[ou812]

The thing is, there is no 'chance'. They are designed to work fine with regular head units. Call them and ask yourself if you don't believe the writing.

If I believed everything printed on a box then a Boss amp should put out 2000 watts with a 20 amp fuse.

 

[djPerfectTrip]

^^^Now you are just arguing to argue.

Think about it. Why would JBL design a speaker that 90% of people wouldn't be able to use unless they had to spend extra to get an amp? Doesn't make sense.

 

[qwertydude]

It also can depend. I've actually had my Pioneer head unit thermal. I've also strangely had it thermal when connecting speakers with piezo tweeters to the head unit when testing. It seems Pioneer head unit amps do not like piezo tweeters, it must have caused inaudible amplifier osscilation, so if it's in a truck and you've got those piezo truck woofer boxes watch out.

So it shouldn't immediately destroy it but listening at loud levels can eventually cause heat to build up especially with 2 ohm speakers. Hopefully the thermal safety is working. I have on the rare occasion had an amplifier that didn't have a thermal safety properly working and burned up the output transistors but that was a long time ago. Basically you shouldn't be relying on your head unit's safety to keep you out of trouble. Just buy an inexpensive amplifier that's two ohm stable. You'll get louder and sound quality will improve with the added power.

The head unit is in an enclosed area with still air and in my car in particular if I had the heater on heat would build up in the dashboard and cause my head unit amp to thermal, it would have been worse if my speakers were 2 ohms.

I have an older Pioneer but it has the same chip amp as the newer ones. So it can depend on install too since I was thermalling and still might if I listen at very loud volumes for a long time with the heater on. And that's at 4 ohms per speaker.

 

[ou812]

Won't do any damage to anything unless they are wired up wrong.

Fair enough...But how much better or more sound did you experience compared to a rated 4 ohm driver on the same hu? At that level of power it doesn't make sense. Keep in mind that this is a rear fill scenario where the overall effect will be minimal at best. Maybe I just like to play it safe.

 

[ou812]

^^^Now you are just arguing to argue.

Think about it. Why would JBL design a speaker that 90% of people wouldn't be able to use unless they had to spend extra to get an amp? Doesn't make sense.

I'm not arguing and I do apologize if it was taken that way.

 

[DBlevel]

Only reason running a 2 ohm speaker wouldn't be a good idea on an OEM HU is if your going to crank the volume up to full tilt!

More distortion at max level, yea that would be a problem.

You are not going to gain much by doing this but it is a noticeable difference.

If your hoping to to do this and getting a huge difference then you'll be disappointed.

Installed dozens of the 2 ohm JBL co-ax at a shop I worked at yrs ago and never had an issue. Other than they came back and added an aftermarket amp and/or HU .......NEVER did anyone come back because the OEM HU was bad due to the 2 ohm speakers.

 

[DBlevel]

Fair enough...But how much better or more sound did you experience compared to a rated 4 ohm driver on the same hu? At that level of power it doesn't make sense. Keep in mind that this is a rear fill scenario where the overall effect will be minimal at best. Maybe I just like to play it safe.

The level of volume between a 2 or 4 ohm aftermarket speaker will be minimal. Noticeable yes, but nothing I'm sure you'll be happy with.

 

[gijoe]

So it sounds like those speakers aren't actually 2ohm speakers, the manufacture is telling you that so you think you're getting double the power. If they are truly 2ohm speakers then no, I wouldn't run them off of the HU if it isn't rated for 2ohms. Chances are, the speakers are closer to 3 or 4ohm speakers that will likely be ok for the HU; maybe they are just trying to appeal to the SPL crowd that thinks lower resistance means more power and better performance.

The way I look at it is that there are 2 possibilities:
1. They aren't actually 2ohm speakers and JBL is giving you very misleading info. They are trying to appeal to a certain crown that thinks lower impedance is better and so they will be fine.
2. They are 2ohm speakers and it's a bad idea to hook them up to your HU.

In both cases I'd look for different speakers.

 

[ou812]

So it sounds like those speakers aren't actually 2ohm speakers, the manufacture is telling you that so you think you're getting double the power. If they are truly 2ohm speakers then no, I wouldn't run them off of the HU if it isn't rated for 2ohms. Chances are, the speakers are closer to 3 or 4ohm speakers that will likely be ok for the HU; maybe they are just trying to appeal to the SPL crowd that thinks lower resistance means more power and better performance.

The way I look at it is that there are 2 possibilities:
1. They aren't actually 2ohm speakers and JBL is giving you very misleading info. They are trying to appeal to a certain crown that thinks lower impedance is better and so they will be fine.
2. They are 2ohm speakers and it's a bad idea to hook them up to your HU.

In both cases I'd look for different speakers.

You kinda hit it both ways. I believe they are actually 3.2 with a meter.

 

[ou812]

The level of volume between a 2 or 4 ohm aftermarket speaker will be minimal. Noticeable yes, but nothing I'm sure you'll be happy with.

