Running an alpine 300w amp for my door speakers. Plus a pioneer 760w for a 12" sub.

Happy with the volume, and the sub keeps up 90% of the time. But if there's a heavier bass hit it clips out the odd time.

Obviously it's not getting enough power to stay happy. From what I've read capacitors are a no-no.

My question is what next on the chopping block? H.O alt? big 3? 2nd Battery?

Basically I want to fix this issue so the odd song that has a heavier bass hit can play through and then back to the music it doesn't have a problem playing.

In lamen's terms I don't want to throw a bunch of money into it, I just want a bit better performance.

Thanks if anyone could offer some help!

 

Better performance would be ditch the pioneer amp and go with a better brand. If you wanna keep it then we need more info, what are the amp specs? The subwoofer specs? What ohm load is the sub wired too? What size power wire did you use? What's the gain set at? Etc..

 

Its a pioneer gm 5400t, bridged at 4 ohms. Gain is set to normal, I think +6db on bass boost. 4gauge power wire, to a distribution block. Then tee's off with two short 8 ga. wires to each amp.

http://www.pioneerelectronics.com/PU...eries/GM-5400T

Subwoofer is an older mtx roadthunder (not the best I know).

http://www.mtx.com/mobile/products/s...ries/show.html

If it matters the speaker enlosure is sealed and a little over a cubic ft. Corresponds with manufacturers recommendation.

The amp is only a yr old, flush mounted in my sub box. in hindsight I should've just bought a smaller mono amp but didn't know any better at the time.

Thanks

 

One problem is the amp is mounted to the box, not the best way to do it because when the bass gets going it can rattle around all the internals a lot more than say if it was just sitting on the floor beside it, so that could be the cause of your problem. Or depending on how high the volume is set on the radio, and where the bass settings are set on that, you could be momentarily putting the amp in protect mode/thermal protect mode depending if the amp is trying to work too hard. You may just have to back down the settings some until you can upgrade the amp in the future.

It's definitely not because the amp isn't getting enough power, that would cause issues more like dimming or fuse popping if it was trying to draw too much. But the big three is still definitely not a bad thing to do, but what you have definitely doesn't warrant the need of a ho alt or a second battery. And for what's its worth another issue could be that of that 380watts rms for 4ohms bridged is only about 2-250 watts of clean power.

Also I'm assumin you have the single 4ohm model of that sub?

 

Yea I believe its a single voice coil.

And I agree about the location I regretted it soon after I built the box. Did some reading and realized its not the best spot.

Funny cause even playing with bass settings etc which are all pretty minimal/moderate. It just doesn't want to play certain notes.

Wonder If I should switch it back to a single channel. I will probably relocate it tonight if I still have enough wiring.

Thought pioneer was a decent brand, but I'll admit I like my alpine components better.

 

Pioneers good for door speakers, they're okay for subs, but their amps are just poor over-priced junk ha. It could be the amp also filtering out certain notes, does the amp have a hi/lo pass filter on it? Also are you still using the stock head unit?

 

Alpine cda 105 yes the amp has a lpf only which is switched on.

Gain was higher than I thought but I've dialed it back and relocated the amp. Thinking of enlargening the speaker box and throwing a port in. Just cause I've always ran vented enclosures in the past.

Thanks a lot for your help so far

 

So I have a few questions. What kind of box is it? Home made? store bought? 1/2", 3/8" 3/4"? how much over 1 cube? What is the gain at on the amp? is the +6 on the deck? is your bass boost on as well? Are you running Low pass RCAs or high level input?

Those aside, yes running 8 guage to those amps, to me at least is a no no. Maybe ok if its true guage OFC but most arent. And a sealed box will NEVER go low and depending on the size and shape it can actually lower the output of the sub.

Yes get that sub into a ported box as close to 2.25 cube and port it to anywhere in the 32-40Hz range you'll be laughing. Do not go lower than 32 Hz, the subs xmax is only a little over 10 MM.

Also, why do you say caps are bad? The cheap ones that say 2,3,4,10 farad and are smaller than a pop can. Yup those are bad. Get a good 1f or 2f. and they are awesome. A new battery like from kinetik or xs power are great but 3 times the cost of a cap. And for what your running you dont need a new bat or new alternator.
Definetly do the big 3 it will help a bit as well.

 

Do you even know what a caps orgininal intended purpose is? It's not to provide extra power, it's to smooth out response for better sq. It's not a fix for dimming issues.

 

Heh, you guys are really racking my brain here lol. That's good though. Ok.

