@Gnobuddy , another theoretical question if I may?
Putting tone quality aside for a second and only focusing on the safety of the speakers, is playing a live guitar + bass any different from just playing music through a HiFi 2.1 system, if we keep the volume appropriate, and convert the signal correctly? I do not mean plugging guitar directly into the amp, I mean turning the unbalanced high-impedance output of the guitars into low-impedance line-in via a DI box or a mixer panel, mixing the guitars, compressing (?) if necessary, and feeding the result into the HiFi. Will this kind of signal be inherently more dangerous to the HiFi than a signal from a CD player? Intuitively, no but perhaps I am missing some details.
I was thinking about perhaps the dynamic range between the peak of the string attack and the long sustain. But it looks like the peak gets clipped anyway, it'll be clipped by preamp or some other component in the chain before it reaches HiFi.
And I assume that the speakers and the subwoofer are protected by the low-and high-frequency filters in the amp appropriately otherwise "regular" recorded music would probably damage them just as well?
I apologize if it looks like I am beating about the same bush. I am trying not to.
Putting tone quality aside for a second and only focusing on the safety of the speakers, is playing a live guitar + bass any different from just playing music through a HiFi 2.1 system, if we keep the volume appropriate, and convert the signal correctly? I do not mean plugging guitar directly into the amp, I mean turning the unbalanced high-impedance output of the guitars into low-impedance line-in via a DI box or a mixer panel, mixing the guitars, compressing (?) if necessary, and feeding the result into the HiFi. Will this kind of signal be inherently more dangerous to the HiFi than a signal from a CD player? Intuitively, no but perhaps I am missing some details.
I was thinking about perhaps the dynamic range between the peak of the string attack and the long sustain. But it looks like the peak gets clipped anyway, it'll be clipped by preamp or some other component in the chain before it reaches HiFi.
And I assume that the speakers and the subwoofer are protected by the low-and high-frequency filters in the amp appropriately otherwise "regular" recorded music would probably damage them just as well?
I apologize if it looks like I am beating about the same bush. I am trying not to.
Ay, there lies the rub, as Shakespeare put it in Hamlet.Crocobar said:
Recorded guitar and bass signals have already been repeatedly compressed and limited, and will inevitably be clipped to the maximum value you can get when all digital bits (in the WAV file) are set to 1. The soundcard in the computer has its own output voltage limits - there is no chance it might suddenly spit out, say, 5 volts RMS.
Live guitar and bass is a different story. For instance, if you first play the guitar lightly with just your fingertips, and then switch to whaling on it with a stiff guitar pick, the output can shoot up by maybe 40 dB. If you've set the gains so you can hear the fingerstyle playing at a comfortable volume, the jump in output might tear the speaker apart almost instantly.
Other things entirely out of your control might result in the same sorts of problems. If your guitar stand falls over with your guitar on it, you might get a dangerously big signal spike. If you set the guitar too close to the speaker with the gain turned up, you can get acoustic feedback from speaker to guitar that will quickly rise to the amplifiers maximum power output.
To put some numbers to it, gently playing an e-guitar might produce only 10 mV p-p from the pickups. At the other extreme, at least one diyAudio member posted oscilloscope captures showing that he can get 10 VOLTS p-p out of one of his guitars using what he described as a rapid flick of his wrist. More typically, it seems quite possible to get 1 Vpp out of a guitar with single-coil pickups like your Strat'.
If you have a linear audio amplifier (like any Hi-Fi or mid-Fi system), it will do its best to transmit that entire huge dynamic range faithfully to the output. Unless you have a system capable of prodigious output, something will clip - and if the thing that clips happens to be a small woofer that was never designed to cope with lots of power, that will be the end of the speaker.
In my experience, bass guitar is even more capable of insanely large changes in signal level. The difference in guitar output between, say, subtle finger-style playing and slap-bass is absolutely enormous. If a rather delicate speaker is just able to cope with the finger style playing, the voice coil might eject itself completely out of the magnetic gap at the very first slap or pop.
For your situation, the simplest way to guard against this sort of accidental speaker destruction is to limit the available maximum power output of the amplifier. If your amplifier output is limited to, say, 5 watts RMS maximum, and the speaker drivers can safely handle that much power, then you might hear nasty clipping noises, but at least you won't fry or tear apart your speakers.
The simplest way to limit amplifier output power is to run your class-D board from a lower voltage power supply.
To estimate maximum output power, realize that the maximum peak amplitude of the output signal will be about 2 - 3 volts less than the supply voltage.
From that, you can calculate maximum RMS sinewave power that can be delivered to the speaker.
If the amplifier is very heavily overloaded, the sine wave will be clipped into a square wave, with the result that roughly twice as much RMS power will be delivered to the speaker. (RMS value of a sine wave is peak voltage / (square root of two), while RMS value of a square wave equals its peak value. Power is proportional to voltage squared. RMS power from a square wave is therefore twice as much as RMS sinewave power with the same peak amplitude.)