What do you mean by that?

 

[DBlevel]

What do you mean by that?

OEM HU is what? 10 watts you double that at most with these it's 20 watts.

Adding these to a OEM HU you will barely notice the difference.

I have a set of the ......

JBL
P963
P662

On the OEM HU wasn't much a difference at normal volume. Noticeable difference but very little.........you won't gain much.

Added an amp with the JBL MS-8 was a big difference.(old school Alpine amp, can't remember the model) maybe 75 rms x 4........

With the MS-8 and a
Memphis Big Belle was a huge difference!

 

[djPerfectTrip]

I'm not arguing and I do apologize if it was taken that way.

No hard feelings

Here is something I found on Crutchfield's forum. The post is from 2007, but it should still hold true:

Hey Guys,

Andy from Harman here...I'd like to clear this up, if I can without having to get too technical.



First, we didn't just decide to make our speakers 2-ohms without doing some serious testing and verifying that it works and that the "technology" is sound. We tested lots of factory and aftermarket head units and none of them failed. Many made more power. A few made less distortion (which was a surprise) AND more power, but none of them failed. In the two years that we've been selling 2-ohm speakers, we have NEVER had a radio fail because it's been hooked up to our speakers. In every case where an installer has suspected that our speakers have caused problems, we've helped them trace wires and measure resistance and have found some other problem...poor connections, short circuits and the like.



In our test, the head unit was connected to the speakers with a 1-foot pieces of wire. That's short compared to the lengths of wire that connect your head unit to your speakers in your car and the wire contributes some additional resistance. Furthermore, after you've played the speakers for a few minutes in the car, the voice coils get hot (that's one of the laws of Physics) and their resistance increases. When that happens, our speakers look to the radio like a 4-ohm speaker and a 4-ohm speakaer looks more like a 5.5-ohm speaker. We're simply giving you back the power that you lose when you actually install the speakers in the car.



Some of you might be surprised to discover that MANY factory speakers are, in fact, 2-ohm speakers and replacing them with 4-ohm speakers DEGRADES the performance of the head unit.







Andy Wehmeyer Product Marketing Manager Harman Consumer Group

 

[DBlevel]

No hard feelings

Here is something I found on Crutchfield's forum. The post is from 2007, but it should still hold true:

Hey Guys,

Andy from Harman here...I'd like to clear this up, if I can without having to get too technical.



First, we didn't just decide to make our speakers 2-ohms without doing some serious testing and verifying that it works and that the "technology" is sound. We tested lots of factory and aftermarket head units and none of them failed. Many made more power. A few made less distortion (which was a surprise) AND more power, but none of them failed. In the two years that we've been selling 2-ohm speakers, we have NEVER had a radio fail because it's been hooked up to our speakers. In every case where an installer has suspected that our speakers have caused problems, we've helped them trace wires and measure resistance and have found some other problem...poor connections, short circuits and the like.



In our test, the head unit was connected to the speakers with a 1-foot pieces of wire. That's short compared to the lengths of wire that connect your head unit to your speakers in your car and the wire contributes some additional resistance. Furthermore, after you've played the speakers for a few minutes in the car, the voice coils get hot (that's one of the laws of Physics) and their resistance increases. When that happens, our speakers look to the radio like a 4-ohm speaker and a 4-ohm speakaer looks more like a 5.5-ohm speaker. We're simply giving you back the power that you lose when you actually install the speakers in the car.



Some of you might be surprised to discover that MANY factory speakers are, in fact, 2-ohm speakers and replacing them with 4-ohm speakers DEGRADES the performance of the head unit.







Andy Wehmeyer Product Marketing Manager Harman Consumer Group

Exactly!

Great post!

Exactly what I was trying to say.

 

[DBlevel]

Where'd everybody else go?

 

[djPerfectTrip]

^^^good question

 

[gijoe]

Haha if Andy says they'll work without issues, then I trust him.

 

[ou812]

There is actually a guy that chimes in on that thread at crutchfield that has an alpine hu that keeps shutting down with 2 ohm drivers hooked up to it. Infinity I believe. I still question the very small return in the end vs using a 4 ohm driver of similar sensitivity. To each their own.

 

[Regus]

I wonder if the guy on Crutchfield has run new wire to the Infinity 2 ohm drivers? As per the information from Andy W (which mirrors that on the Infinity website), when used as direct replacements for OEM speakers, their 2 ohm drivers would present a 4 ohm load once you took into account the overall impedance of the speakers and the OEM wiring loom and therefore will be fine when used with a HU or amplifier stable at 4 ohms. With uprated wiring the load could be low enough to cause a HU to shut down.

OP, are you planning on using these rear fill as replacements for stock speakers with the factory wiring? If so then you are probably fine to go ahead, although for peace of mind it might be worth checking with the HU manufacturer that it won't be an issue.