Cabinet question (and yet another watt/ohm question)

[leechrimes]

Hey all - first time poster, long-time listener (with a brand new account)

UK 5-string player in a sludge metal band (tuned down to A#/Bb) shopping around for possible cabinets to use when local gig backline is bad/not available, trying to figure a few things out to help narrow down options. Weight also an issue - no 20-25kg+ cabs please, I am an old man

I'm running an active Cort Space 5 into a Laney Digbeth DB 500w (solid state) head, so have the ability to get plenty loud (guitarist runs an Orange Super Crush 100w solid state). Thinking a 2x10 or 2x12 is more than enough for my uses - could be a stage volume only thing if I'm going direct, or just something to give me a more consistent sound.

Questions are:

1) My Digbeth head can push 500w RMS at 4 ohms - I know this means I can run a single 4 ohm cab or two 8 ohm cabs, but given I've rarely gone past 5/6 on the master volume thus far, I can safely assume I'm not pushing the full 500w out. How closely does cabinet wattage need to match the amp? Is a 400w, 8 ohm cab going to be a bad mismatch in terms of choking the Digbeth's output, for example? Or do I need to focus on 4 ohm, 500w+ cabs to ensure the best match, or two 8 ohm cabs up to 500w?

Laney do a matching cab for the head, but it's £500 new and a hefty 28kg, so ideally I'm after something with similar specs and a lighter weight (Ampegs are a good example) on the used market.

2) Should I focus on certain speaker sizes to suit my lower tuning? Given I won't be using the cab mic-d up to run the whole gig often, if ever, I'm thinking a 2x10 or 2x12 is plenty loud enough, but am I overthinking this and would a lowly 1x12/1x15 be plenty for small clubs and bars?

Thanks all

 

[Sid the Kid]

With your low tuning I would suggest checking out 2x12 cabs. I think you’ll find the best balance of portability and power in that format while being able to handle everything your head delivers.

I do think you’d be ok with a single 15, the 12 might be a little too lean by itself. I wouldn’t consider speaker size for your tuning but rather the frequency response of the cabinet. A pair of 1x12 cabs might be a solid option if you have the budget, it will be the easiest to load in/out.

You can certainly run more power to a cab than it can handle but use your ears. Even though your master is only at 5 a decent bit of bast boost can push your speaker to failure. Playing with low tunings I’d try to avoid a power imbalance to prolong the life of my cab.

For a light weight 2x12 with the great price point check out the Genzler NC212.

 

[smogg]

If the amp puts out 500w rms @ 4ohms then chances are it's only putting out somewhere between 250 to 300w @ 8ohms. Try to get the best cab(s) your budget allows for. I agree with Sid that a single 1x12 might not cut it (unless it's something very high end, IE: Barefaced or what not)

 

[12bass]

Lots to unpack....

How important is reproduction of the fundamental of those really low notes? There are many factors to consider, beyond weight and speaker size. Physics dictates that there are tradeoffs between small size/weight, efficiency, and low frequency extension, meaning that you can't have all three at once, perhaps two at best.

I'd suggest looking into the fEARful true 3-way cabinets with lower port tuning and extended low frequency response. They are not as loud as the most efficient designs, but provide a decent amount of the fundamental and first overtones of a 5-string bass, and have been designed to be as small and light as possible for this purpose. Driver size is not the most important factor. Cabinet and driver design matter.

Further, just matching power ratings is insufficient when trying to reproduce really low frequencies because power handling is generally rated thermally, not based upon excursion limits, which are the limiting factor for low fundamentals at stage volume. Low frequency power handling is usually much less than the thermal RMS power rating. As such, a nomimal 500W RMS cabinet may only take 200W or less at 30Hz before the drivers reach excursion limits. The fEARfuls with extended shelf are designed with these low tunings in mind. However, there is no silver bullet solution, with deep response, small size/weight, loud, and cheap.

 

[smogg]

@12bass would you happen to know if there are any fEARful builders in the UK as that's where the op is?

 

[12bass]

@12bass would you happen to know if there are any fEARful builders in the UK as that's where the op is?