An example: let's say you find a class-D board that is rated to work on a 12V DC power supply.
Maximum peak output signal will be in the vicinity of 9 - 10 volts (two or three volts will be lost in the saturation voltage of the output devices).
If we assume the bigger number (10 V), then the maximum sinewave RMS power that can be delivered to an 8 ohm speaker will be roughly 6 watts.
If you buy your board from a typical Amazon or Ebay vendor, it may be advertised as a 100 watt, or 300 watt, or 500 watt board, even though it comes with a 12V power supply. This is, plain and simple, utter nonsense. The calculation above will tell you the actual maximum power output that is possible.
If you accidentally overdrive that same amplifier so hard that the output clips to a near square wave, power to the speaker will rise to around 12 watts RMS. This is the worst case scenario.
If your speakers can handle 12 watts of input power long enough for you to reach the volume controls and turn them down, you won't fry your speakers.
This was pretty much my approach with the Flamma Preamp, and a little Lepai class-D power amplifier. I run the Lepai from a 12V DC wall-wart, so it simply cannot put out enough power to do any damage to the little thrift-store-refugee minicomponent "Hi-Fi" speakers I use. (In quotation marks because they aren't Hi-Fi by any means. But I digress.)
Incidentally, 6 watts RMS of power can get pretty loud inside a living room, if you compare with typical listening levels used for music or TV. A typical boombox speaker might have a sensitivity of, say, 85 dB @1W @1 metre. Feed it 6 watts, and SPL at one metre distance should be 93 dB. That is very loud. A typical vacuum cleaner (the loudest sound in my apartment) is around 70 dB SPL.
Musicians, however, tend to be a different breed. Many of them want stupidly loud levels such as 110 dB SPL, even though that will quickly damage their hearing (and result in a visit from the police unless you live in a farmhouse on several acres of land). This is partly because very high SPL induces a euphoric feeling in many people, and partly because modern drumsets have also been evolved to be stupidly loud, so if you play with a drummer, your guitar / bass / keyboards / vocals also need to be stupidly loud.
Those extra 17 dB (going from 93 dB to 110 dB) won't happen with boombox speakers - that's where specialized high-efficiency, mechanically robust, instrument-specific speakers, and high-power amplifiers come in.
And yes, the additional steps you suggested - such as compressing or peak-limiting the instrument signals - may help. (Note that compressing the signal can increase the tendency for unwanted feedback, as the small-signal gain will usually be turned up when the compressor is added to the signal chain.)
-Gnobuddy
So, I am trying to understand what my bookshelf speaker (photo above) claims. I realize that most of the claimed wattage is marketing and has little to do with reality. This ELAC though is supposed to be serious, so the numbers should be interpretable. I see 6 Ohms nominal impedance, which probably means the resistance to DC? It also says max power 120 watt, which I interpret as peak. If those are correct assumptions, I get
120 watt = v_peak^2 / 6 ohm,
which gives me peak voltage that the speaker is likely to withstand to be
v_peak = sqrt(6 *120) ~ 27 volt.
My existing 2.1 class-D is powered by a 24VDC supply - the second board in the pic above. So... with this setup, I should be safe, right?
P.S. If the max power means RMS though, then peak is sqrt(2) larger, which puts it at 38 volt - even safer because I will only get peak of ~21 volt from this class-d with this power supply. Right?
120 watt = v_peak^2 / 6 ohm,
which gives me peak voltage that the speaker is likely to withstand to be
v_peak = sqrt(6 *120) ~ 27 volt.
My existing 2.1 class-D is powered by a 24VDC supply - the second board in the pic above. So... with this setup, I should be safe, right?
P.S. If the max power means RMS though, then peak is sqrt(2) larger, which puts it at 38 volt - even safer because I will only get peak of ~21 volt from this class-d with this power supply. Right?
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Man at clipping it's no longer a sine wave. It's more like DC and that's the stage where the cooking happens. Most speakers will lap up sine waves up to their mechanical limits without exploding. What no one gets is that, with the massive dynamic range potential at the fingertips (or big thumb), change up to a driver with higher mech limits. I find it silly to use hi-fi or pa drivers to make a bold small full spectrum instrument amplifier. HT and pro car audio specific bass drivers have a larger dynamic range ability as they are designed for that. Drop your bass guitar plugged into these type of speakers, and they will think a cute T-rex just went by. Why is this so difficult to comprehend? I have a full acoustic drum set from 1985. There is no prob micing the set into the Z623 soundsystem with the volume up, it just laps up the hits. This kind of repurposing won't be entertained or understood by most unless low basslines are a requirement, and in that case it's all done through an audio interface into DAW anyway or from a synth. There is no real demand for low deep loud basslines from a guitar for most western styles anyway, as people find it easier to do on a synth. Very few will go to my kind of lengths to do it on a bass guitar. Most will already be defeated by the inability of typical bass amps to produce low bass and more will not have that requirement
I think our amps should not be included in discussions of the typical units, as ours aren't meant for the regular rock type sounds but rather to replace the synth with a bass guitar in dub reggae, dance and EDM
I think our amps should not be included in discussions of the typical units, as ours aren't meant for the regular rock type sounds but rather to replace the synth with a bass guitar in dub reggae, dance and EDM
Randy, I do not disagree. My questions go towards just plugging holes in basic understanding of the field, not very specific toward any solution. Over this weekend, I will post my specific wants in a separate thread (was a bit busy at work so far).
