Watts

[speedbump]

I asked this question the other day and from the responses I got,I've come to the conclusion that I just confused everyone.Totally my fault.What I need to know is this .If I have two 8 ohm cabs in parallel,I realize the total ohmage is now at 4 ohms.If each cab was rated at 500 watts,is my wattage now 250 .Some of the replys I got started talking about the power of the amps and that is not the issue.In other words,amp wattage is what an amp is capable of putting out.Speaker wattage is how much a speaker can handle. Is this clear or did I muddy it up even worse ? By the way,is ohmage a word ?

[HolmeBass]

Ohmage is not really a word, but it will work fine in this crowd. The correct word is "nominal impedance".

Each cabinet will get 1/2 of the 500 W put out by your amp- so each one will get 250 W. If their nominal impedances were different, they would not each get the same wattage (that is a word, go figure).

Let's see if I can get this right now- if the cabinets' nominal impedances were different, each cabinet would get wattage in inverse proportion of their impedance. So if you had one 4 Ohm and one 8 Ohm cabinet, the 4 Ohm one would get 2/3 of the total power, while the 8 Ohm one would get 1/3. Notice that 2/3 is 2x1/3, so another way to say it would be the 4 Ohm cabinet would get twice the wattage of the 8 Ohm cabinet.

But you have two 4 Ohm boxes, so each will split the wattage equally.

[tombowlus]

Originally Posted by HolmeBass

Ohmage is not really a word, but it will work fine in this crowd. The correct word is "nominal impedance".

Each cabinet will get 1/2 of the 500 W put out by your amp- so each one will get 250 W. If their nominal impedances were different, they would not each get the same wattage (that is a word, go figure).

Let's see if I can get this right now- if the cabinets' nominal impedances were different, each cabinet would get wattage in inverse proportion of their impedance. So if you had one 4 Ohm and one 8 Ohm cabinet, the 4 Ohm one would get 2/3 of the total power, while the 8 Ohm one would get 1/3. Notice that 2/3 is 2x1/3, so another way to say it would be the 4 Ohm cabinet would get twice the wattage of the 8 Ohm cabinet.

But you have two 4 Ohm boxes, so each will split the wattage equally.

+1 What he said.

[Febs]

1. The word you're looking for is "impedance," not "ohmage."

2. If you connect two 500 watt, 8 ohm cabinets in parallel, the total impedance is 4 ohms. Each cabinet will still handle 500 watts (although the amount of power that the cabinets actually receive will be 1/2 of the amp's output).

3. When you have a clarification of a prior question, it's generally best to post the clarification of the question in the same thread as the original question, rather than starting a new thread.

[Thylacine Dream]

*2 8 ohm. Is it obnoxious to correct that? I'm new! I'm OCD and figured I'd go ahead since things have apparently been muddy for the guy earlier, just so he knows he's getting the right answer. I hope this was relevant.

[Thylacine Dream]

That was in reference to HolmesBass' post, how do I quote/reply to an individual post? I'm on an iPhone if that makes any difference

[Febs]

Originally Posted by Thylacine Dream

That was in reference to HolmesBass' post, how do I quote/reply to an individual post? I'm on an iPhone if that makes any difference

Use the "quote" button.

[Thylacine Dream]

Much appreciated

[Thylacine Dream]

I didn't see the little blue arrow before

[BurningSkies]

Originally Posted by speedbump

I asked this question the other day and from the responses I got,I've come to the conclusion that I just confused everyone.Totally my fault.What I need to know is this .If I have two 8 ohm cabs in parallel,I realize the total ohmage is now at 4 ohms.If each cab was rated at 500 watts,is my wattage now 250 .Some of the replys I got started talking about the power of the amps and that is not the issue.In other words,amp wattage is what an amp is capable of putting out.Speaker wattage is how much a speaker can handle. Is this clear or did I muddy it up even worse ? By the way,is ohmage a word ?

Again, cabinets don't have wattages.
Cabinets usually have a thermal power rating listed (in your case it probably says 500w on the back of your cab?), which is what the voice coil can sustain before it melts into a lump of speaker-turd. With two cabs run in parallel, your total nominal impedance is 4ohms. The cabs are still rated at 500w thermal power handling. Thus together (theoretically and very dubiously true) they have a thermal power handling of 1000w.

