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Discussion Starter #1
Hello!

The original Speakers of Mazda 6 have 4 Ohm impedance.

Would it be possible to put 2 Ohm speakers in the car?

Or is this no good idea and would damage the radio?

How many power has the radio?

Greet`s Erich
 

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unless your putting a seperate amp on them it is not a good idea, the stock headunit is designed to safely power the 4 ohm speakers, most aftermarket head units are only designed for 4 ohm operation. putting 2 ohm speakers on the stock headunit, if it would even work at all, would generate more heat inside the internal amplifier and eventually fry components
 

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f it would even work at all, would generate more heat inside the internal amplifier and eventually fry[/b]
precisely. not a good idea to hook up the 2Ohm speakers to the stock system. it'll work for a minute, and it'll be really loud. then your stock HU will fry and/or catch on fire. FIRE BAD. if you buy an aftermarket amp, buy a 2Ohm stable amp, or you'll have the same problem. you could always rewire your speakers in series behind the radio. say, wire left side & right side in series. this will bring you back to 4Ohm, but you'll lose fade. i would recommend against that as well.
 

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precisely. not a good idea to hook up the 2Ohm speakers to the stock system. it'll work for a minute, and it'll be really loud. then your stock HU will fry and/or catch on fire. FIRE BAD. if you buy an aftermarket amp, buy a 2Ohm stable amp, or you'll have the same problem. you could always rewire your speakers in series behind the radio. say, wire left side & right side in series. this will bring you back to 4Ohm, but you'll lose fade. i would recommend against that as well.
[/b]
Actually it's not quite as catastrophic as this, unless you hook them up and then immediately crank up the volume to maximum.

2 ohm speakers won't damage anything, as long as you don't turn up the volume to the point that the current draw from the amplifier exceeds the rating of the output transistors. The volume control varies the voltage setting across the speaker terminals; that's how it varies the loudness. The greater the voltage, the greater the movement of the speaker coil. The impedance of the speaker coil (2 ohms 4 ohms, 8 ohms, etc) determines how much current will be drawn from the amplifier at any given voltage level.

So you can use 2 ohm speakers but you risk blowing the amplifier if you exceed the current rating (which translates into a power rating), and this is easy to do if you're not careful with the volume control. Having said this, some amplifiers may have impedance sensing ccts and will shut down if too low an impedance is used for self protection.

As far as loudness, the impedance of the speaker has nothing to do with how loud it plays. That is the sensitivity rating. It's a common misconception to equate power rating with loudness. Power rating (ex 50W RMS) just tells you how much power the speaker can handle, and this is a function of the size of the magnet, the size of the voicecoil, and the design of the speaker; essentially all the components that can absorb and dissipate heat. If you turn up the volume loud enough to cause the speaker to draw so much current that it can't dissipate the heat, then the power rating will be exceeded and the speaker will fail (insulation on the voice coil windings typically melt, shorting it out. This usually blows the amp too).
The speaker won't go really loud and then "pop", unless as I stated earlier, you crank the volume to max as soon as you turn it on. This is a careless thing to do with any stereo system and can cause even properly matched components to fail.
 

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less resistance=more current flow=more heat generated inside the amplifier

this will not lead to immediate death, it may work well for a year, a week, 15 minutes, no one can give an answer. but from asking this questions I'lll assume your trying to increase output from the stock stereo, and higher output also means more heat. heat kills electonic components.

if you are looking to increase volume add an amp. at that point you can further evaluate if you want to use 2 or 4 ohm speakers
 

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by halfing your load resistance you're also doubling the currnet draw through the circuit and quadrupling the power output. the stock system was designed to operate off 4 ohm speakers. you will have problems running 2 ohm speakers.

yes, it will be louder, i.e. your volume set at 10 with 2 ohm speakers will be recieving four times more power than when set with 4 ohm speakers. this is not to say they will be four times louder though. ohms law at work.

this point is moot. you shouldn't run 2 ohm speakers on the stock system. dreamweave is right on the money, if you want more power & use 2 ohm speakers upgrade to an external amp as well.
 

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As everybody has stated, it's best to use the correct impedance that the amplifier is rated for. Use 4 ohm speakers if the amplifier was rated for 4 ohms.