But in a nut shell, I am trying to see if i can get away with having just one sound system in the house. Not everyone in our household enjoys free-standing electronics, speakers, wires, and associated equipment in the living areas. So, I am trying to avoid having a HiFi setup and a guitar amp, and a bass amp.
But in a nut shell, I am trying to see if i can get away with having just one sound system in the house. Not everyone in our household enjoys free-standing electronics, speakers, wires, and associated equipment in the living areas.
So, I am trying to avoid having a HiFi setup and a guitar amp, and a bass amp.
I was there many years ago. To the point where even the surround speakers seemed redundant. In our last open-plan kitchen/dining/living room, Mrs was standing at the table, and I was on the sink. We were back to back. At one moment in unison we turned around and looked at the floor for the dog bark that came from there!!! The 3D spatial imaging was that good from a stereo pair of speakers (Aaron AP-3) and a Rotel stereo power amp together with the Z623 plugged in as sub only. Bass guitar, electric guitar, 3 mics, keyboard, acoustic drum set with 3 more mics. These all fed with an old Peavey mixer with a computer inserted into the effects loop. This is when we first rigged up for some live instruments in the mix. It's now even more awesome and developed into what I am currently fitting out this place with. Keep an eye on the Grooveshop thread. Workbench area is now complete and installed, so the studio desk is getting looked at next
Crocobar wrote:
DI boxes exist mainly for two reasons:
1) A DI box provides a pair of matched anti-phase output signals (a balanced signal). Audio signals pick up noise and hum from electromagnetic interference when you run them through a long cable, and this will happen to both of the output signals. However, at the receiving device, if you subtract the two signals from each other, the noise cancels out to a large degree.
2) If your signal source has a high output impedance (guitars and passive bass guitars do), the cable from your source is even more susceptible to noise and hum pick up. A very long cable from a guitar or bass tends to cause lots of unwanted noise and interference.
This can be minimized by running a short cable to a DI box, and the necessary long cable from the output of the DI box to wherever it needs to go. The DI box not only reduces EMI in the long cable because of its balanced output signal, it further reduces noise because it has low output impedance.
The Flamma FS06 already has a low output impedance. Just run a relatively short cable from guitar to FS06, and you should be fine. My humbucker-equipped guitars experience noticeable treble loss with cables longer than 10 feet. I use a 10-foot cable 99% of the time. If I absolutely need to be able to move further away from my amp (when playing on stage or at a jam), I use a 15-foot guitar cable.
The Flamma FS06 does not have a balanced output. This is typical for guitar gear. At the signal and impedance levels of the FS06 output, it's usually not necessary. Almost all guitars, basses and effect guitar pedals have single-ended, unbalanced outputs.
(When it comes to microphones, which produce far smaller output signals, balanced signals are virtually mandatory, and are used in all but the cheapest and nastiest toy microphones.)
Sorry about the months-late reply. Long COVID has made my life quite difficult since late 2022. Most of the time I've been too sick to participate in any non-essential activity.
-Gnobuddy
No, and I don't think you need one for your purposes.
DI boxes exist mainly for two reasons:
1) A DI box provides a pair of matched anti-phase output signals (a balanced signal). Audio signals pick up noise and hum from electromagnetic interference when you run them through a long cable, and this will happen to both of the output signals. However, at the receiving device, if you subtract the two signals from each other, the noise cancels out to a large degree.
2) If your signal source has a high output impedance (guitars and passive bass guitars do), the cable from your source is even more susceptible to noise and hum pick up. A very long cable from a guitar or bass tends to cause lots of unwanted noise and interference.
This can be minimized by running a short cable to a DI box, and the necessary long cable from the output of the DI box to wherever it needs to go. The DI box not only reduces EMI in the long cable because of its balanced output signal, it further reduces noise because it has low output impedance.
The Flamma FS06 already has a low output impedance. Just run a relatively short cable from guitar to FS06, and you should be fine. My humbucker-equipped guitars experience noticeable treble loss with cables longer than 10 feet. I use a 10-foot cable 99% of the time. If I absolutely need to be able to move further away from my amp (when playing on stage or at a jam), I use a 15-foot guitar cable.
The Flamma FS06 does not have a balanced output. This is typical for guitar gear. At the signal and impedance levels of the FS06 output, it's usually not necessary. Almost all guitars, basses and effect guitar pedals have single-ended, unbalanced outputs.
