forsete

To begin with, not only am I a car audio rookie, but English is not my native tongue, so please bare (bear?) with me. My mission is to get an over-all better than stock sound, without spending a lot of money. I have no intention of competing or anything remotely close to it. Most of you would rather listen to your grandma sitting in your backseat singing out of key than to listen to my system, but I am very happy with it. I’m constantly working on improving my stereo system, and until now everything has been smooth sailing.

The Setup:
Head Unit – Stock Delco, with built-in 5-band EQ.
Front speakers – Stock 4x6” super high quality paper speakers running off LF and RF
Rear speakers – 190w 6 ˝ “ 3-way Sony’s running off LF and RF
Subs – two 10” 100w RMS 350w Max Pioneer’s running of LR and RR
Amp #1 ‘6-ch.’ Jensen KA 4040HLx, 500w total power, 150w MAX bridged
Amp #2 2-ch. Phase Linear PL300, 300w (installed, but not hooked up)
Amp #3 2-ch. Phase Linear PL300, 300w (installed, but not hooked up)
(200w RMS, 400w(?) peak bridged)
Sub Box – custom-built fiberglass box, 0.8 cu. Ft. sealed (each chamber)
Monster cables, yada yada yada

Ok, my first question, or statement is; there is no way in hell that I can run all of this on my stock alternator, right? I’m not 100% sure but I think the alternator puts out 85 Ampere. If my calculations are correct I need at least 105-110 Ampere for the 3 amps. So before I hook everything up I will need at least a 140-ampere high output alternator, right?
Besides that, I don’t think there should be any problems. The battery seems to be fairly new. I have never had a problem starting the car, even after 30+ minutes of playing the radio when parked. The battery puts out (maybe wrong terminology?) 630 CA at 32 deg. F. and 525 CCA at 0 deg. F. (I live in So-Cal)

My second question/statement:
Currently I have 8-awg power and ground cable. That will not be sufficient for 600w RMS, will it? (1200w peak?)(Seems grossly over-rated)
Will I need to run 4-awg wire and get a distribution block to run 8-awg to each amp?
And how about fuses and such? Currently I have one 40 (or is it 60?) ampere fuse about 3-6 inches away from the battery. Can I just replace the fuse and/or fuse holder with a 100-ish fuse, or will I need some sort of fuse box type thing (if there is such a monster).

Third question:
Until recently I have had nothing but smooth sailing. Nice, deep, clear bass with distinguishable variations, not just a loud muddy all-in-one bass; but for the past week or so I have had this strange problem with my left sub. Every few minutes the left sub stops working. It makes a sound resembling stretching leather or rubber, raises up as much as is can, then pops as if pressure has been released, then starts working again. The subs are specifically for sealed boxes, so the strange phenomenon completely baffles me. Any ideas? Is my sub about do die?

Fourth question:
What budget ($40-100) 4x6 speakers would you guys recommend as front stage, that works best with 50w RMS, 100W peak? I really need to replace those fine paper coned front speakers.

Thanks for reading this novel and answering any question…

Belker

First off, I'm going to assume that the power output that you stated are peak power and not RMS power. RMS power is much more meaningful than Peak and is what most people into car audio always refer to. So I'm assuming your amps actually put out 250w + 150w + 150w RMS at 4 omhs. Sorry ... I see later that you refer to 600w RMS ... so I guess you already got this.

Now, to calculate the current draw you first need to know the effeciency of your amps and your system voltage. For your amps I'd assume they are 60% efficient and I'll assume your system voltage is 13V (which is close).

250w + 150w + 150w = 550watts output

550w/0.60 = 917watts input

i=p/v, so i = 917w / 13v = 70.5 amps

This is the peak current draw. This sounds much better to you than 110a, right? It gets even better. Because of the dynamic nature of music, the vast majority of the time you will only draw about 10% of this peak value. So ... the vast majority of the time the amps will only draw less than 10 amps. (Note: this is not true for a SPL/dB competition vehicle.)

For the average car, the vast majority of the time it will draw about 30 amps. This is not the case if you were running headlights, foglights, wipers, heater, defroster, horn, power locks and windows, ect. ALL AT THE SAME TIME.

In conclusion, if your car is drawing 30 amps, and your stereo is drawing 10 amps, and you have a 85 amp alternator, then there is NO PROBLEM.

As a side note: most aftermarket, high-output alternators actually put out LESS CURRENT than a factory alternator except at high engine RPM levels.

Another way to look at it is: "If your car starts in the morning, then your alternator is fine."

I would keep your stock alternator (especially if it is the originial Delco unit) and your battery is fairly new ... so you're in good shape.

