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4ohm on one ch, 8 on the other
This thread has 12 replies. Displaying all posts.
Post 1 made on Saturday June 28, 2014 at 09:23
tweetymp4
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Just out in a very simple outdoor audio addition to a sonos system. Added a Sonos connect amp and two russound rock speakers. Just happened to be for my sister. When done she asks if they can add "one more speaker" to the yard at a later date.

I know that sonos connect amps are stable to 4 ohm. Done quite a few without incident. I always avoided a "lopsided" connection (on all amps)... One where one channel sees 8ohm, and the other sees 4ohm. I know there are all kinds of gizmos like mono mixers and summing vc's that can be used.

Any harm in simply loading the amp lopsided.
I'm Not an engineer, but I play one on TV.
My handle is Tweety but I have nothing to do with the organization of similar name. I just had a really big head as a child so folks called me tweety bird.
Post 2 made on Saturday June 28, 2014 at 09:40
highfigh
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On June 28, 2014 at 09:23, tweetymp4 said...
Just out in a very simple outdoor audio addition to a sonos system. Added a Sonos connect amp and two russound rock speakers. Just happened to be for my sister. When done she asks if they can add "one more speaker" to the yard at a later date.

I know that sonos connect amps are stable to 4 ohm. Done quite a few without incident. I always avoided a "lopsided" connection (on all amps)... One where one channel sees 8ohm, and the other sees 4ohm. I know there are all kinds of gizmos like mono mixers and summing vc's that can be used.

Any harm in simply loading the amp lopsided.

If the amp uses discreet components and the two channels are separate, it should be OK, as long as it's happy with a 4 hm load. It's not ideal and it will make more of a difference if the system is cranked, but it should work if these conditions are met. If it has an amplifier chip, I would avoid it but again, it depends on how happy it is with a 4 Ohm load.

So the speakers have dual-voice coil drivers?
My mechanic told me, "I couldn't repair your brakes, so I made your horn louder."
Post 3 made on Saturday June 28, 2014 at 13:26
Ernie Gilman
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Discreet components are ones that won't tell your wife that you're having an affair with the babysitter. Discrete means "in separate parts," such as transistors and resistors, as opposed to circuits that are integrated onto a chip, which have gone so far as to adopt the name ICs.

It's not quite as simple as discrete components guaranteeing no problems. Trash can still be made with discrete components, and the quality of available output ICs has been quite high for forty years.

Other than that, yeah, if it's okay with a four ohm load, it should be okay, period. If the system is okay with a four ohm load, the only thing less than ideal is that it will bother our purist sensitivities and, in the sound environment, one channel will be louder than the other.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 4 made on Saturday June 28, 2014 at 14:14
Impaqt
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"No, this is a stereo system. We can add another pair, or if you really want just one, we can get you a single speaker that can do both channels"
Post 5 made on Saturday June 28, 2014 at 15:14
Zohan
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Is a connect amp sufficient for outdoors?
Always wondered that but never did it, I always use separate amp....how is it?
Post 6 made on Saturday June 28, 2014 at 20:29
highfigh
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On June 28, 2014 at 13:26, Ernie Gilman said...
Discreet components are ones that won't tell your wife that you're having an affair with the babysitter. Discrete means "in separate parts," such as transistors and resistors, as opposed to circuits that are integrated onto a chip, which have gone so far as to adopt the name ICs.

It's not quite as simple as discrete components guaranteeing no problems. Trash can still be made with discrete components, and the quality of available output ICs has been quite high for forty years.

Other than that, yeah, if it's okay with a four ohm load, it should be okay, period. If the system is okay with a four ohm load, the only thing less than ideal is that it will bother our purist sensitivities and, in the sound environment, one channel will be louder than the other.