Not sure. There are likely people there who can build one, though Greenboy seems to have abandoned the project. The design plans are still available via Speaker Hardware: fEARful DIY Speaker Kits for Bass Guitar

Bit of a rabbit hole. The OP may not be interested in diving too deeply. Thought I'd put it out there, if he's looking for a good compromise solution that provides decent efficiency, low frequency response, and size/weight. Barefaced might be worth a look as well for people in the UK.

 

[mmbongo]

"but given I've rarely gone past 5/6 on the master volume thus far, I can safely assume I'm not pushing the full 500w out"

Definitely not a safe assumption. Depending on your gain setting and how they designed the output section of the amp you could very well be maxing it out at halfway.

 

[el murdoque]

UK 5-string player in a sludge metal band (tuned down to A#/Bb)
- no 20-25kg+ cabs please, I am an old man

Barefaced has you covered. Get whatever Alex recommends for your use case and be done with it.

1) My Digbeth head can push 500w RMS at 4 ohms - I know this means I can run a single 4 ohm cab or two 8 ohm cabs, but given I've rarely gone past 5/6 on the master volume thus far, I can safely assume I'm not pushing the full 500w out. How closely does cabinet wattage need to match the amp? Is a 400w, 8 ohm cab going to be a bad mismatch in terms of choking the Digbeth's output, for example? Or do I need to focus on 4 ohm, 500w+ cabs to ensure the best match, or two 8 ohm cabs up to 500w?

Laney do a matching cab for the head, but it's £500 new and a hefty 28kg, so ideally I'm after something with similar specs and a lighter weight (Ampegs are a good example) on the used market.

Your head pushes up to 500W into a 4 ohm load. With an 8 ohm load, it will be a little more than half of that, so 250-300W. If you use two cabs, the power is split between them, so they don't need to be 500W each.
As long as the impedance matches, you can drive any cab with any amp, as long as you use your common sense. The master volume knob does NOT show you how much power you push in any meaningful way, many other factors play into that. Get to know your gear well, and learn the limits.
If the cab starts farting with the bass knob at noon and the master at 5, and you dial back to 4, then everything sounds dandy. However, if you turn up the bass knob now, you'll push the cab over the brink again without touching gain or master.

The most dangerous situation is when you can't hear yourself properly and you turn up, because in those situations you won't hear the warning signs either.

2) Should I focus on certain speaker sizes to suit my lower tuning? Given I won't be using the cab mic-d up to run the whole gig often, if ever, I'm thinking a 2x10 or 2x12 is plenty loud enough, but am I overthinking this and would a lowly 1x12/1x15 be plenty for small clubs and bars?

Forgive my rudeness, but do you guys have a drummer yet? Sludge metal is where you bring the big guns, debating if you get away with a single 4x10 or if you need three of them. Downtuning is where you bring the big guns, because there's not much air moved by a single speaker.
I've never played in a Doom, Sludge, or Stoner band where a single 2x10 would have been enough, and a 2x12 only ever cut it when I had a really efficient top shelf one.

 

[Hawk256]

Downtuning is where you bring the big guns, because there's not much air moved by a single speaker.
I've never played in a Doom, Sludge, or Stoner band where a single 2x10 would have been enough, and a 2x12 only ever cut it when I had a really efficient top shelf one.

This is exactly what I was thinking. The need to move some air is very important in this situation.

 

[leechrimes]

With your low tuning I would suggest checking out 2x12 cabs. I think you'll find the best balance of portability and power in that format while being able to handle everything your head delivers. I do think you'd be ok with a single 15, the 12 might be a little too lean by itself. I wouldn't consider speaker size for your tuning but rather the frequency response of the cabinet. A pair of 1x12 cabs might be a solid option if you have the budget, it will be the easiest to load in/out.

Cheers - I know speaker size is a hot topic and it's not as simple as '15 is bass, 12 is mids, 10 is treble' so am open to being schooled

 

[leechrimes]

You can certainly run more power to a cab than it can handle but use your ears. Even though your master is only at 5 a decent bit of bast boost can push your speaker to failure. Playing with low tunings I'd try to avoid a power imbalance to prolong the life of my cab.

And thanks, also useful intel I've seen another reply on this - I'm a guitarist by trade and new to bass since beginning of 2024, so learning a lot very quickly since joining a giggng band!

 

[leechrimes]

Lots to unpack....

