So I have an aguilar DB 210 that is rated at 8 ohms. I also have a LMII that puts out 500 watts at 4 ohms and 300 at 8 ohms. If I wanted to add another speaker, say a 15 inch, would there be power issues? My question is, would the impedances add to each other (2x10 8 + 15 8 = 16?) or would they make a different circuit? Please help me with my little to no knowledge about speakers and electronics. Any help would be greatly appreciated.
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impedance question
- Thread starter sheepgotoheaven
- Start date
Two 8 ohm speaker cabs in parallel would give your amp a 4 ohm load. So you would be okay. You just need to be careful if your minimum ohm load is below 4 ohms. A quick formula for calculating the ohm load is: (ohm 1st speaker X ohm 2nd speaker / ohm 1st speaker + ohm 2nd speaker). e.g. 8 x 8 / 8+8 = 64/16 = 4 or 8 x 4/ 8+4 = 32/12 = 2.67 (for an 8 ohm cab and a 4 ohm cab) . This is just for parallel applications two outputs from the amp and most "daisy" chain speaker to speaker connections. You need to check to be sure the speaker to speaker connects are parallel (most are). If by chance they are series, then the ohm / impedance will increase. No harm to your amp, it will just seem not as loud.
In your example this would only be the case if the speakers were wired in series. Most always they are parallel. So, if you have the impedances you describe, 2x10/8ohms and 1x15/8ohms, you would have a 4 ohm load giving you full power 500 watts. Other examples 2x16 ohms=8ohms,2x4 ohms=2ohms. If they are different impedances use the formula: R1xR2/R1+R2= Rtotal. ex, (8x4=32)/(8+4=12) Rtot=2.667ohms.
