this takes.  Keep up the good work!

[porkchop 304]

Increased cone area, increased space, increased power, New box design....

Wonder what those results will yield?

[Polish 9]

 

Eight tens would definitely be some fun to play with.  Still tuned in for whatever direction this takes.  Keep up the good work!

 

Thanks. I am leaning hard towards the 8 now, just not sure if I can fit them or not. I am pretty set on a 4th order now. I did lots of playing around in WinIsd last night and it would be pretty close as far as space goes but the results should blow the current ported box out of the water if I can make it fit.

 

Increased cone area, increased space, increased power, New box design....

Wonder what those results will yield?

 

If I don't mess the new box up it should yield some pretty good results. I just need to measure and see if I can fit all 8 for sure. I may have to settle for 6 but we'll see. The 6 would still drop the amp to 1.33ohms and give me almost full power but 8 just sounds so much more fun.

 

I know for sure I can fit it if I wall it off but I am not sure if I want to take that step or not quite yet. If I don't wall it I am not sure which way to face the port either. I am pretty sure it would gain more facing at the hatch but not quite sure and we all know the only way to find out for sure is to build it. 

Edited February 27, 2013 by Polish

[Polish 9]

Small update time. I've been measuring and doing calculations the last couple days here is what I've found. I can fit the 8 10's but the box size is limited so the performance increase over 4 isn't there since I can make the box for 4 much larger per driver. So I am going to stick with the 4 10's for the time being. I really need an amp for my highs anyway along with a front mounted voltage gauge and some other small stuff. So I am going to get that stuff ordered and installed before spending more money on subs I don't really need. The good news is I have come up with a pretty decent 4th order box for the 4 10's. It performs better than the current ported box all the way from 20 - 59hz with a 8-10db gain from 40-50hz. It's a 3:1 ratio so obviously it's going to be a bit peaky but thats fine with me since I am after the maximum spl with these cheap woofers. I'm going to try to get some MDF purchased this weekend so I can get started on the fun, stay tuned for updates.

[Polish 9]

Anyone have any input on the following two variables on my 4th order box.

 

1. Box orientation in car. I plan to face the port at the hatch to get the "loading effect". It seems like this should yield the best results without actually walling it off. Is there any reason to face it forward in a non walled car? The box will be just shy of 40" long in order to get enough air space while keeping the width/height low enough to get it in the car. So the non port end will be right up against the front seats. The port will be about 6" from the hatch. If I flip it the port would be blowing right in between the seats basically but I could slide it all the way back then, which would give me the 6" gap there.

 

2. I see most 4th orders have large vertical rectangular ports. Is there any reason for this aside from a "it's what fit" / "This is how I got enough sq^2 port area" type of thing or does it actually do something. I originally designed mine with a 20" x 8" port but could also do a 12.5" x 12.5" port with the same results - roughly 14-15 inches of port per cube of the ported section. I've read that square ports have a tendancy to be less noisy so I am more inclined to do that but when I see most everyone has these tall semi narrow ones it makes me wonder. I also see a lot of people with VERY short ports on their 4th orders. The only way I see the accomplish this is to be around 7.5-9 inches of port per cube of ported section. Is it that people don't care about sq/inches of port per cube or that they have some secret formula I am unaware of? The length of my port is roughly 9.5" whether square or rectangular.

 

Thanks for anyone who wants to shed share some thoughts.

[Polish 9]

I got my MDF for the 4th order, starting the build this weekend. I doubt I get it done but should have some updates. I sure hope this performs the way I think it should.

 

[Polish 9]

 

Most of the wood is cut, just gotta do the speaker cutouts and cut the wood for the port. I just slid the pieces around my current box to make sure it would fit. Then it's assembly time. 

[Polish 9]

Dang, just read some sound deadening threads and apparently this FatMat deadening I got is basically just peel and seal. That bums me out, I also found some photos of it melted and sliding off someones inner door panel. So that sucks, a lot. I have only done the hatch door, spare tire well and hatch sides with it though. I will get a better product for the doors, floor pan from the hatch forward, and roof. As the saying goes "you get what you pay for", I feel like an idiot. Oh well, live and learn.

[Quentin Jarrell 671]

that port will be too close to the bach hatch

[Polish 9]

It will be slid more forward than that, my current box is under all those panels. It should be about 8-9" from the hatch when I slide the new box against the front seats. I figured that should give it enough breathing room, if not I can flip the box around too and port it forward.

[handman84 60]

Great fun man, thanks for sharing. I'm going to use this to help me convince my buddy to start a build for his Fit! Love seeing the progress as it grows and evolves

[aimone 4]

if you never plan on using that fuse block for its real purpose u can pull the volt meter out. i had one identical to it and pulled the meter and used a length of speaker wire and mounted the meter up front and ran it to my amp. it worked great for a couple of years 

[Polish 9]

Great fun man, thanks for sharing. I'm going to use this to help me convince my buddy to start a build for his Fit! Love seeing the progress as it grows and evolves

 

Awesome, hopefully it helps convince him. There is plenty of room for beat in the back.

 

if you never plan on using that fuse block for its real purpose u can pull the volt meter out. i had one identical to it and pulled the meter and used a length of speaker wire and mounted the meter up front and ran it to my amp. it worked great for a couple of years 

 

Interesting, I never thought about that. I do plan to use it though when I add a highs amp soon.

 

 

Small update time. I made a bit of progress this weekend. In doing so I decided this is the last box I will build without a router, table saw, and nail gun. Doing it with a drill, jigsaw, and circular saw sucks so much. 

 

 

The start of the box itself, freaking huge...

 

 

Double layer baffle for the subs. Glued and screwed. Waiting a day for it to dry before I mount it in place. 

[Polish 9]

 

Got some more goodies for the box today. I guess the price of resin has gone up since I last bought it 10 years ago, or at least I don't remember it being so expensive. So I only got the smaller jug for now. I'll be using the mat pictured on the seams first then depending how much is left I might do some coats in other areas. I got some white paint for inside of the ported section, I've seen some other boxes done like this and like the look. I also got some 3/8" bolts for the port since I want it to be removable. I was going to screw it in but then realized that could be a problem if I need to access or swap the woofers later. Although it will still be hard with only a 13.5" x 13.5" opening but better than 12" x 12" plus the port will obviously not be in the way either. 

 

I also got a can of black plasti dip, didn't plan on it but saw it there and have wanted to try it out. I am going to cover the H logo on the front and rear of the car and see how it turns out. If I like it I plan to do my wheels in the future. 

[Quentin Jarrell 671]

If you want to save yourself some cash return the resin and mat.  It's not needed.  If your cuts are nice and straight all you need to do is run a small bead of wood glue on the inside of the seams.  If not then run a small bead of caulk.