How important is reproduction of the fundamental of those really low notes? There are many factors to consider, beyond weight and speaker size. Physics dictates that there are tradeoffs between small size/weight, efficiency, and low frequency extension, meaning that you can't have all three at once, perhaps two at best.

Further, just matching power ratings is insufficient when trying to reproduce really low frequencies because power handling is generally rated thermally, not based upon excursion limits, which are the limiting factor for low fundamentals at stage volume. Low frequency power handling is usually much less than the thermal RMS power rating. As such, a nomimal 500W RMS cabinet may only take 200W or less at 30Hz before the drivers reach excursion limits. The fEARfuls with extended shelf are designed with these low tunings in mind. However, there is no silver bullet solution, with deep response, small size/weight, loud, and cheap.

As I understand it, by being tuned down and not running a signal necessarily filthy with distortion (Ampeg growl, not Darkglass clang), there's a lower end to the frequencies I'm putting out that I need to keep nice and clean (hence things like the clean blend, HPF in my pedalboard). So it's a case of making sure I'm not choking out that low end in either too much sub boominess. Will investigate fEARful, as per yours and other comments

 

[leechrimes]

"but given I've rarely gone past 5/6 on the master volume thus far, I can safely assume I'm not pushing the full 500w out"

Definitely not a safe assumption. Depending on your gain setting and how they designed the output section of the amp you could very well be maxing it out at halfway.

see -this- is the kind of thing I need to know, thank you!

 

[leechrimes]

Your head pushes up to 500W into a 4 ohm load. With an 8 ohm load, it will be a little more than half of that, so 250-300W. If you use two cabs, the power is split between them, so they don't need to be 500W each.

As long as the impedance matches, you can drive any cab with any amp, as long as you use your common sense. The master volume knob does NOT show you how much power you push in any meaningful way, many other factors play into that. Get to know your gear well, and learn the limits.
If the cab starts farting with the bass knob at noon and the master at 5, and you dial back to 4, then everything sounds dandy. However, if you turn up the bass knob now, you'll push the cab over the brink again without touching gain or master.

The most dangerous situation is when you can't hear yourself properly and you turn up, because in those situations you won't hear the warning signs either.

We have th eluxury of a good practice space with a decent cabinet selection, but as I tend to play through whatever 8x10 is nearest the rehearsal room door, I know I'm not always getting a true picture for when I show up to gigs with some poopy old 4x10 backline. I like to aim for bass I can feel rather than hear, which I like to think has me on the right lines?

 

[leechrimes]

Forgive my rudeness, but do you guys have a drummer yet? Sludge metal is where you bring the big guns, debating if you get away with a single 4x10 or if you need three of them. Downtuning is where you bring the big guns, because there's not much air moved by a single speaker.
I've never played in a Doom, Sludge, or Stoner band where a single 2x10 would have been enough, and a 2x12 only ever cut it when I had a really efficient top shelf one.

No rudeness Yes, four piece band setup, guitarist blasts out that Super Crush through whatever house cab is around (usually a 4x12). They've said their old bassist used a 2x10 that seemed okay, but I'm not convinced by that personally

 

[Hawk256]

We have th eluxury of a good practice space with a decent cabinet selection, but as I tend to play through whatever 8x10 is nearest the rehearsal room door, I know I'm not always getting a true picture for when I show up to gigs with some poopy old 4x10 backline. I like to aim for bass I can feel rather than hear, which I like to think has me on the right lines?

If you are used to using 8x10s and don't like 4x10s, I think a 2x12 isn't going to make you happy.

 

[HolmeBass]

Just to explicitly answer the first question: cabinet power ratings are a limit. So a 400W 8 ohm cabinet is not going to "choke out" your amplifier. The amp will produce its rated power into 8 ohms, about 1/2, maybe a bit more, than the rated power into 4 ohms.

What determines the resulting volume is speaker cabinet sensitivity, which represents how efficiently the cabinet translates wattage into sound pressure.

But as noted above, low frequency extension is different kettle of fish.

I agree with idea of asking Alex at Barefaced. Not cheap, but worth it.

 

[Wasnex]

I've rarely gone past 5/6 on the master volume thus far, I can safely assume I'm not pushing the full 500w out.

No. Knob position does not tell you how much headroom the amp has remaining.

