Wiggybass

[quote name='Mr. Foxen' timestamp='1362934341' post='2006393'] Nope, headphones, passive, powered by ipod, make sound. You can indeed make a horrible clipped sound with an ipod, and that is it distorting, and it won't break a PA speaker. And yes, those bedroom guitarists, and gigging guitarists do get massive distortion and never blow a speaker, because distortion doesn't blow speakers. [/quote] There's any amount of these things online, but here is one that explains it better than I: http://www.prestonelectronics.com/audio/Speakers.htm

[quote name='Mr. Foxen' timestamp='1362933954' post='2006386'] How about asking a speaker engineer? Oh wait, one has posted on the subject a whole load of times on this forum, and another has already been linked in this thread. [/quote] Sure, why not - the answer will be the same if he knows his subject

[quote name='Mr. Foxen' timestamp='1362933752' post='2006382'] Ipods have a power amp, its easy to clip, its how they drive the speakers in headphones. [/quote] Er...no...in this case the iPod would be the preamp. I can make a horrible noise by using an iPod in that way but it would only pose a threat to the PA if the power amp driving that was driven into distortion or oscillation. Look at all the bedroom guitarists who thrash their preamps to get massive distortion and never ever blow a speaker, nor are ever likely to - the pre and power amps are completely different. The preamp exists only to bring the incoming signal from the instrument up to a level where it can drive the input of the power amp.

[quote name='Mr. Foxen' timestamp='1362933719' post='2006380'] If your reconer says that, you'd be better off finding a reconer who knows what they are talking about. [/quote] No need to take my word for it - go find one and ask him, report back

[quote name='Mr. Foxen' timestamp='1362933673' post='2006377'] Clipping and amplitude are entirely unrelated. Clipping limits amplitude if anything. Overpowering damages speakers, waveform bears no relevance. [/quote] By overpowering you mean over-excursion?

[quote name='Jack' timestamp='1362933534' post='2006375'] Wiggy, go plug your ipod into a PA speaker cabinet and really crank it up so it clips. See how long it takes for that horrendous case of underpowering to blow the speaker. [/quote] Crank what up? The iPod or the speaker?

[quote name='charic' timestamp='1362933098' post='2006371'] Wiggy, I would generally side with Foxen on these matter. Chap knows what he's talking about when it comes to amps [/quote] I don't doubt it for a moment - but I say again, ask anyone who recones drivers (and I mean professionally) and every single one will tell you that almost all damage to cone transducers is the result of being continuously driven by power amps producing unintentionally distorted signals for extended periods. There's no mistaking the difference in the damage between this type of damage and that caused by over-excursion.

[quote name='Mr. Foxen' timestamp='1362928638' post='2006289'] Any of it, doesn't matter, clipped waveform is the same. Square waves require infinite bandwidth, and perfect cab behaviour (impedance, inductance etc.) and both amp and cab limit that. The limitations act to round off the square, limit enough and you bring it back to a perfect sine. [/quote] Clipped waveforms might be technically the same but the massive difference in amplitude is what's relevant concerning potential speaker damage. The miniscule voltages in the preamp could never be enough to damage a driver, whereas a power amp driven into clip and / or oscillation will definitely damage transducers if left for long enough (and that may not be very long if it's a low-powered driver). Ask anyone who does recones, they'll tell you what kills drivers.

[quote name='Mr. Foxen' timestamp='1362758266' post='2004402'] All this is not true. Again, 50w guitar head into 300w 4x12, driven far into clipping. Also amplifiers can't put out square waves into cabs. [/quote] Sorry, don't follow the reference - which bit of the guitar amp is / was being driven into clip - pre amp or power amp? Or both? And why can't amps put square waves into cabs?

You'll endanger your cab(s) far more by trying to drive them with an amp that isn't powerful enough than one which is (according to the bare specs) too powerful. Most speaker damage is the result of square-wave distortion which is what amps produce when they're pushed at or beyond their limits. If your amp is producing the volume you need whilst working well within its capabilities then happy days - technically you might be able to push the drivers beyond their excursion limits but with a good brand like a Berg I think you'll reach your desired volume long before that happens. Just as an experiment I ran my old Eden 210 / 115 rig for a few gigs with a Camco Vortex 2.6 in bridged mono, which on paper produces around 2600w. The cabinets loved it, cleanest sound you ever heard, loud as you like and nary a hint of speakers complaining.

