krwlz

I think that within the next few weeks I am getting a pair of these subwoofers. subs What kind of power do I want out of my amp? 1 channel or 2?

Wired in stereo? Or simply in series?

Whats the deal with the ohms?

How do I adjust accordingly?

I know a little bit about sound systems, but if someone could point me in the right direction as for amp choices, and wiring,that would be great.

merkerguitars

find a big amp that is about 800 - 1000 watts rms at 2ohm mono and wire them in parallel

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Nelson

What type of car? Have you considered what type of enclosure you will be using? What other components are you using in the system?

The wiring configuration will depend entirely on what amp you choose. Those subs have dual 4 ohm voice coils. A pair can be wired for any of the following combinations:
2 channel stereo - 8 ohm, 2 ohm
1 channel mono - 16 ohm, 4 ohm, 1 ohm

If you choose a 2 channel amp it should deliver max rated power at 2 ohms stereo or 4 ohms mono. I would look for an RMS rating of around 200W X 2 at 4 ohms (400W at 2 ohms) or 800W X 1 at 4 ohms. That would provide each sub with approx. 400W RMS.

A mono amp should deliver max rated power at either 4 ohms or 1 ohm. Look for the same power - around 800W at either impedance.

I always recommend buying as much power as you can afford. As always - buy a quality name brand from an authorized retailer.

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krwlz

WHat brand amp does everyone recomend? I was looking ot a Rockford, and an audiobahn. Like I said, I'm new to this, so anything you can tell me would be great.

Nelson

Rockfords new line looks pretty impressive. Good value watt/dollar.
If you want to pay for lots of chrome and flash - Audiobahn has that covered.
Beware of over inflated power ratings. Look for the new CEA rating sticker/logo. I strongly recommend visiting a specialty car audio store that carries quality brand names and offers installation.

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BoCo

The subs have a sensitivity rating of 87dB. Two together with 1 watt going into each would hit 93dB in free air, even higher inside the confines of a car. 100w into each would allow you to hit ~113dB which is enough to deafen you permanently over a period of time. To get 100w into the subs, you need an amp that can hit 200w per channel, since they are about 50% or so efficient.

Your smartest bet is 1 sub with an amp that can hit 100w RMS. At that volume, in free air, you could easily hit 104dB, which would be more than enough to do permanent hearing damage, which is what I assume you're striving for.

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Nelson

Someone has been reading a text book Where did you come up with those numbers? It all goes out the window when you actually put things together in the car. The textbook 3dB gain from a doubling in power/cone area is rarely attainable. 104dB at low freq is hardly going to make anyone go deaf. And todays class D amps can achieve greater than 70% efficiency. And with power available for less than a dollar/watt - always buy as much as you can afford.

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brandon11983

I'd put them in the smallest sealed box you can and amp the everloving shit out of them. I'd put 1000 watts on them. They are a pretty inefficient sub, so they'll gobble up the power you throw at them. With mega power in a small sealed box they'll beat your fucking brains in. For amps, I love JL, but they are very expensive. Alpine is really good too, but expensive too. Rockford stuff is rather middle of the line now, I will agree that you get good performance for the dollar.

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krwlz

How about the infinity? Can you explain why the subs are inefficient?

krwlz

Oh, and I did not puchase the dual voice coil subs, Just one each.

brandon11983

They are inefficient because they are rated at 87 dB per one watt of input. I personally prefer inefficient subs. They take more power to move them, but they usually sound cleaner and tighter. I don't mind this because I always amp the shit out of my subs.

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Scorps

Right now I'm running a Rockford Fosgate and it runs cool and looks nice, and the power is crazy!

krwlz

Well, here's the thing. I have this complusion (good, bad or indifferant) to do the entire system from one company, minus the head unit, because infinity doesn't make one.

This is the amp I was looking at, and yes, I realize it would slightly underpower the subs.

610A

So, I also pose the question, can amps run at a lower power then their RMS? Because then I might consider this amp:
1210A

And, last but not least, has anyone ever run an Infinity amp? How's the quality? I've always heard Infinity was good stuff, but I would love to hear some reviews from people that have owned them.

Gnzo

krwlz, sorry I am so late in chiming in guys, been out of town...
how much money do you want to throw at this/these amps? Infinity makes some nice amps, but you're not getting anything extra by staying with all Infinity. If you can give us a price range, we may be able to come up with a couple specific amps to drive those subs. Also, one thing we haven't talked about is the voltage rating of the pre-outs on the deck you are running. What deck are you running? Although this is often overlooked, the voltage on the decks pre-outs makes a difference when paring it with an amp/s.

