Underpowering a cab? (Like, literally)

[trowaclown]

No no this isn't a question about the usual misconception about underpowering.

I'm currently using the Genz Benz Shuttle 3.0-10T combo and I noticed that at lower volumes the cabinet doesn't sound as good as past a certain amount of power, whereby it'll break up nicely and sound great.

I was wondering if this can happen on larger cabs, such as an 8x10. If the head you're using is too low powered (let's say, a theoretical 100 watt head) and doesn't feed enough juice to drive the speakers hard enough to produce their distinctive tone, whatever it is like.

Would this be a good reason to match a head and cabinet in terms of the the wattage of the former and the power handling of the latter?

I'm asking this question because I'm thinking of upgrading to the NeoX series, specifically the 2x12 cabinet. It's got a power handling of 600 watts, but my current head can only put out 300 watts, so I'm worried about underpowering it and not pushing the cabinet hard enough to put out its tone.

Any comments/clarifications are welcomed and appreciated.

[Sten]

Some drivers need higher volume to break up. It depends on the driver and manufacturer very much, but as you see, it is much harder to feed enough power to 8 drivers than to 2 or 4 drivers and therefore the volume before the sweet spot gets considerably louder with 8x10.

You will see here some cabs considered more efficient - they usually need less power per driver to sound better, whereeas some need more. Therefore it is usually not that good idea to have very little power per single driver.

I think the NeoX 2x12" will sound fine with power with your 300W, I think G-K cabs are more on the efficient side. Some unefficient cabs are Edens, Ampeg 410HLF and Acmes according to my knowledge (end long-time experience with the HLF).

[trowaclown]

So the amount of power a speaker needs relative to its max handling capacity, before it starts sounding good, is a function of how efficient it is?

[Sundogue]

I prefer to have more watts available in my head than what my cabs can handle thermally. Not that I use all that power, but I have what I need when I need it.

I have two 210/6, 8 ohm, 400 watt cabs. At bigger gigs I use both, but my head only puts out 400 watts (200 watts each/4 ohm total load) into both cabs. On smaller gigs, I only bring one 210/6 cab. I installed a Series/Parallel switch on that one 210/6 cab so I can run it as a 2 ohm cab when it's on its own. My head puts out 600 watts into 2 ohms. My 210/6 cab at 2 ohms with 600 watts just sounds better than it does at 8 ohms @ 275 watts. Same speakers...same cab, just a switch from 8 ohms to 2 ohms.

I'm not really sure why it sounds better at 2 ohms than 8 ohms when my amp is not putting out anywhere near the cab's thermal rating of 400 watts in either case during a gig. Perhaps it's the amphead itself that makes it sound better when the amp's not being pushed as hard? Is it power compression of the drivers? A combination where I'm near the limit of my drivers yet my amp still has headroom? I'd like to know myself because I've never been totally happy with my tone when I've used an amp rated at less power than the cab, except when I've used a compressor.

Perhaps it's the sound of power compression I dig, because the lower the volume the more compression effect I use. The harder I push the speakers the less I use. Maybe if that's the tone you like, you could use a compressor to simulate it with less power.

[Richard Lindsey]

Originally Posted by trowaclown

No no this isn't a question about the usual misconception about underpowering.

I'm currently using the Genz Benz Shuttle 3.0-10T combo and I noticed that at lower volumes the cabinet doesn't sound as good as past a certain amount of power, whereby it'll break up nicely and sound great.

I was wondering if this can happen on larger cabs, such as an 8x10. If the head you're using is too low powered (let's say, a theoretical 100 watt head) and doesn't feed enough juice to drive the speakers hard enough to produce their distinctive tone, whatever it is like.

Would this be a good reason to match a head and cabinet in terms of the the wattage of the former and the power handling of the latter?

I'm asking this question because I'm thinking of upgrading to the NeoX series, specifically the 2x12 cabinet. It's got a power handling of 600 watts, but my current head can only put out 300 watts, so I'm worried about underpowering it and not pushing the cabinet hard enough to put out its tone.

Any comments/clarifications are welcomed and appreciated.

Are you sure it's your speaker(s) breaking up and not your amp starting to distort?

IME most bassists (unlike a number of guitarists) don't really like the sound of speakers breaking up. In fact, they typically try to design their rigs so
that that does NOT happen. For that group, the idea that you have to pour in a certain amount of power before the speakers "start sounding good" is IMO completely mistaken. As a general rule, whenever you think your cab is sounding better with a bigger amp, it's likely that either (1) you're playing louder, which tends to sound different and better, or (2) your amp is performing better and straining less, and your cab is doing the same thing as it had been, just with a better-quality signal from the amp to work with.

However, if you're one of those who likes the sound of speakers breaking up (and again, if you're sure that's actually what's happening), you would have to hit the speakers with sufficient power to get the sound you want.

[Sten]

So why does louder sound better?

[Richard Lindsey]

Originally Posted by Sten

So why does louder sound better?

Google "Fletcher Munson" or "equal loudness contours."

Or just consider rock 'n roll.

[nobodysfool]

Unless you're going for that vintage Jack Bruce (60's Cream) sound, you probably don't want your speakers breaking up. It usually sounds bad...As for loudness, the Fletcher-Munson curve definitely plays a part. Our ears are designed to hear mid frequencies better than lows and highs. Think speech intelligibility. Consider the telephone and the limited frequency range they employ.