-I'm a carpenter so the box is custom, I rebuilt it last night to 2.25 cf.

- RCA's

-Really. I have 4 ga. extending to the back of the truck then about 20" to the mid amp, and 4" to the sub amp. With those distances I'm surely not losing much voltage I would think?

- I've had car stereo's for a decade, but this so far is as in depth as I've ever been (multiple amp, replacing factory wiring in doors). The box now has a 3" port in one end about 2" from the opposing side/wall. As far as porting it to a specific frequency range. Your speaking a whole different language now, lol.

-I've always read/been told they are a bandaid fix *see below. I suppose because they're used improperly most of the time.

I think I follow what you're saying with "a sealed box with never go low". Now that its ported I can dial back the gain (I always adjust from the amp, then fine tune a bit with the deck).

After running a sealed box for a while I miss the punch a bit. But I guess if I want the best of both worlds I'd need to do a bandpass.

Well I know what they do in that they store energy. Now I may be wrong but I thought they were to reduce whatever spikes you'd have in the voltage system. Or provide a stable current I guess is better wording. I was under the impression they would help with dimming but aren't designed to?

I just recently started learning about adjusting hpf/lpf frequency's. So I'll admit you guys seem to know alot more than I. Thanks for sharing your knowledge.

 

My understanding when amps start clipping it means there isnt enough power or to much power. Would look into mono amp for sub,, which should help the problem. Also maybe find a diff sub to compliment the amp you choose. Maybe use the poineer amp for the doors. Dont think the tech terms help you much. Just rearrange the setup. Maybe replace one or two items (sub and mono amp). Or just use the alpine for the sub.
You sound like you know what your doin or at least have some idea of what your doin.
oh low pass for sub just in case.


good luck

 

Your correct in that they're used to smooth out voltage spikes, but it's to provide an even, smooth current to the amp to take out any "hiccups" in the sound quality. But most people are under the impression that they're like a small battery, and even I'll admit when I first got into car audio that's what I thought they were because that's what most retail shops will sell them as.

Now onto tuning frequency, If you want deep bass and want it to sound good, then port is all key. A 3" port maybe undersized and depending how hard your pushing the sub you may generate some chuffing sound, basically the air coming out of the port may start to become audible. Length of the port is a major factor in how it'll sound. This is how your tuning frequency will be decided. For deep bass most tune to around 32-34hz. To get your tuning frequency you'll need the box volume after both port and sub displacement and then you can plug it into an online calculator to see where your tuned. Generally youll use one of those calcs to see how long your port needs to be by entering air space after displacement, port opening size, and desired tuning frequency.

Deepening where you tuning you can possibly damage the sub if you tuned too low (like below 30hz) because your sub isn't built for that kind of playing. If you tune too high (above 38-40hz) you'll lose majority of both your low end output, and if you try to play rap songs that have low notes you can damage the sun again because you'll essentially be unloading the sub and it will be playing "free-air", basically acting as if it wasn't in a box at all.

I wouldn't recommend bandpass if you want deep bass, bandpass is generally good for the 38ish-45ish hz range and has sharp drop offs outside that range. And sealed boxes can get low, sure not as low as a ported, but its all dependent on the sub and how much excursion it has and how much power your feeding it. In your case your sub really isn't made to get low.

8 gauge power and ground is more than sufficient for the amount of power that amp requires. Going to 4 gauge all the way through wouldn't hurt, but it won't make a lot of difference. Doing the big three is what makes the most difference.

Mono class d amps will draw less current than a class a or a/b amp because those amps aren't as focused on sq as they are on raw power. That's why most subs run of class d (less audible difference of quality) versus door speakers where pretty much everyone runs class a or a/b amps on door speakers because the audible difference is more noticeable.

 

Well that's the good thing about cheap subs, if it goes I get a better one. I don't push it very hard though.

I'll look into calculating my port length. It was a noticable improvement moving the amp and having the re-vamped box. Think cause it's a lower quality sub just having it push more air around helps its cause. It hasn't "clipped out since", and its definitely gained some db.

I read about different class amps when I bought my mid amp. The pioneer was kind of a quick replacement as my Kenwood finally died. But thanks for the reminder.

Alright that's enough brain activity for my tues night hah.

 

I would bet it's an Impedance issue . He said he thinks it's a 4 ohm sub . You need to find out for sure . Is it Svc or Dvc ? You are probably running that amp at 1 or 2 Ohm Mono which is a no no .

 

nevermind