My exact problem is to run 2 sets of speakers (A+B) one is 8 ohms and one is 4ohms. The amp ... ( good old pioneer sa-9800) says 100 watts into 8 ohms and 185 watts into 4 ohms. The problem is that my calculations for the A+B situation is 2.666 ohms.... this doesnt sound like a good scene. so I have been wondering about adding resistance by adding an inline-series resistor to the 4ohm speakers... possibly simply another speaker in series, (like a driver which has had its diaphram cut out so it doesnt really make sound but electricity goes through it and adds the ohms. ) I realize this might cut output levels but im usually not using more than a few watts... as long as it doesnt hurt sound quality..This raises another related question... If you put on an inline passive subwoofer... does that act like series resistance or parallel ? does a subwoofer "double' your effective impedance to that output if its on either the A or the B circuit with the main speakers. ?
2007-02-18 00:35:53 · 3 answers · asked by STEVEN P 1 in Consumer Electronics ➔ Home Theater
I would not use the 4 ohm spkrs on home audio equipment 8 ohms is for home audio and 4 ohms is for car audio If it dos'ent sound like a good scene dont try it other wise your amp may end up as a over sized paper weight The more connections you have (amp---->resistor--->coil------->speaker ect) the more possable shorts are likely to happen
2007-02-18 00:49:39 · answer #1 · answered by Anonymous · 0⤊ 0⤋
You're right about the 2.666 ohms: don't do it because you might burn out the amp (or pop fuses)
I take it that you want to be able to switch the speakers separately, so hooking the speakers up in series is not a desireable option. Adding an inline resistor (4 or 5 ohms) is a good option.
On your related question: the impedance of speakers varies across the whole sound spectrum. The subwoofer may be 8 ohms at 80 Hz, but drops off to 30 ohms at 1000 Hz. Most subwoofers have an electrolytic (NP capacitor) to cut off the high range. You want to be sure that you're not overloading the amp at any range, especially in the lower range. If your speakers have a deep base range, then adding the subwoofer (which is hooked up in parallel) could drop the base impedance below the safe limit for your amp. The solution is to add a coil in series (or a capacitor in parallel) to your speakers, to cut off the bass. Hard to say what size of coil you need without knowing the subwoofer range, but something with a 100 Hz (12.74 mH) cutoff will probably do the trick.
2007-02-18 00:57:25 · answer #2 · answered by Rando 4 · 0⤊ 0⤋
Want to be loud? Don't buy Kicker or Boss.
2016-03-29 01:09:31 · answer #3 · answered by Anonymous · 0⤊ 0⤋