Four Heresy IIs at Once

[analogman]

Gentlemen, Would someone please tell me how to wire four Heresy IIs in order to use them together with my two channel amp.My amp only provides for one stereo pair at the time.

Thank you for your consideration,

Analogman

[dougdrake]

Probably the safest way to wire them is to put 2 in series on each channel. To wire in series, go from + on amp to + on speaker A1, from A1- to A2+, from A2- to amp -. Do the same for the other channel (. That will cause a higher resistance to the amp which is generally safer. However, it can result in reduced power from the amp, but with relatively high efficiency speakers like the Heresy that should not pose a problem.

[analogman]

Thank you, DougDrake

The IIs in question are rated at 4ohm nominal

Should I add their values and use my 8ohm taps, or stick with the 4ohm?

Thank you again,

Analogman

[DrWho]

If your speakers are both 4 ohm, then you'd probably be better off wiring them in series... + from the amp into the + on the first speaker and then the - from that speaker into the + on the next speaker and from the - on that speaker back into the - on the amp...do the same for both channels. Doing this would present an 8ohm load to the amp (whereas wiring in series would be a 2ohm load which is too low).

And use the 8ohm taps when you do this

[analogman]

Even wired in series will not the two four ohm systems still "behave" the same with regard to impedence dips as the audio signal is AC and each box is still using it's own crossover? Please bear with me as I am an auto mechanic by trade and have a hard time thinking in terms of AC rather than DC.

Thanks to everyone again,

Analogman

[DrWho]

what do you mean by behave the same?

each speaker itself acts like a 4ohm load...

but the amp itself only sees an 8ohm load (4ohms + 4ohms). This is exactly how circuits work in DC. The only difference with AC is that the ohms change with frequency (but this doesn't affect how you add the ohms up together).

when connected in parallel, you add the inverse of the ohms together and then take the inverse of that (1/4 + 1/4 = 1/2 => inverse of 1/2 = 2). so putting two 4ohm speakers in parallel presents a 2ohm load to the amp.

basically, the amp sees everything in it's circuit as one speaker...so when we're adding the ohms together, we're finding what the amp is seeing and what the amp sees is what we want to set the taps to. but while all this is happening, the speakers are still acting the same in that they are still 4ohms. just the amp is seeing everything together as one "speaker".

i hope this made sense, i know i presented it in a wierd way, but i think i made sense and answered all your questions

[Kartracer77]

If they are 4 ohm then Wire in series then use your 8 ohm outputs from your amp. That way speaker load will match amp output load.

[Olorin]

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On 2/14/2004 5:01:28 PM analogman wrote:

Thank you, DougDrake

The IIs in question are rated at 4ohm nominal

Should I add their values and use my 8ohm taps, or stick with the 4ohm?

Thank you again,

Analogman

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Where did you get 4 ohm H II's? They're 8 ohms in their stock config. http://www.klipsch.com/product/product.aspx?cid=8

Not saying yours aren't four, just curious how they got that way.

[analogman]

heretic,

I have two pair of 4ohm nominal (identified as such by Klipsch) Heresy IIs. Their serial #s identify them as 1985 production.

Analogman

Thank you EVERYONE for your inputs!

[Olorin]

I don't mean to dog you, but I'd rather have you annoyed at me than annoyed at your blown amp. Have you metered them yourself?

[analogman]

heretic,

they are that way because Klipsch and Associates made them that way, way back in 1985

Analogman