8 ohms + 4 ohms = ????

[OoMesKoO 10+ year member]

Im putting together a little setup for my HT. Nothing crazy at all. Just 2 15" Electrovoice drivers, with 2 tweeters. But... the tweeter is 4 ohm, and the Electrovoice is a 8 ohm driver. But if i wire them together in parallel, what ohm load does it give?

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[matrxx dude 5,000+ posts]

6 i think

 

[matrxx dude 5,000+ posts]

aint sure on this 1,might be 3

 

[OoMesKoO 10+ year member]

I was thinking 1.3 for some reason?

 

[matrxx dude 5,000+ posts]

3 4 ohm drivers equals that

 

[bk12321 10+ year member]

2.67 ohms wired in parallel

 

[OoMesKoO 10+ year member]

2.67 ohms wired in parallel

Thank you sir!

 

[thylantyr 10+ year member]

Im putting together a little setup for my HT. Nothing crazy at all. Just 2 15" Electrovoice drivers, with 2 tweeters. But... the tweeter is 4 ohm, and the Electrovoice is a 8 ohm driver. But if i wire them together in parallel, what ohm load does it give?

You don't wire up 15" woofers in parallel with tweeters. You need at least

a tweeter crossover. If you have one, then the amplifier will probably

see the 15" woofer as the hardest load @ 8 ohms, the 4 ohm tweeters

won't stress the amplifier, power consumption is low for tweeters.

 

[GLN305 10+ year member]

2.67 ohms is correct. One simple rule to remember is that when wiring speakers in parallel that the overall load is going to be lower than the lowest impedance speaker. To calculate the impedance, you use this formula or calculator:

http://www.csgnetwork.com/parallelresistcalc.html

 

[joetama 5,000+ posts]

You don't wire up 15" woofers in parallel with tweeters. You need at leasta tweeter crossover. If you have one, then the amplifier will probably

see the 15" woofer as the hardest load @ 8 ohms, the 4 ohm tweeters

won't stress the amplifier, power consumption is low for tweeters.

Truth...

The tweeter wouldn't last very long wired up with the woofer.

 

[blackbonnie 5,000+ posts]

You don't wire up 15" woofers in parallel with tweeters. You need at leasta tweeter crossover. If you have one, then the amplifier will probably

see the 15" woofer as the hardest load @ 8 ohms, the 4 ohm tweeters

won't stress the amplifier, power consumption is low for tweeters.

he just wanted to know what the final load was going to be. if he wanted to ask if he was suppose to wire a 15" woofer with a tweeter then your post would be helpful. just give him the final load and leave it at that.

 

[bk12321 10+ year member]

2.67 ohms is correct. One simple rule to remember is that when wiring speakers in parallel that the overall load is going to be lower than the lowest impedance speaker. To calculate the impedance, you use this formula or calculator:
http://www.csgnetwork.com/parallelresistcalc.html

just remember the formula for parallel...

1 / [( 1/a ) + ( 1/b )]

a and b are the 2 resistances that are being put in parallel

so for this, it would be:

1 / [( 1/4 ) + ( 1/8 )] = 1 / .375ohms

= 2.67 ohms

 

[thylantyr 10+ year member]

he just wanted to know what the final load was going to be. if he wanted to ask if he was suppose to wire a 15" woofer with a tweeter then your post would be helpful. just give him the final load and leave it at that.

>>But if i wire them together in parallel, what ohm load does it give?

The post says that both woofer and tweeter are wired in parallel //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

This is not how you hook up tweeters.

If a tweeter crossover is used, then the final impedance won't be 2.6 ohms

because impedance various with frequency. At high frequency, the amplifier

may see a 4 ohm load, at low frequency, the amp may see an 8 ohm load,

it's a variable.

How do you think a common loudspeaker with an 8 ohm tweeter,

8 ohm midrange, 8 ohm woofer, three drivers in a cabinet, yield

an 8 ohm impedance ? It's not considered a 2.6 ohm impedance loudspeaker

as each driver has it's own bandpass region.

 

[blackbonnie 5,000+ posts]

he didnt specify if he was using his crossover. so we assume he is wiring it in parrallel with the woofer. of course thats not how its suppose to be done, but let him learn that

 

[ballstothewall 10+ year member]

Just stfu.