Hi. I have a Dodge Charger w/ the Beats audio system and am looking to replace the 3.5" dash speakers. I know that the system has a 12 channel, 552W amp, so I'm assuming each speaker is getting 46 watts (prolly peak, not RMS).
I know the stock speakers are 2 ohm, but I do not know the sensitivity. I've been reading up on sensitivity vs. impedance, but I am still not sure of the following question: Sound quality and distortion and all other matters aside, which of the following replacement speakers would provide the most volume (as in loudness).
a 2 ohm speaker with a sensitivity of 89 dB - or-
a 4 ohm speaker with a sensitivity of 91 dB.
I know obviously the higher the sensitivity, the more volume per given power, but I also know that using a 4 ohm speaker on a system driven at 2 ohms can reduce the wattage being delivered to the speaker, which I'm assuming might also reduce the volume.
Are there any mathematical algorithms to help compare the volume output of the two example above?
Thanks all.
I know the stock speakers are 2 ohm, but I do not know the sensitivity. I've been reading up on sensitivity vs. impedance, but I am still not sure of the following question: Sound quality and distortion and all other matters aside, which of the following replacement speakers would provide the most volume (as in loudness).
a 2 ohm speaker with a sensitivity of 89 dB - or-
a 4 ohm speaker with a sensitivity of 91 dB.
I know obviously the higher the sensitivity, the more volume per given power, but I also know that using a 4 ohm speaker on a system driven at 2 ohms can reduce the wattage being delivered to the speaker, which I'm assuming might also reduce the volume.
Are there any mathematical algorithms to help compare the volume output of the two example above?
Thanks all.
Hi,
Sensitivity is not the same as efficiency. Its output for 2.83V input.
The 4ohm/91dB should be louder than the 2ohm/89dB by 2dB,
and be (2+3) 5dB more efficient, implying it likely has less bass.
rgds, sreten.
Sensitivity is not the same as efficiency. Its output for 2.83V input.
The 4ohm/91dB should be louder than the 2ohm/89dB by 2dB,
and be (2+3) 5dB more efficient, implying it likely has less bass.
rgds, sreten.
No, 4-ohm/91dB/2.83V/1m speaker will be 2 dB louder than 2-ohm/89dB/2.83V/1m speaker at ANY volume, including max volume! And on top of that, it will soak only half of the power from the amplifier, compared to 2-ohm speaker. Sensitivity (dB/2.83V/1m) is the king of the SPL empire.
Aside of the sensitivity Vs efficiency debate,
the most important thing is safety : if 12 channels, I doubt that
the amplifier is stable at 2 Ω load. Check at which impedance the output is given and if a single channel can drive safely a 2 Ω load.
the most important thing is safety : if 12 channels, I doubt that
the amplifier is stable at 2 Ω load. Check at which impedance the output is given and if a single channel can drive safely a 2 Ω load.
Wrong.
Sensitivity is measured with 1 Watt applied at the nominal/rated speaker impedance.
So 2.83V is valid for 8 ohms rated speakers, BUT for 4 ohms speakers test voltage is 2 Volts and for 16 ohms speakers test voltage is 4 Volts.
Many datasheets specifically state so, black on white, and those which don't, don't care because they are showing then 8 ohms rating only, but speakers available in different impedances do.
Now car audio speakers usually "forget" to make that clear, so speakers enjoy an inflated 3 dB increase in printed specs sensitivity.
Hi,
Nonsense.
All sensitivity measurements are taken at the equivalent of 2.83V/1m.
(Efficiency, not sensitivity, is defined as the output for one
real watt into the given nominal driver / speaker impedance.
Hence for a given sensitivity, 4 ohm efficiency is 3 dB lower. )
No attempt is made to adjust drive for impedance, as the impedance
curve of a complete loudspeaker is all over the place and the frequency
response of a complete speaker is the given sensitivity curve.
I'm getting very bored with your amateur contradictions of my posts.
rgds, sreten.
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So you still try to prove that 2+2=5 or whatever.
maybe there's some psychological problem somewhere, by systematically contradicting whatever is posted, no matter where, all over the Forum. Oh well.
Maybe you should write Eminence and also call *them* amateurs 😛 , because this is what they write in their official datasheets (in this case for the 820H speaker) http://www.eminence.com/pdf/820H.pdf or, say,
http://www.eminence.com/pdf/Copperhead.pdf
They took care to add a footnote *explaining* how they measure, because the Net is full of IGNORANT people spewing nonsense:
JBL goes even further, mentioning the same voltages as I did, depending on nominal/rated impedance.
Just have a look at this attachment, copied and pasted straight from a JBL datasheet.
Of course you could make a CC copy of your Email and also call JBL "amateurs" 🙄 :
Attachments
Hi,
Still you you don't understand the difference between sensitivity and efficiency.
I don't systematically contradict anyone - you do - In my case and its boring.
Boring because your always wrong, claiming some wrong nonsense is right.
rgds, sreten.
Still you you don't understand the difference between sensitivity and efficiency.
I don't systematically contradict anyone - you do - In my case and its boring.
Boring because your always wrong, claiming some wrong nonsense is right.
rgds, sreten.
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Measuring speaker frequency response (and average "sensitivity") with standard 2.83 V regardless of it's nominal impedance is very beneficial, especially when comparing different drivers and loudspeakers and designing crossovers.
