What spec amp/amps will I need?

[Kieran263]

Hey guys, I'm very new to anything audio in a car, at this stage I only have a pioneer headunit deh3100ub.

I'm probably showing my ignorance here but I'm looking to power 4 8" woofers, 8-ohm 300watt or similar. What spec amp/amps will I be looking at? I'm not looking for top of the range but I would rather overcompensate than not have enough range.

Thanks

[lunchbox.inc]

why 4x 8"s woofers? are you talking about subs or full range speakers...?

[acarmody]

Are you putting these in the doors or something?

[Kieran263]

Just subwoofers sorry, probably should have made that clearer. I'm gonna put 2 in the rear parcel shelf and I'm changing to buckets
in the rear so I'll most likely put the other two between the rear seats along with something else.

[mistergTRx]

for output i would be going for amps rated higher then the subs combined (that way you dont blow amps and you have alot more control over bass and they wont be run at full power, so less chance of overheating)
monoblocks are always (IMO) the way to go when running only subs but that would mean you have four in your boot
i would also suggest (if you havent already) you look at running capacitors with these, and for that amount of bass you're probably best to look at the 2 farads caps, otherwise you will get some severe power drawn from your battery (which itself would need to be a fairly hefty cca type battery or better yet a gel type battery)
but to get a much better answer on the topic, what else are you running?
what size speakers are you gonna run with these?
or are you planning on running the subs without speakers?

[HCVP]

1 - A capacitor does not effect the current draw of an amplifier.
2 - You would not have 4 amps, just because you have 4 subs.

Being 8 ohm drivers i would first assume they weren't originally designed for car audio use. Is 300 watt the nominal power handling?

Parallel wiring to 2 ohm and just about any 2 ohm mono block will work. How much were you wanting to spend?

If your budget extends to it, i would consider using a subsonic filter. It's not entirely nessacary, but it would be quite easy to bottom out a set of 8'' drivers if not careful.

[mistergTRx]

1 - A capacitor does not effect the current draw of an amplifier.
2 - You would not have 4 amps, just because you have 4 subs.


Parallel wiring to 2 ohm and just about any 2 ohm mono block will work. How much were you wanting to spend?

what i meant with the caps was that they charge up, so the battery doesnt drain as much
i didnt even consider parallel wiring for the monoblocks, my bad :$

[Kieran263]

They're JL subs, 300 max, 150 RMS. I'm not set on these BTW so I'm open to suggestion, but I do want to stay
with 8" subs. My budget all depends on how much I decide to spend on my engine. I'm working with a baseline
budget of around $1400ish for the audio. As for other speakers I'll stick with just some new 6" doors, nothing too
fancy until I can go all out.

[HCVP]

what i meant with the caps was that they charge up, so the battery doesnt drain as much
i didnt even consider parallel wiring for the monoblocks, my bad :$

A capacitor won't substitute for an inadequate power supply. If the battery and alternator are not up to the task, a capacitor won't make the slightest difference.

Mate if you using 6'' speakers in the doors, then 8'' subs aren't exactly ideal. Especially 4 of them. The fq response between the 2 different sized driver's wouldn't be all that much.
8'' drivers are becoming a bit more common today in front stage setups where extra midbass is required, but locating them to the rear is a different story.

A better match would be a 10-12'' driver. The amount spent on 4 cheap drivers, would be better spent on a single quality driver, which in turn would also take up less space.

But again, where does the 8 ohm impedance come from? Do you have a link to the components you had in mind? 8 ohm components are usually associated with home audio equipment...

[Kieran263]

Just a mate had a good price on the 8 ohm ones. I think these are the ones. Ryda Car Audio -JL Audio 8W1V28 8" Subwoofer($169.85)
I liked the look of them I want to fill the parcel shelf with something. It seems like there's more to this game than I first thought.

[HCVP]

Hot tip > Fill parcel shelf with carpet, not speakers

An array of 8'' drivers won't do much except give a midbass kick from the wrong side of the car.

You mentioned upgrading the front at some stage - Well you may aswell begin here, rather than saving it until last.

Your front speakers are responsible for all but about 60hz of the frequency spectrum. With a $1400 budget, a decent front stage is achievable, with enough left over for a suitably sized sub to bridge the fq gap and round the system out nicely.

I'd hate to see you burning up your hard earned cash, on a bunch of components that put simply would be a waste of money.

If your after some honest advice send me a message and i can help you out.

Also Joe our forum sponsor for car audio Shopping Secure is quite good to deal with, and working from home means he can actually make sure you get the one on one time needed to ensure you end up with the right type of components, rather than giving you a bum steer in a retail store..

[Kieran263]

message sent Thanks for all the help, I really appreciate it.