leftybassman392

Any photos?

[quote name='Twigman' timestamp='1335209988' post='1627400'] [b]not read the thread [/b]but isn't the OP question akin to : How can our eardrums hear more than one sound at a time? or How can a microphone pick up more than one sound at time? Speakers are just ear drums/mics in reverse, aren't they? [/quote] In all humility, might I respectfully suggest that you actually read the thread? A lot has gone by since the OP first posted this thread.

Welcome aboard from another lefty. Plenty of downsides to playing upside down like that, but look on the bright side - next time you bump into Jimmy Haslip you'll be able to play his basses.

[quote name='flyfisher' timestamp='1335024600' post='1624927'] Well, yes, but our brains detect [i]everything[/i] we perceive so I'm not sure that really helps answer the original question. Eyes receive light, brains make pictures, etc. A speaker may only transmit a waveform, which as you rightly say can be displayed on an oscilloscope without needing a brain to hear the 'sound', but that waveform is comprised of many individual frequency components, which can also be displayed on a spectrum analyser without needing a brain to hear the 'sound'. That's basic physics. How the brain makes sense of the received air pressure wave "data" and turns it into sound "information" is indeed a very complicated matter, but the incoming waveform has to somehow contain all the necessary "data" for the brain to decode in the first place. Surely the "data" are the individual frequency components that make up the complex waveform in question? [/quote] If you'll forgive me saying so, and with great respect, I think we're talking at crossed purposes. The reason it answers the OP's question is that a speaker doesn't emit sound at all - it emits a pressure wave whose intensity at any given instant is related to the voltage level present in the speaker coil at approximately that same instant. And yes, the pressure wave is highly complex in nature even with a single instrument due to the harmonic overtones present in the original wave created by the instrument (which I think is what you're referring to and which enables an experienced listener to identify the instrument as, say, a piano). However complex, what arrives at a listener's ears is still a single wave. Broadly speaking the data does contain all the necessary components for the brain to reconstruct it. (At very low frequencies, the brain analyzes the harmonic components and extrapolates downwards to 'insert' the fundamental frequency though the speaker is not physically reproducing it.) As you have rightly pointed out, an audio frequency spectrum analyzer can identify and display the various components. In hearing sounds, the brain is acting as an extremely sophisticated spectrum analyzer, with the bonus that it can, with training, reassemble the components so as to be able to identify the instrument that made them. Moreover, it is able to do this even when there are multiple notes and even multiple instruments. Exactly how it does this is a little beyond my knowledge, but I suspect that it has to do with prioritising components from the incoming data in some way. Even more impressively, over time it can learn to recognise familiar patterns very rapidly, thereby releasing 'processing power' for less familiar elements. In truth there's even more than that going on in the brain when we listen to music, but perhaps another time? The main difficulty in all this (as I hinted at in a previous post) is that the language we use when describing musical information is so centred on the source of the sound that we find it hard to think about it in any other way - "This bass has a great sound" is so much easier to deal with than "my brain is really enjoying analyzing this pressure wave". For everyday use there's no reason why we need to do anything different, but for the scientific analysis required to properly address this type of question, it's slightly misplaced. I'm not trying to be contentious or argumentative in saying all this - all I'm trying to do is answer a question from a fellow forum member. If that answer happens to be difficult for people to grasp, then so be it. It is what it is.

[quote name='flyfisher' timestamp='1335016562' post='1624763'] Hmm. Seems like this could do with some more detailed definitions of what's meant by "one sound" or even "one waveform". I'd agree that a speaker can only produce one waveform, after all it can only move back and forth, but one waveform can contain many 'sounds'. Thus a single 'sound' is a collection of individual frequencies, hence my earlier point about an "A" played on piano as sounding different to an "A" played on a guitar - a single 'sound' but many different frequencies at many different amplitudes. [/quote] There's an analogy here that might be useful. In the old days of Computer Science, teachers like me used to try to get students to understand the difference between 'data' and 'information'. [b]Data [/b]is what the technology processes. It doesn't know or care about the data, it's simply a machine following instructions that it's been given. [b]Information [/b]is what people make of that data. At this point it acquires 'meaning'. Moving back to the speaker system, the waveform is data. The speaker is simply reacting to the changing voltages it's presented with. If instead of a speaker the voltages were fed into an oscilloscope it would display the waveform. Neither the speaker or the oscilloscope know or care about the data, and are simpy reacting the way they've been designed to. The words 'hearing' and 'sound' are associated with animals (in this case, humans) and are words we use to describe (i.e. give meaning to) what's going on. I know this is hard to get to grips with (the notion of [i]objects [/i]making [i]sounds [/i]is deeply ingrained in our thinking - it's how we make sense of what our ears detect), but speakers don't produce sounds. They produce waveforms that travel though the air in the way Eddie Himself described. There needs to be somebody there to receive the data and make sense of it. In an earlier post I talked about thinking of the ears as very sensitive and hugely complicated pickups. It's a very good analogy, because the ear detects a waveform and transmits an electrical signal in much the same way as a guitar pickup. Hearing goes on in our heads, not in our ears. The word 'sound' refers to our perception and analysis of the waveforms our ears have detected. Long story short - speakers transmit waveforms, brains detect sounds. Simples.

