More watts vs. more speakers.

[aende]

To my mindset:

Speakers mean impact to the audience - More speakers = more air shifted

Headroom means volume before it distorts - More headroom means more depth, clarity and sensitivity

More Watts means drive for the speakers - Overall guts of the rig and how much wind you can shift

But this is how my brain works and how it feels to me......completely non technical....!

[TimR]

There are a couple of things to be aware of:

1) As you add more speakers your source becomes wider. As it approaches 1/4 of the wavelength the sound becomes directional. This directional 'beam' becomes narrower as the frequency rises. Think of it like the twist focus on a torch, raising the frequency is like twisting the focus. Normally this won't be a problem; the wavelength of sound at 40Hz is 8.5m, at 220hz it's 1.5m, at 340Hz it's 1m and at 1khz it's 0.34m. So your 15" (0.38m) speaker will be directional at anything over 220Hz and your 10" (0.25m) at anything over 340Hz. You can notice this as you walk across the room the sound is brighter in front of the speaker than it is to the side (this is known as off-axis response). If your cab was as wide as 2m the sound will become directional at 40Hz. Theoretically - I don't know about practical limitations. So I suspect having 2x4x10" next to each other would create problems.

2) Individual speakers next to each other create interference patterns. Those of you who paid attention in Physics lessons will remember the 2-slit light experiment where you shine a light through two slits and get patterns of dark and light on the wall. Again you can experience this as you walk across the room when a 4x10" is used and get different tones.

You can get around this by vertically stacking two 2x10" to create a 1x4 configuration instead of the traditional 2x2 configuration of the 4x10"

It's a lot more complicated than this when you start adding in room reflections, but in essence if you can't hear your bass it nay well be because you're not standing in the area where the frequency you want to hear, over the other instruments, is directional.

Hope this is right and not too much of a lecture. I'm happy to be corrected.

[Mikey R]

[quote name='scalpy' timestamp='1357213464' post='1919093']
You don't need an Italian supercar to do 150 miles an hour, but I'm guessing it's fun. Likewise, you don't need a massive fridge of a cab to be loud, but it's so much fun when you do. A lot of number crunchers forget this. From this viewpoint- more speakers.

Interestingly, I also think the people you work with or play to judge the volume you play at with their eyes, ie they take one look at you squeezing through a door to a band call with a 410 on your chest and your face redder than a baboons arse and they think "the bass is too loud" before you've even plugged in. Turn up with the cab in one hand you can play the same volume and you can be complimented for being "sensitive!" In that respect (and it does earn you more money!) - more watts.
[/quote]

Putting it the other way, is there a danger of arriving with a 1x12, and the band leader thinks "this guy is never going to keep up"?

[Lozz196]

[quote name='Mikey R' timestamp='1357994880' post='1931508']
Putting it the other way, is there a danger of arriving with a 1x12, and the band leader thinks "this guy is never going to keep up"?
[/quote]

Good point, I`m sure many would look at my Markbass CMD121P and think it was a digital radio and why hadn`t I brought my amp along. Until they heard it.

[Guest bassman7755]

[quote name='0175westwood29' timestamp='1357222044' post='1919293']
when i asked if they could mic my cab they'd say no! i asked them again saying i used pedals and that i bought my cab for a reason,
[/quote]

Well by the time the sound has been through a mic and PA speakers it probably wont sound like "your cab" any more. A signal chain involving 2 sets of speakers is very likely to result in a horrible and muddy sound unless the PA mics and caps are seriously premium quality.
Its one of the reasons I always go getting tone from my amp and using neutral speakers - I can be sure my tone will be reasonable well preserved by DI-ing into a PA.

Edited January 12, 2013 by bassman7755

[Phil Starr]

[quote name='stingrayPete1977' timestamp='1356785858' post='1913560']
So why does anyone have anything more than 100watts? Why do barefaced cabs get a reputation for being power hungry etc?
[/quote]

Amplifying electric guitar or bass is a matter of design philosophies and compromises. If you are amplifying double bass or an acoustic guitar then you are usually trying to get a 'natural' sound but there's nothing natural about amplified electric bass.

All speaker design is a matter of compromise. For example you can have a speaker that goes deep, you can have a speaker that is efficient and you can have a speaker that goes loud but you can't have all three because they place different demands upon the voice coils, magnets and cones. I'll explain:

To make a cabinet go deep you need to add weight to the cone and put in a long voice coil to get the extra movement. A heavy cone is harder to accelerate so the speaker is less efficient. The longer voice coil means most of it will be outside of the magnet gap and you lose more efficiency.

To make a speaker more efficient you can make sure all the voice coil sits inside the magnet gap so all the electrical input is used, but as soon as you put a signal in it moves out of the gap and the speaker starts to compress and distort. the deeper the bass the more air you need to move so if you want to get efficiency this way you have to limit the bass response and the power you feed to the speaker. To get the cab to be loud enough you're going to use a lot of speakers or put up with bass being limited.

The one positive thing you can do is to increase the size of the magnet, There's a limit to this though, partly because the cost gets to be extraordinary and also the weight becomes significant, Eventually you also have problems with saturation of the pole pieces and so it goes on. The advent of neodymium magnets has given us a bit more wriggle room and new opportunities but at significant cost.

Designers like Barefaced have grasped the opportunities of new materials and cheap amplifier power. By using long throw speakers they can get more sound out of single drivers and they can get deeper bass without compression or exceeding the limits of speaker movement but the 'cost' is very good drivers, which are expensive, and long coils which are by their nature less efficient, This isn't a problem in a world where you can buy lots of watts for relatively little outlay. The big plus is a versatile sound and light weight.