Is a 400w, 8 ohm cab going to be a bad mismatch in terms of choking the Digbeth's output, for example? Or do I need to focus on 4 ohm, 500w+ cabs to ensure the best match, or two 8 ohm cabs up to 500w?

A good rule of thumb is the speaker should be able to handle at least as much power as the amp will deliver. Use RMS power ratings.

AFAIK the DB500H does not have published specs rated power at 8 ohms Usually solid state amps make more power as the impedance goes lower. Available power at 8 ohms could be 250W or as much as 350W. So if you have one 8 ohm cab, you would want it to be able to handle at least 350W. Not problem if it can handle more.

The RMS power rating only tells you part of the story. Basically the RMS rating tells you have much power the voice coil can handle without burning up. More important for bass cabs can be the mechanical power limits below 100hz. The mechanical power handling relates to how far the driver can move without tearing itself apart. Unfortunately most companies don't post any information on their speaker's mechanical power handling. The Mesa Subway line is an exception.

I will try to explain the problem:

Let's use a large Eminence cab design for the 2512, which is rated 250W RMS.

If you chart the excursion plot for a woofer in a ported design it will have sort of an S-shape. See excursion plot below. As the frequency drops below 500hz, cone excursion will increase. Usually a bit below 100hz, the port will start to become resonant. This resonance suppresses cone excursion. The port is tuned so it becomes active at about the same frequency where the woofer starts to cut off. The idea is to use the port resonance to smoothly extend response a bit lower. At resonance (Fb), the port is making most of the sound and providing maximum suppression to cone excursion. Below Fb system response drops of quickly and the driver unloads and starts bouncing around.

Here are the response and excursion plots for the 2512 in a large cab. This is the second design in this doc: https://www.parts-express.com/pedocs/more-info/290-593--eminence-deltalite-2512-cabinet-design.pdf

The first thing to notice is the cab is mechanically limited to 100W and requires a steep HPF at 40. I will remind you here that the driver is rated 250W RMS.

Notice the S-shape of the excursion plot.

Fb is 50hz. Notice the dip in the excursion plot is centered at 50hz.

Max linear excursion (Xmax) for the 2512 is 4.9mm. With 100W excursion approaches 4.9mm at about 70hz and exceeds 4.9mm as the frequency dips below about 40hz.

The -3dB point (F3) for this design is 58.71hzf and response drops off quickly below that.

You could use EQ to extend LF response a bit, but EQ will not allow the design to produce more output or handle more power. EQ is only effective if you don't need much volume. If you look at the excursion plot, the design is capable of about 112dB at 48hz. At this point response is down about 6dB. With the right EQ curve and 6dB of boost, the design could have flat response to 48hz, but it will still only be capable of 112dB.

 

[Wasnex]

The first thing I think you need to accept is that it's not realistic for your rig to have flat response down to the fundamental of your lowest notes. It's possible to buy gear that will play this low, but it will be very expensive and also big and heavy.

The good thing is our ears trick us into thinking there is more fundamental than there is. As a minimum you need a speaker with strong response to the first overtone, which is the octave above the fundamental. The fundamental for A#0 is about 28hz, so you need strong response down to 56hz or lower. This is very doable.

In order to protect a ported design I suggest using a steep HPF (24dB per octave or better).

You can do the rice test to determine Fb, and then set the HPF at or slightly below Fb. The rice test is basically lay the speaker flat on it's back and put a few grains of rice in the cone. Then do a frequency sweep and note the frequency where the excursion dips. The rice is to help you see the dip. There are online tone generators you can use to do the frequency sweep.

Most people adjust the HPF to the point where it starts to thin out the sound, and then back it down a hair. Although it may seem counterintuitive, a properly adjusted HPF may actually fatten and focus the lows a bit.

Alternately you could spend a fortune and buy subs that will play as low as you want. Danley DTS10 has response down to 10hz. One weighs 285lbs, and you may need multiples.

DTS10 | Danley Sound Labs

The DTS10 theater subwoofer is the ideal subwoofer for home theatre and cinema use with a powerful low end sound.

www.danleysoundlabs.com

 

[waveman]

I would use a 410 cab on top of a powered subwoofer, and run the FX line out from the Digbeth to the sub. That should give the feel.