(When it comes to microphones, which produce far smaller output signals, balanced signals are virtually mandatory, and are used in all but the cheapest and nastiest toy microphones.)
Sorry about the months-late reply. Long COVID has made my life quite difficult since late 2022. Most of the time I've been too sick to participate in any non-essential activity.
-Gnobuddy
I am sorry that I didn't see this post sooner. Unfortunately I've been away from the forum for months due to ongoing health issues.
I hope I'm not too late, and that your ELAC speakers have not already been destroyed. Fingers crossed.
Speaker wattage ratings tend to be a can of worms at best, and even worse than that (what's worse than a can of worms?) for speakers made by today's marketing-driven companies that long ago lost all concept of truth in advertising.
Let me give you the bottom line first: if you were to apply 10 watts RMS of sine-wave audio power to your speaker at a frequency of, say, 5 kHz, I can almost guarantee that your tweeters will fry within seconds.
(And by "fry", I mean that the voice coils will overheat to the point of complete mechanical and electrical failure, as the baked-on varnish insulation on the hair-thin voice coil wire turns into charred carbon.) The tweeters will be destroyed. They will need to be replaced, if ELAC will actually sell you replacements. If not, you're out the entire price of your speakers.
If you use this type of speaker for live sound, as I think you intend to, its quite easy for the scenario I outlined to occur. Simple acoustic feedback ("howl around") should the microphone get too close to the speakers would do it. Your tweeters would fry before you could get to the volume control to turn it down. Those ELAC monitors are not cheap, and I don't think you would be at all happy about this scenario.
So forget about 120 watts, RMS or otherwise. Forget about even 12 watts. What you actually need to do is restrict maximum power into the tweeter, worst case, to no more than, say 5 watts. Otherwise your tweeters are living on borrowed time.
As I indicated months ago, the key is very low power supply voltage to your class-D amplifier. If you lower your amplifier power supply to 12 VDC, maximum power into a 6-ohm load drops to about 8 watts RMS, which your tweeters might tolerate long enough for you to leap at your volume control and turn it down. Your current 24V power supply is far too much for this type of use - using that much power supply voltage is practically begging for your tweeters to be destroyed.
It would be quite a wise thing to do to insert a 12-volt, 12-watt automotive incandescent (filament) light bulb in series with each loudspeaker wire. This will give considerable protection to your expensive speakers - as speaker current approaches 1 ampere RMS, the tungsten filament heats up, its resistance increases dramatically, and this keeps speaker current from rising to levels that will fry your drivers (particularly the delicate tweeters).
The light bulbs will have some unwanted side effects (including power compression and likely changes in frequency response). But those are minor problems compared to total destruction of the tweeters in a $250 - $300 pair of speakers.
Note that this only works with incandescent light bulbs, not the new-fangled LED replacements. Incandescent automotive bulbs are starting to get thin on the ground now, so if you plan to go this route, snag them quickly, before LEDs replace them all.
The exact model of light bulb doesn't matter. It's the 12-volt, 12-watt rating that's key. This basically means that the bulb has a designed operating current of roughly one ampere (running on a 12V auto battery). In series with your loudspeaker, it will more-or-less limit maximum current to 1 ampere, preventing your tweeters from frying. (It might be rated 12.6 V or 12.8 V - that's of no consequence. Basically it's designed from a nominally 12-volt lead acid battery.)
This article by Rod Elliot on the subject of loudspeaker failure is well worth reading: https://www.sound-au.com/articles/speaker-failure.html
-Gnobuddy
@Gnobuddy , thanks for your responses! I know you are having health issues - I appreciate all the time you spare on your responses regardless!
I did get the FS06, and it does sound much better than whatever I was able to achieve without it (although, interestingly, the second best tone I get on my squier strat is through my daughter's bass setup, which is a sonicake bass multipedal preamp, which claims to emulate AMpeg amp, and the accompanying compressor).
Now I have an embarrassment of riches of sorts, and not sure what to do with it: the 7 clean + 7 distorted FS06 channels, with 5-way tuning each, and with the cab simulator, give me way more degrees of freedom than I know what to do with, at the moment.
I end up googling what a particular artist used, finding the closest model on FS06, and set the knobs around the midpoint. Hopefully, I will eventually know better.Totally, totally, and hope you are recovering as fast as possible!
Not destroyed, as far as I can tell. I did turn them on but never loud enough I think: never louder than what I can do on an acoustic without trying too hard.
That said, I am not really hell bent on using ELACs. Thanks for your hack with the incadescent lightbulbs but I think I don't need to go that way if ELACs are really such an unnatural speaker for my purpose.
My main interest in exploring the non-guitar speakers is two-fold, you probably already picked up on that: I like to understand the technology I am using to some degree so I don't do stupid things too often (like redundancy in speakers but also using a wildly wrong type), and to avoid unnecessary clutter of equipment that may be standard but not really necessary for my uses.
