Mar 18, 2008 11:00 pm Aw man! I just wrote this massive reply to your question, and the HRC server timed me out. So my post didn't go throw. Give me a little bit. I have to do the whole thing all over again. ARGGGGGGG!
Series / Parallel / Bi-Amp
Posted on Mar 18, 2008 10:07 pm
madsoundster
Member Since: Mar 17, 2008
Can anyone explain in simple terms the following and its ways of connecting? ie. how to connect and what are the common mistakes.
Also, would be appreciated if you can give scenarios as to why certain connections are done in a particular way.ie. Why would I wanna run the speakers in parallel or why series?
Thank you.
PS Rob: Bro, I still have some unanswered questions that I need your kind help on with regards to my last post of "bi-amping". Thanks in advance for sharing your knowledge on that.
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Mar 18, 2008 11:00 pm Aw man! I just wrote this massive reply to your question, and the HRC server timed me out. So my post didn't go throw. Give me a little bit. I have to do the whole thing all over again. ARGGGGGGG!
Mar 18, 2008 11:25 pm OK, in the Ohms post, I gave some information on how everything is wired for various connections. And how to calculate what the ohm total will be. I'll walk you though the complete set up procedure for the rest of info.
Mar 18, 2008 11:34 pm Series: In order to wire in series, you take the positive wire from your amp, run it to the positive terminal of the speaker. Then you take the negative terminal, and put a wire from there to the positive of the next speaker. Going from the negative of that speaker, you then return to the negative of the amp.
This is used when you have more then one of the same type of driver in a box. Such as 2 15" speakers.
Lets say that your 15" drivers are 4 ohms each. You need 8 ohm's total. This is where you would wire the 15's in series, inside the box.
Common use of this is for 2 boxes that have 2 15's in each. If you where to wire all of these speakers in parallel, you would wind up with a 2 ohm load. This may be to low of a ohm load for your amp. And this may cause the amp to clip to early. So, a heavier ohm load may be called for.
Mar 18, 2008 11:44 pm Parallel: You go from the positive of the amp, to the positive of the first speaker. Staying with the same positive terminal of the speaker, you then take a wire to the positive of the next speaker. You do the same for the negative terminals as well. Out from the amps negative, to the negative of the first speaker. And then same neg. goes to the next neg. of the other speaker.
This is the most common method for connecting more then one speaker box together. Instead of adding all the ohms together, and winding up with a ridiculous ohm load, such as over 16 ohm's, we divided the ohms instead.
Example: You own 8, 8 ohm speakers. You want to use 4 per side. Here 4 8 ohm speakers wired in parallel will give you a 2 ohm load. As opposed to wiring it all in series, which would give us a 32 ohm load. Which, I don't think that there is an amp out there that would drive a 32 ohm load.
Mar 18, 2008 11:53 pm Bi-amp. This is commonly used where high SPL (Sound Pressure Level) is required. By bypassing the passive crossover in the speaker box, we can now apply more current to the separate drivers. Passive crossover burn a lot of current before it reaches the drivers in the box.
Now, by having each driver connected straight to the amp, we can control our settings more accurately. And not have a lose of power due to the passive crossover.
Mar 18, 2008 11:57 pm Sorry dude, it's after midnight here. And I've been at work all day, I'm wiped out. I'll finish the rest tomorrow. If you have any question over what I just posted, I'll try to answer them first, before continuing.
Mar 19, 2008 09:16 pm OK, coming back to this now.
How to determine when to use the different ways of wiring.
First you must know how many drivers you will be connecting to each side of your amplifier. Their ohm load. And the ratings of your amp at different ohm loads.
All of this will help us make the right choice for wiring the drivers to the amp.
Lets start with a small amount of drivers at different ohm loads. And we will see how they wire up.
When we only have one driver, then there is only one way to wire it up. All of this is for two or more.
If we have 2, 8 ohm drivers with a 200 watt rating each. We start by looking at the amp. What is it's output at a 8, 4, and 2 ohm load.? Let's just say that our amp has a rating of 300 watts at 8 ohms, 425 at 4 ohms, and 500 at 2 ohms.
We want to connect both drivers up to one channel of this amp. Well, we are already past the 8 ohm rating in load, and power. (In order to get the most out of the power, we need to have at least have 400 watts 200 + 200 = 400.)
The closest to our example is 4 ohms at 425 watts that we want to get to. So, here we would choose to wire in parallel. Because wiring in parallel, we get a 4 ohm load out of our 2 8 ohm drivers. And we need 400 watts to run them. The amp is providing 425 watts at this ohm load. So, this is a perfect match for our example.
Let's move on to another one. We will use the same amp in this example as well. In this case we have 4, 4 ohm 100 watt drivers.
We still need 400 watts to drive these 4. So, that means we still want to get to a 4 ohm load.
Here is this example, we will use both methods for connecting our drivers.
