What does 250W RMS (500W clean) mean?

[thebrig]

The Barefaced ONE10t states that the Max amp power is 250W RMS (500W clean), and the Nominal impedance is 8 ohms.

 

What exactly does "clean" mean?

 

Does this mean I could run my Genz Benz 9.2 Shuttle head through it, which is is rated at 500W/8ohms, 900W/4ohms?

[Downunderwonder]

Very strange.

 

Ordinarily a cab rated for 250w RMS would be clean, to whatever standard of small amount of allowed distortion, up to 250w of whatever standard signal applied.

 

Sure you can run that amp into it. Just don't make it sound nasty and stop turning it up when it doesn't get any louder, turn it back down a bit!

[warwickhunt]

250W RMS (500W clean) means very little regardless of who is stating it as they are nominal ratings based upon the manufacturers parameters.  There isn't a 'standard' that every producer of musical equipment HAS to adhere to, they can all manipulate the figures by selecting certain frequencies and tolerances of distortion etc (as @Downunderwonderstated).  Saying that... RMS is a rating which we should all be able to use as a benchmark/guide and is a generally accepted term.  

Your issue might be that the figure quoted would allude to the fact that Alex knows that what some manufacturers call 500W is actually a lot less than that, possibly as low as another manufacturers 250W (or vice versa) and could be allowing for the difference between a solid state and a valve amp (I'm not trying to say valve watts are louder but the delivery is different). 

re. plugging your amp into the cab - go for it!  You could plug an amp rated at 1000W RMS Clean @ 8ohms into it and you'd not blow it up... unless you were stupid enough to try and run it flat out which you couldn't/wouldn't do!  I've ran 1000W amps into 200W cabs with absolutely zero negative effect because I've used my ears PLUS an amp rated at 500W @ 8 ohms will only push out that for short periods and nobody ever runs an amp at max capacity.  Plug it in, turn it up slowly to required volume and listen for farting; if it farts turn it down or adjust your EQ (less lows to start with).   

[chyc]

I've been caught out by that but it's been clarified on a thread on BC: 250W RMS does not apply to the cabinet, but to the amp! So what it's saying is that an amp which says 500W on the side is fine, so long as the signal is clean. If you look closely there is no mention of the thermal limit of the cabinet anywhere on their website.

 

I'll be honest, I think that's a bit cheeky as, surprise surprise, the number BF posted is higher than the equivalent number posted by most other manufacturers, but I know about it now and can apply my mental compensators accordingly.

[thebrig]

Thanks for the replies so far.

 

I don't like playing too loud, and I never use much gain on the amp because I like a clean sound when I play, so I guess I should be alright. 😉

[Bill Fitzmaurice]

6 hours ago, thebrig said:

The Barefaced ONE10t states that the Max amp power is 250W RMS (500W clean)...

What exactly does "clean" mean?

I have no idea. It's not like Alex to create terms of out thin air. I'd ask him.

[PaulThePlug]

Possibly a Jazz term indicating a nice neat sinewave... of whatever note that may come to mind... but without those horrible distortion type peaks...

 

 

 

Edited March 22, 2022 by PaulThePlug

[Merton]

It simply means that the cab can cope with 250W RMS as a general rule, but if you’re running clean signals you may be able to push up to 500W through it. 

[Downunderwonder]

11 hours ago, chyc said:

500W on the side is fine, so long as the signal is clean

I see what you're getting at but hopefully you misstated whatever Alex was saying.

 

Any amp is fine so long as the cabinet isn't distorting or going so far into power compression that it burns up.

 

I guess Alex slapped on a 500w ''safety'' limit out of desperation, knowing that your average '500'w amp these days is more like 250wRMS anyway.

[chyc]

1 minute ago, Downunderwonder said:

I see what you're getting at but hopefully you misstated whatever Alex was saying.

You can decide for yourself if I'm misstating it. This is from his old website:

 

 

https://barefacedbass.com/product-range/one10.htm

[Phil Starr]

8 hours ago, thebrig said:

The Barefaced ONE10t states that the Max amp power is 250W RMS (500W clean), and the Nominal impedance is 8 ohms.

 

What exactly does "clean" mean?