Although in the books standard definition of efficiency is ratio between acoustical and electrical power of the loudspeaker expressed as percentage (and not in dB!), and standard definition of sensitivity is average SPL in dB at 1 m at 1 W input with nominal impedance taken in the account (2V/4ohm, 2.83V/8ohm, 4V/16ohm), in practice can be very difficult to declare which is the (real?!) nominal impedance of the loudspeaker. For drivers it is a little bit easier, if we accept old German DIN standard that minimum measured impedance is 80% of the nominal impedance of the loudspeaker (3.2 ohm for 4 ohm nominal and 6.4 ohm for 8 ohm nominal). But which is the nominal impedance of the driver with measured minimal impedance of 5 ohms? Or 10 ohms? Also, for a complete loudspeakers (drivers in the box, with crossover) impedance can drop briefly to 2.8 ohms in a very small bandwidth and be over 8 ohms in the rest of the spectrum - then which is it's nominal impedance?!
Eminence indeed is using nominal 1 W at nominal impedance for specifying the sensitivity as average SPL but it is using fixed voltage (4 V at 16 ohms nominal, 2.83 V at 8 ohms nominal) for measuring frequency response because most of the amplifiers, and especially those used in measuring, are almost ideal voltage generators. That old practice has no real advantage over measuring sensitivity with fixed 2.83 V regardless of impedance, especially when it is accompanied with measured impedance vs frequency.
Maybe it is time to abandon old definitions and move on practical measuring of sensitivity with fixed 2.83 V, regardless of the elusive nominal driver impedance.
Although in the books standard definition of efficiency is ratio between acoustical and electrical power of the loudspeaker expressed as percentage (and not in dB!), and standard definition of sensitivity is average SPL in dB at 1 m at 1 W input with nominal impedance taken in the account (2V/4ohm, 2.83V/8ohm, 4V/16ohm), in practice can be very difficult to declare which is the (real?!) nominal impedance of the loudspeaker. For drivers it is a little bit easier, if we accept old German DIN standard that minimum measured impedance is 80% of the nominal impedance of the loudspeaker (3.2 ohm for 4 ohm nominal and 6.4 ohm for 8 ohm nominal). But which is the nominal impedance of the driver with measured minimal impedance of 5 ohms? Or 10 ohms? Also, for a complete loudspeakers (drivers in the box, with crossover) impedance can drop briefly to 2.8 ohms in a very small bandwidth and be over 8 ohms in the rest of the spectrum - then which is it's nominal impedance?!
Eminence indeed is using nominal 1 W at nominal impedance for specifying the sensitivity as average SPL but it is using fixed voltage (4 V at 16 ohms nominal, 2.83 V at 8 ohms nominal) for measuring frequency response because most of the amplifiers, and especially those used in measuring, are almost ideal voltage generators. That old practice has no real advantage over measuring sensitivity with fixed 2.83 V regardless of impedance, especially when it is accompanied with measured impedance vs frequency.
Maybe it is time to abandon old definitions and move on practical measuring of sensitivity with fixed 2.83 V, regardless of the elusive nominal driver impedance.
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Hi,
Sorry but more nonsense.
There is an international standard that defines sensitivity, and it
specifies that sensitivity be referred to SPL @ 1m for 2.83V input.
It has nothing to do with impedance, though nominal impedance
should be stated to aid interpretation of the sensitivity stated.
rgds, sreten.
http://www.audioholics.com/loudspeaker-design/loudspeaker-sensitivity
Sorry but more nonsense.
There is an international standard that defines sensitivity, and it
specifies that sensitivity be referred to SPL @ 1m for 2.83V input.
It has nothing to do with impedance, though nominal impedance
should be stated to aid interpretation of the sensitivity stated.
rgds, sreten.
http://www.audioholics.com/loudspeaker-design/loudspeaker-sensitivity
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I agree that loudspeaker sensitivity should be measured with 2.83 V at 1 m regardless of the loudspeaker nominal (rated) impedance (and including data about impedance), but International Electrotechnical Commission standard IEC 60268-5:2003 says:
20.3 Characteristic sensitivity in a stated frequency band
20.3.1
The sound pressure output shall be specified in a stated frequency in accordance with 20.1.1, referred to a input power of 1 W and to a distance of 1 m on the reference axis.
20.3.2
Measurements shall be made in accordance with 20.1.1, and they shall be referred to voltage Up corresponding to a power of 1 W, where Up is numerically equal to the sqrt(R) value and where R is the rated impedance.
In other words, IEC specifies measurements of sensitivity to be taken with a 4 V signal for 16-ohm rated loudspeaker (Up=sqrt16=4V), 2.83 V signal for 8-ohm rated loudspeaker (Up=sqrt8=2.83V) and 2 V signal for 4-ohm rated loudspeaker (Up=sqrt4=2V), all equal to a 1 W at rated impedance. Not to my liking, but there it is.
Requirement for minimum impedance to be more than 80% of the rated impedance is also included in the IEC standard.
20.3 Characteristic sensitivity in a stated frequency band
20.3.1
The sound pressure output shall be specified in a stated frequency in accordance with 20.1.1, referred to a input power of 1 W and to a distance of 1 m on the reference axis.
20.3.2
Measurements shall be made in accordance with 20.1.1, and they shall be referred to voltage Up corresponding to a power of 1 W, where Up is numerically equal to the sqrt(R) value and where R is the rated impedance.
In other words, IEC specifies measurements of sensitivity to be taken with a 4 V signal for 16-ohm rated loudspeaker (Up=sqrt16=4V), 2.83 V signal for 8-ohm rated loudspeaker (Up=sqrt8=2.83V) and 2 V signal for 4-ohm rated loudspeaker (Up=sqrt4=2V), all equal to a 1 W at rated impedance. Not to my liking, but there it is.
Requirement for minimum impedance to be more than 80% of the rated impedance is also included in the IEC standard.
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