You could take a completely different design philosophy though. Since the whole sound of electric bass is artificial anyway then go for the distortion, embrace the 'natural sound' of 'under-powered' valve amps driven hard and the 'louder' sound of a short voice coil in a speaker with prominent peaks in the bass and mid-range. Valve amps are pricey so you are stuck with low watts or an overdraft but you can spend on extra speakers to give you more sound for your watts. You'll lose deep bass and your top end will be restricted by the problems of multiple drivers but you'll have the classic sound of rock and incidentally the look which 'modern' designs probably still don't quite achieve.

These design philosophies are only two of the options though. BFM designs for example use horns to raise efficiency, which imposes a different set of compromises and there are other conventional designs which just set the compromises in different parts of the spectrum.

[Guest bassman7755]

[quote name='Musicman20' timestamp='1357198762' post='1918879']
Potentially it does make a difference, but then others prefer an amp that's being pushed, so lower wattage,
[/quote]

Indeed, its a tradeoff.

Tone from preamp through super clean power amp: same tone at all volume levels - almost always more volume on tap without affecting tone should you require it.
Tone from hard driven power amp: much lower power amp spec required but tone is dependent on volume.

[Mikey R]

[quote name='Phil Starr' timestamp='1358001512' post='1931639']
Designers like Barefaced have grasped the opportunities of new materials and cheap amplifier power. By using long throw speakers they can get more sound out of single drivers and they can get deeper bass without compression or exceeding the limits of speaker movement but the 'cost' is very good drivers, which are expensive, and long coils which are by their nature less efficient, This isn't a problem in a world where you can buy lots of watts for relatively little outlay. The big plus is a versatile sound and light weight.
[/quote]

From the Barefaced website, the basic Compact, which is a single speaker in a well designed box, has a sensitivity of 100dB - this is rediculously good, which means the cab is incredibly efficient.

If Barefaced do have a rep of requiring lots of watts, it could be because people dont understand how it works. Just because the compact can handle a 600 watt amplifier, it doesnt need 600 watt.

When Im at home, I run a 30 watt bedroom blaster head through my Compact and get tons of SPL. Just ask my neighbours.

[quote name='bassman7755' timestamp='1358002888' post='1931669']
Indeed, its a tradeoff.

Tone from preamp through super clean power amp: same tone at all volume levels - almost always more volume on tap without affecting tone should you require it.
Tone from hard driven power amp: much lower power amp spec required but tone is dependent on volume.
[/quote]

And thats why I like the 30 watt Ashdown LB, by the time youre pushing the power valves, youre really starting to get some grit, but you can do that at a reasonable volume.

Im planning sorting out a much larger amp for working with the full band, but in the mean time Ive got the Hartke. It will get the job done but with less style.

Edited January 12, 2013 by Mikey R

[stingrayPete1977]

[quote name='Phil Starr' timestamp='1358001512' post='1931639']
Amplifying electric guitar or bass is a matter of design philosophies and compromises. If you are amplifying double bass or an acoustic guitar then you are usually trying to get a 'natural' sound but there's nothing natural about amplified electric bass.

All speaker design is a matter of compromise. For example you can have a speaker that goes deep, you can have a speaker that is efficient and you can have a speaker that goes loud but you can't have all three because they place different demands upon the voice coils, magnets and cones. I'll explain:

To make a cabinet go deep you need to add weight to the cone and put in a long voice coil to get the extra movement. A heavy cone is harder to accelerate so the speaker is less efficient. The longer voice coil means most of it will be outside of the magnet gap and you lose more efficiency.

To make a speaker more efficient you can make sure all the voice coil sits inside the magnet gap so all the electrical input is used, but as soon as you put a signal in it moves out of the gap and the speaker starts to compress and distort. the deeper the bass the more air you need to move so if you want to get efficiency this way you have to limit the bass response and the power you feed to the speaker. To get the cab to be loud enough you're going to use a lot of speakers or put up with bass being limited.

The one positive thing you can do is to increase the size of the magnet, There's a limit to this though, partly because the cost gets to be extraordinary and also the weight becomes significant, Eventually you also have problems with saturation of the pole pieces and so it goes on. The advent of neodymium magnets has given us a bit more wriggle room and new opportunities but at significant cost.

Designers like Barefaced have grasped the opportunities of new materials and cheap amplifier power. By using long throw speakers they can get more sound out of single drivers and they can get deeper bass without compression or exceeding the limits of speaker movement but the 'cost' is very good drivers, which are expensive, and long coils which are by their nature less efficient, This isn't a problem in a world where you can buy lots of watts for relatively little outlay. The big plus is a versatile sound and light weight.

You could take a completely different design philosophy though. Since the whole sound of electric bass is artificial anyway then go for the distortion, embrace the 'natural sound' of 'under-powered' valve amps driven hard and the 'louder' sound of a short voice coil in a speaker with prominent peaks in the bass and mid-range. Valve amps are pricey so you are stuck with low watts or an overdraft but you can spend on extra speakers to give you more sound for your watts. You'll lose deep bass and your top end will be restricted by the problems of multiple drivers but you'll have the classic sound of rock and incidentally the look which 'modern' designs probably still don't quite achieve.

These design philosophies are only two of the options though. BFM designs for example use horns to raise efficiency, which imposes a different set of compromises and there are other conventional designs which just set the compromises in different parts of the spectrum.
[/quote]

Thanks, thats a good reply I actually dont really like much colour to my sound so I am after clean volume hence the Genz gear (all shuttles not streamliners) and a range of their cabs which the 2x12T is along the lines of what you are talking about anyway afaik. Also I play Db through the various rigs so I am almost after a clean single channel pa system to myself, the 3.0 and 2x12 is about as close as I can afford and a popular choice amongst uprightists (? )

Thanks