Also, (sorry if I missed it above) what kind of car is this? Brandon is correct about the infinity subs needing a lot of power. Because you have two of them, and going with Brandon's recommendation about lots of power, you really should also consider caps at the very least, in not also a second battery. I know I might take some heat for suggesting this, as people might see this as overkill, but if you want clear sound and you are talking about 2 1000w amps, just don't rule it our right away. (you can always do this part later).

krwlz

i dont think i need that much power, being as the wiring of the subs creates a 2 ohm situation right? So, I need something like 800-1000 watts on one channel for 2 ohm, if I go with that much power right? Regardless, I would consider spending up to 400 bucks or so. The infinity amp I was looking at I can get for 300.

Its a 2004 Honda Civic, sealed enclosure of .75 cubic feet, per sub.

Clarion deck, but in the long run, I kinda want to replace it. It claims a 50 watt x 4 output. I could look up the rest of the info later.

Scorps

If your looking to spend 400 and the amp is 300 your not going to get a new deck and to subs for under 100.

krwlz

NO no no, 400 tops on the amp.

The subs are in the car, using an amp a fiend gave me for the time being, while i save the cash for a new one. 750 watts on this one.

The deck comes along even further down the road.

tkv00

You can never have too much power, buy the biggest amp you can get right off the bat, overpowering subs doesn't kill them (unless its a whole lot of power) underpowering is what kill speakers, underpowering causes distortion, which is harder to hear from a subwoofer, so your looking to kill it if its underpowered, plus, if you buy the biggest amp you can afford, you can always upgrade the rest down the road. My final thought is installaton: A good install can make cheap or decent equiptment sound good, a crappy install can make high end equiptment sound cheap.

mercury-hg

most of what you mention here is good advice, but this underpowering myth is crap that, for some reason, gets quoted like the bible:

a brief excursion in electrical engineering, hopefully without too mnay equations or EE-speak:
an amp takes a waveform (music), makes it bigger but proportionately identical, and sends it to the speakers. problems occur if the "speaker level" version of the waveform is clipped (a form of distortion, but not the only type). this can occur if the output waveform (a) exceeds the amp's voltage rails or (b) the amp can't source enough current to the speaker, causing the voltage to "sag". a speaker's displacement is proportional to the voltage waveform it gets from the amp, so when a waveform is clipped, full power (P=VI) is pumped into the speaker, but the speaker is fully extended and immobile. this stresses the speakers structurally and doesn't displace the heat cause by the high power level. generally, this situation is what kills a sub.

if "underpowering" damages speakers, then we all would destroy speakers simply by turning the volume knob counterclockwise.

krwlz

Thank you for clearing this up. Ive heard countless people say it, but going to school for engineering, could never rationalize it through actual physics principles.

The coil heating thing always seemed something that would happen after a speaker couldn't move any further out, and the energy from the current gets turned to heat, rather then movement. And as most (at least old) volume controls were a simple rheostat, (variable resistance) to control the current, THe underpowering kills speakers never made sense.

Regardless, the install went very very well, as I built a custom fiberglass enclosure, sealed to .75 cu ft per sub, which was one of the recomended set ups for the subs in the manual.

Now any thoughts on best amp brands? I've heard brandons advice, and no offense, but he pretty much likes JL and only JL, so I was looking for some people that maybe had some broader experience.

(I do appreciate everything you've been able to tell me so far though brandon, just looking for more, broader opinions.)

Rockford could be a choice, but again, I simply want as many opinions, and reasons for them that I can get my hands on, so I can make the best informed decision I can.

tspikes51

Glad you went with the Perfect 10's over the Rockfords. I just don't like Rockford...

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Scorps

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krwlz

For arguments sake, say I decided to go all infinity. That amp I linked to does something like 450 watts at 4 ohms. Were I to go with two amps, well, both subs would be powered nicely.

SO if i was to do this, how exactly would you wire that? DO you wire the amps together, and then to the subs? Or an amp to each sub? if an amp to each sub, how do you deal with the RCA cables? a left to one and a right to the other? or sumhow split it, and a R and a L to each?

Any knowledge is good knowledge guys, so Im open to anything you can tell me.

mercury-hg

don't limit yourself to infinity, jl, rockford, etc unless you aren't concerned with $$. you can do just as well or better with a brand you may not know yet:

tru
arc audio
pheonix gold
orion
old soundstream
zapco

search the forums at http://forum.elitecaraudio.com/ if you want more resources/opinions.

as far as power/# of amps, get one amp (stable to 2 ohm) and wire your two SVC subs in parallel for a 2 ohm load.

Scorps

You kjnow thats a good question...I only got one amp at the moment, that would be a good question to ask the guy at the local mod shop they should know!

Well I would like to know that to, for future use

krwlz

I have a friend that is telling me that they make splitters for your power cable (from the battery) RCA's and obviously splitting a remote is easy. You then run both left and right to each amp from the split RCA.