 

Does this mean I could run my Genz Benz 9.2 Shuttle head through it, which is is rated at 500W/8ohms, 900W/4ohms?

Light the blue touch paper and retire eh?

 

I suspect all Barefaced are trying to do is to protect the horn drivers from their customers so they don't have too may repair claims from crazy amp mis-matching. Playing with a heavily distorted sound passes much more energy to the horn so 

 

Barefaced seem to use OEM Eminence drivers. Nice speakers but still subject to the laws of physics. The driver is rated at 250W as the result of a test where filtered noise is driven through a sample speaker for hours at 250W. If it can take the heat it passes. That doesn't mean it can handle all the power at all the frequencies. For the bottom octave of a 4 string I doubt that there are many (any?) 10" speakers that could handle 250W and indeed Eminence state that their 250W Neo bass speaker should be de-rated below 80Hz in a medium sized box. That's because those power levels at low frequencies ask the cone and coil to move beyond their excursion limits.

 

Let's be fair about this, giving advice on reasonable use isn't simple for any manufacturer as you have no idea what a customer is going to do with the speaker. Since the amp is only rarely going to get anywhere near it's peak output which will only be for a fraction of a second the heating limit of the speaker will rarely if ever be reached. Fortunately most bass guitars don't pump out much fundamental so the excursion limits are rarely breached.  Bass guitars don't have a lot of top end to trouble the horn driver either so you can usually get away with an amp which is higher rated than the speaker. Obviously the seller has to balance the extra sales appeal of calling their speaker 500W against the chance of somebody actually doing that and making the speaker fart out by boosting the bass  or blowing the tweeter with lots of distortion and having to deal with returns and a reputation for failures. The clincher is usually that you can't sell your speaker if you don't make the same claims as your rivals so in the end they all give in to over-claiming

[Phil Starr]

15 minutes ago, chyc said:

You can decide for yourself if I'm misstating it. This is from his old website:

 

 

https://barefacedbass.com/product-range/one10.htm

QED

[agedhorse]

250 watts RMS is a (reasonably) clear term meaning that it's the thermal limit without the additional information regarding mechanical limits. Anything beyond this is speculation, and if you were to damage the cabinet with 500 watts, the question would then arise about what that 500 watts really means in terms of any warranty coverage.

 

Now it's possibly that the 500 watts is being used as a representation of "program" power handling, but since program power is generally a thermal rating as well, in practice it really represents a reduction in the crest factor of the test signal waveform (an increase in thermal duty cycle). 

 

It clearly does not apply to distorted signal, from my reading of that statement.

 

Regarding the use of the amp in question, I would recommend a healthy dose of caution and good judgement. The ShuttleMax 9.0 is rated at 500 watts RMS into 8 ohms, certainly enough to cause damage without good judgement.

Edited March 22, 2022 by agedhorse

[Downunderwonder]

6 hours ago, thebrig said:

Thanks for the replies so far.

 

I don't like playing too loud, and I never use much gain on the amp because I like a clean sound when I play, so I guess I should be alright. 😉

Too loud is all relative.

You could find yourself in the danger zone I mentioned in the first reply.

 

This is when you turn up just a little more, and a little more, then a little more doesn't add any more volume but cooks the driver.

 

Beware of volume creep over the course of gig or rehearsal.

[itu]

6 hours ago, Bill Fitzmaurice said:

I have no idea. It's not like Alex to create terms of out thin air. I'd ask him.

Exactly. Clean does not mean a thing. Distortion is there, the amount is just not specified.

 

Watts (RMS, 8 ohm) is a common (comparable) way of explaining the output power of an amp, or the input power of the cab. This may include distortion at certain level, like 1 %. It is meaningful to understand that bass can withstand up to around 10 % of distortion (nothing to do with the effect), and still sound decent.

 

Remember: watts is about electrical power, not loudness, although they are faintly connected.

 

Peak levels are funny, because they are so high, and people think that they represent something like ultimate loudness. Which is not true.

 

If we have numbers like output and input watts, they do not represent loudness levels. dB can describe loudness, but calculating loudness from plain watts - no chance. We need more parameters.

