You've probably heard it like everyone else, "It takes 10 times the wattage to double in volume."

Well, just how much does wattage mean, then??? I remember, years ago when I was active on this website, thinking that the wattage amount was infinitely important to volume and that a 600 watt 8 ohm cab would be noticeably quieter than a 600 watt 4 ohm cab running from the same amplifier.

There are so many more variables than wattage, such as sensitivity, xmax, speaker size, and speaker quantity. I'm beginning to learn more and more that the wattage of an amp is at best a suggestion as to how loud it may be. I remember being terribly let down by the volume of my Carvin Redline 1000 watt bass head or my 1000 watt Kustom 3x10 combo amp. I used to own a 300 watt Markbass Combo that was just as loud as either of those pieces.

So, if any of you are interested, I'd like you to do an experiment and post your results.

Simply try different cabs you own, or may have access to, with a single amp head. Note the wattage of the amp at each impedance rating, the impedance of each cab, number of speakers, and how loud you perceive the cab to be. This doesnt have to be totally scientific, but I would be thrilled if we could come across a general consensus.

I have three cabs at the moment: an Avatar 2x10, an Acme 2x10, and a MesaBoogie 4x10.

I'll put each of them through my Carvin BX500 head sometime this week and post my results in this thread.
...it was bright as the sun, but with ten times the heat
Experimenting is good the basis of science. So I'd encourage you to try this out. However the science is pretty well worked out already.

Loudness depends upon three things:

Amplifier power, doubling the power gives an extra 3db and yes you need 10x the power to get double the volume

Speaker efficiency, a speaker with 99db/watt is going to need half the power of one which gives 96db/watt for the same level

Frequency response, these are never flats so lumps and bumps can make a speaker sound louder, especially if these are in the mid ranges where our ears are most sensitive

Here you go https://www.ultimate-guitar.com/lessons/the_guide_to/making_it_loud.html
Since the human ear is not the most discriminating thing in the world, you might also have to consider the question of perceived loudness as opposed to a quantifiable standard. Some amplifiers/rigs seem to be louder than others, and the room can play a big part in this. I've played through amplifier/speaker combinations that sounded colossal in some rooms, but not nearly so much so in others. There is a practical difference between a measurement in sound pressure levels and perceived loudness. Both of them involve some serious mathematics.

The more speakers you have; the more air you are moving. But how much of it is getting wiped out by the particulars and acoustics of the room?

Interesting idea you've got there.
"Maybe this world is another planet's hell?" - Aldous Huxley
Last edited by FatalGear41 at Nov 4, 2016,
I know there is a science behind all of this. I just wanted to make a fun thing to do for the bass forum and maybe some of us would learn something. I think it would be interesting to hear people's experiences.
...it was bright as the sun, but with ten times the heat
Experiences,,,,

A. 2x10 or 4x10 on the floor does not sound as loud as 2x12 stacked vertically, as the height of the cabinet to the ear makes a difference.

thus, a 4x 12 inline stack with the bottom two speakers off, will sound louder than the same stack with the top speakers off, still running the same wattage. Once put a 1x12 combo on a table and it still filled the VFW Hall, so even decoupling from the stage may not effect loudness.

B. Loudness in a closet or 10x12 room cannot compare to the expanse of s stage.

C. Relative to B, distance from a Cabinet can make a significant difference in the tonal and volume experience, as some cabiners need 20 feet of throw to develop the sound and fury. Often complained to a guitarist for microwaving me with his 1x12 Engl on a 4x12 cabinet on the other side of the stage as a side wash. If he was using feedback I can understand, but he as not, and needed the rig on the other side of the stage if he wanted to hear better.

D. Some amps can claim 1000w, but is that peak or program? Actual power? Genz Benz claimed that their engineering of the GBE series amps sounded 2x louder than the published power ratings. after running 2 GBE 1200 power sections in a 10K seat arena at about 3, I am almost convinced.