Mainly, I would like to try to avoid having 1-2-3 guitar amps in the corner (I now have two strats and one acoustic guitar with an under-the-bridge piezo pickup, which I installed myself), and one bass amp, and a set of stereo speakers.
It looks like studio engineers sort of avoid this: presumably, they output the mix to a single set of speakers/monitors rather than one speaker per instrument. So I am aiming at something like poor man's home studio, that would allow live family jamming (at a room levels, not stadium or even club levels), and recording.
I think I am getting there: I now have that Allen & Heath mixing desk with a 4-channel interface built in, still learning to use it. I can connect a strat to FS06 and into the deck, and the bass into Sonicake multipedal and into the deck, and I used the ELACs to play it all at a very quiet levels because I wanted to be cautious, and I don't need volume usually anyways.
That said, it looks like I still need to find a suitable set of speakers/monitors/sub for this setup. I don't mind spending a bit on this, my goal is not to be absolutely limited by what I have at hand but rather to make a reasonable inexpensive setup.
I do have the specs of your monitors and sub but that sounds pretty high end and expensive for me, at the moment; I don't think I could justify it to myself even though I can afford it. And I still don't quite get what makes a set of monitors suitable for this and different from something like those ELACs - probably a different tweeter technology.
I also realized, following your hints, that even with my standalone class-D contraption I am behind times, and the cheap powered speakers are in abundance. Which makes me think that peerhaps I just need to get a pair of $50-100 powered bookshelf speakers for this? Or they will have the same issue with burining tweeters despite having presumably the "correct" native power supply?
No, I don't think I destroyed anything yet: but I went really cautiously volume-wise, never turned it on louder than a typical acoustic guitar level.
I have an alternative hookup too, mostly used by my daughter on bass in another room: her bass multipedal has an XLR out, which could be used in parallel with the regular ubnbalanced line out. So I hook up my cheap fender guitar amp to the line out, and an old Yamaha home theater subwoofer that I had in the garage to the XLR out, and the resulting sound is pretty satisfying for her and me.
(In fact, I accidentally stumbled on an infinite sustain that I get if I hang the bass on the wall in the usual slot, which is close to the sub, and gently pluck one of the strings - it keeps the bass tone going forever.
)
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If you like how a bassline sounds than my fav Z623 would sound even richer and deeper and prolly louder than even the Yamaha subs that I know. From the sounds of things I gather that you and your daughter also prefer a bassline over percussive banging and slapping played on a bass instrument. Also if you main interest is rock type stuff than again you might want to cut more of the lower bass and add a tweeter to the sub
I can't understand this playing percussive stuff on the bass guitar and calling that 'bass' the way I hear most people here think of, that is not a bassline. You can put pickups on most things around you and bang and crash that and slap ones self silly for pretty much the same effect. Again, that is not a bassline. Turn away from rock and look at most coloured music, and you will find that the treble and mid-knobs are turned way down
I also would suggest that take all the advice from the interest with a grain of salt as you may not always be getting an informed and qualified feedback
Instead, find some songs that you like the basslines of. Take it to the music shop and plug your phone into the AUX input of most bass amps. If you hear one produce the sound in the way that you like, follow that route whether DIY or prerolled
I can't understand this playing percussive stuff on the bass guitar and calling that 'bass' the way I hear most people here think of, that is not a bassline. You can put pickups on most things around you and bang and crash that and slap ones self silly for pretty much the same effect. Again, that is not a bassline. Turn away from rock and look at most coloured music, and you will find that the treble and mid-knobs are turned way down
I also would suggest that take all the advice from the interest with a grain of salt as you may not always be getting an informed and qualified feedback
Instead, find some songs that you like the basslines of. Take it to the music shop and plug your phone into the AUX input of most bass amps. If you hear one produce the sound in the way that you like, follow that route whether DIY or prerolled
Tomorrow is eisteddfod day for primary schools here. Jiya has been asked to perform with her amp instead of the house amp as her teacher says it sounds so much better and powerful than the school stock Rumblys
I have to totally disagree with this idea that played bass should be limited in the high-end extension and focus on the upper bass. I am guessing this stems from the fact that such folks with such opinions just might not be using equipment that can allow such a signal to be appropriately monitored. Like trying to listen to a reggae or EDM type of bassline through small bookshelf speakers, no chance of making a correct call!
I have to totally disagree with this idea that played bass should be limited in the high-end extension and focus on the upper bass. I am guessing this stems from the fact that such folks with such opinions just might not be using equipment that can allow such a signal to be appropriately monitored. Like trying to listen to a reggae or EDM type of bassline through small bookshelf speakers, no chance of making a correct call!
Glad to hear you like your FS06!
Oh-oh. You are now standing at the top of a very long, very slippery, potentially very expensive slope.