Now to your wiring. Upgrade the factory ground for the battery. Upgrade the factory ground between the engine block and the chassis. Upgrade the factory wiring from the alternator to the battery. This will be alot cheaper than a HO alt. and will allow your stock alt. to work to its full potential.

Also, upgrade your stereo power wire and grounds. They should both be the same size. 8awg is too small. 4awg should work ok but I'd get 2awg because it won't be all that much more expensive and it will keep you from having to upgrade the wire again in the future. The amp's ground wires should be as short as possible and have good connection points (ie.- ground to the floor pan, sand off the paint, and use a bolt).

Fuses: You should use a fuse close to the battery. This fuse is to protect the power wire running to the back of the vehicle from shorts, nothing else. 60a is the biggest you can get in a AGU style. If thats what you have, I'd just keep it and see if it blows before upgrading. You may need a ANL style fuse holder and fuse.

You should also USE A FUSED DISTRIBUTION BLOCK. The fuses in the block will protect the smaller wires between the d-block and the amps in the event of a short. Anytime you have a reduction in wire size you should use a fuse to protect the smaller wire.

The amps should each have fuses. These fuses protect the internal circuitry of the amps (and you should never change them to higher value ones). The other fuses (above) are to protect the wires.

You strange SUB PROBLEM: I'd try this. Remove the left sub and mount it in the box where the right one is right now. Put the right one where the left is. Do you still have the problem? If so, then you've eliminated the amp, wiring, or connections as being the sourch of the problem. If the problem went away, then its obviously one of those three things.

It way be that you have a large piece of dust stuck in the voice coil of the sub. The only remedy (without rebuilding the sub) that I can think of is to manually push the cone up and down with your hand a bunch of times. This may dislodge the partical or break it up into smaller pieces. This could damage the coil but you really have nothig to lose.

4x6 speakers: I strongly recommend that you do not get Pioneer, Sony Explode, or budget brands like Jenson, ect. I like Boston Accoustic. Look for a company that makes some of the best speakers on the market and then buy their lower line models. Others may have good recommendations for you to consider.

LASTLY --- On a message forum, such as this, it is almost always better to post your questions separately. Asking a whole bunch of questions at once makes it less likely for people to answer all questions and the people who can answer them may miss it.

Hopefull I helped. Good luck.

Eric's85TA

iTrader: (4)

I am running Eclipse 4x6s that I picked up for about $70 and I think they sound great. As for your sub, I am not really sure as I have not had this problem before, but a friend of mine had this happen to his. He took it back to the store, they said it was blown, and they gave him a new one because it was under warranty. Hope this was helpful.

forsete

Thanks for all the info, and again, sorry for the long, multiple question post. I just wanted to get everything out while it was still fresh in my head, and I didn’t want to clutter the board with several posts.

To clear things up a little…
The Jensen amp, 4x50w RMS, will power front stage (getting new speakers soon) and rear fill (6 ˝” Sony 100-ish w RMS, 190w peak). Each 10” Pioneer sub (100w RMS, 350w peak), will be powered by it own Phase Linear amp, 200w RMS, 400W peak, all at 4 ohms. Will this be too much for my subs, even at a low, ear-friendly sound level? (I very rarely play it loud enough to get any cops attention.)

Hmmm, can’t think of anything else right now. I’m sure more questions will pop up after I do some more work…

thanks guys…

Belker

You can never have too much amplifier power. The reason all amps have a gain control is so that you can turn it down to match the requirements of the rest of the system.

cbpldc

I had that Jensen amp. Is it the Chrome one or the dark-grey one. They were both real problems. Not to dog your setup, but I think the amp is causing your problem. My amp did the same thing that you are describing to both of my subs. I replaced the amp and it never happened again. I personally think that if you are going for budget 4x6's look at the blaupunkts. They are cheap yes, and can't really handle much power but sound very clean. I used a set in a Lumina that I set up. I personally like the 4x6 plates from Infinity. They sound great, are crystal clear and can handle plenty of power.

Pukka

Seems like a pretty good setup for something not used for competion. For the 4x6's, I use MTX's and the sound is pretty good. They can be purchased for about $80. No matter what you buy, you won't get any bass out of a speaker that small. Suggest you use them for just the high freqs.

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92 Camaro RS LO3, 5-spd, T-tops
Performance:
SLP 1 3/4" Headers (Coated by Paul Barry Motorsports), Flowmaster Catback Exhaust, Fastchip Performance PROM, Centerforce Dual Friction Clutch, Xact 8mm wires, Open Air Element w/K&N Filter, Z28 Grille w/aftmkt fog lamps
Electronics:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-846 Amps powering 2 12" Pro Red subs, 2 Pioneer 6x9 and 2 MTX 4x6 speakers.
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