[quote name='thinman' timestamp='1334945583' post='1624002'] I thought I'd have a go at answering the original question... As previously pointed out if a speaker was producing a simple sine wave then the cone would move back and forth smoothly at the wave's frequency. If it is having to produce a complex wave, say the result of two sine waves of different frequencies, the form might look like the lower frequency but with ripples on it of the higher frequency. The cone will therefore follow the shape of that wave - in general moving back and forth at the lower frequency but rather than smoothly it will be making much smaller back and forth movements at the higher frequency. As I understand it that is what makes speakers imperfect (but not impracticably so) because the above behaviour introduces Doppler distortion. (The effect of a fire engine's horn apparently changing pitch as it passes you). Imagine the cone is the fire engine and its horn the higher frequency - the fact the higher frequency is being produced by something that is itself moving. [/quote] Well yes, this is ok up to a point but there's more going on than that (and the Doppler effect, although very complex in a real-life situation, is actually minimal and hence not really much of an issue beside the main one from the OP's question - and in any case the brain simply filters it out so that what you hear is the sound you were supposed to hear). In real-life sound production from loudspeakers the cone movement is extremely complex, having to resolve audio components from a whole range of instruments (anything up to around 100 in the case of a symphony orchestra), each of which has it's own characteristic and complex waveform. However complex it gets though, the basic principle behind it is pretty straightforward: 1. The speaker unit moves in response to electrical inputs from the amplifier, and if wired correctly will move the cone forward in response to a rising voltage and backwards in response to a falling voltage. Therefore we can move a step nearer the amp and study how the voltage is changing (we don't have to, but it's a bit easier to explain if we do because the voltage behaviour is a step nearer the wave behaviour of the instruments). 2. At any given instant, the voltage value (and hence cone position - sort of) is the mathematical sum of all the individual voltages derived from the different instruments (again, the maths gets a bit fiddly in a real-life scenario so I'm trying to avoid getting too far into that side of it). At that instant some of the voltages will be positive and others will be negative. At the next instant all the individual voltages will be different so the voltage sum will be different (theoretically the voltage sum could be the same but in practice it just isn't). And on to the next instant; and the next; and so on. In other words the voltage present at the speaker is constantly changing. The way the voltage changes can be calculated if you have enough information about the waveforms of the individual instruments (which are themselves pretty complex!), but there is only one voltage present at the speaker at any given instant 3. Therefore, and as has been said before, a single speaker (or even a collection of speakers in a single cabinet) can only produce a single waveform. However, because the speaker is responding the best it can to a voltage that is changing in a very complex way, the cone movements will generate a single, highly complex audio waveform. That is what reaches your ears - and hence your brain. The rest is up to how your brain processes the information. So to answer the OP's original question 'how does a speaker make more than one sound?', the answer is as it was before - it doesn't.

[quote name='BigRedX' timestamp='1334925853' post='1623561'] When you get amp inputs that say Hi and Lo do they mean high and low gain or that they are for high or low output basses? [/quote] Good question! I've seen examples of both before now. Easiest way to find out is to plug into both alternately without touching the volume on the bass and see which one is louder. That will be the high gain input - for low output basses...

[quote name='essexbasscat' timestamp='1334922273' post='1623471'] Question. Using entirely hypothetical, random figures here; If one instrument plays a note of say 240 Hz and a second instrument plays a note of 435 Hz, why does the speaker produce two notes and not the one note associated with the sound of 240 + 435 = 675 Hz ? [/quote] The speaker doesn't produce two notes. It combines the information from the original sources into a single waveform that's more complex than either of the originals (Mart's excellent post shows what it would look like if you could see it). It's your brain that works out that there are 2 notes being played. To explain properly how the source notes are combined would take quite a lot of hard sums that basically explain what's happening in Mart's graphs. Are you sure you want that? (Before answering, read Eddie's astute post then put your hand on your heart and come back and tell us that you understood it.) Edit: Or of course you could just take our word for it that it does....

[quote name='xgsjx' timestamp='1334923896' post='1623506'] One company who might have labelled their inputs more accordingly was Carlsbro. On my old Cobra head it said "Low Gain" & "High Gain" as opposed to the usual "Passive" & "Active". [/quote] I've got that on my Cornford guitar amp. I just plug everything into the high gain on the grounds that more is better!

[quote name='ShergoldSnickers' timestamp='1334910145' post='1623216'] It always amazes me when you see electron micrographs of LP grooves. The fact that the stylus - for the most part - manages to track the waveforms, but also has to cope with two independent waveforms, one on each groove wall. It's staggering how good this simple mechanical arrangement can sound if the engineering within the cartridge, arm and turntable is right. [/quote] ..... and a testament to the genius of the engineers who designed and developed it.

