help with working out how much wattage i need!

[Phil Starr]

21 hours ago, Wombat said:

So what is true?

 

On 23/04/2025 at 14:10, sky said:

ive seen a peavey minimega used that i might make an offer on, but with 1000w is that too much

Confusing isn't it?

 

The simple answer is that most amps nowadays are using pretty much one of two or three power amp circuits and just about every manufacturer offers a class D amp which gives 300W into 8ohms and 500W into 4ohms. They don't all sound the same but all of them will be loud enough into almost any but the smallest speakers and most speakers will be able to handle that power. The straighforward answer is that you can choose from any one of those amps and you wont break the 4x10's you are using in the rehearsal room. When you get to gigging any one of them will do the job with 90% of the speakers on sale. If you are using a Peavey 4x10 you don't need to use a Peavey amp, any brand will do. I like and own a Peavey Minimax whch has a good range of sounds but the best thing you can do is try a few of these amps out and see if you like them. We all have different tastes.

 

If you want a simple version of the technical stuff then try this. Some speakers are much louder than others with the same amp. This is measured in how many decibels of sound you can make with one watt. Most bass speakers will vary between 90db/ W (not very loud/efficient) to 103db/W (loud) Each extra watt can only add to that sound level, ten times the power adds 10db and doubling the power adds 3db, so a 100W amp with add 20db to whatever the one watt figure is and 200W will add 23db. To work out how loud a system will be you need to know the power of the amp and the efficiency of the speaker. Either on its own won't tell you anything, you need both numbers.

[Dan Dare]

On 03/05/2025 at 21:29, Phil Starr said:

The simple answer is that most amps nowadays are using pretty much one of two or three power amp circuits

 

This. Most class D amp heads use power modules from Hypex, IcePower, Pascal and similar. The modules are readily available, proven, reliable designs and it simply isn't worth amp makers designing their own/reinventing the wheel.

 

Most modules are at or around two power ratings - either 300w into 8 ohms/500w into 4 ohms or 500w into 8 ohms/700w into 4 ohms. Some amp brands inflate their power claims. I have a Carvin that claims 1000w, but it's no louder than my 700w Aguilar if you turn both up to the point that the clip light flashes. I wouldn't be surprised if the Peavey mentioned is the same.

 

Watts are cheap nowadays. All amps have a volume control, so unless funds are really tight, buy the more powerful version, be sensible with the volume control and don't over-drive your speakers (you'll know when you do because they will make horrible noises). Your sound will benefit from the additional headroom and when/if the time comes to up the size of your rig, the amp will still be up to the job, saving you from having to sell and upgrade it (which always costs).

Edited yesterday at 11:24 by Dan Dare

[lemmywinks]

If you're worried about damaging loaned cabs then your overall volume and low end content are more important than watt rating, you can blow drivers with comparatively low power amps if you're an idiot - ask me how I know! Most micro amps will have some sort of built in HPF to remove extreme lows, I'd guess rolling off sharply at around 30hz or something like that. Just listen for speakers distorting (may be harder if you have a driven sound) and roll off the volume/bass as needed.

 

For something tiny which might get close-ish to your big amp the TC RH series or Orange Terror Bass might be worth looking at, they're small class D amps which are designed to sound closer to old school valve amps but go about it in different ways - the Orange uses a valve pre you can drive and the TC uses a digital approach which seeks to emulate valve compression/saturation. RH series are usually dirt cheap on the used market, should be able to grab an RH750 for £200-£250.

[agedhorse]

6 hours ago, Dan Dare said:

 

This. Most class D amp heads use power modules from Hypex, IcePower, Pascal and similar. The modules are readily available, proven, reliable designs and it simply isn't worth amp makers designing their own/reinventing the wheel.

 

Most modules are at or around two power ratings - either 300w into 8 ohms/500w into 4 ohms or 500w into 8 ohms/700w into 4 ohms. Some amp brands inflate their power claims. I have a Carvin that claims 1000w, but it's no louder than my 700w Aguilar if you turn both up to the point that the clip light flashes. I wouldn't be surprised in the Peavey mentioned is the same.

