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  1. #1
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    how do I set the ohms?? please help

    ok first hi and thanx for everyones help ahead of time..lol

    I bought a onkyo 601 receiver and I have a older bose dual cube speaker system.

    the onkyo can go down to 6ohms and the bose say they can handle 4-8ohms.


    but i do i know im putting 6ohms out? i want to put 6ohms instead of 8ohm
    there is no switch in back of the receiver to do it.


    anybody???...thanx

  2. #2
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    You are misunderstanding "ohms"

    An ohm is a measure of electrical resistance (Impedance actually since this is AC current we are discussing traveling in your speaker wires. The speakers provide electrical resistance to the flow of electrical power from the amplifiers in your receiver. The quasi "standard" in home audio is an 8 ohm speaker, although there are a lot of 4 ohm speakers as well, and a few 6. This number is sort of an "eyeball average" of the speaker's impedance (resistance) curve. The actual amount of this resistance (ohms) changes by the millisecond as your speaker is working. At some points an 8 ohm speaker my be down around 4 ohms, and at other times it could be at 64 ohms, or even higher. When your impedance (ohms) are halved (ex 8 to 4 ohms) the current demand, or demand for the amplifier to deliver more raw electrical power into the speaker is doubled. Essentially, the amplifier will have to work harder to provide the speaker with what it needs to work properly. This extra work creates heat that the amplifier has to dissipate (get rid of) faster than it can build up. If it can't do that, then the amplifier overheats and shuts down.

    This is why it is incredibly important to buy a BETTER receiver rather than one with a higher watt rating. Your Onkyo is a pretty nice piece, you did well there. The Bose speakers impedance rating of 4-8 ohms is a joke. It would be considered a 4 ohm speaker. You wouldn't want to run it with a cheesy receiver like an entry level Sony, Pioneer, JVC, or the like. They would tend to shut down at anything over quite modest volume levels. Your receiver should deal with this pretty well.

    On the speaker front, you could have done better, but you made the best mistake you could possibly make. The Bose, besides being a bit difficult to drive, have satellites that don't integrate into the Bass Module very well. The problem is that the drivers (individual speaker units) in the cubes are too small, and because of that don't go low enough to blend into the sound that the Bass Module makes. The Bass Module isn't a subwoofer, since it has to play very high frequencies, and doesn't go as low as a subwoofer would. It is pretty easy to figure out what I'm talking about. Since it is an older system with the 6th order bandpass module, make a ball out of a pair of socks and use that to plug the hole on the bass module. Play the system with the socks in the port for a while, you can use movies or music, although music is often better. After a few minutes, pull the socks out of the port and listen. With the socks in, the sound is really tinny and nasty sounding. What you will find is that once you have identified that sound, you will always hear what the satellites are doing and be aware of the shortcomings of the Bose design.
    The upside to this is that Bose speakers have the best resale value of any speakers out there. There is someone born every minute who will pay top dollar for them, so when you decide to get out of them, you aren't going to take the hit that you would with any other brand of speaker. Then take your money and buy an Energy Take 5.2 system with an 8 or 10" subwoofer. Then, don't look back.

    But don't worry about the ohms thing, you are okay with the receiver you bought.
    Space

    The preceding comments have not been subjected to double blind testing, and so must just be taken as casual observations and not given the weight of actual scientific data to be used to prove a case in a court of law or scientific journal. The comments represent my humble opinion which will range in the readers perspective to vary from Gospel to heresy. So let it be.

  3. #3
    Forum Regular Monstrous Mike's Avatar
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    Quote Originally Posted by bhd812
    but i do i know im putting 6ohms out? i want to put 6ohms instead of 8ohm there is no switch in back of the receiver to do it.

    anybody???...thanx
    The switch at the back related to ohms (on some receivers and amps) is simply a setting for the protective circuits of the amp. By adding a little resistance in the amp, the protection circuit for the amp being overdriven will be a little more sensitive.

    If an amp is capable of fully driving 4 ohm loads it will not need this switch. Some people have reported that it even hinders normal operation.

    If your amp has no switch than the designers are confident it can handle the loads it is specified and the protection circuitry will operate correctly.

    In general, you still drive 4 ohm speakers with an amp that is only rated for 8 ohms but you do run the risk when you play at very loud volumes. Remeber, this ohms thing really only comes into play when we are approaching the maximum output of the amp. This should be a rarity for most people. But if you are one of those that needs to turn the volume up past 10 then yeah, you should pay attention to this.
    Friends help friends move,
    Good friends help friends move bodies....

  4. #4
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    Quote Originally Posted by Monstrous Mike
    The switch at the back related to ohms (on some receivers and amps) is simply a setting for the protective circuits of the amp. By adding a little resistance in the amp, the protection circuit for the amp being overdriven will be a little more sensitive.

