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#1
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Posted to rec.audio.opinion
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I have read in a few posts that if you have a multi speaker setup,
surround I guess, it is very important that all speakers be of the same impedance, or you could damage the equipment. How true or important is that? Thank you in advance ... |
#2
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Posted to rec.audio.opinion
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On Jun 2, 9:44 pm, "Soundhaspriority" wrote:
There is no need for the main speakers and the surround speakers to have the same impedance. There is one common caution: if two pairs of mains are attached to a typical HT amplifier that contains an integral A/B speaker switch, the minimum allowable impedance is typicall 8 ohms. I am using a receiver with 2 sets of outputs: A and B. There are separate switches to turn on or off the A and B outputs. I have a pair of speakers which is 4 ohms, main I would say, hooked up to the A output. Can I hookup a pair of speakers say with 6 or 8 ohms to the B output? |
#3
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Posted to rec.audio.opinion
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On Jun 2, 10:00 pm, "Soundhaspriority" wrote:
You take a risk if you do. Not advisable, unless you conscientously remember not to activate both sets at the same time. So, in my case, I need to have all speakers to have the same impedance 4, 6 or 8 ohms, if I want to have them on at the same time? Am I about right? |
#4
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Posted to rec.audio.opinion
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On Jun 2, 10:36 pm, "Soundhaspriority" wrote:
No (sorry.) If there are two pairs, and you want to use them simultaneously, and this is a mass-market HT receiver, then the impedances must be 8 ohms. In case you want to know why, this is how it goes. Two speakers in parallel have half the impedance of one. Two 8 ohm speakers = 4 ohms. Two 6 ohm speakers = 3 ohms. Two 4 ohm speakers = 2 ohms. The lower the impedance presented to the amplifier, the more the output transistors will heat. If the impedance is too low, it will either kill it slowly by excessive heat, or fast, by "thermal runaway." This last is the solid state equivalent of nuclear explosion ![]() That's a very nice explanation. Makes a lot of sense. I assume anything that's not custom made, but made and sold in bulk is a mass- market HT receiver. I am wondering if I am already on the wrong track. I think the receiver is rated 8 ohms and the pair of speakers that I am using are rated 4 ohms. It's been like that for several months without any deterioration in sound quality that I can tell. In fact, I recently replaced the 16 gauge wires with 14 gauges, and think they sounded better than ever. |
#5
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Posted to rec.audio.opinion
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On Jun 2, 10:36 pm, "Soundhaspriority" wrote:
No (sorry.) If there are two pairs, and you want to use them simultaneously, and this is a mass-market HT receiver, then the impedances must be 8 ohms. In case you want to know why, this is how it goes. Two speakers in parallel have half the impedance of one. Two 8 ohm speakers = 4 ohms. Two 6 ohm speakers = 3 ohms. Two 4 ohm speakers = 2 ohms. The lower the impedance presented to the amplifier, the more the output transistors will heat. If the impedance is too low, it will either kill it slowly by excessive heat, or fast, by "thermal runaway." This last is the solid state equivalent of nuclear explosion ![]() That's a very nice explanation. Makes a lot of sense. I assume anything that's not custom made, but made and sold in bulk is a mass- market HT receiver. I am wondering if I am already on the wrong track. I think the receiver is rated 8 ohms and the pair of speakers that I am using are rated 4 ohms. It's been like that for several months without any deterioration in sound quality that I can tell. In fact, I recently replaced the 16 gauge wires with 18 gauges, and think they sounded better than ever. |
#6
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Posted to rec.audio.opinion
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On Jun 2, 11:49 pm, "Soundhaspriority" wrote:
wrote in message It depends upon how loud you habitually listen. If you're into rock, the magic smoke may come out eventually ![]() I usually listen at low to moderate volumes, and am not really much into rock, hard rock anyway. If I have to grade the type of music that I like by the music channel descriptions on my TV, I'd say Adult Alternative. What you explained was very valuable information. That was very kind of you. |
#7
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Posted to rec.audio.opinion
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wrote in message
