Ohms and wattage output....need input bad!

[selftitled907]

Ok im currently looking into a new amp for my 410 cab. my cab is 8ohms/800w. im looking into getting the new GK MB 800 to power this and in the near future another cab. the question i have is this.

When i add another 8 ohm cab to this amp...im pretty sure that (and correct me if im wrong please) the total imp. becomes 4 ohms and i would be getting the full potential out of the amp at 800W....my question is would both cabs be getting 800W or would i be getting a total of 800W. @400w per cab?

Please i need help!?!?!

[Sartori]

The power is split between the two cabs, since they're both 8 ohms.

[tooloudalex]

because they are in series the power would be split yes, if you ran them in parallel then you would run them both at 8 ohm with whatever the 8 ohm power rating is (sorry on my phone cant look it up right now lol)

im pretty sure any way. someone with more smarts than me may correct me but i think thats what it is.

[Bass_Pounder]

Originally Posted by tooloudalex

because they are in series the power would be split yes, if you ran them in parallel then you would run them both at 8 ohm with whatever the 8 ohm power rating is (sorry on my phone cant look it up right now lol)

im pretty sure any way. someone with more smarts than me may correct me but i think thats what it is.

Running them in series would result in a 16 ohm load,

He would be running in parallel, and they split the 4 ohm output (has nothing to do with getting the 8 ohm ratings).

[Sartori]

I probably don't have much smarts compared to some on here, but most of the time, amps are wired to run two or more cabs in parallel, not in series. Same with cabs that allow "daisy-chaining."

While the OP's gear could be among the few exceptions, it's not especially likely. The amp will probably be running the cabs in parallel. In this case, two 8 ohm cabs will appear as a 4 ohm total load to the amplifier.

In series, the two 8 ohm cabs would appear as a 16 ohm load. But that's not likely the case.


OP: Your amp will read the two 8 ohm cabs as a 4 ohm load, bumping its wattage up to 800 watts. This means 400 watts will go to each cab. Get a twin of whatever cab you have.

[jay_meister]

The impedence of the the 2 together will be 4 ohms (in parallel, the most common connection) and the output is split between the two. At 8 ohms that amp puts out only 500 watts and may be underpowered for the the single 800 watt cab alone. Underpowering can cause clipping which damages speakers.

(I have no idea what tooloudalex means!)

[Marginal Tom]

Your amp would deliver 800 watts total to eight speakers, 100 watts to each speaker and 400 watts to each cab.

[Sartori]

Originally Posted by jay_meister

The impedence of the the 2 together will be 4 ohms (in parallel, the most common connection) and the output is split between the two. At 8 ohms that amp puts out only 500 watts and may be underpowered for the the single 800 watt cab alone. Underpowering can cause clipping which damages speakers.

(I have no idea what tooloudalex means!)

Not the underpowering myth again. Speakers don't care whether the power they get is clipping or not. Only whether it's enough power to blow them.

A 500 watt amp is capable of putting out a lot more than that when it's clipping, but it's overpowering the speakers, not the clipping itself that damages them. For example 50 watt amp will probably not blow the speakers in a cab rated for 1600 watts, even when clipping hard, because even then, it's probably not producing the power it would take to blow the speakers.

Conversely, an 800 watt amp can easily blow the speakers in an 800 watt cab, even if it's not clipping at all, through dialing in too much low end at high volume, causing over-excursion of the speakers.

[i_got_a_mohawk]

Originally Posted by jay_meister

The impedence of the the 2 together will be 4 ohms (in parallel, the most common connection) and the output is split between the two. At 8 ohms that amp puts out only 500 watts and may be underpowered for the the single 800 watt cab alone. Underpowering can cause clipping which damages speakers.

(I have no idea what tooloudalex means!)

Underpowering is a wonderful myth.

If the single cab was 500 watts, it would still risk damage in the manner you are talking about.

What you are talking about has little to do with the capacity of the speakers, it's a result of pushing an amplifier too hard, trying to get more output than the amplifier is safely capable of.

[selftitled907]

yeah im not worried about clipping/damaging my amps i know how to tune them in and in a band setting if you have to crank up the vol enough to cause clipping or anything that would cause dmg.....maybe everyone needs to turn down.

all i was wanting to know is if i would get a double load or, 800W to each cab. Or if the load was split giving a total of 800w @ 400w per cab.

again thank you for all the input on this thread it has been a huge help.


thanks
gabe

[jay_meister]

I am sorry to say you are incorrect- underpower damage is not a myth!! It is not the underpowering per se that causes the damage and the damage is not a blown speaker cone but a burned voice coil.

http://www.formaudio.com/technical-a...ering-speakers

From Peavey:
http://www.peavey.com/support/techno...MUCH_POWER.pdf

From Hartke:
"About Power Handling
There is a lot of heated discussion around power handling. Is it better to over power
a cabinet, or is dangerous to under power a speaker? While it is certain that the
debate will continue far into the future, the fact is that both are true. If you are using
an amplifier with a lot of power, you can damage your speaker by running the amp
to the maximum and pushing the speaker beyond it physical limits When using too
little power, there a tendency to push the amplifier into overload, which will generate
enough distortion to burn the voice coil. The most important point to consider is how
the power is used in order to ensure the speaker is presented with a clean signal. Be
sure that you amplifier is producing a good clean signal. If your amp has a on-board
compressor or limiter, we recommend you use it to protect the speaker. If the sound
is getting distorted you’re probably starting to damage the speaker."

I hope you guys keep a fire extinguisher handy!