[trowaclown]

Oh no I don't mean 'breaking up' like it's being pushed to it's limits and is near farting out. Maybe it is indeed the Fletcher-Munson effect in place. I didn't consider that point when I asked the question.

[Sten]

Originally Posted by Richard Lindsey

Google "Fletcher Munson" or "equal loudness contours."

Yes, but these curves seem quite similar at different dB levels. Is it that at lower volumes, the lows are weaker compared to mids/highs and as the volume rises, they even up a bit?

[JimmyM]

pretty much, yeah. all frequencies are not created equal.

[trowaclown]

Supposedly, there is a magic loudness level (measure in db at your ears IIRC) whereby your hearing of all frequencies is pretty much linear. Somebody correct me if I'm wrong.

[bolt_thrower]

Originally Posted by Sten

I think the NeoX 2x12" will sound fine with power with your 300W, I think G-K cabs are more on the efficient side. Some unefficient cabs are Edens, Ampeg 410HLF and Acmes according to my knowledge (end long-time experience with the HLF).

What are some other efficient cabs that you could rec?

[Bruce Lindfield]

Originally Posted by bolt_thrower

What are some other efficient cabs that you could rec?

I always avoid efficient cabs as they are usually the ones that sound worst!!

I have found by trying as many cabs as I possibly could, that universally the best-sounding cabs are the least efficient!

An efficient cab may help you sound loud, but that doesn't necessarily mean good...

[bolt_thrower]

Yeah, that's true. Any 4 ohm 2x12"s that you could rec?

[Sundogue]

Originally Posted by Bruce Lindfield

I always avoid efficient cabs as they are usually the ones that sound worst!!

I have found by trying as many cabs as I possibly could, that universally the best-sounding cabs are the least efficient!

An efficient cab may help you sound loud, but that doesn't necessarily mean good...

It depends on what you are looking for in a cab. Typically, what makes bass cabs more efficient is a design that pushes upper bass/low mids at the expense of the low end, i.e.- that mid bass "hump". It allows a cab to get louder with less watts, but the deep low end is typically lacking. Not necessarily bad, and more likely sound better within a band context than alone, especially in a loud rock band. Think Schroeder.

Whereas inefficient cabs (cabs that require more power to get loud) have a flatter response curve that push the deeper low end as much as the upper bass/low mids. So the more power you throw at them the louder it gets over the entire spectrum, but they require much more power to get loud (and low frequencies need more power). More even sounding and sound better alone or in a quieter band setting unless you've got a lot of watts to throw at them. Think Acme.

[Bruce Lindfield]

Originally Posted by Sundogue

It depends on what you are looking for in a cab. Typically, what makes bass cabs more efficient is a design that pushes upper bass/low mids at the expense of the low end, i.e.- that mid bass "hump". It allows a cab to get louder with less watts, but the deep low end is typically lacking. Not necessarily bad, and more likely sound better within a band context than alone, especially in a loud rock band. Think Schroeder.

Whereas inefficient cabs (cabs that require more power to get loud) have a flatter response curve that push the deeper low end as much as the upper bass/low mids. So the more power you throw at them the louder it gets over the entire spectrum, but they require much more power to get loud (and low frequencies need more power). More even sounding and sound better alone or in a quieter band setting unless you've got a lot of watts to throw at them. Think Acme.

Well - as I play Jazz and want an accurate reproduction of my bass sound - the last thing I want is to sound like a loud rock band!!

[agedhorse]

There are other ways to extend low frequency response by designing the driver to work in the smaller box rather than using an off the shelf driver with bastardized tunings. Managing the tradeoffs well is something good engineers develop an art for. There is not just one tradeoff.

[dubcut]

Oughta be fine. I woudnt expect any volume increase, maybe justa different frequency response fom a cab change...

Power amplifiers are alittle cleaner at half(or so) power than full tilte....That is why the frequencyresponse changes when cranked to the max - different frequencies otput different,impedance curves happen, and I am more of a fan of clean amp, clean speaker than any overdrve in a bass rig.

Jumping up to 450-500 watts won't make a TOTAL maxxed out amp volume differenc, but would gain more headroom within the confines of the clean volume capability of the amp.

An eficent cab helps volume, at 50 percent underpowerin, you will probably find the bass thickness less at higher output. Which is why am an "overpowered slightly" type guy.

A mor powerful amp,at lower output, is the sound I prefer.

Originally Posted by trowaclown

No no this isn't a question about the usual misconception about underpowering.

I'm currently using the Genz Benz Shuttle 3.0-10T combo and I noticed that at lower volumes the cabinet doesn't sound as good as past a certain amount of power, whereby it'll break up nicely and sound great.

I was wondering if this can happen on larger cabs, such as an 8x10. If the head you're using is too low powered (let's say, a theoretical 100 watt head) and doesn't feed enough juice to drive the speakers hard enough to produce their distinctive tone, whatever it is like.

Would this be a good reason to match a head and cabinet in terms of the the wattage of the former and the power handling of the latter?

I'm asking this question because I'm thinking of upgrading to the NeoX series, specifically the 2x12 cabinet. It's got a power handling of 600 watts, but my current head can only put out 300 watts, so I'm worried about underpowering it and not pushing the cabinet hard enough to put out its tone.

Any comments/clarifications are welcomed and appreciated.

[Sten]

Originally Posted by dubcut

Power amplifiers are alittle cleaner at half(or so) power than full tilte....That is why the frequencyresponse changes when cranked to the max -

That's strange, all PA manufacturers seem to recommend turning the PA volume to maximum and adjust the overall level from preamp for more headroom.