    If an amp is capable of fully driving 4 ohm loads it will not need this switch. Some people have reported that it even hinders normal operation.

    If your amp has no switch than the designers are confident it can handle the loads it is specified and the protection circuitry will operate correctly.

    In general, you still drive 4 ohm speakers with an amp that is only rated for 8 ohms but you do run the risk when you play at very loud volumes. Remeber, this ohms thing really only comes into play when we are approaching the maximum output of the amp. This should be a rarity for most people. But if you are one of those that needs to turn the volume up past 10 then yeah, you should pay attention to this.
    ahh yes thanx so Now I understand why my old technics amp used to get soooo hot. thank you

  5. #5
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    Quote Originally Posted by spacedeckman
    An ohm is a measure of electrical resistance (Impedance actually since this is AC current we are discussing traveling in your speaker wires. The speakers provide electrical resistance to the flow of electrical power from the amplifiers in your receiver. The quasi "standard" in home audio is an 8 ohm speaker, although there are a lot of 4 ohm speakers as well, and a few 6. This number is sort of an "eyeball average" of the speaker's impedance (resistance) curve. The actual amount of this resistance (ohms) changes by the millisecond as your speaker is working. At some points an 8 ohm speaker my be down around 4 ohms, and at other times it could be at 64 ohms, or even higher. When your impedance (ohms) are halved (ex 8 to 4 ohms) the current demand, or demand for the amplifier to deliver more raw electrical power into the speaker is doubled. Essentially, the amplifier will have to work harder to provide the speaker with what it needs to work properly. This extra work creates heat that the amplifier has to dissipate (get rid of) faster than it can build up. If it can't do that, then the amplifier overheats and shuts down.

    This is why it is incredibly important to buy a BETTER receiver rather than one with a higher watt rating. Your Onkyo is a pretty nice piece, you did well there. The Bose speakers impedance rating of 4-8 ohms is a joke. It would be considered a 4 ohm speaker. You wouldn't want to run it with a cheesy receiver like an entry level Sony, Pioneer, JVC, or the like. They would tend to shut down at anything over quite modest volume levels. Your receiver should deal with this pretty well.

    On the speaker front, you could have done better, but you made the best mistake you could possibly make. The Bose, besides being a bit difficult to drive, have satellites that don't integrate into the Bass Module very well. The problem is that the drivers (individual speaker units) in the cubes are too small, and because of that don't go low enough to blend into the sound that the Bass Module makes. The Bass Module isn't a subwoofer, since it has to play very high frequencies, and doesn't go as low as a subwoofer would. It is pretty easy to figure out what I'm talking about. Since it is an older system with the 6th order bandpass module, make a ball out of a pair of socks and use that to plug the hole on the bass module. Play the system with the socks in the port for a while, you can use movies or music, although music is often better. After a few minutes, pull the socks out of the port and listen. With the socks in, the sound is really tinny and nasty sounding. What you will find is that once you have identified that sound, you will always hear what the satellites are doing and be aware of the shortcomings of the Bose design.
    The upside to this is that Bose speakers have the best resale value of any speakers out there. There is someone born every minute who will pay top dollar for them, so when you decide to get out of them, you aren't going to take the hit that you would with any other brand of speaker. Then take your money and buy an Energy Take 5.2 system with an 8 or 10" subwoofer. Then, don't look back.

    But don't worry about the ohms thing, you are okay with the receiver you bought.
    this set-up was for my parents mostly, they wanted to remodel the basement and put in a hometheater, so after they got this big "L" leather couch we only had like a 10x10 area to cover.
    I had this bose system with a cerwen-vega sub (15inch, 500watt). the bose was from my setup when i was 14, the sub is a few years old but never used,,, so i gave them this.
    they bought a sony kv40xbr800 tv and I bought them a onkyo 601 and onkyo dvcp701 dvd changer to, I have a onkyo 989 and had the 787 before for my set-up and I love onkyo. i wanted the 801 but it was to big for this size area.
    all together they are running 6 channels and about $500 in connecting wires (all monster cable, i know i know but thats what they wanted).
    its a nice system all together and it is alot better then if they would of bught the receiver and sort. my dad keeps asking why i didnt spend $200 on a receiver, or he keeps bugging me to put the tv in the corner. but im standing firm.

    they think a home theater setup is just a big tv, like my brothers have nice setups but nothing complete, one has all the stuff but its not setup, and the other doesnt have surrond speakers.
    all in all i spent about three days wiring it all up, there is 150 feet of speaker cable (monster xp)

    thanx for your help though, i thought you need to tell the amp to run 4ohms, but i huess it does automatically..

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