hey guys..

i have two 12" JL 4ohm (single voice coil) subs running in parallel to a zapco 200 amp.

i heard that i am supposed to be connecting them both to the 2ohm terminals on the amp, but when i do that, i can barely hear the power of the subs... it barely even sounds like i have subs!

So then i connected them to the 4ohm terminals on the amp and now they pound.

do i risk damage to my amp? speakers? or is this setup ok? what should i do?

if it's LOUD be PROUD!

sorry... i realy dunno that amp. someone on here can probably fill you in though!

Livin Loud

but do i risk damage??

[ December 07, 2004, 12:32 AM: Message edited by: fillytown ]

I would run it out of the 4 ohm terminals, even though it is a little more risky. I always end up running my amps at about half their rated impedence for daily anyways because with impedence rise it will be seeing closer to 4 ohms at normal bass frequencies.

i didnt really understand your last sentence there, but sounds good..... what do i risk damaging if i run it from the 4ohm terminals.

I actually thought you got more power if you connnected it to the 2ohm, but damn was i wrong!

reminder: i am running two 4ohm subs in parallel to an amp connected at the 4ohm terminal..

The 2 ohm terminal will put about the same power to a two ohm load as the 4 ohm will put to a 4 ohm load. It is just to give you more subs options.
The last sentence of my above post was jsut refering to what is called "impedence rise" due to the inductance in the voice coil. Basically, when you put an alternating current through a coil of wire, you get extra resistance that increases with frequency.
So, playing actual music, the subs will be seeing close to 4 ohms anyways

Basically the amp will just get hotter and might have a higher chance of blowing when running from the 4 ohm terminals, but if you don't have gains maxed and don't drive it with a clipped signal you should be fine.

what exactly do you mean by clipped signal?

i just wanna make sure i get this right [img]smile.gif[/img]

Clipped signal is when the wave coming out of the amp starts to become non-linear with the input signal or a "square wave." It can also come from the deck putting out a distorted signal to the amps.
You can hear it in your subs becaus they will sound "distorted". If you have ever turned up speakers running of deck power too high and the music starts to sound bad and the bass is almost crackling, you are hearing a square wave. It is a little hard to explain, but once you hear it, you will know.

yeah, ok, i know what you mean.. my amp actually sounds really good and i keep feeling it and its not hot at all..

zapco is a really good name that i trust, so that large sum of money i paid for the amp might actually be paying off [img]smile.gif[/img]

There are a couple factors not yet considered..

A good 4ohm stable amp will run down to around 3ohms without running out of current or poping an output... but running like this for long periods may exeed thermal limits...

In your case I will assume you have W0s, and the amp is probably seeing around 1.9ohms nominal when you first turn it on... as you play music the sub's voice coils will heat up... -this is a factor that depends on the subs- if you have W0's nom. impedance will probably rise to more then 2ohms... if you have W6s you are probably staying closer to 1.5 nom. all the time...

The other thing to consider is your box.. as seege mentioned the average impedance will be significantly higher... this depends on the particular sub and box... if its sealed with w0s you are probably looking at more then 3 ohm for anything over 20hz... w6s in a box ported low could mean you are down to 2ohm at some frequncies..

If you are running down to the point where you are current clipping you are going to be getting less clean power and more distortion... it would reason that if your gains are set properly you will get less clean power overall then if you were running a proper load...

If sounds fine, then that isn't a big concearn... but the point is that just because the powersupply has the current, dosen't mean the outputs on the amp can handle it for exended periods of time...

hope you see how this can also depends on the sub and box...

EDIT^ if it sounds fine and isn't heating up I wouldn't worry about it.... watch out in summer on long drives and keep in mind you will be most likly to pop something from excess current flow when the subs are cold playing low frequencies...

[ December 07, 2004, 04:28 PM: Message edited by: Haunz ]