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Someone explain Ohms to me...

2K views 24 replies 8 participants last post by  FunFordCobra 
#1 ·
What should I look for when buying subs? 2ohm, 4 ohm, 8 ohm?
What is the differance?
 
#2 ·
ohms

Ohms means resistance.
On a sub the higher the resistance the better quality sound, thus 8 ohms is high quality but you need major amperage to run them, 4 ohms does well for most people and alot of people that are just looking for thump goto 2 ohms or even 1-ohms.

If you want more info pm slow90vert, he does car audio stuff so he knows more than me
 
#3 ·
Ohms is a measure of resistance,

but an just because a speaker is rated at 8 ohms, does not mean it will sound better than a 4 ohm speaker.

I think what you are reffering to is:

when an amplifier is bridged or is run into a lower impedance you lose some dynamic range

this is really not important in the lower frequences of a sub


As for the orginal question,

You should pick your subs Ohms base on the number of subs you want to run and the capabilities of your amp.

Most amps are 2ohm stable.

If you are going to bridge a 2 channel amp, and run a pair of subs, I reccomend 8ohm subs wired in parallel.
Wiring the subs + to+ and - to- will give you a 4 ohm load.
Any bridged amp wil "see" half the load you put on it, hence 2 ohm load.

If you are going to one run one sub and a 2 channel amp, get a 4 ohm sub.

If you are going to run a mono amp, mutipule subs, etc...
E-mail me

James
 
#4 ·
I cant say anything these guys said.

Its just resistance.

Say you have an amp that pushes 500w at 4 ohms.
Put a dvc 4 ohm speaker on that amp (wich lowers resistance by 1/2) so the amp can make more power with less resistance.

Ex: My rockford BD1000.1 is rated at 500w at 4 ohms.
With a dvc 4 ohm solobaric, the amp is putting over 1100w out.
Just make sure your amp is 1-2 ohm sable or youll burn that bitch up!
 
#9 ·
Oxidizer187 said:
Run 2 8ohm subs wired in series to drop the resistance to 4ohm. Find an amp rated for equal max of the subs at 4ohm mono bridged. Even though some manufacturers rate their amps 2ohm stable they heat up very quick and shut off. Been there done that.
If you series wire two 8 ohm subs you will get a 16 ohm load.

Remember, when you bridge an amp it will "see" half the load you put on it. So, if you paralell two 8 ohm subs (equals 4 ohms), then put this load on a bridged amp, the amp will "see" a 2 ohm load.

n737nc,

I would base what impedance subs you buy, on which amp you have or will have for the subs.

What is nice, bass is very forgiving, it is not nescessary to spend $$$$, it is more important that you match your amp, subs and enclosure (capabilities not brand).

James
 
#12 ·
stangcrazy said:
Ok, say i was to get my hands on two jl audio 10w6's. In your guys' opinions, what amp and enclosure would run them the best for a 92 hatchback? 2 or 4 ohm.
stangcrazy,

One of the great things about a hatchback, is that it will be 3 to 6 db (2 to 4 times) louder than a sedan.

I would go with a sealed box, it will give you the tightest most accurate bass in the smallest and lightest box. A sealed box will require more power than ported or bandpass.

Of course if you are not concerned about space or weight you could go with a ported box and get even more output.

W6's are dual 6 ohm subs. They are also a little power-hungry.

If I were running two of them:

On a 2 channel amp, I would wire the voice coils on each sub in series to get a 12 ohm load, then wire the subs in parallel to get a 6 ohm load. The bridged amp will "see" a 3 ohm load.
(Kicker ZR600, PG XS2500, RF 800.2 etc...)

On a 4 channel amp, I would wire the voice coils on each sub in parallel to get a 3 ohm load, then bridge the amp to a two channel and run one sub off of each channel.
(Kicker ZX460, PG ZX475, RF 800.4 etc...)

On a mono amp, I would wire the voice coils on each sub in parallel to get a 3 ohm load, then wire the subs in parallel to get a 1.5 ohm load.
(Kicker DX 700, RF BD1000, JL mono amp not sure of model #)


James
 
#21 ·
That is not 100 percent right

89lx5.0 said:


If you series wire two 8 ohm subs you will get a 16 ohm load.

Remember, when you bridge an amp it will "see" half the load you put on it. So, if you paralell two 8 ohm subs (equals 4 ohms), then put this load on a bridged amp, the amp will "see" a 2 ohm load.

n737nc,

I would base what impedance subs you buy, on which amp you have or will have for the subs.

What is nice, bass is very forgiving, it is not nescessary to spend $$$$, it is more important that you match your amp, subs and enclosure (capabilities not brand).

James
I agree with the 16 ohms and the 4 ohm scenario you are talking about. But the amp sees the load you present it. If you hook it up to a 4 ohm speaker it sees 4 ohms. Thus if you hook it up to two 8 ohms wired in parallel which is 4 ohms, the amp still sees 4 ohms. When you bridge an amp all you are doing is combining the stereo channels to make 1 channel. You are correct in saying that most amps are only 2 ohm stereo stable which would make them 4 ohm mono stable. Just my .02 cents worth.
 
#23 ·
Re: That is not 100 percent right

MUSTANG MAN said:


I agree with the 16 ohms and the 4 ohm scenario you are talking about. But the amp sees the load you present it. If you hook it up to a 4 ohm speaker it sees 4 ohms. Thus if you hook it up to two 8 ohms wired in parallel which is 4 ohms, the amp still sees 4 ohms. When you bridge an amp all you are doing is combining the stereo channels to make 1 channel. You are correct in saying that most amps are only 2 ohm stereo stable which would make them 4 ohm mono stable. Just my .02 cents worth.
I see your point, but understand I was just trying to explain this in a way that everyone can understand.

I still say that the easiest way to do that is say...a BRIDGED amp will "see" half the load presented to it.

That is why the stereo ohm rating is lower than the bridged rating.

James
 
#24 ·
Re: Re: That is not 100 percent right

89lx5.0 said:


I see your point, but understand I was just trying to explain this in a way that everyone can understand.

I still say that the easiest way to do that is say...a BRIDGED amp will "see" half the load presented to it.

That is why the stereo ohm rating is lower than the bridged rating.

James
I am glad you see my point I am just trying to keep someone else from frying their equipment. I have been doing stereo installs for 10 years now and have seen a lot of people fry their shit because someone confused the living hell out of them.
 
#25 ·
this is the longest thread I have ever seen in this forum!:eek:
 
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