View Full Version : Speakers

John A langley
02-28-2010, 3:57 PM
Okay guys. Somebody out there has always been able to solve our problems. There is a great amount of knowledge. I've answered a few questions but never asked one myself. So here is my questions:
My wife gave me, for my birthday, a Sirius radio for my shop. Because of the size and shape of the shop I would like to have 4 3-way speakers. What I've learned is, the receiver, in order to handle 4 speakers, the speakers have to be 16 ohm. I can find all kinds of 8 ohm that have a U shaped bracket that I can mount to the wall but I can't find any 16 ohms - especially at a reasonable price. My end result is to have a Sirius radio hooked to a receiver and 4 speakers. Best Buy is of no help. I really appreciate the help. Thank you.

Jamie Buxton
02-28-2010, 4:14 PM
If the speakers are all identical, you can hook two 8-ohm ones in series to make a 16-ohm one. Because they're identical, half the power will get applied to one speaker, and half will get applied to the other one.

John A langley
02-28-2010, 4:34 PM
Jamie - The receiver I had, had 4 places on the back for speakers - two were A and two were B. The receiver's manual said that if I were going to use the two "A" recepitcals I could use 8 ohm speakers. If I were to use all four recepitcal for 4 speakers I would need 16 ohm speakers. Are 8 ohm larger than 16 ohm or the other way around. If I understand what you are telling me, I can put two pluses and two negatives in one set of connections to feed two speakers. Thanks.

Ken Fitzgerald
02-28-2010, 4:51 PM

Ohms is a measurement of resistance or impedance.

8 ohms is 1/2 the impedance of 16 ohms.

To hook 2 - 8ohm speakers in series, you would hook the negative of one speaker to one of the "A" connectors" (connector would probably be marked "-") ....you would hook the + of that same speaker to the negative of the 2nd speaker......and then hook the positive of the 2nd speaker to the other "A" connector.

Thus.....the current would flow from one A connector through the first speaker....through the second speaker...and to the 2nd A connector. The speaker are then "in series".

Repeat the procedure for the 2nd set of 2 speakers and the "B" connectors.

Ken Fitzgerald
02-28-2010, 4:55 PM

With the speakers "in series" their impedance (8 ohms each) become additive and thus 8 ohms + 8 ohms = 16 ohms.

It's important that you get these hooked up correctly to prevent damaging the amplifier in your radio.

Tim Morton
02-28-2010, 8:02 PM
What receiver are you using? And what speakers are you looking at?

You might want to consider a speaker switch. This would have built in impedance control to protect the amplifier from over heating.

Eric DeSilva
02-28-2010, 9:08 PM
I doubt it will matter at all, frankly. Speakers aren't a fixed load anyway--the load resistance varies as the voice coil moves in and out. Not something--in my mind--to worry about at all. The reverse, speakers that dip to a very low load, are much more difficult for an amp to drive (trust me, I had some electrostatic speakers that ranged from 4 ohms to a half ohm).