A miracle indeed. As a musician with a bit of a scientific bent I suppose I would say this but I happen to think that the human brain's ability to identify and locate multiple individual sound sources from a single, unbelievably complex waveform virtually in real time is one of our more remarkable abilities - and the more remarkable in that it requires little or no conscious intervention from us.

[quote name='1970' timestamp='1334877528' post='1622983'] BUT HOW DOES TV WORK? [/quote] It's all Yogi Bear's fault.

[quote name='barneyg42' timestamp='1334904783' post='1623125'] I'm taking passengers to Warwick castle Saturday and might give him visit, what's the parking like? I'm only in a small minibus (transit size) also is it a good place just browse without an appointment, I'm not after anything specific. [/quote] No problems. From the castle head out towards the M40 via the A429. Take the southbound exit and come off again almost immediately at j. 14 and go straight across the first roundabout. At the big roundabout head for Leamington, then look for the Heathcote industrial estate. Turn into Rigby Close and follow your nose round to the right. Plenty of parking space. Word of warning though - it's clearly marked but is not a 'normal' shopfront. Edit: he closes early on a Saturday (2.30 IIRC)

I get the feeling that amp makers have started to realise this and are moving away from that design philosophy (TC Electronic and GenzBenz being cases in point).

Like a few people on here I think, I may be in that very fortunate position if my PPI complaints come through. However, I've already got all the basses I need for today so probably some mild performance tweaks on the roadster and the balance on a really nice holiday in, say, Sri Lanka.

Most of it's been said already. The bit that seems to be confusing you turns out to be going on inside your head. The single, er, wibbly wobbly wave that hits your ears (think of them as highly sensitive and incredibly complex pickups) gets turned back into a bunch of different instruments by your brain (which is very VERY good at decyphering the components of the, er, wibbly wobbly wave and deciding what combination of original sounds caused the, er, wibbly wobbly wave in the first place). As well as this, it's very good at deciding where the different sounds are coming from (so, for example, if you're having a chat with a bunch of people it's possible to close your eyes and still be able to point to each person very accurately). And here's the best bit, it's all completely automatic so you don't even need to think about it! Generally speaking musicians are better at it than ordinary mortals because we spend more of our time doing it, but anybody can do it.

Yup, I'd agree with all of that. Posters had discussed some apparent anomalies as between active and passive. I just decided to point out an aspect that nobody had yet raised. I have some knowledge of pickup types and characteristics and I'm familiar with the principles of electromagnetic induction - which is why I suggested that in otherwise identical instruments most people would, I suspect, feel entitled to expect higher output from an active circuit even with the eq set flat. Otherwise why are we all having this discussion?

I don't think anybody's mentioned pickup height yet, which can have a dramatic effect on output level. I think it's the case though that for any given instrument and setup, you should normally expect more output from an active circuit than a passive one (passive circuits are subtractive and cannot add voltage whereas active circuits have an additional power source that can be used to boost the signal level). I'm no expert in this kind of thing, but I'm pretty sure there's plenty of power available to run the active eq with plenty to spare for signal boost.

Don't know about anybody else but my eyes are starting to hurt!

[quote name='LowdownRumble' timestamp='1334776604' post='1621200'] Is there such a thing as an active/passive bass? Such as, when the battery dies switch to passive and rock on? [/quote] My Regenerate Axiom has a pull-passive function on the volume control, plus an old-school passive tone control hardwired. Also the output is quite low for an active preamp - hardly more than my passive Jazz. So if the preamp dies for any reason I just pull out the volume pot and hey presto! Passive Jazz bass just like Leo made 'em. Pre and pickups were all Nordy items. Also I had a Shuker with a passive bypass switch, but IIRC it overrode everything and gave a 'default' tone so you could at least finish the gig.

Wait a minute...... you guys are talking about sex! I'm telling my mum! Then you'll all be in big trouble - you just see if you're not.

Given his importance in the history of popular music, I'd have to say that all the prices quoted are very conservative (economic issues notwithstanding). I'd be surprised if some of it doesn't wind up in the R'n'R Hall of Fame in Cleveland - particularly the recording equipment. They already have some of his stuff, and I can foresee a much-expanded display taking shape. Like others here I'll be watching this with interest.

Personally I've never got Rickenbackers (which I'm sure is a personal failing and something I should work on, etc., etc.). This business of 'coaxing' the tone out of them sounds far too much like talking a vintage car into working for long enough to get you where you're going. I have a gorgeous headless Sei that's as easy to play as most of my guitars, plus a GB amp with a Vanderkley cab - and they sound to my ears like they were born to be together. I don't get why you should have to work so hard to get a good sound out of your gear. It's not even as if they're reasonably priced. I was a huge fan of 'Yes' though, so WTF do I know about it?

It's been said already - headphones. You can play as loud as you like and nobody will hear you. You should still have access to all your amp/bass/pedalboard settings. Where's the downside? Just make sure you have a decent set.