 

Cabs and amps can produce more or less sound. Watts, sensitivity... Before you certainly know the output level, you have to test the rig, or get lots of data and calculate. The question about the power levels, and their mismatch is mostly academic: it is very seldom the amp is fried if the load is more than 4 ohms. It is rare you can fry a cab if the powers and signals are at somewhat sensible level. I do not say it is impossible. Users can act erroneously, but hopefully this community can help those before any damage will happen.

[thebrig]

11 hours ago, Downunderwonder said:

Too loud is all relative.

You could find yourself in the danger zone I mentioned in the first reply.

 

This is when you turn up just a little more, and a little more, then a little more doesn't add any more volume but cooks the driver.

 

Beware of volume creep over the course of gig or rehearsal.

The cab is intended mainly for home practise, but I will use it for quieter rehearsals on occasions.

 

When I say I don't like playing too loud, I really do mean it, my ears are already shot, our drummer is technically good and doesn't beat the life out of his kit, so I think the ONE10 should be able to keep up with him without pushing it, and if the guitarist says he can't hear me, then I'm not going to budge on my levels, he will have to turn down. 😉

[Downunderwonder]

Any too loud guitarist made to point his own cab at his own head will turn down voluntarily.

[Muzz]

30 minutes ago, Downunderwonder said:

Any too loud guitarist made to point his own cab at his own head will turn down voluntarily.

And this is the key to Volume Wars, which we've all experienced, I'm sure...after triggering my tinnitus from a gig years ago where a dep geetard put his 112 combo on a bar stool just behind me, and turned up and up, I (belatedly, unfortunately, in the second set) pointed the thing at his head and hey presto, he turned it down, I do this all the time now...happens with 412 users who stand directly in front of their cab in rehearsals so it's projecting mostly below waist height; get them to stand across the room and suddenly they're managing their volume levels better...

[fleabag]

I kinda of guessed that the ' clean ' bit was about running bass guitar through heavy overdrive or distortion pedals, rather than blasting the amp volume into distortion.

 

I could be wrong

 

 

[chris_b]

On 22/03/2022 at 08:14, thebrig said:

The Barefaced ONE10t states that the Max amp power is 250W RMS (500W clean), and the Nominal impedance is 8 ohms.

 

What exactly does "clean" mean?

 

Probably means what they say on their website. . . .

 

Recommended Amp Power

100-250W RMS
(safe with up to 500W if you're running fairly clean sounds)

[barkin]

10 hours ago, fleabag said:

I kinda of guessed that the ' clean ' bit was about running bass guitar through heavy overdrive or distortion pedals, rather than blasting the amp volume into distortion.

 

I could be wrong

 

 

As we're talking about the signal being sent to the cab, does it matter if any distortion is from an overdriven amp or a pedal?

I suspect not.

[Downunderwonder]

2 minutes ago, barkin said:

As we're talking about the signal being sent to the cab, does it matter if any distortion is from an overdriven amp or a pedal?

I suspect not.

Alex is covering his end by insisting that the eventual tone is clean(ish). That way the speaker can't be easily overdriven as it would then not be clean.

 

There is still a risk that someone could high pass the pish out of the signal and send that at max volume melting the drivers.

[Bankai]

On 23/03/2022 at 08:41, Downunderwonder said:

Any too loud guitarist made to point his own cab at his own head will turn down voluntarily.

I recall a band about ten years ago come to play a set at our (very) small local venue. It was just two guitarists and a drummer. They prided themselves on (their words) being the loudest band in the county.

 

Each guitarist only had a 2x12 combo but set it at their feet running full volume straight into the first row of the audience.

 

They cleared the venue (including me) within a minute, sadly to the detriment of the bands who were following them later in the evening. 
 

I wish I were the engineer that night because as you say, I’d have used a beer crate and angled those things back so they fired straight at their own head-height and no doubt things would have changed *very* quickly. Alas, the engineer appeased them and just raised everything else to match the guitar volume.

 

 

Edited April 1, 2022 by Bankai

[agedhorse]

On 01/04/2022 at 00:58, barkin said:

As we're talking about the signal being sent to the cab, does it matter if any distortion is from an overdriven amp or a pedal?

I suspect not.

It doesn't matter where the distortion comes from, the distorted signal and the level is what matters to the speaker.

[barkin]

👍