what is low imp?

[tyronekndrck 10+ year member]

what exactly does low I'm subwoofer mean. looking at the subwoofer wire diagram on crutchfield and it has a wire option for low imp subwoofer. what does that mean I have 2 dual 2 ohms and whats considered low imp

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[ronin1717]

Impedance is a caculation of resistance and reactance

The diagram more than likely is referring to the resistance *ohm load presented to the amp by the speakers

 

[adulbrich 5,000+ posts]

Link?

If you have 2 dual 2 ohm subs, .5 would be what I would consider low. You should probably stick with 2 ohms overall though. What amp are you using?

 

[BOOMINGRANDPA 5,000+ posts]

what exactly does low I'm subwoofer mean. looking at the subwoofer wire diagram on crutchfield and it has a wire option for low imp subwoofer. what does that mean I have 2 dual 2 ohms and whats considered low imp

yeah if it shows 2 different diagrams 1 will be how to wire it to 4 ohm other with be to 1 ohm (per sub) so that would be the low imp., like he said 2 of those will be 1/2 ohm i doubt u wanta do that.. u need to tell us what amp you have., if it's 2 ohm stable wire each to 4 ohm., if u don't have pretty expensive amp u cannot wire them to 1 ohm each it won't work and u may fry something..

 

[sfall]

This is a really important topic, and unfortunately most people don't have a very good understanding of resistance. Impedance is resistance, and is measured in ohms. Less resistance means less ohms, and higher is more. You need to be careful when working with speakers with low resistance. To visualize, no resistance, or 0 ohms, is the same as taking your speaker cables and touching them together. Commonly referred to as a dead short. So, with a 2 ohm load, you're 2 ohm's away from a dead short. That's why you have to be careful. Where most go wrong, is they see this as a good thing. They see an amp that is rated for 2 ohms has more watts available, so they get a 2 ohm speaker. Understand that while you can get more power by doing this on paper, its very hard on your amp. If you can do the same thing with a 4 ohm load and less watts, its a much better choice. Higher resistance means the amp has to work less, and usually sounds much better because its not straining.

There's also a couple of other concepts that are important to know. When you are looking at a 2 or 4 ohm speaker, keep in mind those are just averages. When in use, the speakers resistance will vary. At any given time it can possibly be a 7 ohm load, and at others, a 1 ohm load. Frequency is what determines this. High notes are more resistant, and ohm ratings will be higher at those frequencies. A lower note, means less resistence. Manufacturers often fail to accurately disclose this type of information. You need 2 numbers. One is the average like we've been talking about (2 ohms, 4 ohms.....). But the more important number is the lowest it will drop. It looks something like: 4 ohms nom, 2.5 ohms min. 4 is the average and 2.5 is the lowest it ever drops. The industry is doing a much better job with these specs in home audio, but car audio needs to catch up.

So, now applying this to your situation, you're looking at a 2 voice coil sub. As I'm sure you already know, this allows you to use 2 channels of an amp to power the speaker. The choice you need to make is, wire the connection in series or parallel. Series will create a 1 ohm load and parallel will create a 4 ohm load. Unless you have some very expensive, high end amps that can be put through hell, wire the sub in parallel and you should have no problems at all.

 

[shredder1 10+ year member]

This is a really important topic, and unfortunately most people don't have a very good understanding of resistance. Impedance is resistance, and is measured in ohms. Less resistance means less ohms, and higher is more. You need to be careful when working with speakers with low resistance. To visualize, no resistance, or 0 ohms, is the same as taking your speaker cables and touching them together. Commonly referred to as a dead short. So, with a 2 ohm load, you're 2 ohm's away from a dead short. That's why you have to be careful. Where most go wrong, is they see this as a good thing. They see an amp that is rated for 2 ohms has more watts available, so they get a 2 ohm speaker. Understand that while you can get more power by doing this on paper, its very hard on your amp. If you can do the same thing with a 4 ohm load and less watts, its a much better choice. Higher resistance means the amp has to work less, and usually sounds much better because its not straining.
There's also a couple of other concepts that are important to know. When you are looking at a 2 or 4 ohm speaker, keep in mind those are just averages. When in use, the speakers resistance will vary. At any given time it can possibly be a 7 ohm load, and at others, a 1 ohm load. Frequency is what determines this. High notes are more resistant, and ohm ratings will be higher at those frequencies. A lower note, means less resistence. Manufacturers often fail to accurately disclose this type of information. You need 2 numbers. One is the average like we've been talking about (2 ohms, 4 ohms.....). But the more important number is the lowest it will drop. It looks something like: 4 ohms nom, 2.5 ohms min. 4 is the average and 2.5 is the lowest it ever drops. The industry is doing a much better job with these specs in home audio, but car audio needs to catch up.

So, now applying this to your situation, you're looking at a 2 voice coil sub. As I'm sure you already know, this allows you to use 2 channels of an amp to power the speaker. The choice you need to make is, wire the connection in series or parallel. Series will create a 1 ohm load and parallel will create a 4 ohm load. Unless you have some very expensive, high end amps that can be put through hell, wire the sub in parallel and you should have no problems at all.

I tried to PM this member so he would have a chance to fix his advice before someone takes it and smokes an amp. Parallel on a dual 2 ohm is 1 ohm... Series on a dual 2 ohm is 4 ohm... hopefully nobody took this as advice.

 

[Buick_66]

After such a long and detailed explanation he chokes on series/parallel...ooooohhhh.