 

Watts are cheap nowadays. All amps have a volume control, so unless funds are really tight, buy the more powerful version, be sensible with the volume control and don't over-drive your speakers (you'll know when you do because they will make horrible noises). Your sound will benefit from the additional headroom and when/if the time comes to up the size of your rig, the amp will still be up to the job, saving you from having to sell and upgrade it (which always costs).

You just might be misunderstanding how power amps are rated and specified however, therefore your generalization inaccuracy.

Edited May 8 by agedhorse

[FugaziBomb]

On 02/05/2025 at 13:48, Bill Fitzmaurice said:

One watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V). Period.

But measured at 1% (I think?) THD.  The reason tube amps sound louder is because they are delivering more watts than their rating as the are routinely pushed passed that percentage of THD.  If you do that with a solid state amp, it hard clips and sounds nasty, but tube amps sound nice when they start to clip.

[Bill Fitzmaurice]

Tube versus SS watts has been covered here ad nauseam to the extreme. I'm sure you're just trying to be helpful but what you're saying has been covered here in detail going back over dozens of threads for as long as this forum has existed.

[chris_b]

On 23/04/2025 at 14:10, sky said:

heyo, just wondering if anyone could help with working out sortof how much wattage would be good to go for, im looking for a lighter smaller amp that i can walk to rehearsals with, ive got an old sound city head which is awesome but the thing weighs like 50kg so obviously not particularly portable.

 

It's simple. All you need to know. . . . you need a 500 watt D class amp. It will be loud enough for any gig and rehearsal and it will weigh around 5lbs.

[agedhorse]

9 hours ago, FugaziBomb said:

But measured at 1% (I think?) THD.  The reason tube amps sound louder is because they are delivering more watts than their rating as the are routinely pushed passed that percentage of THD.  If you do that with a solid state amp, it hard clips and sounds nasty, but tube amps sound nice when they start to clip.

Solid state amps don’t have to sound nasty beyond 1% THD, those that do haven’t designed around this parameter. Some tube amps clip very similarly to some solid state amps. Some us different than all. 

[Sean]

My general guideline that has served me well is, if you can lift it into the car by yersel and without the help of your biggest gym-bunny mate, it's not got enough heft and you need to think again.

 

Another ticket closed.

😉

[Dan Dare]

On 08/05/2025 at 22:50, agedhorse said:

You just might be misunderstanding how power amps are rated and specified however, therefore your generalization inaccuracy.

 

Not sure I understand what you've written. It seems there may be some missing words. If you compare the spec's of many of the class D amp heads from the usual suspects, they do produce approximately the outputs I mention. There may be small variations, but for real-world, practical applications, the generalisation will suffice. Not all of us wish or need to delve that deeply into specifications, etc. We just want to know what will work for us.

[agedhorse]

8 hours ago, Dan Dare said:

 

Not sure I understand what you've written. It seems there may be some missing words. If you compare the spec's of many of the class D amp heads from the usual suspects, they do produce approximately the outputs I mention. There may be small variations, but for real-world, practical applications, the generalisation will suffice. Not all of us wish or need to delve that deeply into specifications, etc. We just want to know what will work for us.

Your understandings and conclusions based on how you are reading the specs from the data sheets is flawed. 

[Phil Starr]

On 08/05/2025 at 16:24, Dan Dare said:

Some amp brands inflate their power claims.

 

On 08/05/2025 at 22:50, agedhorse said:

You just might be misunderstanding how power amps are rated and specified however,

I don't think Dan was talking about the relatively small differences in quoted power that you can get by using different criteria when measuring. For example you can inflate the power rating by measuring  at 10% distortion rather than at 1% but it won't be hugely different. Wikipedia quotes a variation of 10-20% between power as measured to EIA and FTC standards. That's confusing for many consumers but not actually dishonest, especially if the measuremnt criteria are disclosed. I think Dan was simply warning the OP who is not a technical person that sometimes advertisers tell lies. A good example of that would be Bugera who rate their BV1001M at 2,000W when it actually measures in at just over 700W into 4ohms at the point it starts clipping.