E. Wattage is work [movement and heat] and is the energy of sound. Nevertheless, sum Ohmage of the cabinets in use determines if the power system is operating within the confines of its design to produce useful energy to move speakers properly to create loudness, or is just melting itself out while not beng able to produce any spl.
Ibanez BTB 1006 Fretless and 405 (no Barts)
456 & 455(w/Barts)
Genz Benz NeoX400 112T & NeoX 112T cab.
Digitech BP-8 (x2)
Yamaha PB-1
Boss: SYB-5, PS-2, OD-20, EQ-20, PH-3,BF-3, CE-20, DD-20
Morely A/B
Quote by FatalGear41
Since the human ear is not the most discriminating thing in the world, you might also have to consider the question of perceived loudness as opposed to a quantifiable standard. Some amplifiers/rigs seem to be louder than others, and the room can play a big part in this. I've played through amplifier/speaker combinations that sounded colossal is some rooms, but not nearly so much so in others. There is a practical difference between a measurement in sound pressure levels and perceived loudness. Both of them involve some serious mathematics.

The more speakers you have; the more air you are moving. But how much of it is getting wiped out by the particulars and acoustics of the room?

Interesting idea you've got there.

Some folks think that a bass that's booming away in a particular bandwidth (say lower mids) is louder than one that's producing things with a pretty flat response. Perceived loudness often has nothing to do with real volume.

Speaker volume isn't determined by cone area alone. It's a *volume* of air that's moved, so if you have a voice coil on a 15" speaker that that only moves 1/4", it's not going to be able to produce as much volume as a 15" speaker whose voice coil can move 1/2". That means that a single speaker with 1" of Xmax () can move a larger volume of air (be louder) than two speakers with 1/4" each.
Quote by c3powil

One thing that you must grasp is the difference between loudness and volume. in the past multi loaded speaker cabs were the norm (two 4x12 cabs) because of the low power handling of the speakers available. 12s were around 15-25 watts handling, the most powerful UK bass speaker being the 18" Goodmans Audiom 90 at 50 watts. Also the rule back then was if you h 100 watt amp then you needed 200 watt of speakers
4x12"s gave you the volume of sound that was loved whereas today I gig with just my 15" Markbass which is just as louder if not louder than the old 4x12s and easier to carry around. But remember loudness and volume are two Different things.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
One thing today is that you can run an amp that has more watts output than the speaker handling unlike yesteryear (A) your amp will run less hot so (B) your speakers won't receive damaging square waves from the output stage.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
Quote by John Swift
But remember loudness and volume are two Different things.

Hmmmmm, well I would qualify this as "perceived loudness" and measured volume are two different things. If you measure the SPL of both loudness and volume in db, they are indeed the same thing.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Hmmmmm, well I would qualify this as "perceived loudness" and measured volume are two different things. If you measure the SPL of both loudness and volume in db, they are indeed the same thing.
You've obviously not compared the volume of sound from two 4x12s loaded with 25 watt speakers with a single combo with one speaker of the same wattage as the two cabs combined fed by the same amplifier there is a noticeable difference.
Perceived loudness and what you hear are not the issue, the loudness from a 1x12 200 watt combo is much harsher on the ears than two 100 watt 4x12 cabs where the increased volume of sound is more acceptable though not necessarily louder.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
John Swift

Nonsense. Perceived loudness IS what you hear (perceive with your ears). See what I did there? And measured SPL is measured SPL. It doesn't matter whether you generate 120db with 4x12s or a single EVM12L. 120db is still 120db. Everything else is voodoo, witchcraft, and anti-science.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Last edited by Cajundaddy at Nov 1, 2016,
John Swift

Nonsense. Perceived loudness IS what you hear (perceive with your ears). See what I did there? And measured SPL is measured SPL. It doesn't matter whether you generate 120db with 4x12s or a single EVM12L. 120db is still 120db. Everything else is voodoo, witchcraft, and anti-science.
Obviously due to inexperience you have not stood off stage and experienced volume compared to loudness.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
I prefer to measure volume and loudness objectively with a SPL meter or RTA, not my gut instinct.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Last edited by Cajundaddy at Nov 4, 2016,
I prefer to measure volume and loudness objectively with a SPL meter or RTA, not my guy instinct.

