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Orange Bass Terror and cab ratings.

Posted: Wed Oct 05, 2011 7:52 pm
by pikeybeatz
Hi, my main amp setup is the Orange Bass Terror with the SP212 600w cab, i was wondering if as a backup a 200w ashdown mag amp would be able to power the cab in a gig situation, or if it would damage the head?

Cheers,
Dan

Re: Orange Bass Terror and cab ratings.

Posted: Thu Oct 06, 2011 12:43 am
by Randy Bass
The 200-watt Ashdown would be absolutely fine with the SP212. The thing you want to avoid is turning the amp up all the way to full since the power section may be capable of hard clipping (I'm not entirely sure how it's designed). You could conceivably blow a 600-watt cab with a 20-watt solid-state amp if its' power section is distorting. If you can get enough volume out of the Ashdown without the volume on 10, it should be a suitable backup.

Re: Orange Bass Terror and cab ratings.

Posted: Sun Oct 09, 2011 10:32 am
by a.hun
Randy Bass wrote:The 200-watt Ashdown would be absolutely fine with the SP212. The thing you want to avoid is turning the amp up all the way to full since the power section may be capable of hard clipping (I'm not entirely sure how it's designed). You could conceivably blow a 600-watt cab with a 20-watt solid-state amp if its' power section is distorting. If you can get enough volume out of the Ashdown without the volume on 10, it should be a suitable backup.
Hi there. Me again! :wink:

Agree with the first bit, not the second.

Blowing speakers is a complicated subject, with many different factors and different ways of doing it. But it is always (in one way or another) too much power which blows speakers.

When you push solid state ('s.s.') amps beyond their clean ratings into power section distortion (= at too high volume settings) they very quickly go into 'hard clipping' distortion. They simply can't put out a clean waveform beyond their rated power so the tops and bottoms of the waveform they then output are clipped off = distortion. (Valve amps clip more softly - the waveforms instead of being cut off flat are rounded off. Their 'soft clipping' distortion sounds much more natural and the power doesn't increase so dramatically quickly.) The problem with pushing s.s. amps into 'hard' clipping is that when you do they can very quickly put out up to about double their rated (clean) power output. A hard clipped 200W s.s. amp for example will pretty soon be putting out up to about 400W. It isn't so much the hard clipping waveform itself which is bad for speakers though, it is the unexpected sudden increase in power, as opposed to the much more progressive 'squashing' of 'soft clipping' valve distortion.

A 200W s.s. amp really isn't likely to blow a (genuinely) 600W rated cab by simply overpowering it. Damage CAN happen, but not simply through sheer output wattage. See below*! And with a 20W amp that just won't happen!!!

So yeah, the 200-watt Ashdown would be absolutely fine to use with the SP212. If you push it too hard and hear nasty sounding distortion (like a tranny radio turned up too loud) just turn it down a bit! You'll want to anyway - sounds horrible!

FWIW you can't damage a speaker by 'underpowering' it by using a 'too low power rated' amp. That myth simply comes from the fact that any s.s. power amp cranked into distortion will far exceed its clean power ratings, so running a 100W amp into say a 150W speaker isn't safe if you crank it beyond its clean limits into output section distortion.


Since we are talking about bass gear here, which is different from guitar amplification, there are a couple of things worth knowing.

For starters with bass the speakers 'thermal power handling' = the power the voice coil can handle (= the only wattage rating manufacturers normally give) isn't usually the main limiting factor to what the speaker will safely handle! :shock:

Most of the power that goes to your speaker turns into heat. Well over 90% of it ends up as heat, not as sound energy. If the voice coil gets too hot (= too much continuous power for too long) than it can be damaged. But that doesn't mean that a 100W rated speaker will die as soon as you put a signal of 101W into it. Or 150W. Or even 200W. What it means is that it can't take continuous and sustained power levels above 100W. It is an 'average power' thing, and normally a voice coil won't sustain thermal damage from brief signals of even several times its rating, as long as there are sufficient gaps between bursts of high power for it not to overheat.

This means that the peak power levels a speaker can handle are MUCH higher than its continuous average (RMS) rating.

BUT...
Putting out low frequencies at high power means a lot of cone travel. (Hit a big low bass note and you can see the speaker cone move backwards and forwards - quite a lot!) If the amp is set to put out a lot of low bass you may exceed a speakers mechanical limits and blow it, even without getting anywhere near its thermal power rating! :shock: :shock:

This is called 'excursion limited power handling' (*), and has to do with the speakers low frequency power handling. Some speakers, even of the same rms power rating, will have much higher low frequency power handling than others. Guess what, with bass amplification this tends to be much more of a limiting factor than the thermal power rating to what you can get away with.