For my money, the best preamp / DI you can buy - obviously designed by and for working bass players. I use mine as a straight preamp, i.e. the effected unbalanced output goes into the instrument input of my Markbass head. You'll need to juggle the output of the RBI against the input gain of the amp to get the levels right but there's so much adjustment available that it's not a problem. With some fiddling about, almost any sound you'll ever need is in there with the exception of massive distortion / fuzz. Having two sets of EQ is also very handy (i.e. one on the RBI and another on the amp), and I tend to use the RBI EQ, input gain and blend to get the sound I want from my bass, then use the amp EQ to handle any adjustments I might need for the room. The only thing it won't do very well is drive a power amp, it just doesn't have enough output (well, at least not for a pro-spec stereo power amp with a fixed input sensitivity of .775v RMS, which is pretty standard) but to be honest stereo power amps always sound too hi-fi and full-rangey to me. The RBI into the front of a Markbass sounds great to my ears, and I've tried the same setup into various rehearsal-room amps and it always sounds good. The RBI also has a well thought out variety of balanced and unbalanced wet and dry outputs (ideal for connecting to a PA or for recording), a dual-level FX loop and even a rear instrument input connector. I've gigged mine for ten years and it's never missed a beat. If you find a used one then don't hesitate - it's the one piece of kit that I use for every gig without exception.

I've spent years fiddling about with dual-path signal systems. The simplest way of doing it with some effectiveness that I've found so far is to use a SansAmp Bass Driver and a Boss LS2 (as mentioned above), switched to 2-in / 1 -out mode. The bass goes into the SABD and its main (wet) output goes into one input of the LS2. The parallel output of the SABD goes into the other input on the LS2, then the output of the LS2 goes into the amp. This gives you a combination of the pure, dry bass sound and the effected output of the SABD which can be blended together using the rotaries as you prefer, then the whole sound can be EQ'd (if necessary) on your amp. Despite my high hopes, it didn't make me sound like Geddy Lee. My latest incarnation of this project (which frankly is getting out of hand) goes like this: I use the unbalanced wet and dry outputs from a SansAmp RBI which is racked with a Mark Bass head. The dry output goes into an EBS compressor (just to add some level), then into an EBS chorus (because I had space on the pedalboard), then into one input on an LS2. The wet output from the RBI goes into an EBS overdrive, then into the other input of the LS2. The output from that goes into aTU2 tuner and from there into the amp. Haven't had a chance to gig it yet but it's fairly promising. The clarity and punch comes from the overdriven side, then I can dial in or out as much 'body' as I want using the dry channel control on the LS2. It's quite different from using low frequency EQ on the amp because the 'body' of the racket is not distorted. Also, having the chorus only on the dry channel means that it adds some interest and a different, usable sound because it's quite subtle and not splashed all over everything. I still don't sound like Geddy Lee though.

I think the more recent Ampeg 8 x 10s have the ability to run bi-amped, i.e. as two 4 x 10s as well as a single cab, and thus have a plethora of connectors on the back to allow this (and daisychaining multiple cabs in either mode). Wiring details here: http://www.ampeg.com/pdf/svt810eav.pdf It shouldn't be a difficult mod to do to an older cab, though personally I'd ditch all the jacks as Speakons are a dedicated connector for loudspeakers. It would be a lot easier if you only want to use it in one configuration, i.e. either as an 8 x 10 OR two 4 x10s.

As the hole is that big already you might as well take it up to 10mm and fit a set of these: http://www.jimdunlop.com/product/flush-mount Obviously you'll have to enlarge the other strap button screw hole but once fitted these things are just about foolproof.

[quote name='Count Bassy' timestamp='1352721334' post='1866433'] And if fitting them yourself make sure that you use the copper ferrule that is supplied with the plug. [/quote] Are they still supplied with those? I remember using them on the first version but haven't seen them in years