What are you trying to do? Do you have 2 ohm speakers lying around and just want to make use of them? Are you considering a specific brand and model of speaker that is only available as 2 ohm loads (ex. current Infiinity Kappas)? Are you trying to get more SPL without changing the amplifier?

If you want to get the most SPL from a given power output, use a speaker that has the highest sensitivity rating you can find. For example, the current range Infiinty Reference speakers are rated at approx 92dB. The current range of Infinity Kappas are rated at 94-95dB. That is, with the same voltage level (which equates to a volume setting), the Kappa will play louder than the Reference. 3dB is noticecably louder, but not twice as loud (human hearing is not linear). Still, looking at it another way, to get the Reference speaker to play at the same level as the Kappa, the Reference speaker would have to draw double the power that the Kappa would.

Unfortunately the Kappas are 2 ohm loads, vs 4 ohms for the Reference, so not really usable in your case, unless you upgrade to an amp that can handle 2 ohm loads. And remember, the above is only one of many factors when considering the purchase of a speaker. Physical compatibility (will it fit), sound quality, tonal neutrality, etc, all have to be considered to.

The logical process would be to find speakers that sound the way you like, can be made to fit into the car, and then get an amplifier that will drive them to the volume level you desire. But, if you have different priorities, then the process has to be adapted to fit your requirements. I don't listen to my music that loud, and I wanted to do as little custom mods as possible while still getting some improvement in sound quality, so I experimented with just replacing the stock speakers and applying sound deadener to the doors. I went the opposite direction that you're proposing; I have the Bose system which has 2 ohm speakers. I put in 4 ohm Infinity Reference (I prefer the highs of the sof dome tweeter) speakers in all 4 doors, driven off the stock Bose amp. I have to turn the volume control up higher than with stock (probably due to the References being less efficient, ie lower sensitivity, than the stock speakers), but it still plays loud enough for me. The setup meets my needs for now; the remaining question is whether I should replace the Bose sub.
 

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Discussion Starter #8
Thanks a lot for your hints :D

I own a Mazda 6 build 2003 - European version.
One friend figured out that this versions radio only supports 4x15 WATT :irate:

This is horrible!

I can turn the radio to 33 - I think this is max. loudness - but it doesn`t sound loud.

My friends Mazda 6 build 2005 - after face lift - has 4x40 WATT (no Bose System)

He is using the JBL Speakers JBL GTO 8627 5"X7" @ 2 OHM impedance.
For him they are working fine with his original HeadUnit.
He told me that the sound is great,...

I have too less power in my car I guess :huh:

Maybe you know other speakers which sound great ?

Mazda 6 needs 5x7'' Speakers

The INFINITY REFERENCE Speaker 6812CF also fits
Maybe you have them "Super Car Tastes - Skoda Budget" ?

For an amplifier I need High/Low Converters + the effort of wirering is enormous.


looking forward to hints

Greet`s Erich
 

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Thanks a lot for your hints :D

I own a Mazda 6 build 2003 - European version.
One friend figured out that this versions radio only supports 4x15 WATT :irate:

This is horrible!

I can turn the radio to 33 - I think this is max. loudness - but it doesn`t sound loud.

My friends Mazda 6 build 2005 - after face lift - has 4x40 WATT (no Bose System)

He is using the JBL Speakers JBL GTO 8627 5"X7" @ 2 OHM impedance.
For him they are working fine with his original HeadUnit.
He told me that the sound is great,...

I have too less power in my car I guess :huh:

Maybe you know other speakers which sound great ?

Mazda 6 needs 5x7'' Speakers

The INFINITY REFERENCE Speaker 6812CF also fits
Maybe you have them "Super Car Tastes - Skoda Budget" ?

For an amplifier I need High/Low Converters + the effort of wirering is enormous.
looking forward to hints

Greet`s Erich
[/b]
Hi Erich, welcome to the forum. I am using the 6802cf in the rear doors, which is just a one year earlier version of the 6812cf. There isn't really much difference between the two. The rear doors will take 6x8 or 5x7. Most 6x8 speakers have multiple mounting holes to fit either 6x8 or 5x7 openings.

My Bose system has 6.5" round speakers in front, with separate tweeters in the upper corner, against the window glass. I replaced the stock ones with the Infinity 6010cs component system, and mounted the Infinity tweeters in the stock location. I cut the plastic ring on the Infinity tweeter and removed the grille. It fit very well, without requiring any modification of the stock tweeter housing.