If you want to know about that you need to look up things like 'Xmax' and 'Xlim' ratings, but basically Xmax is the maximum excursion a speaker can travel with less than 10% distortion (a distance then!), and Xlim is the maximum excursion before actual physical damage happens. I've been reading up on this stuff a lot lately and used to think that you'd not really hear things happening there before they suddenly stopped happening. But while that is true with most 'hi-fi' type speakers, most quality professional speakers apparently do have a much greater difference between these two figures so you will get some warning (in terms of audible distortion) before you actually destroy the speaker. There you go, live and learn.


Another thing to think about with bass cabs is that clipping distortion (yep, that stuff again) usually causes most power increase in the higher frequencies. This is due to increased harmonics being created (= harmonic distortion). This tends to blow HF tweeters so if running cabs with tweeters you want to be especially careful. Normally the HF component of your sound only needs a small proportion of the amps power, but the increase in power output at higher frequencies can be dramatic with hard clipping and tweeters if fitted will usually be the first thing to blow. So listen out for them having a hard time and if you hear them distorting turn something down! Either the amp or at very least the tweeter itself if the cab is fitted with a separate tweeter control.


Main difference with guitar amps / speakers is that there you are mostly talking about mid range frequencies, not the high or low frequency extremes of bass amplification. (I know, people think 'electric bass' is all about bass frequencies, but it is actually a much more full range instrument than electric guitar. In fact electric guitar is almost all about the midrange frequencies, and bass signals can go both lower and much higher!) So for guitar the main limiting factor to what the speaker(s) will handle is the thermal (RMS) power handling rating. Basically with guitar speakers you want to make sure you never exceed that so having speakers rated for double the amps output rating is in most cases perfectly safe.

Guidelines for bass are significantly different and as you see a bit more complicated. But whatever amp you are hooking up to whatever cab for bass the simplest answer is always to listen to your speakers! If they sound like they are in distress THEY PROBABLY ARE!

Hope that helps some. :)


Andy.

Re: Orange Bass Terror and cab ratings.

Posted: Sun Oct 09, 2011 10:44 am
by a.hun
pikeybeatz wrote:Hi, my main amp setup is the Orange Bass Terror with the SP212 600w cab, i was wondering if as a backup a 200w ashdown mag amp would be able to power the cab in a gig situation, or if it would damage the head?

Cheers,
Dan
I think the MAG200 was rated to give its full power output into a 4 ohm load. (Correct?) If so than running it into an 8 ohm load (like the SP cab) will be totally safe, but the amp will simply put out less power. Probably only something like 130W or so.

As the SP cabs probably aren't the most efficient (= loudest per Watt) out there you'll probably find the maximum clean volume pretty disappointing compared to using the more powerful BT. That is where the temptation to push the volume higher and the amp into distortion comes, especially in the heat of a gig. However I really don't think you'll do any harm to the speaker so try it and see.

I do know that some of the earlier Ashdown amps had a bad reputation for unreliability issues (overheating --> failure) that has since been sorted. I'm not sure if that applies to your amp or not.

You can always dial things back a bit, mic the cab and send that signal to the PA. That or run a DI output from the MAG to the desk. Should be fine, and means that you could definitely use the amp as a backup.


Andy.

Re: Orange Bass Terror and cab ratings.

Posted: Sun Oct 09, 2011 2:30 pm
by Randy Bass
I managed to blow a 70-watt guitar speaker with a 15-watt s.s. guitar amp in less than two minutes. I must be special :( .

Re: Orange Bass Terror and cab ratings.

Posted: Sun Oct 09, 2011 2:51 pm
by a.hun
Randy Bass wrote:I managed to blow a 70-watt guitar speaker with a 15-watt s.s. guitar amp in less than two minutes. I must be special :( .
I managed to blow a stock Fender speaker with a 15W Fender valve amp SET FOR CLEAN RUNNING, playing guitar in approximately under 1/2 a second. That speaker would quite happily take the full cranked output of the amp all day long. We are clearly BOTH special! ;)

So what exactly were you doing / using to do that? What sort of guitar / bass / amp / speaker / impedances etc. Any effects / special settings? Have to say that is a quite extreme example though I quite believe you of course. Interesting to find out exactly what went wrong though.

There are lots of ways to blow speakers. Care to guess how I managed it?

PS I've mentioned it before, though since then I've discovered enough to revise my thoughts on exactly how I did it! :wink:


Andy.

Re: Orange Bass Terror and cab ratings.

