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Cabling car speakers as home speakers (is it really that stupid?)

When I was younger, I used to play a fair bit with car speakers and connect them to my home Pioneer hifi separates. I blew a couple of speakers in this way (as you do) and when I discussed it with an installer a while later was told that this was due to the impedance on the car speakers being 4 ohm and the house speakers being 8 Ohm. He suggested 'wiring the speakers as a pair' in parallel or series - I forget which, but basically I think he meant splitting the source wire into two sources and then feed to a speaker each one. This should in theory bring the total impedance to 8Ohm. Now I am all grown up (36) I am looking to install a home AV system around several rooms in the house and am wondering whether or not I could use something like this to utilise car speakers in the ceiling in place of very expensive house speakers which are fitted into the roof (they all seem to be over £100 \ £150 a pair!!) I'd like some common sense advice here please, is there a way I can wire a pair of car speakers to provide some sound around the house (cheaply) or do I HAVE to go with dedicated 8Ohm house speakers for the job. Aside from anything else, it seems as though there is an awful lot more choice when it comes to car speakers than there is for in-ceiling house speakers. Is it bad for the speakers, or amp or what? I'm looking for background to medium type noise levels etc, I'm not turning the house into a nightclub!! Thanks in advance guys!! Jag

Posted by Jag Gill on

  • Jag Gill Apr 30, 2007

    Thanks for the advice. Much appreciated.

    Can you provide a little more detail on this part of it?

    "this type of connection will tire your amp as well as the capacitors of the car speakers. Furthermore, you can get unwanted peak sounds from car speakers."

    Is there a way of 'cleaning the signal' to prevent the peak sounds? I am not too concerned at replacing speakers as I am intending on using £30 - £50 a pair speakers, but would be concerned at burning out an amp!!

    BTW, it's not for a 'home theatre' use it's as a housewide switched speaker installation to let me listen to mp3's etc throughout the house. Again, I have to re-iterate, it's more of a background type music effect I'm going for rather than a nightclub at home.

    P.S. I am using quality 8Ohm speakers for my Home Theatre setup.



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If you wire the speakers as a pair in parallel; (For two 4ohms car speakers) 1/R=1/4 + 1/4 1/R=2/4=1/2 R=2 ohms (the resistance value you'll get) (don't even think of trying it!) in serial; R=4+4 R=8 ohms (this mostly fits to home amplifiers, however, they provide 6ohms as well) I recommend that you use reasonable 8ohms speakers for the home theater amplifier you have. Despite the fact that the impedance value fits to 8ohms when you wire two car speakers as a pair in serial, this type of connection will tire your amp as well as the capacitors of the car speakers. Furthermore, you can get unwanted peak sounds from car speakers.

Posted on Apr 26, 2007

  • Anonymous May 01, 2007

    It's surely possible to find a way to clean the peak sounds. How? You can have the advantage of using an equalizer. If you add an equalizer to your system (before the amp), I believe you'll be able to eliminate unwanted peak sounds by adjusting some Hz. values especially between the range from 8kHz to 16 kHz. But, you have to make sure that the equalizer you may want to use doesn't have to have preamp function. For once, I've experienced a problem with my old Technics SH-GE 90 EQ just because of the reason that the relevant device had a pre-amplifier. As a matter of fact, it had increased the overall volume of my music system, and those peak sounds have even worsened.
    I want to give you another example as well. In my current home theater system, I use a pair of car tweeters (4ohms), which are additional speakers to use with my 8ohms home stereo speakers. I've needed to use them because my stereo speakers haven't provided clear sound as much as I've expected. Anyway, I've wired those tweeters as a pair in parallel to my 8ohms ones. At first, they've given me peak sounds especially while listening to mp3 files. After that, I purchased an equalizer, and eliminated those high frequencies.




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Question: Although you can get good sound with the car stereo speakers using EQ (and maybe a notch filter or two in the crossover), will you get good dispersion? Car speakers are designed to operate in an enclosed air space in front of the cone (the car's cabin), while the back air enclosure is either very limited in size (a door, for example) or VERY spacious (a trunk). Those considerations make me wonder if the dispersion will be less than optimal.

Posted on Sep 26, 2009


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