#171259  by Chocol8
 
wabisabied wrote: Thu Jul 08, 2021 12:46 pm Since the Copperback is rated to 250 watts and the CRex is only 50, I figure most of the sound I’m getting is from the Copperback, but my assumption could be wrong - I’m hardly an expert."[/i]
That rating only tells you how much power they can generally take before damage occurs.

The numbers you are looking for is the sensitivity rating which is decibels of output at 1 watt input. The more sensitive speaker will be the louder one, but sensitivity can vary by frequency even though the published specs rarely offer any detail.
 #171262  by wabisabied
 
Chocol8 wrote: Wed Jul 21, 2021 6:25 pm That rating only tells you how much power they can generally take before damage occurs.

The numbers you are looking for is the sensitivity rating which is decibels of output at 1 watt input. The more sensitive speaker will be the louder one, but sensitivity can vary by frequency even though the published specs rarely offer any detail.
Interesting, thank you.

The Copperback’s sensitivity is listed as 100dB.
https://celestion.com/product/neo-250-copperback/

The Cannabis Rex is listed as 101.8dB.
https://www.eminence.com/speakers/speak ... nnabis_Rex

According to what I’ve read on Celestion’s website, that's a negligible difference to our ears.
https://celestion.com/blog/sensitivity- ... s-it-mean/

Also the round, seemingly less precise number for the Copperback makes me wonder if it’s really an approximation.

Based on all that I would conclude that both speakers are producing nearly equal volume, with the CRex possibly sounding sightly louder.

Another spec that can be seen on the above pages is Resonant Frequency (Fs). There’s a much bigger variance, with the Copperback at 55Hz and the CRex at 96Hz, but I don’t know how that might effect tone and/or volume, other than to speculate that we might hear more Copperback at lower frequencies, and more CRex at higher frequencies. Although according to some info I gleaned HERE, the frequency range of a guitar in standard tuning is about 90-1300Hz, so maybe the lower Fs of the Copperback would only be apparent in a drop-tuning or with a bass guitar.

For whatever it’s worth, the frequency range on the Copperback is 70-5500Hz, the CRex is 80-4500Hz.

Regardless, the combo sounds great to me and I’m having a lot of fun with it.
 #171265  by Chocol8
 
Lots to digest there…

Starting with the last point, the published frequency response number is typically the point where output level is down by 3 db. It starts rolling off slightly above there, but -3 db is used for a variety of reasons.

For a guitar in standard tuning, and with an amp that is likely already rolling off bass (especially with a Jerry setting of bass on 0!) you won’t here much difference between a FR to 70 vs 90, but other differences between the two can make the low end sound significantly different, particularly a hump in bass response which is common and also cab dependent.

1.8 db is both a lot and also not that big of a deal. People can generally hear about a 0.5 db difference between two identical sounds. 1.8 is certainly in the realm of audible, but the speakers are different and both have deviations from a flat response that are much more than 1.8 db. It is very likely that there are some frequencies where the C-Rex is louder and some where the Copperback is louder. Then there is the issue of off axis response. As you move around, which one is louder will change!

Human hearing and the db scale is a bit weird. To go up 3 db you need to double the power, so a 100 watt head is about 3 db louder than a 50 watt version, all else equal. That doesn’t sound like double to a human ear though. It sounds a bit louder. It takes more like 10x the power for people to perceive a sound as being twice as loud. So 1.8 db is a lot from a power perspective, you would need to add 51% more power to match levels, but from a hearing perspective, it is not much.

All that to say, there is nothing wrong with pairing those speakers. The C-Rex may be a bit louder at some but not all frequencies, and if the pair sounds good, they sound good.