Posted: Sun Oct 09, 2011 4:45 pm
by Randy Bass
Mine was just a case of s.s. clipping at full power as far as I can tell. It was a Crate GX-15 combo (4 ohms min.) with a factory 1/4" speaker output connected to a 16-ohm M*rshall-branded G12M-70 in an open-back cab. The guitar was straight in, light-gauge strings, standard E tuning, medium-output humbuckers and playing power chords. The Gain and Volume on the amp were nearly maxed and it started to sound nasty. I figured it was just the amp, but I backed off the gain and still heard a buzz playing clean. Then I tried a different amp (set clean) through the speaker and the buzz was still there. No more horsing around with that amp for me.

Re: Orange Bass Terror and cab ratings.

Posted: Mon Oct 10, 2011 9:54 pm
by a.hun
Yeah I can see exactly why you'd think that amp blew your speaker, but honestly whatever happened it didn't just kill it by by simple 'torture by distortion'.

As a 15w into 4 ohms amp it would probably have been putting out somewhere around 7 watts clean into 16 ohms, up to double that fully distorted - say 15W or so max. Strange things can happen, but there is always a rational explaination to find somewhere with no need for 'magic' or 'voodoo' explainations. 15W (distorted or not!) just isn't enough to harm a healthy 70W speaker. Really not!

Please read these two links...
http://www.thegearpage.net/board/showpo ... ostcount=4" onclick="window.open(this.href);return false;
http://www.thegearpage.net/board/showpo ... ostcount=6" onclick="window.open(this.href);return false;
...which both pretty much echo what I was saying above - a fully distorted amp (valve or solid state) can put out up to about double the amps actual clean capability. Though that may well then be concentrated at particular frequencies, low and high.

I know that putting too much DC or a 'relatively close to DC, with added HF transients sort of signal' ain't good for speakers. But again with a distorted amp waveform that is about the power, not the signal waveform itself. At reasonable power levels clipping distortion won't kill speakers. Enough people have used solid state fuzz and distortion pedals or preamps through clean running amps over the years to prove that. Why should that situation be any different? If you are talking about solid state power amps it really isn't and PLENTY of people have used things like Roland JC120 amps with distortion pedals to great effect.

Also, think about this: if you test a speaker for correct function or polarity with a 9V battery you ARE feeding it true DC, 9VDC to be precise. Done fairly briefly that is regarded as a safe and normal check. (With lower rated speakers you don't of course want to do it for too long, but a second or two isn't going to melt anything worth using.) In fact thats how I'd suggest you check that speaker for voice coil rub. If present you'll hear it as a sort of grating sound. If the voice coil is moving freely you'd just hear a sort of click or thump as the cone moves in or out as you make / break the contact.

So what happened with your speaker? There are of course various possibilities...

Maybe the driver was faulty from the off? Rare but not unknown. Did you buy it new, know its full history? What other use had it had before unleashing the Crate on it?

Could it have suffered a voice coil misalignment from mishandling, eg being dropped or severely vibrated in transit when not packed cone up or cone down? Physical damage like that can sound exactly like a 'blown' speaker.

Maybe it had previously been damaged, but you only noticed it after 'abusing' it. That is a very common scenario, and more down to our own psychology than to physics. Just look at the number of nervous posters here for example who have had a 'no speaker load' situation with their amps, (usually due to bandmates or members of another band! :wink:), and suddenly the amp 'doesn't sound quite right' to them any more. While as we both know the OT (and other components) will almost always either survive such episodes totally unscathed or be very obviously sick. Chances are the sound was always there, but never noticed before. Possible?

Or maybe (very possibly if you really thrashed it!) there is a problem with the amp, especially its output section, and what it was putting out wasn't just the normal signal (or 'normal what you'd expect fully distorted' signal), but something with an unwanted higher voltage component. Some DC through a blown cap or shorted output transistor for example. Lets face it, there are plenty of ways you could have fried something in the amp with that sort of abuse which could then have fried the speaker. (That is also much more likely with solid state amp failures than with valve amps as s.s. amps don't normally have output transformers isolating the amps circuit from the speaker. OTs block DC for starters.)
Also it isn't as if Crate (bless 'em, I own a Crate amp too!) were ever the pinnacle of high grade engineering. Very much made to a price in fact, so much less likely to stand up to severe abuse (like yours got) than something like a nice Orange / Hiwatt / Mesa amp. I'm not meaning to be be nasty to Crate, thats just the plain truth.

Anyway if you haven't had that ruled out by a good tech then you can't really rule it out either. In fact if I was a betting man (I'm not) that would be where my main money would (very probably) go. I think you've been wise not to use / abuse the Crate again since, but had you ever thought of having it checked over?

Then again there is always the chance that the speaker isn't actually blown at all. There are various (as in quite a few!) other possibilties. Things like vibration problems with the speaker cab / mounting, speaker magnet assembly working loose from the speaker basket, particles / flakes of something in / near the voice coil gap causing rub, a cone problem, loose speaker wire connections (?spade connectors!!!), probably a good few more I've never even thought / even heard of.

