Hi and a question.

wriggler · Post by **wriggler** » Wed Nov 02, 2005 8:09 pm

Hello,
I'm Andy. Just this second registered. I have been into car audio systems for quite some time now (about 7 years)). I have installed numerous systems (about 10). I have acquired vast amounts of knowledge within this time.
But there is one question that has been buggin me for years. I heard this rumour that decreasing the load to a sub decreases the power it can handle? For example a sub wired at 4 ohms can handle 500 watts but wired at 2 ohms it can only handle half of that?
Now im thinking that its probably false but anyone like to tell me to confirm, cheers.
Andy.

Darthness · Post by **Darthness** » Wed Nov 02, 2005 8:36 pm

its the other way around.. i'm extremely amazed and disturbed that you've been "installing" systems and don't know how ohms and such work.

first of all.. a SVC sub will only be able to be wired at what ever ohm load the VC's are.. (say 4 ohm). a DVC sub (say, dual 4 ohms) would give an amp a either a 4 ohm load or a 8ohm load i belive. as far as i know, you can't wire a sub at either 4 or 2 ohms... thats amps. and as i said, kyou ahve it the other way around. the general way most manufacturers make their amps (afaik) put out a certain amount at 4 ohms (say, 400w RMS) And at 2 ohms, it mighit do 800w Rms, just as an example... a 2ohm load is double that of 4 ohms.

edit: sorry if thats not really put together well. basically, you were told worng.

wriggler · Post by **wriggler** » Wed Nov 02, 2005 8:42 pm

yeah but, I wasnt asking that.
Im not bothered about whether the sub is SVC or DVC, nor how many watts it is.
My question was, if the impedence shown to the sub is lower, does it mean that the wattage it can handle is lower too?

Darthness · Post by **Darthness** » Wed Nov 02, 2005 8:47 pm

a sub will only run at one impedence... so if you mean that if a 4ohm sub will handle more power than a 2 ohm sub, it depends on how the manufacturer builds it.. in most cases 2ohm drivers handle more than 4ohms though.. but like i said, its all on how they built it....

wriggler · Post by **wriggler** » Wed Nov 02, 2005 8:55 pm

no man i dont mean that. Sorry for the confusion. ill give an example.

say the sub is getting 400w at 4 ohm. Now say its getting 400w at 1ohm.

Does it make a different as to how many watts the sub can handle?

William from NOLA · Post by **William from NOLA** » Wed Nov 02, 2005 9:51 pm

I understand what you are saying, and what you were told was completely false. However, 4 ohms or at 1 ohm does affect the sub; more specifically, if wired in parallel or series, the Le (mH) of a driver changes. The Le is double when wired in series compared to parallel.

Straight from our FAQ section:

Le
This is the voice coil inductance measured in millihenries (mH). The industry standard is to measure inductance at 1,000 Hz. As frequencies get higher there will be a rise in impedance above Re. This is because the voice coil is acting as an inductor. Consequently, the impedance of a speaker is not a fixed resistance, but can be represented as a curve that changes as the input frequency changes. Maximum impedance (Zmax) occurs at Fs.

wriggler · Post by **wriggler** » Wed Nov 02, 2005 11:17 pm

Thank you for the prompt reply. My question has now been answered. Nice site by the way!
Thanks again,
Andy.

Ryan from Ohio · Post by **Ryan from Ohio** » Thu Nov 03, 2005 4:09 am

Ok...

A sub has Impedance as its AC. AC is a variable frequency. With that being said the Ohm of the sub is variable. The numbers we see are the NOMINAL numbers. Thats what we base all of our wiring off of.

A subs power handling capability wont change on Ohm configuration.

A amplifiers power output will vary depending on ohms though.

Robert Wollenberg · Post by **Robert Wollenberg** » Thu Nov 03, 2005 5:34 am

The way I'm reading it, the guy asking the question is under the assumption that somehow the amplifier shows impedence, or load, to the driver. What he needs to understand is that the driver IS the load, or impedence, shown to the amplifier. Not the other way around. You don't show a load to the speaker. The speaker is the load. Usually a SVC at 4 ohms or perhaps DVC with 4 ohms each wich can be wired to either a 2 ohm load or 8 ohms. And so on depending on how many dirvers, voice coils and how they're wired.

Robert Wollenberg · Post by **Robert Wollenberg** » Thu Nov 03, 2005 6:48 am

And, after reading his initial question again, I think what he's expressing is the power output change from the amp in regards to the impedence presented to it. It's not that the sub handles more or less, rather that the amp puts out more or less depending on the impedence presented to it. An amp that puts out 100wrms at 4 ohms typically puts out 200wrms at 2 ohms, 50wrms at 8 ohms, etc. Hopefully this helps.