Pairing Speakers - Wattage vs. Sensitivity
Pairing Speakers - Wattage vs. Sensitivity
Written by: Kenny Prochazka
So you have a shiny new 2x12 Mojotone speaker cabinet, and you have two particular speakers in mind. But how can you be sure if they will play well together?
Besides some very personal opinions on tone, break-up and other variables, there are two major specifications that you should keep in mind when pairing speakers: Wattage and Sensitivity.
Wattage seems pretty straightforward - most of us would think twice about pairing a 25 watt BV-25M speaker with a 70 watt Greyhound speaker, or even a 50 watt Anthem speaker. But what about a 25 watt BV-25M and a 30 watt BV-30H? That is where the subject gets interesting and potentially confusing, but the reality is actually pretty simple.
Electrically, a dual speaker setup will always evenly divide the wattage, with a ceiling based on the rating of the lower-rated speaker. So if you have a 25 watt speaker and a 60 watt speaker paired in a cabinet, you have a cabinet that can handle a total of 50 watts (25 watts going to each speaker).
The same will happen no matter how powerful the higher-rated speaker is, so a 200 watt speaker paired with a 25 watt speaker would not be able to handle a 100W amplifier without blowing the lower-rated speaker. This also applies to any cabinet with multiple speakers, whether it be 2,3,4 or more. The lowest-wattage speaker will always dictate what the entire speaker setup can handle.
Sensitivity (or Efficiency) can be a bit more difficult to wrap your head around, because of the way it is measured and displayed. To measure a speaker's sensitivity, we give the speaker 1 watt of power, and measure the Sound Pressure Level (SPL) in decibels (dB) from exactly 1 meter away. (This is typically performed in a flat-response, non-echoing chamber or room.) This measurement lets us know how loud the speaker will get with a particular amount of power, otherwise known as sensitivity or efficiency.
It seems intuitive that a more sensitive speaker will sound louder than a less sensitive one, but it is the amount of difference that often surprises people. A rule of thumb in the industry is that a speaker's required power doubles with every 3dB decrease in sensitivity (or halves with every 3dB increase). Let that sink in for a second: a speaker with a sensitivity of 100dB will therefore sound twice as loud as one with 97db sensitivity, even if they are rated for the same wattage. This is why it is typically best to pair your speakers so that they are within 3db's sensitivity of each other, to avoid one overpowering the other(s).
For this reason, all of our 12" British Vintage and Anthem speakers have sensitivities between 97-99dB, so that they will all play well together depending on the wattage needed. Our Greyhound speakers are a louder 101.3dB, which pairs well with both our Anthem 12" and our BV-30V at 99dB.
Hopefully you understand a little bit more about the ratings listed on speakers, and how to match them with each other. There is a world of speakers out there to fall in love with, and now you are armed with the right information to find your best sound and love your tone!
10 comments
Hey guys, i appreciate this tidbit. I just wondered if you could elaborate on how or if these rules of thumb apply to speaker cabs wired in series vs parallel. Years ago an amp builder buddy told me that, all else being equal, if you pair a speaker rated for a higher wattage with a lower wattage speaker in series, you would want the higher wattage speaker to be first in the series from the amp. Does that ring true to you at all? Does it impact speaker durability in any way? And does series vs parallel wiring impact sensitivity in any way? Appreciating your info when you have time to share these kinds of things
Do you carry a 10 in
Speaker that fits a Vox ac4 blue. To get more low end
Yeah, I’ve done some pairing and the result is quite a turkey shoot. I’ve come to think of it as being kinda like a stereo speaker having a tweeter and a woofer. Many of those have a way to dial the tweeter, mid range and woofer in as a mix. My old JBL Horizons had that. Sometimes the brighter speaker fills in just the right amount even if it’s a speaker with less sensitivity. Once I tried a Celestion Greenback (25watt) with a Weber Hemp Cone Silver Bell (75 watt) I had laying around in a 2 × 12 cab I had. I got lucky on that one, the balance was great. The Greenback adding some great high end articulation to the mix. But really, there are so many variables, keeping the speakers similar is probably the best advice.