I have read in a few posts that if you have a multi speaker setup, surround I guess, it is very important that all speakers be of the same impedance, or you could damage the equipment. How true or important is that? The above statement has just about everything wrong with it. But there is a germ of truth. First off, it is unclear as to what it is talking about. Is it talking about a multi-speaker setup as in a surround system, or is it talking about a multi-speaker setup as in something like a distributed sound system in a residence or office? Secondly, in either case, surround or home/office distributed, it is relatively unimportant as to whether the speakers all have the same impedance. Thirdly, if this is a distributed sound system, the usual means by which people design the system improperly, is to hook too many speakers in parallel. Hooking too many speakers in parallel will create a speaker system whose impedance is impractically low, no matter whether the speakers have the same impedance or not. Fourthly, while it is possible that with improperly designed amplifiers, it is possible that attaching a speaker system, whether an individual speaker or a number of speakers in parallel, whose impedance is so low that the amplifier will overheat and/or otherwise burn out. However, a properly-designed amplifier is supposed to detect the incorrect load and protect itself. The germ of truth is that speakers, and combinations of speakers can have impedance that is so low that they make up an impractical load for some amplifiers. One common way to create a speaker load that is impractically low, is to hook up a distributed sound system in an office or home with all of the speakers hooked in parallel. If you want to set up a distributed sound system in an office or home, you either need to learn about the special methods that are used to do that, or hire someone who knows how to do it right. |
#8
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Posted to rec.audio.opinion
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wrote in message
On Jun 2, 9:44 pm, "Soundhaspriority" wrote: There is no need for the main speakers and the surround speakers to have the same impedance. There is one common caution: if two pairs of mains are attached to a typical HT amplifier that contains an integral A/B speaker switch, the minimum allowable impedance is typicall 8 ohms. I am using a receiver with 2 sets of outputs: A and B. There are separate switches to turn on or off the A and B outputs. I have a pair of speakers which is 4 ohms, main I would say, hooked up to the A output. Can I hookup a pair of speakers say with 6 or 8 ohms to the B output? Probably. Most amplifiers and receivers that have terminals for multiple speakers use special switches to avoid damging themselves by hooking the speakers up in parallel. The usual trick is to hook the speakers up in series, which has a number of adverse effects on sound quality. |
#9
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Posted to rec.audio.opinion
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On Jun 2, 10:00 pm, "Soundhaspriority" wrote: You take a risk if you do. Not advisable, unless you conscientiously remember not to activate both sets at the same time. So, in my case, I need to have all speakers to have the same impedance 4, 6 or 8 ohms, if I want to have them on at the same time? Am I about right? No. If you want to avoid the most risk, all of your speakers should be 8 or 16 ohms, and 16 ohms would be preferable. The best of all worlds is to simply have a separate receiver for each pair of speakers. Then the people in the vicinity of each pair of speakers can choose their own music, and the sound coming out of the speakers will be optimal, and the possibility of damaging the speaker will be minimized. Receivers and music players have become so inexpensive that this is a very practical alternative. |
#10
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On Jun 2, 10:36 pm, "Soundhaspriority" Makes a lot of sense. I assume anything that's not custom made, but made and sold in bulk is a mass- market HT receiver. Petty much so. I am wondering if I am already on the wrong track. I think the receiver is rated 8 ohms and the pair of speakers that I am using are rated 4 ohms. It's been like that for several months without any deterioration in sound quality that I can tell. As long as you don't play the speakers too loud, most receivers that are rated at 8 ohms, can drive 4 ohm speakers indefinately without damage. The most common situation is that someone decides to demonstrate how nice and loud their system can play, or tries to run a dance party with this marginal system, and destroys the receiver. If the receiver is destroyed by abuse, and it does not do a good job of protecting the speakers, you may damage the speakers as well. In fact, I recently replaced the 16 gauge wires with 14 gauges, and think they sounded better than ever. This can happen if the speaker cables are rather long, such as a receiver in the family room, and the speakers on the patio. The best solution for having good sound with a second pair of speakers at a remote location, is to simply get a second receiver. |
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