Without knowing what kind of head you're running, this is fairly meaningless info. If you have a 50w amp that can take a 4ohm load, each cab is getting 25w. If you have a 500w amp that can take a 4ohm minimum load, then you get 250w per cabinet.

[bassgod0dmw]

Originally Posted by speedbump

If I have two 8 ohm cabs in parallel,I realize the total ohmage is now at 4 ohms.If each cab was rated at 500 watts,is my wattage now 250

Not really. Each cab is still rated at 500w. It has nothing to do with how much wattage they will be getting, just a recommendation of how much power they can handle. On an amp with a 4 ohm minimum load each cabinet will receive about half of the power....whatever it may be.

If the amp is 200w @ 4ohms, each cab will get 100w
If the amp is 500w @ 4ohms, each cab will get 250w
If the amp is 1000w @ 4ohms, each cab will get 500w

And so on and so fourth...

[ian_s]

Sometimes the Amps forum is like EE for Bass Players.

[Alex1984]

I thought Ohm's law was high-school physics stuff. To recap, each cab gets half of what your head's dishing out.

[bassgod0dmw]

Originally Posted by Alex1984

I thought Ohm's law was high-school physics stuff. To recap, each cab gets half of what your head's dishing out.

That's constructive.

[BurningSkies]

Originally Posted by bassgod0dmw

That's constructive.

The constructive part is that in two threads about this topic, the OP hasn't listed what head he's using, what wattage it has, nor its minimum load capacity. All of which are needed to discuss the wattage received by the cabs.

[Alex1984]

I should've quoted the statement I was responding to...

"Sometimes the Amps forum is like EE for Bass Players."

[cchorney]

Speedbump,

Wattage ratings on cabs get added together. Got two 500 watt cabs? They (theoretically) can handle 1000 watts. But they don't because cab manufacturers don't measure the point at which your cab is farting like a sick dog, it measures the point at which you go from having a cab to having a fried cab. Ish. I would divide their number in half, and go lower from there if you are using distortion or cranking the lower frequencies (or turning down the mids ans highs).

Putting two cabs in parallel will make the same amp at the same volume setting sound louder. This is because an amp capable of running at 4 ohms driving just one 8 ohm cab is only running at about 60% of what it can do at 4 ohms.

So it would look like this:
Amp: MarkBass LittleMark III, rated at 500watts@4ohm,300watts@8ohm
Cab: Markbass 102HF, rated at 400 watts RMS

Example 1:
1 amp and 1 cab: 300 watts going into 400 watt capacity (and you will start farting out around 3 or 4 on the volume setting)

Example 2:
1 amp and 2 cabs: 500 watts going into 800 watt capacity (and you will start farting out around the same spot, but it will be louder)

Hopefully this helps.

[Bassorama57]

[iPhone Apps] Carvin Impedance Calculator 1.1 download free. Install Carvin Impedance Calculator

So happy I don't have to remember any of my college EE anymore. Carvin has an app that does the math for you. Carvin Impedance Calculator 1.1 is the actual name of the app. Only time it gets confusing is when you start mixing and matching odd "ohmage" cabinets. you tell it what the impedance is for each speaker; whether they're in series or parallel, and it'll give you the right answer no matter how many preshow beers you've had.
Ex: If you had an 8 ohm and a 6 ohm cab in series, that's 14 ohms...! ("I can't hear you!"); but in parallel, that's 3.428571 ohms, which, if you have a minimum 4 ohm amp, is bad voodoo. Etc. The lower the impedance, the more wattage the cab will draw (speakers "draw" power, something with infinitite resistance wouldn't draw any no matter what your amp put out). So in the above oddball example, the 6 ohm cab will be louder.
The best diagram of all the oddball combinations you can have that I've found is here: Shavano Music Online - Speaker Wiring/Loading Examples

[speedbump]

That's the best answer yet ! Thank You, Speedbump

[speedbump]

Thanks also to cchorney.