View Poll Results: Which is the better choice for me? Running an Alpine 9857 and Audison LRx 300.4
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Component Sets
02-03-2007, 10:32 PM
#11
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so, the kappa 60.7 is 2 ohm and the alpine type-s is 4 ohm. if the head unit was sending 20 watts to the speakers, the kappa would be louder... right?
sorry, i do not mean to thread jack
sorry, i do not mean to thread jack
02-04-2007, 03:28 AM
#13
Originally Posted by Aze85,Feb 3 2007, 11:22 PM
question... if impedence is 2 ohms that mean that it takes less power than the 4 ohms to produce the same volume, right?
Lets say your head unit is rated 20w @ 4ohm....
If a speaker is 4 ohm, it will draw 20w
If a speaker is 2 ohm then it will draw roughly 40w of power (half the resistance, twice as easy to pass power)
Think of it like light bulbs..
If you have a 60w bulb it will use 60w of power....
If you have a 120w bulb it will use 120w but be twice as bright.
In many cases a head unit is only stable @4ohm. The more power you pass through it the hotter it gets, the harder it is on the amp or head unit. Most amps are 2 ohm stable and often 1 ohm stable too.
I have a Kenwood Excelon head unit and ran a set of the 2 ohm Infinity kappas for 2 years without any problems.
Your efficiency rating is the Sensitivity rating. If you have a speaker that has a Sensitivity rating of 90 db and a speaker with 95 db then the speaker that is 95 db would be significantly louder then the 90 db speaker by more than 2X. I don't know the exact numbers, but for roughly every 3 db you double the volume. If that number is wrong then it wont be long before someone corrects me
*edit*
smurf2k helps me with the math below
02-04-2007, 03:48 AM
#14
Speaker:---------Sensitivity rating:----------Power needed
--------------------------------------------------to produce a given volume:
Speaker A----------85 dB---------------------100 watts
Speaker B----------88 dB---------------------50 watts
Speaker C----------91 dB---------------------25 watts
A speaker with a sensitivity rating that's 3 dB higher than another speaker's
only needs half as much power to deliver the same amount of sound.
-Crutchfield.com http://www.crutchfieldadvisor.com/learning...tml#sensitivity
02-04-2007, 04:22 AM
#15
another things to consider is the recommended power range:
the rule of thumb is anything with a <8 watts recommended power range [RPR] can be run off a head unit and anything >8 watts RPR will need to be amplified.
for zample...
Infinity Reference 6010cs
6-1/2" component speaker system has a RPR of 2-90 watts RMS with a sensitivity of 92 dB
you could easily run this set of components with your head unit.
on sort of a flip side
Alpine SPR-17S
6-1/2"/6-3/4" component speaker system has a RPR of 8-110 watts RMS with a sensitivity of 87 dB
you would not be happy with the performance of these speakers running off your head unit, they would need to be amplified. also note the sensitivity. it would take almost 4x the power to get same volume out of the Alpines vs the Infinity's
Sound quality is subjective but if you fail to run a speaker properly it will never be as good as it can be.
the rule of thumb is anything with a <8 watts recommended power range [RPR] can be run off a head unit and anything >8 watts RPR will need to be amplified.
for zample...
Infinity Reference 6010cs
6-1/2" component speaker system has a RPR of 2-90 watts RMS with a sensitivity of 92 dB
you could easily run this set of components with your head unit.
on sort of a flip side
Alpine SPR-17S
6-1/2"/6-3/4" component speaker system has a RPR of 8-110 watts RMS with a sensitivity of 87 dB
you would not be happy with the performance of these speakers running off your head unit, they would need to be amplified. also note the sensitivity. it would take almost 4x the power to get same volume out of the Alpines vs the Infinity's
Sound quality is subjective but if you fail to run a speaker properly it will never be as good as it can be.
02-04-2007, 09:15 AM
#16
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Originally Posted by TheOtherHalf,Feb 4 2007, 06:28 AM
Yes and no... sort of....
Lets say your head unit is rated 20w @ 4ohm....
If a speaker is 4 ohm, it will draw 20w
If a speaker is 2 ohm then it will draw roughly 40w of power (half the resistance, twice as easy to pass power)
Think of it like light bulbs..
If you have a 60w bulb it will use 60w of power....
If you have a 120w bulb it will use 120w but be twice as bright.
In many cases a head unit is only stable @4ohm. The more power you pass through it the hotter it gets, the harder it is on the amp or head unit. Most amps are 2 ohm stable and often 1 ohm stable too.
I have a Kenwood Excelon head unit and ran a set of the 2 ohm Infinity kappas for 2 years without any problems.
Your efficiency rating is the Sensitivity rating. If you have a speaker that has a Sensitivity rating of 90 db and a speaker with 95 db then the speaker that is 95 db would be significantly louder then the 90 db speaker by more than 2X. I don't know the exact numbers, but for roughly every 3 db you double the volume. If that number is wrong then it wont be long before someone corrects me
Lets say your head unit is rated 20w @ 4ohm....
If a speaker is 4 ohm, it will draw 20w
If a speaker is 2 ohm then it will draw roughly 40w of power (half the resistance, twice as easy to pass power)
Think of it like light bulbs..
If you have a 60w bulb it will use 60w of power....
If you have a 120w bulb it will use 120w but be twice as bright.
In many cases a head unit is only stable @4ohm. The more power you pass through it the hotter it gets, the harder it is on the amp or head unit. Most amps are 2 ohm stable and often 1 ohm stable too.
I have a Kenwood Excelon head unit and ran a set of the 2 ohm Infinity kappas for 2 years without any problems.
Your efficiency rating is the Sensitivity rating. If you have a speaker that has a Sensitivity rating of 90 db and a speaker with 95 db then the speaker that is 95 db would be significantly louder then the 90 db speaker by more than 2X. I don't know the exact numbers, but for roughly every 3 db you double the volume. If that number is wrong then it wont be long before someone corrects me
half the resistance = double the current
double current = square power .:. half resistance = 4x power
v=ir; p = r*i^2
not 100% true in audio world.. amp wont have same efficiency at diff level
3db = double power...
6db = double sound pressure level
but dB describes a relationship, not a unit of true perceived loudness. actually its hard to quantify perceived loudness so there isnt a measurement for it
