Custom Sub Box Project

[Sammy Sandbag]

Originally Posted by dman

Actually I think you are receiving TOO MUCH gain since you are using the high level outputs probably after the OEM amp. You are getting too much wattage from the OEM amp driving the inputs into your RF aftermarket amp causing the output of this amp into your speakers to be too powerful hence you have to turn the gains all the way down to compensate. You definitely need to use a LOC as smoke suggests. Should sound great afterwards. Good luck!

Well I got a LOC, and same thing happened. Then I tried splicing into the rear channel, and it worked using the amp's speaker inputs. The factory sub inputs must be really weird or something. Either way, I got it tweaked to about my liking. Now I'm working on the amp install and wiring it up permanently.

[smoketitan]

Originally Posted by sammy sandbag

Well I got a LOC, and same thing happened. Then I tried splicing into the rear channel, and it worked using the amp's speaker inputs. The factory sub inputs must be really weird or something. Either way, I got it tweaked to about my liking. Now I'm working on the amp install and wiring it up permanently.

so you pliced after the stock amp with your loc, or at the deck rear channels?? I got a little confused. when you had the problem with your gain did you splice using the front channels at the deck or after the stock amp??

[Sammy Sandbag]

I was splicing post OEM amp, right at where the factory connector plugs into the amp. Now I've removed the B pillar platic and spliced into the speaker wires for the driver side rear door.

[smoketitan]

Originally Posted by sammy sandbag

I was splicing post OEM amp, right at where the factory connector plugs into the amp. Now I've removed the B pillar platic and spliced into the speaker wires for the driver side rear door.

now I see why you had a prob, as you were splicing into a amplified signal if I read you right ( post OEM amp??) . anyway it is always better for SQ to splice as close to the sound source as possible ( ie at the deck), since as you can see the stock wires are rally small somthing like 18 to 20 guage--so you are sending a weakend signal over a longer distance--therefore more voltage drop----

if you are spliced after the amp you are dealing witha signal that is not only amplified at 2 ohms (not 4ohms like I assume your amp is as most are), but the stock amp especially at the sub channel ,and tweets crosses over the sound at a certain khz spot---designed by fosgate. so taking that signal will cause mucho problems at the new input ( your aftermarket amp)


. may I ask though what is the b-pillar plastic??

[Sammy Sandbag]

Well, amps aren't rated in ohms, speakers are. You can change the ohm load by how you wire you speakers, parallel, series, mono/stereo, etc. That shouldn't matter as long as I get a decent signal. The problem was the factory sub works off some funky freqs that my subs didn't like, plus I didn't have enough gain adjustment to make it work. Running it off a full (non crossover) signal gave me a better signal and I was able to adjust it down using the crossover on the amp. It's good enough for me, I'm not planning on digging under the dash to find pre amp signal wires. B-pillar: crew cabs have a A, B, and C pillar. A being at the windshield, B being between the front and rear seats, and C being at the rear glass. The B pillar is the one that the front seat seat-belts attach to. I took out the interior plastic moulding to get at the speaker wires for the left rear door's speaker. BTW, positive is black with a yellow stripe and negative is baby blue.

[smoketitan]

got ya on the pillar now I just didnt know that was what is was called9 I have a crew also). I am pulling the whole interior out this weekend so getting to the dash is no worry for me--but either way I am glad you got yours to work to your liking

[Sammy Sandbag]

Thanks for the help smoketitan, even though the LOC wasn't needed, it was worth a try. Trial and error and so forth. I bought the LOC at a local shop and made sure I could return it, so no sweat off my back. Right now I'm making a mount for the amp under the driver's seat, then all I have left to do is finish the wiring. I just got a call telling me that I'll be heading out of town for work, so I probably won't get to it till later tomorrow.

[Sammy Sandbag]

Okay, here's the update. Got everything wired up. Let's just say I'm not really happy with the sound. It's got a nice thump, but not what I was hoping for. Overall, it's got more bass but at a lower quality than the factory sub. Well, this is how we learn, trial and error.

So here's my next proposal: make a new sealed box with a single 10" powered by the same amp bridged. My amp specs say 250W rms at 4Ω when bridged. So, I looked at the Crutchfield catalog to see what they had in that range. The closest canidates are the Infinity Reference 1030w with a power range of 50-250 watts rms. Also the JBL GT Series GT100 with a power range of 55-250. There's also the Infinity Kappa 100.3dvc, Pioneer TS-W254f, and MTX Thunder 4500 that are all close to that power rating.

So can I get some advice on what to do here? If I do do this, I will probably also take smoketitan's advice and wire the amp from a LOC between the HU and OEM amp and wire the RF amp with some RCA cables. As of now, I'm getting a "pop" from the subs when I first turn the key to on, probably because of the high powered inputs.

[smoketitan]

Hey sammy here is the deal I just mounted my fronts, I will get to the rest this weekend (waiting for the post man to deliver my new wire) let me get back on how it sounds from the deck to the LOC--so I can give you first hand experience for a 10" woofer Id highly recommend looking at a adire audio koda 10" ($229 300w rms) http://www.adireaudio.com/StockProdu...rs.htm#KodaSub or a id10 v3 ($129 250w rms) http://www.cardomain.com/item/IDSID10V3D2


I have a small ecosure to put under the front seat like stock using a RE 8 that I also still waitng for. anyway good luck. be careful with that pop not to damage your sub

[Sammy Sandbag]

Thanks SmokeTitan. I'm not looking to spend a whole lot of money here, so a $229 sub is out of the question. Those that I provided links for are more in my price range, the image dynamics one you list is do-able. The plan is to mount it facing down similar to other boxes people have posted on here, just under one seat though. The required volume should work. As for the pop, it's not loud, just noticable. I think it's the speaker inputs, because it never did it with my RCA inputs in my old truck. A coworker has two Kenwood 10's for sale, but I haven't got a chance to look at them or get the specific model numbers. What is Kenwood's reputation these days? I know their HU's aren't all that great.

[smoketitan]

kenwood subs are okay---You may want to check out two eights with your power limitations--250w isnt a lot for a high end sub---what can you get at 2 ohm??. you can get two Resonant engineering 8" woofers for $50 each(http://www.respl.com you have to buy direct to get the cheaper price)--send your 250W @ 4ohms, or even better run them at 2ohmns for more power and they will sound as good as most average 12" woofer for a hunderd bucks plus shipping. of those you posted the infinity kappa will probably sound the best.

so anyway good luck

[Sammy Sandbag]

The amp I have, minimum load is 4Ω when run in mono. So 250W rms is the most it can push. But if those subs I listed have a max rms of 250w, it should be good right? Like I said earlier, I'm no audiophile. If I went with a higher end 10" that required more power, I'd have to get a new amp as well. 2Ω subs would have to be DVC to run it in mono.

[smoketitan]

cool then just go with the id 10 I recommended or the infinty kappas (these are cool 10's)--before you buy more speakers though try the loc at the head unit and use the rca inputs. it may save you some money--but wil require more time or just wait until sunday or monday and I can tell you how mine goes to give you more of an idea on your next step

[Sammy Sandbag]

Well, I'll be waiting anyways, I'm headed out of town. I've never heard of the id's, do you know of any good review sites out there. The cardomain site didn't have any reviews listed for it. The kappas had good reviews though. I doubt locating the loc at the HU will improve the sound that much. These 8's are pretty old and pretty cheap. A sealed box with a mono sub with more power should give me a better sound anyways.

[jimcav]

great job on the sub enclosure did you do something with the head unit and or add amps