Speaker sensitivity and wattage

[Freestyle_Pete]

Hi all

 

I'm still a bit fuzzy on how sensitivity and wattage works, here's what I'm lead to believe from what I've learned so far

 

I'm looking at 2 different speakers with the following stats

 

Speaker A HK CN115

 

Rated: 400 Watts RMS

Sensitivity: 106db @ 1w at 1 meter

 

Speaker B EV ZX5

 

Rated: 600 Watts RMS

Sensitivity: 99db @ 1w at 1 meter

 

 

Now from what I've read speaker A will give roughly twice the output of speaker B even though it requires less wattage, because the sensitivity rating is so high, and increasing it by 3 db doubles the required power to get the same volume and therefore because it's 7db more than speaker B will more than triple it, does that make any sense?

 

Also which of these cabs would you recommend from experience

 

Cheers

 

Pete

[Shez]

This will help you calculate the spl from the sensitivity and power handling:

 

dBspl = sensitivity + 10.log(power)

 

It's ballpark as other factors do come in to play but is useful for comparison purposes.

[J Pearce]

The HK is a good quality ply box, painted tough black and looks smart. The EV is a plastic box that will scratch fairly easily and won't repair with a lick of paint.

 

Sound wise, I haven't heard that particular HK wedge, but I've never been disappointed by their wedges before. The EV I found a touch too warm, lacking the bite that is often needed for a monitor. I also found its dispersion very inconsistent across the frequency range, especially at the crossover point.

[Simon Lewis]

Speaker A = 106+10log400 = 132dB SPL

Speaker B = 99+10log600 = 127dB SPL

 

Shez's equation does not take power compression into account. Also, the sensistivity rating may well be taken from the most sensitive part of the loudspeaker's range - so unless the manufacturer provides more detail, it's hard to see how accurate such figures are.

 

However, I would lean towards the more sensitive unit!

 

Simon

[Freestyle_Pete]

dBspl = sensitivity + 10.log(power)

 

If only I knew what the hell that meant I'm not quite that mathematically advanced I'm afraid

 

Both cabs are within a few db of each other depending on which spl stats you use, I reckon they would both be a similar volume in real life situations

 

I can probably get hold of a second hand pair of HK CN115s for about £1000 if all goes to plan, cheers for the advice

 

Pete

[lostinvegas]

You might find this useful just over half way down the page: http://en.wikipedia.org/wiki/Loudspeaker

 

Chris

[Rob_Beech]

On paper the HK is quite significantly louder for less power in.

 

EV are normally very good with their figures and tend to give lots of information on the actual results rather than just picking out what looks good. Whether this works on all boxes or just the touring stuff I do not know. HK are somewhat less accurate but again I'm not familiar with how much data they give you on that particular range.

[Rich]

The HK's sensitivity is quoted in half space.

 

Take a look at this box. The half space sensitivity is 103 dB, full space is 97dB. The driver with the lowest sensitivity is the bass driver, and it has a sensitivity of 98dB (1dB is lost in cabinet tuning) for LF extension.

 

I would imagine that the sensitivity of the EV cab is measured in full space, half spece looks good on paper.

[J Pearce]

However, its not unreasonable to measure a wedge in half space, as it will live on the floor.

That said it makes it harder to compare it with manufacturers who quote full space.

[Rich]

However, its not unreasonable to measure a wedge in half space, as it will live on the floor.

That said it makes it harder to compare it with manufacturers who quote full space.

 

Yeah that doesn't really help to answer the original post, and to be fair, it's a mulit role cab.