Yeh you meet a lot of Technos who can tell you what should sound right despite what the audience thinks, I've been to the odd concert recently where the so called professionals left much to be desired and there are people like me who do it through experience, 54 years of experience who works with and without massive rigs and even built gear.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
I think you guys are talking at crossed porpoises.
What sounds nice and what's louder are two different things.

One of you is saying you like loudness generated by a whole bunch of speakers and that it's prettier than loudness generated by a single speaker (which ain't necessarily true) and the other is saying that sound pressure is sound pressure (which is true) no matter what it sounds like.

And what the OP is asking ("Simply try different cabs you own, or may have access to, with a single amp head. Note the wattage of the amp at each impedance rating, the impedance of each cab, number of speakers, and how loud you perceive the cab to be") just isn't going to happen. It's an absolutely subjective and anecdotal pursuit that ignores a ton of parameters that can influence sound.

As for the "technos who can tell you what should sound right...", I was taught to use my measurement tools when the sound DID sound right at some point in the middle of a concert, and to log everything every night. And then some night when things were off, take a look at what my measurement tools were telling me and see what the differences were, and try to bring everything back into spec as *part* of the process of figuring out what was off. Outdoors was always a challenge; dry crisp fall air sounds a whole lot different from humid heavy summer air for starters, and when an arena is giving you fits just because of its physical design, you quickly learn what works and what doesn't. Indoors, even in venues that just hold hundreds or just a few thousand, the body mass alone will change the acoustics. A season or two of doing this every evening or so will give you most (not all) of the experience you need.
Pulling the "I'm old and I've been doing this a long time, whippersnapper" card isn't going to convince anyone of anything.
On the other hand, experience certainly has its place, and I've had people over MY shoulder who listen for five seconds and instantly know what's off with the sound, reach over and flip a couple of switches or run on stage and move some things around and suddenly we're both happy.
All good.
Quote by dspellman
Pulling the "I'm old and I've been doing this a long time, whippersnapper" card isn't going to convince anyone of anything.
On the other hand, experience certainly has its place, and I've had people over MY shoulder who listen for five seconds and instantly know what's off with the sound, reach over and flip a couple of switches or run on stage and move some things around and suddenly we're both happy.
All good.
You can't buy experience, experience is gained over years, being able to take a last minute gig and sett up and sound check in a very short time has been my forte for many years now, I have nothing to prove but what does pee me off is how long some bands etc thud and clang for ages.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
John Swift

Yep, you and I came through the same school of hard knocks and excessive years at this game, just on opposite sides of the pond (My 1st paid gig was in 1969). Done sound in a backyard with 4ch mixer for 30 people--- check. Outdoor shows with line arrays for 20k people-- check, and everything in between--- check. Thousands of live shows--- check. Built and tuned my own cabinets in the 70s and 80s--- check.

I do appreciate experience but I gotta agree with dspellman. "Sounds good" is an entirely different animal than loudness or volume in my book. Maybe you guys just use different definitions back in the old country but here in the colonies us Yanks use tools to measure loudness and volume. We prefer ears for the "sounds good" part.

Carry on John Swift.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Last edited by Cajundaddy at Nov 4, 2016,
Cajundaddy 1969, wow by then I'd played through Beatlemania, toured the UK, lost the support slot on a Beatles show on the flip of a coin, joined the army 66 and became a full time musician Bass Guitar and Sax, attended Knellar Hall The Royal Military School of Music London on Bb Tenor Sax 1967/8 and left the army in 69.
I've built cabs as well, even for Def Leppard in their early days and still build and play today. regarding difference between volume and sound well you don't have to be a trained ear to hear the obvious difference.
Take care friend.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
Quote by FatalGear41
The more speakers you have; the more air you are moving.

This isn't true at all at a given power level.

At a fixed power level, adding more speakers will do nothing but increase power handling, and give lower distortion because each driver will be receiving less power, and therefore won't move as much (the more excursion, the more distortion you get).

The potential is there to move more air, but you need more amplifier power to accomplish it. You can't magically add power by adding speakers, and it takes increased power to move more air.