So to clarify, coils in series makes 4 ohm subs. Then subs in parallel brings down to 2 ohm final load. Should be able to bridge most amps at 2 ohms and have most/all it's power. (Unless you spend $$$)

 

[ronin1717]

I tried to PM this member so he would have a chance to fix his advice before someone takes it and smokes an amp. Parallel on a dual 2 ohm is 1 ohm... Series on a dual 2 ohm is 4 ohm... hopefully nobody took this as advice.

also impedance isn't technically resistance

 

[shredder1 10+ year member]

also impedance isn't technically resistance

This type of information is what confuses new guys... "TECHNICALLY" speaking... LOL!.. 25 years doing car audio and nothing fails to amaze me!

 

[Boomin_tahoe 5,000+ posts]

JL Audio » header » Support » Tutorials » Tutorial: Wiring Dual Voice Coil (DVC) Subwoofer Drivers

This diagram has some low imp wiring you can read/study on it. Low impedance is just that: wiring subs for a lower final ohm load to amp. Some people run 1 ohm, others 1/2 an ohm.

 

[sfall]

I tried to PM this member so he would have a chance to fix his advice before someone takes it and smokes an amp. Parallel on a dual 2 ohm is 1 ohm... Series on a dual 2 ohm is 4 ohm... hopefully nobody took this as advice.

You're right. I typed that out when I was in a hurry. Thanks for spotting it.

OP,

Everything in my first post still applies. In the last sentence, just swap series and parallel. It was a typing error.

 

[Boomin_tahoe 5,000+ posts]

You're right. I typed that out when I was in a hurry. Thanks for spotting it.
OP,

Everything in my first post still applies. In the last sentence, just swap series and parallel. It was a typing error.

Reason why your ignoring me?

 

[BOOMINGRANDPA 5,000+ posts]

You're right. I typed that out when I was in a hurry. Thanks for spotting it.
OP,

Everything in my first post still applies. In the last sentence, just swap series and parallel. It was a typing error.

long explainations never go well here lol.. i can't spell 5 words right in a row anyway..

 

[The_Quiet_One 10+ year member]

This is a really important topic, and unfortunately most people don't have a very good understanding of resistance. Impedance is resistance, and is measured in ohms. Less resistance means less ohms, and higher is more. You need to be careful when working with speakers with low resistance. To visualize, no resistance, or 0 ohms, is the same as taking your speaker cables and touching them together. Commonly referred to as a dead short. So, with a 2 ohm load, you're 2 ohm's away from a dead short. That's why you have to be careful. Where most go wrong, is they see this as a good thing. They see an amp that is rated for 2 ohms has more watts available, so they get a 2 ohm speaker. Understand that while you can get more power by doing this on paper, its very hard on your amp. If you can do the same thing with a 4 ohm load and less watts, its a much better choice. Higher resistance means the amp has to work less, and usually sounds much better because its not straining.
There's also a couple of other concepts that are important to know. When you are looking at a 2 or 4 ohm speaker, keep in mind those are just averages. When in use, the speakers resistance will vary. At any given time it can possibly be a 7 ohm load, and at others, a 1 ohm load. Frequency is what determines this. High notes are more resistant, and ohm ratings will be higher at those frequencies. A lower note, means less resistence. Manufacturers often fail to accurately disclose this type of information. You need 2 numbers. One is the average like we've been talking about (2 ohms, 4 ohms.....). But the more important number is the lowest it will drop. It looks something like: 4 ohms nom, 2.5 ohms min. 4 is the average and 2.5 is the lowest it ever drops. The industry is doing a much better job with these specs in home audio, but car audio needs to catch up.

So, now applying this to your situation, you're looking at a 2 voice coil sub. As I'm sure you already know, this allows you to use 2 channels of an amp to power the speaker. The choice you need to make is, wire the connection in series or parallel. Series will create a 1 ohm load and parallel will create a 4 ohm load. Unless you have some very expensive, high end amps that can be put through hell, wire the sub in parallel and you should have no problems at all.

A for effort, but you're spreading some misinformation.

1) Impedance is not resistance; it's impedance, resistance is reserved for DC current. Impedance, in regards to car audio subs ratings, is typically a nominal measure of how much an AC current is "impeded" by the load.

2) 2 ohms away from a dead short is very much an overly dramatic description. You are NEVER going to get close to a dead short with a subwoofer when it's wired at 2 ohms. You WILL NEVER reach an impedance below the DCR (DC Resistance) of the voice coil, which typically is only a few tenths lower than the rated impedance in most car audio subwoofers. Also impedance typically rises in practice due to heat, box rise, inductance, etc. You definitely can't make make a blanket statement about frequency's effect on impedance when a large portion of the dynamic load is due to extremely complex EM interactions between any induced EMF and the subwoofer motor.

3) A 2 ohm subwoofer amp is typically designed to handle the higher current associated with a lower impedance load. Unless your charging system is garbage or you bought a low quality amp it won't be overly hard on an amp. Have some faith in the engineers who designed some of the solid amps on the market today. Note: Typically it's much cheaper per watt to purchase an amp that produces solid power at lower impedances, and that power isn't just "on paper." High voltage amps tend to be a bit pricey and to maintain a similar power output at 4 ohms or higher is cost prohibitive to most consumers. I can find you a dozen affordable,reliable amps that make 2000 Watts at one ohm and handle it all day. 2000 Watts is a lot more difficult to find at 4 ohms, and you will likely be paying for it unless your willing to go with a Brazilian design.

4) As others said you seem to have the concept of parallel and series wiring backwards.

5) You were right this is an important topic and it's important that people have correct information

OP we need to know what amp you're using to really suggest the best wiring option. You've got the choice between 0.5, 2, and 8 ohms if you have 2 d2 subs

 

[sfall]

also impedance isn't technically resistance

In the context of this discussion, its not an issue. When discussing the AC circuit between the amp and speakers, the audio industry uses the terms resistance and impedance interchangeably. Shredder1 is correct. There's really no reason to split hairs here. We'll just end up confusing the OP.