In other words, a whole universe of guitar effects pedals awaits your explorations (and the contents of your wallet).
A good-sounding reverb is one effect pedal that virtually always improves the sound of any guitar, electric and acoustic. Decent reverb pedals used to be large and expensive, but decades of Moore's law have made them small and affordable.
As you've already found out, the Sonicake and similar multiFX pedals are an option worth exploring as well. Often the quality of individual effects is not as good, but there is usually a dramatic reduction in price.
In my case, I was sufficiently impressed by the Flamma Preamp to try some of their other pedals too. They make a couple of very nice reverb pedals, which have also become mainstays for me.
It's an interesting problem, isn't it? An embarrassment of riches, which no beginner guitarist would have encountered had they been starting out, say, fifty years ago.
I recall a book titled "The Paradox of Choice" written by a psychologist about twenty years ago, that explored some of the downsides of having too many choices: https://en.wikipedia.org/wiki/The_Paradox_of_Choice
But don't feel pressured to find a use for every sound; it's okay not to eat everything on the smorgasbord table! There are artists like the late B.B. King who basically found one single sound, and stuck with it for their entire career. And there are artists like the late Jeff Beck, an extremely creative man who was constantly exploring new sounds and new techniques.
Sounds like a good way to get started!
Until I got my Flamma Preamp, I was quite limited in the sort of sounds I could explore with my guitars and the amplifiers I had. One of the things I really like about the FS06 is that it's allowed me to explore so many other sounds and playing techniques. I am never going to shell out several grand for a real high-gain tube amp, but with the FS06, I can play around with rock licks, two-handed tapping, and other tricks that were impossible with my previous equipment.
Of course you don't have to reproduce the original sounds in the original song you're covering (unless you want to). It can also be fun to explore what the same song sounds like if you make entirely different choices than the original musicians did.
Since your daughter plays bass you've probably heard Muse's "Hysteria" a few too many times; personally I cannot enjoy the coffee-grinder distortion on the original bass line, but I quite like the lyrics and the vocals. Not long ago I found this acoustic-guitar cover that I like much more than the original:
That hack is a very clever one (and has been in use for a long time. I can't take any credit whatsoever for it.) It's quite a good solution to your situation - and easy to undo if, for some reason, you don't like the result. Why not try it?
And if you're dead set against the light bulb power limiter, all you have to do is limit maximum amplifier output power to, say, 5 watts RMS, by lowering power supply voltage appropriately, and your ELACs should cope. Just drop the power supply voltage to the power amp, as discussed previously. (Note that most power amps have a lower limit of supply voltage, below which they will not function at all.)
This all works very well at quiet levels. The trouble is the potential for (accidental) loud sounds that will almost instantly fry your tweeters. I realize that the whole issue of which tweeters are suitable and which aren't is still not clear, and I'll take another stab at trying to clarify that in a moment.
I bought my passive Alesis monitors for, IIRC, $160 USD for the pair off Amazon circa 2009 or so. I think they were surprisingly cheap back then because the home / small business studio industry had mostly already shifted over to powered monitors, so passive monitors were uncool and therefore had to be sold off cheap. The same speakers had sold for around $400 USD each when they were first launched circa 1999 or thereabouts.
I bought the 10" Velodyne subwoofer on sale from Fry's Electronics not long after I bought the Alesis Monitor One MkIIs. Long COVID has wreaked havoc on my memory, but for what it's worth, my recollection was that I paid under $120 USD. It might have been $117.
Those days are long gone, sadly. I think we're seeing some of the predictions of the mathematical modelling in 1972's "The Limits To Growth" coming true, including plunging natural resources and exploding costs of manufacture and distribution of products. The COVID pandemic may have helped accelerate the process a little further.
Let me try to take another stab at this.
Thing one: comparing the sort of woofers and tweeters used in Hi-Fi speaker systems, all else being equal, woofers can handle more power than tweeters. This is simple thermodynamics - woofers have bigger voice coils wound with fatter wire, and with more radiating surface area to get rid of heat. So you can feed them more watts before the voice coil wire fuses or the coil insulation burns.
Thing two: music has an energy spectrum that tilts down as frequency increases. With a suitable crossover network, much less power is fed to the tweeter than the woofer. This allows 10-watt tweeters to survive in a system rated for 50 watts or more.
Thing three: If you took a generic Hi-Fi 50-watt speaker system, and ran a swept sine-wave signal into it, starting from, say, 100 Hz and moving up to 10 kHz, setting the power level to 50 watts, you would fry your tweeters. That's because once the input frequency was well above the crossover frequency, you would be feeding a full 50 watts to tweeters that can barely cope with 10 watts. The sine wave drives the same amount of power into its load at every frequency, unlike music.
Thing four: If you feed white noise (all frequencies, equal energy in equal frequency bandwidths) to the speaker, and gradually turn up the power level, the tweeter would fry long before the woofer.