[GrowlerBox]

Originally Posted by jay_meister

I am sorry to say you are incorrect- underpower damage is not a myth!! It is not the underpowering per se that causes the damage and the damage is not a blown speaker cone but a burned voice coil.

http://www.formaudio.com/technical-a...ering-speakers

From Peavey:
http://www.peavey.com/support/techno...MUCH_POWER.pdf

From Hartke:
"About Power Handling
There is a lot of heated discussion around power handling. Is it better to over power
a cabinet, or is dangerous to under power a speaker? While it is certain that the
debate will continue far into the future, the fact is that both are true. If you are using
an amplifier with a lot of power, you can damage your speaker by running the amp
to the maximum and pushing the speaker beyond it physical limits When using too
little power, there a tendency to push the amplifier into overload, which will generate
enough distortion to burn the voice coil. The most important point to consider is how
the power is used in order to ensure the speaker is presented with a clean signal. Be
sure that you amplifier is producing a good clean signal. If your amp has a on-board
compressor or limiter, we recommend you use it to protect the speaker. If the sound
is getting distorted you’re probably starting to damage the speaker."

I hope you guys keep a fire extinguisher handy!

Right -- so it's still overpowering, just from the uncontrolled spikes generated by a clipping amp running beyond its capacity.

[billfitzmaurice]

Originally Posted by jay_meister

I am sorry to say you are incorrect- underpower damage is not a myth!! It is not the underpowering per se that causes the damage and the damage is not a blown speaker cone but a burned voice coil.

http://www.formaudio.com/technical-a...ering-speakers

From Peavey:
http://www.peavey.com/support/techno...MUCH_POWER.pdf

From Hartke:
"About Power Handling

From the first link:
"When an amp is clipping, it will output a DC signal."
No, it will not. Period. The author has no clue what he's talking about.

From the second link:
"First … let’s stop the spread of a big myth. You cannot burn out a speaker by
using too little power. If that were the case, then anybody turning down their
system would be frying their drivers.
Speakers are burned for these reasons:
-By applying too much power and exceeding the thermal (heat) rating of the
speaker, or
-By applying too much power at too low a frequency (excursion rating),
thereby mechanically ripping the driver apart."
Correct.

As to this quote from Larry "When using too
little power, there a tendency to push the amplifier into overload, which will generate
enough distortion to burn the voice coil" is just plain incorrect. It's not the first instance of someone who should know better making a similar statement, and won't be the last. But where distortion (clipping) is concerned it does not burn voice coils in woofers. It can in tweeters and the occasional midrange.

[selftitled907]

Thank you all for your input on the topic of the initial question as to multi-cab hook up and wattage distribution. Somehow this turned into a conversation about a topic that is going to always be argued.

So...because i started this thread here is my two cents on clipping/damaging your gear based on your particular rig. If its a rig you play often and know how to adjust your setting based on your surroundings...then you should never have a problem damaging your gear. if you do damage your gear somehow, other than shear lack of knowledge for knowing how to hook up your gear properly....you should probally consider it an internal problem. yes i know that eventualy speakers wear out as do tubes, cords, strings and drum heads. just always make sure to use a big enough rig so that A- you can be heard in the mix without having to turn up rediculosly loud...pushing your amp to its limits....blah blah blah....my signature pretty much sums up the rest of this statement. and though its not common....i like to think all bass players alike for the most part have more than most people.

cheers to you all for the great information that was shared to me.

Gabe

[Munjibunga]

Originally Posted by tooloudalex

because they are in series the power would be split yes, if you ran them in parallel then you would run them both at 8 ohm with whatever the 8 ohm power rating is (sorry on my phone cant look it up right now lol)

im pretty sure any way. someone with more smarts than me may correct me but i think thats what it is.

You would be more helpful if you knew what you were talking about. The cabinets will be in parallel, the total impedance will be four ohms, and each cab will get half the power provided, up to the theoretical 800-watt maximum.

[dincz]

"When an amp is clipping, it will output a DC signal."

When an amp is faulty, it may output DC if its protection circuits are inadequate.

If it outputs DC when it's not faulty, read the manual and find out that it's actually a battery charger.

[i_got_a_mohawk]

Originally Posted by jay_meister

I am sorry to say you are incorrect- underpower damage is not a myth!! It is not the underpowering per se that causes the damage and the damage is not a blown speaker cone but a burned voice coil.

http://www.formaudio.com/technical-a...ering-speakers

From Peavey:
http://www.peavey.com/support/techno...MUCH_POWER.pdf

From Hartke:
"About Power Handling
There is a lot of heated discussion around power handling. Is it better to over power
a cabinet, or is dangerous to under power a speaker? While it is certain that the
debate will continue far into the future, the fact is that both are true. If you are using
an amplifier with a lot of power, you can damage your speaker by running the amp
to the maximum and pushing the speaker beyond it physical limits When using too
little power, there a tendency to push the amplifier into overload, which will generate
enough distortion to burn the voice coil. The most important point to consider is how
the power is used in order to ensure the speaker is presented with a clean signal. Be
sure that you amplifier is producing a good clean signal. If your amp has a on-board
compressor or limiter, we recommend you use it to protect the speaker. If the sound
is getting distorted you’re probably starting to damage the speaker."

I hope you guys keep a fire extinguisher handy!

That isn't underpowering a cabinet, that's trying to get too much from an amplifier.

Guess what, that would cause damage if:

Using a 500 watt amp with a 250 watt cab.
Using a 500 watt amp with a 500 watt cab.
Using a 500 watt amp with a 1000 watt cab.

[PSPookie]

This thread should be made into some sort of sticky on how NOT to answer technical questions.

If you don't know what you're talking about, then please don't chime in.