Basically what I'm trying to say is that you shouldn't assume the amp killed the speaker by simply going into hard distortion as
A. frankly it didn't (as in couldn't have!) and
B. there are so many other possible explainations. Perhaps you can work a couple more out I've not mentioned.


Anyway... if you really believe that a (healthy) amp can blow a speaker rated for 30 times its rating you are welcome if you ever come over here to try to blow up my new 450W bass cab with a 15W s.s. amp, or my 600W one with a 20W one. Good luck on that! Or we could really push the boat out and plug my 3W Micro Crush into my 50W 1x12 Mesa cab. (Preferably without blowing the amp up - I really like it! :lol:) I'll even supply ear plugs and book us an hour in a rehearsal room, as long as we can then have a proper jam after the 'experiment', and a beer or two to follow. Deal? :)


Andy.

Re: Orange Bass Terror and cab ratings.

Posted: Tue Oct 11, 2011 2:17 am
by Randy Bass
I'd have to assume the amp has an issue in the power section, though it sounds like poo even when functioning properly, so it's hard to say. It usually serves as a doorstop anyways, so there's no point having it checked out.

Re: Orange Bass Terror and cab ratings.

Posted: Tue Oct 11, 2011 12:52 pm
by zefarelly ad200bass
Off on a slight tangent . . . . any ratings on the SP212

I have an AD200 and am thinking about getting a pair to rplace the 410 and 115 as they're just massive and heavy ( getting old! and no roadies!)

loathe to give up what is the best rig I've ever had and am ever likely to get, but if the new isobarics are any good it makes a lot of sense

Re: Orange Bass Terror and cab ratings.

Posted: Tue Oct 11, 2011 5:19 pm
by Dark Helmet
Randy Bass wrote: It usually serves as a doorstop anyways, so there's no point having it checked out.

:lol: :lol: :lol:

I soooooo know this feeling.... just with race-car parts.

Re: Orange Bass Terror and cab ratings.

Posted: Thu Oct 13, 2011 5:12 pm
by bassdrop
zefarelly ad200bass wrote:Off on a slight tangent . . . . any ratings on the SP212

I have an AD200 and am thinking about getting a pair to rplace the 410 and 115 as they're just massive and heavy ( getting old! and no roadies!)

loathe to give up what is the best rig I've ever had and am ever likely to get, but if the new isobarics are any good it makes a lot of sense
*Slight hijack continued- Keep in mind that a rig of two SP212's are going to be far less efficient than your current rig (i.e. much quieter). If this could be a problem you may want to reconsider. Part of the problem, for me at least, is that Orange don't like putting casters on their cabs which can make them harder to move (one of a number of reasons I don't use the Orange cab- my Aguilar DB410 is very efficient, and has both casters and an adjustable horn). Some folks like 8x10's better for this reason since you can move them like a refrigerator on a dolly.

*Hijack off** What Andy said.

Re: Orange Bass Terror and cab ratings.

Posted: Fri Oct 14, 2011 10:04 am
by a.hun
Yep, agreed. The isobaric SP cabs are designed primarily to give a lot of low end for the size of cab and to handle a lot of amp power. They aren't particularly light (by todays standards for high end bass cabs I mean) and won't be particularly efficient full range so won't sound as loud as some others eg your conventional full sized Orange cabs.

Discussed HERE.

There are plenty of other compact and efficient bass cab designs around these days, but with the current Orange range it is one or the other I'm afraid.


Andy.

Re: Orange Bass Terror and cab ratings.

Posted: Tue May 15, 2012 9:32 pm
by pikeybeatz
Thanks for the replys, luckily ive only ever had to use the ashdown as a backup once when my bass terror fused and it did work (sounded horrible in comparison though).....slight different question now, what sized cab would the bass terror be able to power, e.g orange/ampeg 4x10 6x10 or 8x10 etc...the stereotypical cab sizes.

Re: Orange Bass Terror and cab ratings.

Posted: Wed May 16, 2012 2:26 am
by bassdrop
pikeybeatz wrote:Thanks for the replys, luckily ive only ever had to use the ashdown as a backup once when my bass terror fused and it did work (sounded horrible in comparison though).....slight different question now, what sized cab would the bass terror be able to power, e.g orange/ampeg 4x10 6x10 or 8x10 etc...the stereotypical cab sizes.
Any and all really as long the cab could handle the power. Otherwise you're referring to tone which is far more subjective, and convenience, where you may want a BIG cab for BIG tone or a small cab for a happy back. Did I mention casters? I know, it was a while ago.