First thing you want to do, is wire 2 pairs of drivers in series. This will give us 2, 8 ohm loads. Remember, when wiring in series we add the ohm loads together. Now, we simply wire the 2 pairs together in parallel. Which divides the total ohm load in half. This will now give us a 4 ohm load, with a 400 watt rating. Which is perfect for our amp.
I understand that this may be confusing at first. But, once you have done it a few times, you will get the hang of it.
Let me know if this answers the questions that you had. If not, I'll try to go in to more detail.
Dec 12, 2009 01:03 am How can you tell if you are connecting your speakers parallel or in series.
For example, I am trying to connect 3 of these monitors pro-audio.musiciansfriend...Horn?sku=600819 to one channel on a Mackie 2500 amp: www.amazon.com/Mackie-FR2...r/dp/B000QDNPA8
So I think I have 1200 watts at 2 ohms, 750 at 4 ohms, and 500 at 8 ohms.
From your post, it sounds like I could assume that taking speaker cables from one to the other monitor is connecting them in parallel. So that means that the 3 monitors connected by quarter inch cables would need 300 watts (assuming that I go by RMS Watts) at 2 ohms. Is this okay to have 1200 driving the three speakers?
Dec 12, 2009 01:37 am Sorry to say that your links aren't working to well. I didn't take me to any product page. So, I can't look at the specs of your gear.
But, assuming that the monitors are 300 rms, and the amp is 1200 @ 2 ohm load, then your perfect!
If you add the wattage together, they equal 1200. Can't ask for any thing better.
Wattage of speakers get add. They act as a sponge. Soaking up the wattage.
So, the way you are connected, does seem correct. And assuming that the monitors are an 8 ohm load.
Dec 12, 2009 01:48 am Here is a link to an illustrated guide that I wrote for here. It may help a little bit more.
www.homerecordingconnecti...ory&id=1578
Dec 12, 2009 02:15 am I fixed the links. Sorry about that. Thanks for the quick reply.
I just realized the Kustom speakers say 100 Watts RMS. So it would actually add up to being 300 watts for the three speakers. Is this still okay to power them with the 1200 watt amp?
Dec 12, 2009 02:41 am Rob,
Your link is excellent! I would have loved to find that about 4 years ago. I am definitely bookmarking that page. All of that makes complete sense.
The areas that I get confused in live sound is:
1. How you know if you are connecting Parallel or Series when you connect speakers together. I have seen cables that definitely create a parallel connection because of how they are wired, but on stuff like these Kustom speakers, you don't know what is going on inside the box. When the speaker doesn't say what it is, is it most likely going to be parallel? Or is it quite common to see them either way? Hopefully their user manuals tell you, but sometimes you don't have access to the specs.
2. When adding more speakers in parallel, you lower the ohms which gives you more power. This seems backwards to me. You get more power from your amp by adding more speakers? Also, do you just add up the RMS power of all of the speakers whether they are in parallel or series?
Finally, after reading your link, it answered my question about too much power for the speakers. So I should be okay if I turn down the input knob (on the front of the amp) that is going to those speakers?
Dec 12, 2009 04:46 pm Well, for the Series/Parallel, around 90% of all jacks on the side of the speakers, are wired in parallel.
The only way to truly know for sure, is to open up the panel on the side and look at the wires.
If the wires go to the other jack. Then it's in parallel.
If the wires go to the speaker from one jack, then back to the other jack. With no wires going in between the two jacks, then it's in series.
The reason that power goes up on the amp, is the fact that the ohm load is going down. The closer you get to a dead short (No ohm load) the more power an amp can deliver.
Remember, a speaker acts like a resistor. And a resistor resists current. And wattage is current. The measurement of V squared (V times it's self) divided by ohm's is wattage. (Ohm's Law)
By turning down the output knobs on the front of the amp. (Yes, they are output) will help a lot. You know that your ohm load is 2. So, take a multimeter and look at the voltage. Do the Ohm's law calculation, and you should know where to run the knobs.
Dec 12, 2009 05:28 pm Great! Makes sense. One last question.
When determining how many watts are needed for a channel on an amp, do you always just add the RMS values together whether it is series or parallel or a combination?
Then I've been reading that it is actually good to have 1.5-2x the amount of power available for the RMS value that you calculate. Does this sound correct?
Dec 12, 2009 05:37 pm The wattage is the same whether it's in series or parallel.
Wattage is a measurement of heat absorption. The rms values are telling you how much heat a driver can absorb before doing damage.
This is why it doesn't matter which way it is wired.
And there is also a peak reading on your speakers as well. This is how much heat it can take is small amounts. So, you don't have to struggle to keep everything at rms.
So, by being just a slight amount over the rms is fine. You just don't want to be there all of the time.
Music is dynamic. Meaning that it is not a constant. Small hits at peak is just fine. And being in between the rms and peak is the norm.
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