Bass amp question(s)
Question:
> The guitar frequencies are shorter in wavelength and use less power to be a > certain loud than those of a bass. > EXCEPT…read this
< snip long drawn out sad song> guitar freqs will always be shorter. I shouldn’t have said "EXCEPT" I should have said "now for something entirely different…" Advice is given best by the more articulate. "over and out" SC
Response:
Hi Dave, Sounds like a simple question but it sure isn’… You’ve got a lot of variables to play with here… Let’s start at your ears and work backwards ok? For lower volumes, your ears are much more responsive to mid frequencies. This is reduced somewhat as the volume levels rise so people invented loudness buttons to give what seemingly to the ears is a similar sound at lower volumes by boosting the bass and treble frequencies. Then you’ve got the speakers. Not all speakers are equal in terms of have a flat frequency response for the sake of argument. 1/32 of the power is needed for your 4×12 as for your 1×12 or in other words, 7.8W delivered to the 4×12 will produce the same sound pressure levels as 250W delivered to your 1×12… Not all speakers are equal in terms of frequency response either though which basically means that if you want to produce a loud noise at 40Hz and the speaker’s resonant frequency is at 80Hz, you’ll need a lot more watts to produce the same volume levels as you would with one that’s designed for a flat response down to 40Hz. Speaker design also plays a big role. The right volume for your enclosure is a good start and then you’ll have closed cabinets and ported cabinets which both have their advantages and disadvantages. Ported ones tend to be flatter at the bottom end with a sharp rolloff and slightly louder than closed back cabs which have a more curved frequency response and more geltle rolloff. Moving on to the amp. Not all amps are designed to reproduce the bottom end of the bass guitar (as are speakers) but assuming both are (you’ll be risking the amp if this isn’t the case) you’ll be interested in the frequency response and transient response of the amp. In other words, some amps will amplify different frequencies by different amounts – others will be flat. Valve amps also allow you to amplify sounds and distort nicely at the same time. This means that although you won’t HEAR any distortion, you’ll percieve the amp to be much louder and maybe call the distortion "voicing". Generally however, a bigger amp, the better its transient response and the less likely it is to clip and destroy things when you’re playing bass through it. Now for the preamp – my favorite piece of kit. Preamps – often integrated into power amps perform 2 basic functions – they amplify the bass signal and they mess with it. The messing with it bit is the interesting part. By messing, I mean non-linear amplification and distortion. Basically, changing the tone controls vary the degree that different frequencies get amplified and most probably limit the maximum percieved output of your system by pushing some frequencies harder than others making you reach the system’s limit sooner. e.g. a +6db bass boost, all things being equal will "force" the system to operate at 1/4 of the power for non-boosted frequencies all other things being equal. Not good eh? The other non-linear factor is compression – the more a preamp compresses, the less transients are amplified (relative to the mean) and the louder sustained notes will sound (almost exactly the same as the using a valve amp just below hard clipping. Conversely, if your sound is all about pops, less compression means that pops will emerge better out of the mix BUT compressed (limited if you like) pops are easier to handle. Lastly, cheap cabs shouldn’t be expected to outperform high quality cabs built for the purpose now should they? Remember that speakers are what people listen to! cb
– Hide quoted text — Show quoted text -> I have a Dean Markley 250 watt bass amp. It’s good for what I need it for > right now. I also have a Fender Squire 15 watt practice amp that our rythym > guitarist is using for practices. > Am I wrong in assuming that the higher the wattage, the louder the amp is? > The Fender seems to be able to keep up the volume level as my Markley amp, > but I’m not sure. Also, I may buy an inexpensive cab to plug the DM amp > into for shows. Any suggestions?
Response:
I have a Dean Markley 250 watt bass amp. It’s good for what I need it for right now. I also have a Fender Squire 15 watt practice amp that our rythym guitarist is using for practices. Am I wrong in assuming that the higher the wattage, the louder the amp is? The Fender seems to be able to keep up the volume level as my Markley amp, but I’m not sure. Also, I may buy an inexpensive cab to plug the DM amp into for shows. Any suggestions?
Response:
The guitar frequencies are shorter in wavelength and use less power to be a certain loud than those of a bass. EXCEPT…read this An Electrovoice engineer once told me that mid frequencies make your eardrum beat the hardest, and electronically, the lower the frequency the more power you need… up to a point. Unbelievably, once you get towards the extreme bottom of the audio spectrum the signal becomes less continuous and becomes more of a pulse or spike. Then it ironically consumes less power. I learned that the hard way when my drummer bought two and I bought one of the Electrovoice 30 inch woofers model 30W. The specs said "input power 72 the first rock band to shut down a nightclub by causing a foundation shift in the building. The drummer could back the nails out of the roof rafters with pulses from his digital kick, but mine continuous bass signal sounded wimpy as all hell, and we were both using the same cabinets nine cubic feet! This was the same speaker that comprised the famous SENSURROUND system used in movie theatres during the 1970’s for the movie "Earthquake". It didn’t work for shit with a bass guitar. It was for different frequencies. I have since come to love cabinets loaded with tens. I have used the gauntlet of 12’s 15’s 18’s and yes, 30" but I have never seen a better mix of clarity and power than that of 10" woofers. They respond quicker and there is strength in numbers, my friend. Not just any 10’s but ones that have magnets with lots of ass, like the ones in a David Eden, SWR, Ampeg, you name it cabinet. Also, having more amplifier power than you need will increase your signals headroom for a given loud and will keep your power from clipping. Also, most important of all, experiment with your eq. Sometimes that’s all it takes. "over and out" SC
Response:
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