Mix and match speaker impedance

Dave, I can't do that

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Sep 22, 2011, 11:00:10 AM9/22/11

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Hi All,

I have a Panasonic SAHT670 that has worked well for quite a few years
and it kinda died. The details are in my other post here "Panasonic
Home theater unit - mods?"

I am wondering if I just buy a new stereo amplifier and use the
existing 5.1 speakers. I have
4 x 6-Ohm - 55-Watt for FR, FL, RR, RL
1 x 6-Ohm - 160-Watt Center
1 x 8-Ohm - 220-Watt Subwoofer.

So here's what I am thinking and ignoring any technical rights and
wrongs of mixing speaker impedance. {grin} I am not an audiophile and
never have the volume cranked up high.

The Stereo amp I am looking at has...
2 x 3-Ohm speaker outputs.
1 Subwoofer 1v-120K (I think it was) output.

What I would like to do is serial and parallel the 5 speakers. The FR,
RR and the FL, RL are easy, but the Center has two tweeters so it is
important for highs I am guessing, so I would like to incorporate that
too.

I can get a 100-Watt plate amp and attach that to the back of the
subwoofer box, so that's easy.

I do not want to buy a new home theater unit as when I installed this
one I made cut-outs in the walls for the speakers and all the units I
have recently looked at, the speakers are too big or the price is too
big for the near enough sized speakers.

I looked at 5.1 amps and/or receivers and they are out of my price
range right now.

So any suggestions here?

I am cross-posting to "sci.electronics.repair" (got yelled at here the
last time I duplicated a post at "repair" and didn't cross-post
instead) Hope I got it right this time.

Thanks

Dave

John Larkin

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Sep 22, 2011, 11:57:50 AM9/22/11

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Hook them up any old way. It's just audio. It doesn't matter.

John

Tom Del Rosso

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Sep 22, 2011, 4:47:48 PM9/22/11

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John Larkin wrote:
>
> Hook them up any old way. It's just audio. It doesn't matter.

Some people like the reproduced audio to sound like the original audio.

--
Reply in group, but if emailing add one more
zero, and remove the last word.

NT

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Sep 22, 2011, 7:16:34 PM9/22/11

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On Sep 22, 4:00 pm, "Dave, I can't do that" <davenp...@gmail.com>
wrote:

You could put on each of the 3 ohm channels 2x 6 ohm LSes, plus one of
the tweetered 6 ohms via a capacitor. Put all 3 in parallel. It gives
you 3 ohms at lf, 2-6ohms at hf, which is all good. Any modern IC
output amp will protect itself if you max out the volume, and speaker
impedances are only nominal, they vary quite a long way out in
reality.

NT

David41616

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Sep 22, 2011, 8:41:41 PM9/22/11

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On Sep 22, 4:16 pm, NT <meow2...@care2.com> wrote:

> You could put on each of the 3 ohm channels 2x 6 ohm LSes, plus one of
> the tweetered 6 ohms via a capacitor. Put all 3 in parallel. It gives
> you 3 ohms at lf, 2-6ohms at hf, which is all good. Any modern IC
> output amp will protect itself if you max out the volume, and speaker
> impedances are only nominal, they vary quite a long way out in
> reality.

Hi NT, thanks for that, but could I trouble you for an ASCII
schematic? Or a pic of a sketch. I am not as smart as you think I am.
What kind of cap, what value and voltage? If polarized, which way
around?

Thanks

Dave

spamtrap1888

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Sep 22, 2011, 8:52:29 PM9/22/11

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On Sep 22, 8:00 am, "Dave, I can't do that" <davenp...@gmail.com>
wrote:

> Hi All,
>
> I have a Panasonic SAHT670 that has worked well for quite a few years
> and it kinda died. The details are in my other post here "Panasonic
> Home theater unit - mods?"
>
> I am wondering if I just buy a new stereo amplifier and use the
> existing 5.1 speakers. I have
> 4 x 6-Ohm - 55-Watt for FR, FL, RR, RL
> 1 x 6-Ohm - 160-Watt Center
> 1 x 8-Ohm - 220-Watt Subwoofer.
>
> So here's what I am thinking and ignoring any technical rights and
> wrongs of mixing speaker impedance. {grin} I am not an audiophile and
> never have the volume cranked up high.
>
> The Stereo amp I am looking at has...
> 2 x 3-Ohm speaker outputs.
> 1 Subwoofer 1v-120K (I think it was) output.
>
> What I would like to do is serial and parallel the 5 speakers. The FR,
> RR and the FL, RL are easy, but the Center has two tweeters so it is
> important for highs I am guessing, so I would like to incorporate that
> too.

Leave out the center channel. I don't see how you would drive it in
phase given only two amplifiers. In terms of the driving amplifier,
the nominal impedance applies only to the piston band region of the
woofer, and only part of that. (Voice coil inductance raises driver
impedance.)

> I can get a 100-Watt plate amp and attach that to the back of the
> subwoofer box, so that's easy.

You can afford three channels but not four?

>

> I looked at 5.1 amps and/or receivers and they are out of my price
> range right now.

Too bad. What I have done on a tight budget is buy pro grade equipment
second-hand.

John Larkin

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Sep 22, 2011, 9:23:58 PM9/22/11

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On Thu, 22 Sep 2011 16:47:48 -0400, "Tom Del Rosso"
<td...@verizon.net.invalid> wrote:

>John Larkin wrote:
>>
>> Hook them up any old way. It's just audio. It doesn't matter.
>
>Some people like the reproduced audio to sound like the original audio.

After all the processing it's been through?

John

NT

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Sep 23, 2011, 12:53:57 AM9/23/11

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. -----+-----+-----+
. | | |
. LS LS LS
. | | |
. | | C
. | | |
. -----+-----+-----+

Cap value, if we wanted 2ohms at 1kHz so it doesnt affect the existing
cap noticeably, that's 80uF. 47-100uF would be fine. Less might or
might not be ok.

NT

John S

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Sep 23, 2011, 1:29:44 AM9/23/11

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Apparently, you forgot that he requested the polarity, NT.

NT

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Sep 23, 2011, 1:58:19 AM9/23/11

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there is no polarity for the capacitor. Do you always think people
have forgotten something if they dont answer it?