You will need to check about your front speakers. I seem to remember earlier Mazda6s came with 6x8 in the front door too, same as in the rear doors. You could get adapters to put in different speakers, but again more work and cost.

BTW, I believe JBL is made in the same factory as Infinity. Both are owned by Harmon Kardon now, and if you look at their current lines of speakers, they are almost a direct match to each other. The exception is with impedance. If I remember correctly, the JBL equivalent to the Infinity Kappas (they both run more powerful neodymium magnets, so are more efficient) are actually 4 ohms instead of 2. They are as efficient as the Kappas (94 to 95 dB) but 4 ohm impedance. These would be a good match up to your system with the stock amplifier/head unit. Check them out.

I feel for you about the wiring. I used to do all kinds of custom mods in my car when I was young (25yrs ago) but now I'm too old, lazy and cheap to do this. I'll take panels off and change out speakers, add sound deadener, etc, but I don't want the hassle of running new wiring everywhere and forcing something to fit where it wasn't really designed to.

I don't know if putting the JBLs will get you more sound pressure level. Stock speakers are usually designed to be very efficient, to maximize sound level output from cheap, underpowered head units. Of course, what they give up to achieve this is sound quality. Using the JBLs with the neodymium magnets may not get you any louder sound, but would definitely improve sound quality. That's my opinion anyways. Stock speakers, even in the Bose system, are really cheap and poor quality. Lots of boomy midbass, very little high end, and not very clean in the critical 1kHz range (human voice).
 

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Discussion Starter #10
The JBL have 2 Ohm impedance :sarc:

SPECIFICATIONS
General
Power Handling, RMS 60 Watts
Power Handling, Peak 180 Watts
Frequency Response (±3dB) 50Hz-21kHz
Sensitivity 92dB
Mounting Depth 2-1/16" (58mm)
Cut-Out Diameter 8-11/16" x 5-7/8" (126mm x 183mm)
Impedance 2 Ohms [/b]
See JBL GTO 8627


The Infinity

Specifications
MSRP U.S. $: 119.95
Power Handling, RMS: 60 Watts
Power Handling, Peak: 180 Watts
Sensitivity: 92dB
Frequency Response: 49Hz - 21kHz
Mounting Depth: 2-7/16"
Impedance: 4 Ohms [/b]
See Infinity - 6812CF

If I would know that the radio has good fuses and wouldn`t burn - I would try the JBL @ 2 OHM :zzz:

Greet´s Erich
 

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The JBL have 2 Ohm impedance :sarc:



See JBL GTO 8627
The Infinity



See Infinity - 6812CF

If I would know that the radio has good fuses and wouldn`t burn - I would try the JBL @ 2 OHM :zzz:

Greet´s Erich
[/b]
Hi Erich, looks like my memory was wrong. Thought I saw models in JBL's line up that matched up to the Kappas but were 4 ohm impedance. If you're still considering 2 ohm speakers, then you'd be better off with the Infinity Kappa 682.7cf:

Specifications:
Power Handling, RMS 100 Watts
Power Handling, Peak 300 Watts
Sensitivity 94dB
Frequency Response 40Hz - 25kHz
Mounting Depth 2-1/4"
Impedance 2 Ohms

Note that higher sensitivity of 94dB for the Kappa 682.7cf over the JBL GTO8627 (92dB). The decrease of 2dB sensitivity in the JBL speaker means it would draw 2/3 more power to attain the same sound pressure level as the Kappa 682.7cf.

For 4 ohm speakers the Infinity Reference 6812cf would be the better choice.

Edit: I was checking around and found these Polk Audio 5x7 speakers :http://www.polkaudio.com/caraudio/specs/db570/

Driver Complement
Mid/Woofer 1 - 5" x 7" (12.70cm x 17.78cm)
Polymer/Mica Composite cone with rubber surround
Tweeter 1 - 3/4" Diameter (1.91cm)
Silk/Polymer composite dome

--------------------------------------------------------------------------------

Electrical
Overall Frequency Response 52Hz-22KHz
Nominal Impedance 4 ohms
Power Handling (continuous) 60 w
Power Handling (peak) 180 w
Efficiency 93 dB

They're a bit more efficient at 93dB, and should fit too.
 
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