Thing five: If you feed pink noise (power spectral density inversely proportional to the frequency of the signal) to a speaker system and turn up the power, you are much less likely to fry the tweeter.
Thing six: In a live music setup, there is significant potential for loud noises at high frequencies to be accidentally generated. For example, if gain on a vocal microphone is turned up too far and you get acoustic feedback, the power amplifier can almost instantly reach full power. If the frequency of the resulting powerful screech is above the tweeter's crossover frequency, bye-bye, tweeter.
The same thing can happen in many other ways. For example, if you play an electronic keyboard into a Hi-Fi speaker, it is quite possible to blow the tweeters, since high notes on the keyboard can generate sustained, high-power, high-frequency signals.
Thing seven: powerful P.A. speakers are subject to the same risks of tweeter burn-out. One way to reduce the risk is to use much more sensitive tweeters; if you can get 100 dB SPL out of the tweeter for 1 watt RMS of drive power, rather than 90 dB, that means the tweeter needs to cope with only one-tenth as much drive power to generate the same SPL.
How do you get 10 dB more sensitivity out of a tweeter? You mount a horn in front of it. In physics terms, the horn improves the impedance match between the dense vibrating speaker dome, and the very low density of air. In auditory terms, the horn makes the tweeter much louder - but there is a price to pay. Horn tweeters (aka compression tweeters) tend to have extremely erratic frequency responses, and if you have decent ears, they can sound horrid.
There are also piezo tweeters. These use a piezo-ceramic element that turns AC signal voltages directly into vibration. There is no delicate voice coil to burn out. The ceramic element itself has many unwanted mechanical resonances. Additionally, a horn is mandatory for high SPL - and with the horn comes its own nasty frequency response and nasty sound. To me, most piezo tweeters are almost unbearable to listen to. They produce that awful sound sometimes described as "being stabbed in the ears with needles".
You will not find delicate Hi-Fi dome tweeters in dedicated powerful P.A. speaker systems. Most of the time you get nasty-sounding compression horn tweeters, particularly at the affordable price end of the spectrum.
Thing eight: According to the mathematics, if the tweeter was a point source, and the horn was infinitely long, and manufactured to infinite precision, it would have a perfectly flat frequency response. In practice, none of those things is possible. More expensive horn tweeters sometimes sound pretty good - you may find these on premium-priced P.A. speakers that cost several thousand dollars for a pair, though there is no guaranteed that more money will always translate to better sound.
And if they're not expensive? Then the failings of the horn and the attached drive unit tend to be dramatic. To my ears, cheap horn tweeters almost always sound utterly horrible. But they are widely used at the affordable end of the small P.A. system market, because it's the only way to get high SPL without frying tweeters.
Thing nine: Music that has been properly recorded and mixed has also been "sanitized". There is no danger of full-power high-frequency blasts suddenly appearing to fry your tweeter. Playing back pre-recorded music via Hi-Fi speakers works fine.
In a nutshell, the problem comes down to this: if you need very high SPL, or there is any chance of brief (or long) spikes of high power at high frequencies, then dome tweeters are verboten. They are unusable, because they will not last long.
However, dome tweeters, in general, sound far better than the alternatives that tolerate high power better.
The problem you (and I) are trying to solve is relatively simple: how do you use delicate dome tweeters for live music, and still guarantee that the tweeter never seems more power than it can handle, given the vagaries of live music?
The small light-bulb in series with the tweeter is actually a really good solution. Yes, it will introduce some artifacts, but only at high power levels - power levels which would otherwise fry your tweeter. Not a bad trade off at all.
They have the correct power supply if they are fed a music signal that will never contain excessive energy at frequencies above the tweeter crossover.
In other words, they will be just fine if you keep power levels appropriate, and feed them Debussy's "Clair de Lune", Beethoven's "Eroica", or even Slipknot's most thunderous track.
But a quick blast of high-frequency feedback from a vocal mic might blow the tweeters almost instantly.
You probably know that Robin Trower, Jeff Beck, Jimi Hendrix, Eric Johnson, and probably lots of other guitarists have used that technique as part of their playing.
Not coincidentally, I think every one of those people also suffered significant hearing loss from the exposure to insanely high SPL levels.
-Gnobuddy
Electric guitar to Yamaha MG12UX console to Logitech Z623 2.1 speakers. Nothing blows up at even very high volumes and just smashing away at the strings. Three mics plugged in and on as well as a bass guitar. No feedback or blown tweeters. No tweeters to blow up!! The satellites have very capable full range drivers designed to create THX levels of sound and cope with massive dynamic range. Problem solved
Interesting!Randy Bassinga said:
The Z623 was probably designed to survive loud shoot-em-up video games, which might be one reason your guitar doesn't kill it.
The usual trade-off for increased speaker toughness is reduced audio quality (i.e. a more restricted and more uneven frequency response.)
Unfortunately the best-sounding tweeters tend to also be the most delicate ones.