[Bill Fitzmaurice]

Don't forget about TC watts. 🤪

[Dan Dare]

5 hours ago, Phil Starr said:

 

I don't think Dan was talking about the relatively small differences in quoted power that you can get by using different criteria when measuring. For example you can inflate the power rating by measuring  at 10% distortion rather than at 1% but it won't be hugely different. Wikipedia quotes a variation of 10-20% between power as measured to EIA and FTC standards. That's confusing for many consumers but not actually dishonest, especially if the measurement criteria are disclosed. I think Dan was simply warning the OP who is not a technical person that sometimes advertisers tell lies. A good example of that would be Bugera who rate their BV1001M at 2,000W when it actually measures in at just over 700W into 4ohms at the point it starts clipping.

 

Thanks Phil. My main point (and yours, if I understood you correctly) was that people shouldn't worry too much about claimed power outputs. As we both stated earlier, many amp manufacturers add an off-the-shelf power module from one of relatively few companies to their own preamp design. Those power modules are pretty similar in performance at a given price point. They have to be to be competitive in the market.

 

As a designer, agedhorse will be interested in reading data sheets, etc, but the great majority of amp buyers won't be. They just want something that will do the job for them. Most class D heads, save for those made by those who like to gild the lily a little (Behringer, TC, we're looking at you) do have similar claimed power outputs, which is unsurprising, given that they are using similar power modules. Tonal differences are largely due to preamp designers' preferences, who they are aiming their product at (Is it good for metal?), etc.

 

When I bought my AG700, I spent several hours at Bass Direct and compared products from most of the usual suspects. I chose the AG because it was the closest to an all-rounder and worked well with the cabs I use (PJB). My choice may well not suit others, hence the need to audition/try gear and not buy on recommendation alone.

[itu]

5 hours ago, Dan Dare said:

As a designer, agedhorse will be interested in reading data sheets, etc, but the great majority of amp buyers won't be. They just want something that will do the job for them.

Then, me as a player, and @agedhorse as a designer, we are interested in specs. Whether they are comparable or not is up to us players. We should want comparable, fair numbers, not marketing hype.

 

2 kW looks good, although it has not very good relation to reality, especially in this known case. And watts are not about loudness. dB is the right number, but without a cab and its specs, it cannot be given. (I understand marketing a bit here.)

 

Try before you buy is the best option for us players. What is a problem, is the space where the combo is tried:

I set my amp exactly the same way in big venues and in our rehearsal space, but the "thundering lows" are hidden for some reason (size matters) in the latter.

[Bill Fitzmaurice]

That would be a combination of hearing the subs in a big venue, and boundary reflection cancellations in the rehearsal space.

[JJTee]

How about C.K.Watt?

 

 

[Lozz196]

What?

[Lozz196]

It’s over there, between the land and the sky!

[agedhorse]

9 hours ago, Dan Dare said:

 

As a designer, agedhorse will be interested in reading data sheets, etc, but the great majority of amp buyers won't be. They just want something that will do the job for them. Most class D heads, save for those made by those who like to gild the lily a little (Behringer, TC, we're looking at you) do have similar claimed power outputs, which is unsurprising, given that they are using similar power modules. Tonal differences are largely due to preamp designers' preferences, who they are aiming their product at (Is it good for metal?), etc.

 

 

Understood, though the assumption that Behringer and TC are using similar power modules (actually, the power amp and power supply are an integral part of the main board) isn't accurate. The power supplies/power amps are very different, though they both share a similar ambiguity (creativity) with regards to the way they rate their output power.

 

I was referring specifically to those who quote power off of a power module data sheet, without understanding the depths of what they are looking at. There is a ton of critical data between the lines of the data sheet, in fact that's what my US patent is based on with regards to some specific technology applications with a couple of lines of older ICEPower parts. We received this patent while working with directly the ICEPower engineering team on some of these off-sheet attributes, and these basic concepts got incorporated into the newer series power modules. This is what allowed us (Genz Benz) to do what everybody said could not be done, and we did it with higher reliability than those who used the modules within the limitations of the data sheets too. All Shuttle, ShuttleMax and Streamliner amps use various portions of that patented technology, them the patent was acquired by Fender and was theirs to use as well.