But he is only slightly more informed then I am, haha, so still any ones else advice on the matter would be great.

mercury-hg

there's really no reason to run 2 amps to 2 subs. you can pick up a distribiution box that'll split power to multiple amps, but only do that if you NEed to stress your alternator/battery. (you don't need to)

1 amp = less current draw on the alternator = longer alt life and no light dimming, etfc

i'm drunk and shoudl go to the bed

krwlz

Wouldn't 2 400watt amps draw the same total current as one 800 watt amp? Just out of curiosity.

My beef being, if at all possible, I would like to stay with all infinty, and if I used an amp per sub, I could do that, and still get the power I want.

So as before, for the sake of argument, is this the best way to do it?

mercury-hg

each amp will have a certain idle current draw, whether that is significant or not depends on the amp. suffice it to say, there's a 99% chance that a single amp will strain your elec. system less than 2 amps that add to the same rated power.

as far as powering the subs... well, i mentioned this before but maybe you missed it. you have two 4 ohm subs. wiring them in parallel give you a 2 ohm total load (as seen by the amp). wiring them in series gives you an 8 ohm load. both amps you referenced are stable to 2 ohms, ie they'll work with a load as little as 2 ohms. in this configuration (parallel), the 610a will provide ~761 W to the pair of subs (~380 W to each). the 1210a will provide ~1516 W to the pair of subs (~758 W to each). as you can see, a single 610a will probably be fine. you're wasting your money if you don't wire your subs in parallel and instead use 2 amps.

i guess you want all infinity so that your amp and speakers match? cool if that's the case, but i wouldn't limit my options for asthetics that'll be hidden in the trunk all the time

krwlz

WHat is the differance between dynamic power (the one you referanced) and the other power rating (657 watts) that they list for 2 ohms on the infinity site, as well as every single retailer I have yet to look at? Thats why I assume ~ 330, which is less then I want.

Scorps

Why not use a CAP?

mercury-hg

Um, nothing that is addressed here calls for a capacitor. Even in situations where a cap is used it could probably be be ommitted.

krwlz

Why is that? I mean, a CAP is basically a very short term rechargable battary (without getting into the physics of it) how could this be bad thing?

Scorps

Ya I only have one amp at the moment when I get new subs and another amp I will be using a CAP just to save my alternator.

krwlz

Damn, from an engineering standpoint, I'm finding that a lot of what people swear is true in stereo... just isn't. I'm thinking maybe I ought to just work it all out myself!

Nelson

edit post X2

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Nelson

Nelson

And alot of what your reading hear is just as bogus/not true

Run one amp. Unless you have money burning a hole in your pocket - why add the complexity of a second 'box' if you dont have to?? Unless your in the mood to buy more cables and trunk jewelry

And a cap?? Unless they are used properly (95% arent) they will do little to improve the true performace of any car stereo. They are not a cure for dimming lights. They will NOT make the amp produce more power. They will NOT make the system 'sound' better. A 1/2 farad cap (for up to 1000W), mounted within 6" or so from the amp, with NO fuse between it and the amp MAY slightly improve some aspects of performance.

You will have very little strain on your factory electrical system with the equipment you have/plan to have. In most cases anything less than 1000 watts (rated power) will be no challenge for your stock charging system. Its that damn physics/engineering babble that looks good on paper but changes drastically when you talk about power, cars, and recorded music.

An amplifier, in a car, rated at 1000W will HARDLY EVER produce near its rated power while listening to MUSIC. Simply hook up a VOM to the output of your amp and measure A/C voltage while listening to music at regular volume levels. Use ohms law to calculate output power. Use either 13.8 (engine on) or 12.5 (engine off) for 'V'. It wont be 100% accurate but you will be very surprised how much power that 1000W amp REALLY produces during average use.

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mercury-hg

well... DUH! why wouldn't you want to understand what you're doing to your car?!?! not to bash TFP, but there's probably a couple hundred better places to research audio on the internet. TFP is a melting pot, which is cool... but jack of all trades, master of none.

that said, i've got an EE degree and a minor audio obsession, so hopefully you've gotten some decent advice. Nelson is spot on, too.

in summary:
- run one amp that is rated ~800 W at 2 ohms. doesn't really matter if it's marginally above or below that rating.
- run two 4-ohm subs in parallel to the amp. put them in boxes as suggested by the manufacturer.

that's all you need to do for now. if you have light dimming or other problems, it's time to troubleshoot, but $1 says a cap won't help.

krwlz

So to redirect this, say I take the advice, and go with one amp. I would, as mentioned, prefer to stick with infinity, so probably that amp I mentioned.

Can someone just define the differance between the Power Handling (656 watts) and the dynamic power (761 watts)?

Also, what other places are great for asking, and learning car audio?