The only exception to this would be if you're adding speakers with lower impedance, but the increase wouldn't because of adding the speakers, it would be because the lower impedance causes the amplifier to deliver more power (this obviously doesn't apply to tube amps).
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude
Last edited by Prime2515102 at Dec 8, 2016,
Prime2515102 The vast majority of Bass amps that I see being used today are solid state etc. Valve amps are ridiculously expensive and heavy. When I started playing transistor amps were only just starting to emerge and quite frankly they sounded terrible.
With a solid state amp yes you will get more wattage output by lowering the impedance when you add more speakers wired in parallel, it will give you more volume of sound due to the lower impedance but not as much as you think because the amp now sees more voice coils to drive.
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
Quote by John Swift
Prime2515102 The vast majority of Bass amps that I see being used today are solid state etc. Valve amps are ridiculously expensive and heavy. When I started playing transistor amps were only just starting to emerge and quite frankly they sounded terrible.
With a solid state amp yes you will get more wattage output by lowering the impedance when you add more speakers wired in parallel, it will give you more volume of sound due to the lower impedance but not as much as you think because the amp now sees more voice coils to drive.

This is because overall efficiency is going to change (that is a really complicated explanation that I am not yet clear about as I am not a physicist).* Two identical drivers in parallel will definitely draw twice as much current/power, but that doesn't necessarily mean you'll get twice the output.

*I was going to try to explain the reason for that but I was about a quarter of the way through the paper on it and my face started to twitch, so I had to stop. lol
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude
I dont have much experience but i will play the game since i just swapped speakers in my homemade cab. I use a hartke transient attack 140watt amp. The cab is a 2 1/3 cubic foot box with a tuned port tuned to attenuate(i think thats the word) 44hz. First speaker was a deltalite2512 250watt 8ohms(actual resistance in 6.5 ohms). That speaker was very loud. The second speaker was a jbl 200 watt 4.5ohm speaker. That speaker was also very loud. Im talking percieved volume here, nothing scientific. The jbl was not twice as loud and i really couldnt tell that it was very much louder but it did easily vibrate the amp off of the cabinet(i caught it). Both speakers vibrated things in the house but the jbl vibrated more things and started knocking cds of the shelf. I think that the deltalite,being only like 3.5 lbs, didnt shake the cab as much as the jbl which weighs more like 7-10 lbs.
Quote by Prime2515102
This isn't true at all at a given power level.

At a fixed power level, adding more speakers will do nothing but increase power handling, and give lower distortion because each driver will be receiving less power, and therefore won't move as much (the more excursion, the more distortion you get).

The potential is there to move more air, but you need more amplifier power to accomplish it. You can't magically add power by adding speakers, and it takes increased power to move more air.

The only exception to this would be if you're adding speakers with lower impedance, but the increase wouldn't because of adding the speakers, it would be because the lower impedance causes the amplifier to deliver more power (this obviously doesn't apply to tube amps).

There's nothing magical about it. The sound radiated by a speaker diaphragm is proportional to the square of the surface area. Speakers are very inefficient at transferring movement of the cone to movement of the air, usually only 2% of the energy goes to sound the rest to heat. Doubling cone area gives you an extra 3dB for the same power because you aren't wasting amp power just squashing air, if you double the power as well by having a lower impedance you'll get another 3dB giving 6dB overall. In practice you don't often get twice the power going to 4 ohms so it is often more like 5dB depending upon the make and model of the amp.
Quote by Phil Starr
There's nothing magical about it. The sound radiated by a speaker diaphragm is proportional to the square of the surface area. Speakers are very inefficient at transferring movement of the cone to movement of the air, usually only 2% of the energy goes to sound the rest to heat. Doubling cone area gives you an extra 3dB for the same power because you aren't wasting amp power just squashing air, if you double the power as well by having a lower impedance you'll get another 3dB giving 6dB overall. In practice you don't often get twice the power going to 4 ohms so it is often more like 5dB depending upon the make and model of the amp.

hmmm... I shall get a sound pressure meter and test this.
"Practice doesn't make perfect. Perfect practice makes perfect." -some dude