OK, ya got me. Just making sure you're paying attention.
My mechanic told me, "I couldn't repair your brakes, so I made your horn louder."
Post 7 made on Saturday June 28, 2014 at 21:22
Ernie Gilman
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On June 28, 2014 at 14:14, Impaqt said...
"No, this is a stereo system. We can add another pair, or if you really want just one, we can get you a single speaker that can do both channels"

"Of course, we'll have to dig up your garden to add a second pair of wires to make that double-voice coil speaker have both channels. Shouldn't be more than a few hundred dollars."

Slap a speaker where it's needed, connect where you can, be done. They really don't care.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
OP | Post 8 made on Sunday June 29, 2014 at 13:13
tweetymp4
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On June 28, 2014 at 15:14, Zohan said...
Is a connect amp sufficient for outdoors?
Always wondered that but never did it, I always use separate amp....how is it?

Yes, just know its limits. Big yards really need separate amps. In this cae, it's a very small yard.

This is one of this instances where adding an amp, or adding mor wire is really easy to do so I'll go that route when the time comes. Just curious about the amp loading question, it's something that I've always wondered about.
I'm Not an engineer, but I play one on TV.
My handle is Tweety but I have nothing to do with the organization of similar name. I just had a really big head as a child so folks called me tweety bird.
Post 9 made on Sunday June 29, 2014 at 13:55
Impaqt
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On June 28, 2014 at 21:22, Ernie Gilman said...
"Of course, we'll have to dig up your garden to add a second pair of wires to make that double-voice coil speaker have both channels. Shouldn't be more than a few hundred dollars."

Slap a speaker where it's needed, connect where you can, be done. They really don't care.

Sorry, I'm not a fan of half-assing stuff. not even for family.

Are you somehow adding one more speaker without adding new wire?
Post 10 made on Sunday June 29, 2014 at 14:17
buzz
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tweetymp4,

It is the current delivered by the amplifier that will trip the protection circuit. The amplifier has no means to look down the wire and count the number of bodies connected. As long as the impedance is 4-Ohms or above on both channels, the amplifier will not care about the imbalance. Really, the magnitude of the impedance varies (wildly) with frequency. If one wanted to keep the impedance matched on all channels at all times, on would need to play mono music or never use multichannel amplifiers.
Post 11 made on Sunday June 29, 2014 at 20:09
Ernie Gilman
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No, nobody imagined adding a speaker without wire. I imagined adding a speaker and figured the OP would know wire was needed.

buzz,
that's a neat picture to paint, that it can't look down the line! True. All it can do is see the impedance right at its output terminals, and that includes the speaker and the wire along the way. In both directions... but it can't tell how much wire there is; it can only see the effect of the load.

It's not as simple as "the impedance varies wildly."  The impedance does not vary at all, actually.  It's different at different frequencies, but that's not something varying, that's something looking different from different points of view. But I think you know all this: The impedance is what it is at each frequency, so if you measure the impedance and don't notice that you're changing frequencies, you'll think the impedance is changing. The impedance at any one frequency is the same all the time unless you squeeze the wires or add or subtract capacitors or inductors without noticing. (I say without noticing because you will expect the impedance to change if you know caps and coils are being changed.)
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw
Post 12 made on Sunday June 29, 2014 at 20:50
buzz
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Ernie Gilman,

The complex impedance is what it is. That's why I specified "the magnitude of the impedance".
Post 13 made on Monday June 30, 2014 at 02:58
Ernie Gilman
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Okay, buzz, but the rest of what you said implied that the impedance changes over time. The impedance does not change, though the load does.

Let's say you have a pair of identical speakers with a bass resonance at 60 Hz with a 50 ohm impedance, and a midrange impedance trough at 500 Hz with an impedance of 4 ohms. The impedance is matched on both channels.

But if you play a 100 Hz tone through one channel and a 500 Hz tone through the other, the impedance of each speaker will stay the same at 100 Hz and at 500 Hz for both the speakers, but the LOAD on the two channels of the amp will be different due to the different frequencies of the signals being sent.
A good answer is easier with a clear question giving the make and model of everything.
"The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw


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