Interesting, because omitting tweeters drastically limits the high frequency response of a speaker system.Randy Bassinga said:
I found a pic online - what are those rectangular doodads near the top on the front panel of the Z623? (See attached pic)
Those things aren't piezo tweeter horns by any chance, are they?
I have an old Yamaha electronic keyboard (PSR-E4-something-something). Like most of these keyboards, it has little power amps and a pair of speakers built in. And those speakers, obviously, survive whatever the keyboard can throw at them.
I think low maximum power output (from the built-in power amplifiers) is likely a key factor.
The keyboard appears to have two tweeters, one at each end. They look like dome tweeters, but I suspect they are actually piezo tweeters. A lot of older boombox and mini-component speakers contain five-cent piezo tweeters disguised with a Mylar dome over the top to make them look like dome tweeters.
Piezo tweeters sound nasty, but are very hard to kill. Supposedly you can crack the ceramic element if you feed it sufficiently high signal voltage, but it takes a lot of voltage to do it.
Raising the tweeter crossover frequency quite high - 5 kHz, say - minimizes the nasty sound quality of the piezo tweeters. This might be what Yamaha does in their keyboards.
Yamaha also plays tricks (custom EQ) to make those tiny speakers in those tiny plastic enclosures create tolerable quality sound over the entire frequency range of the keyboard.
-Gnobuddy
Attachments
Gnobuddy, that was designed to THX specs, it says so on the item with a big bright logo. I think you know very well what the THX specifications are and the minimums for sound quality that is acceptable under the standard. I think speculating on an item that you have never heard in person is not very productive and as can be seen that the speculations are way off the mark
This is starting to sound silly as parts express browse shows plenty of tough drivers in the PA catalogue that are also highly regard in the Hi-fi community
What does delicate tweeters have to do with bass anyway? If you have your filters right, they will never see any input! Anything else is not bass. If the guitar output of your flamma is frying drivers then your gain staging is off! As a line level output, it should be well able to set a correct output signal to drive any power amplifier and your patches should include compression and such to give its output stage a safe signal. Check your settings and patches
Disagree, Parts Express catalogues plenty of full range drivers that appear to be highly acceptable in this community. You must realise that there are even full range drivers in high-end PA vertical arrays and things
Review the dangers of speculation, the doodads are covers for screws. Those full range drivers are delivered 35wrms each
Built-in keyboard speakers are not very capable but if you have previously mentioned listening through thrift shop bookshelf speakers that come from budget micro systems and then they can be comparable but a totally useless monitor for serious scrutinising
Seriously? Built-in keyboard speakers and their technology is totally irrelevant to both this thread and Croc's query. The one practical and serious recommendation is still a Z623 capable of ticking all the boxes in one value package that is tried and tested in both domestic and gigging
@Randy Bassinga , I find @Gnobuddy 's posts very educational. Your point about Logitech Z623 is well-taken, and, as you know by now, I have no prejudice against it. That said, I am not eager to jump on it either: I have no access to it at junkyard prices, and paying full price does not yet make sense to me. I have an acceptable short-term solution, and I am still deliberating about my specs for longer term - but more about it in a separate thread that I am preparing.
My short-term solution is a cheap Squier guitar amp jerry-rigged together with a Yamaha sub:
My short-term solution is a cheap Squier guitar amp jerry-rigged together with a Yamaha sub:
Jiya has now used her bass amp to finish year 5. That has now been a solid two years of regular use in a band and ensemble, as well as weekly classes. The amp has performed exceptionally well and proven more reliable than the Rumble on stage. With the volume at half way, it fills the school hall and Brolga Theatre in Maryborough with beautiful deep melodic bass lines
In doing this, it has proven the value of system efficiency over driver efficiency in a big way. Everyone argues that more efficient PA and Instrument speakers are needed for such projects for high output, but I have only heard JL Audio argue for system efficiency and present low efficiency drivers as high output, and they are right about this every time. Here is a 7" driver outperforming and lasting 12 and 15" drivers
I have been holding off on making a start on my commercial bass amp inspired from this project until the Eisteddfod at Brolga Theatre. Hoping to put the prototype through trials in the new school year
In doing this, it has proven the value of system efficiency over driver efficiency in a big way. Everyone argues that more efficient PA and Instrument speakers are needed for such projects for high output, but I have only heard JL Audio argue for system efficiency and present low efficiency drivers as high output, and they are right about this every time. Here is a 7" driver outperforming and lasting 12 and 15" drivers
I have been holding off on making a start on my commercial bass amp inspired from this project until the Eisteddfod at Brolga Theatre. Hoping to put the prototype through trials in the new school year
https://www.diyaudio.com/community/threads/uffornica-bagheera-build-log.406729/
A link to the build log of the new bass amp that Jiya will be putting through its paces in the new year
A link to the build log of the new bass amp that Jiya will be putting through its paces in the new year