2. amps-preamps
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How Does a "HI-LEVEL IN" Affect Impedance Load?

I'm looking at adding a sub (possibly a used Sunfire MK2) to a 2-Channel integrated tube amp, with no pre-amp/sub outputs. Would it be ill-advised to connect (in parallel) the speaker outputs with the Hi-Level In, on the sub? What effect. if any, does this have on the impedance load? The currently-used (custom built) speakers run around 6-ohm, and the amplifier (Jolida) does have both 4, and 8-ohm terminals, for whatever that information is worth.  

Thanks!

-Brian
brian_stabinger

Showing 1 response by erik_squires

erik_squires
16,592 posts
 
Sub speaker level inputs are usually in the range of hundreds to tens of thousands of Ohms.

So, doing the normal math for parallel resistance (which is close enough to impedance for us to illustrate) :

R = 1 / (1/8 + 1/10000)

where 8 is the speaker impedance, and 10,000 is the sub impedance, gives us 7.99 Ohms, and a difference of around 00.1%.

It’s insignificant to a power amp.
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