Thread: Fitting 6 ohm speakers to 4 ohm unit

Is the result of fitting 2 rear , 6 ohm speakers to my 4 ohm / 60 watt output x 4 head unit ( that already has 2 x 4 ohm speakers fitted) that the 6 ohm speakers will only operate at .75 of thir power or 40 watts

Wow that is a question and a half. Now I am not a tech but have quite a bit of experience in car sound.

The answer is YES but the actual result depends on many things.

What is the speaker efficiency? Speakers vary in output per watt. Efficient speakers will have the same volume for fewer watts. What is the max input of the speakers? Related to the previous sentence. Usually speakers with high input capacity will have poorer efficiency.

Is the 60W per channel real RMS or some spurious "max output"? If the amp goes into clipping at a low output , you could damage the speakers if on high volume.

I reality I think it will work OK . You should just suck it and see. At least a higher impedence will not hurt the amp, as lower than designed impedence would/could.

Regards Philip A

I agree with Philip

Having said that, most modern head units and amps can run 4-8ohm no issues.

Believe it or not Phillip I am no techo either

That's just a result of the good oil I got from this site

I am just looking to fit a set of outdoor speakers to the back of the 02 Defender in line with another AULROIAN's project.

The Head Unit is a Clatronic Radio DVD complete with 5 inch Alpine 2 way speakers , that I picked up for a good price

Now the tech data under the wiring diagram says " Please use speakers with a 4 Ohm Impedence "

The Alpines are 4 ohm speakers.

The choice for Outdoors to the rear are ;

1. Bunnings 5th Room. 4" , 2 way , 100 watts max , freq 75 hz-20khz , 6 ohm ( didn't write down the efficiency ) for $ 69 or;

2. Some off Fleabay from a place called VFM audio in QLD. Specs are ; 140 watt , 3 way , hi fi (?) , freq 80-18 kHz , 70 watts each , impedence 8 ohms , for $ 77 deliv to Melb.
Now , the man from VFM tells me that these are 4-8 Ohm speakers and if impedence is measured across the back , they are 4 ohms

Given that I'm not looking for Doof doof , the extra 40 watts for the VMF means naff to me ( why does he then say 70 watts each ?) and even with 3way system , the top end is only 18 khz , I'm thinking the 5th Room ones from Bunnings might do ?

Pete

Both should be fine, but be aware that in my experience the outdoor speakers are very inefficient because the cones have to be waterproof and AFAIK makes them inefficient.

IE you may not get a great deal of volume.

BTW a bigger watt handling capacity of a speaker in itself does not give more volume.

The amplifier capacity for transients will largely determine the DOOF DOOF as DOOF DOOF is bass which depends on large deflections of usually a large speaker cone. Treble takes hardly any watt output to drive. That is why subs are used.

BTW2 Unless you are a dog the difference between 18Khz and 20Khz is immaterial and not heard by the usual human ear. AND if you plan to use MP3 those frequencies are taken out in the compression.

Regards Philip A

So , do you think the 3 ways are a better option Phil ?

I am no audiophile , I just like to hear all around noise from my stereos.

pete

In Theory:
Speaker resistance (ohms), in its simplest terms, is the load you will be putting on your amplifier, and is an average value, based around the 1k soundband. So in your case, if your desired speaker is 4ohm, then it will have a 4ohm load at roughly 1kHz. Higher frequencies produce a larger ohm load and lower frequencies produce a lower load. A speaker rating is approximate because every sound that you hear carries a different load to it. So it's not this magical fixed value that has to be adhered to, within reason of course. It's more of a bandwidth of resistances that the speakers should fall between.

If you were trying to match a 4ohm speaker with a 6ohm output, you would run the risk of overloading the source, but in your case, attaching a larger 6ohm speaker, means that the sound levels will simply decrease.

In Practice:
Yes you can, but it will not be as loud as it would have been had a 6 Ohm speaker been used.

So , do you think the 3 ways are a better option Phil ?

I am no audiophile , I just like to hear all around noise from my stereos.

Probably, but again they could be crap. But you will probably get more and accurate volume from nominal 70watt 4 OHM indoor speakers, than the 100watt input outdoor speakers. This means you can run the volume lower and avoid clipping in the amps. ie louder without distortion.

I once had a great result by fitting quality (Pioneer) 4 inch car speakers into the boxes of a small stereo that my son had blown the drivers out of.

Regards Philip A

Thanks Guys.
Now I am going to throw in a curve ball.
Can't you buy desk top / indoor speakers in 4 ohm that are small on size but big on bass/volume/ depth of sound?
Do these have their own power source/