Page 2 of 15
#41
Originally posted by Bubonic Chronic
You only get a 3dB increase for a doubling of the power. That means 2X12 is only barely louder than 1X12. 2X4X12 is just a touch louder than 4X12...

That's why it's a good idea to buy good speakers in the first place.


good speakers are vital. I 100% agree with you there, that doubling the power doesent make a substantial volume difference. My only problem with that is i have always thought that decibles are on an exponential scale, like the richer scale for earthquakes. This contradicts what i noticed about more power not meaning tons more volume.
#42
Power is misleading with speakers. It's a grossly oversimplified figure, and doesn't really mean as much as people think it does. For example, if sound can actually impinge on the back of the speaker cone, you can feed them 500 watts of low frequency energy and get next to nothing in terms of dB.

Efficiency is really more of a factor than power handling. A speaker acts a lot like a light bulb; you've got coils of wire connected to a pair of charged leads. In fact, you can connect a light bulb to speaker wire and it will light up - don't try it, though. That situation gives you a lot of electromagnetic engergy, mostly in the form of heat. So as your cones heat up, that's wasted energy.

Better cones will give off less heat (coils are designed better, higher quality magnets, better wire, etc.)

Another reason wattage is misleading is that lower frequencies require more wattage. If you're putting out 3,000 Hertz, you could probably get 100 dB out of 5 watts or less. Alarms are quite loud, eh? NO power. Just high frequency speakers with a little 9V battery rigged up to 'em.

To put out 50 Hertz takes a lot of power. 40 Hertz, quite a bit more. Frequency response falls off sharply with most amps/speakers. That's why many bass amps are ~700 watts, while guitar amps are, like, 80 watts.

If you're designing something from scratch, it's good to look at something that's already been built. Pick up a broken cab and reverse engineer it. What looks like quality design? What looks like shit? A lot of that cab design goes into the efficiency, which is the main factor that will affect loudness. Good speakers will handle just about any amplifier.
"Virtually no one who is taught Relativity continues to read the Bible."

#43
As Bubonic says it takes power (watts) to produce high levels of sound at low frequencies.
Any body can build a 5000 watt speaker but if its only 90db at 1watt 1 metre its useless
That is why you should study the parametres of the speaker before you buy. Good manufacturers provide a graph of the individual speaker's performance these days.

Good speakers have venting for the voice coil to help with cooling and therefore reducing thermal compression, twenty plus years ago as the night whent at a gig you would have to keep turning the volume up on the PA. The following night at the next gig it would feedback if left at the same levels, this is the result of 'thermal compression' the hotter it gets the impedance curve rises.
As I said in an earlier answer wattage wise you have to times by ten to double the Dbs (accoustic power), Dbs are on a logarithmic scale not linear.

G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#44
Speaking of loudness, is there any scientific explanation as to why tubes make amps sound louder than the are?
#45
Originally posted by Afroman
Speaking of loudness, is there any scientific explanation as to why tubes make amps sound louder than the are?
Yes.

When you amplify something with a tube, you get a type of harmonic distortion that is pleasant to the ear. It's like adding a choir of voices to a vocal track (kind of), only the choir is singing octaves of the original.

So your tube amps sound louder for two reasons:

A) The harmonic distortion gives you more energy in the 2,500 Hz range, which is the frequency range to which we are most sensitive - it's also a range that doesn't require much power to amplify.

B) The effect of the "octave choir" thing (even harmonic distortion, I believe, but it's been a few years) is to make the sound louder psychoacoustically.

You see, the word "loudness" implies psychoacoustics, which is our perception of the sound, instead of acoustics, which is the actual physics of sound. If you say, "that's loud!", that doesn't necessarily mean it's a powerful signal - like your fire alarm. That's got very little power, but the sonofagun is loud, eh?

It is high dB, though.

But loudness is slightly different than dB. You can have 120 dB of 30 Hz and it will sound like 80 dB. (Just a rough guess, but not far from the truth.) We are less and less sensitive the lower you go. So the loudness is equivalent to, say 80 dB of 1000 Hz, hypothetically.

Kind of like wind chill or heat index vs. temperature.

When it's 80 and humid, if feels like 95, you know?

Or if it's 45 and windy, it'll feel like it's 29?

That's the idea.

So a tube amp is like heat index. You turn it up to 100 dB, it sounds like 105 because of those harmonics.

Good question.
"Virtually no one who is taught Relativity continues to read the Bible."

#46
Awesomely well explained. I am frightened by the fact that i understood that. My hat is off to you, Bubonic Chronic.
#47
You certainly know your stuff Bubonic

Valve amps are great but for bass they are also very heavy, the last valve amp that I used was an Orange 120 watt after that it was solid state for me.
as I said they sound great on bass but my days of lugging a valve amp around are long gone.

G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#48
^^ Props to you, too, on your knowledge of porting.

I studied room acoustics heavily, but only touched upon transducer design. What I know I have pieced together from theory and practice, it's good to have someone like you around with some real world experience.
"Virtually no one who is taught Relativity continues to read the Bible."

#49
Hi Bubonic
Just thought that you and other Bassists would like to know about the light at the end of the tunnel regarding lighter speaker magnets.
I'm due to take delivery of a 15" Neodymium magnet speaker, Ive already got a 600 watt 18" with a Neodymium magnet which is smaller and lighter than the magnet on my 10"s..
Iv'e also been testing some lightweight panel speakers they are about 30"x 30" with what are called exciters on the back of the panel, the same sound comes out of the rear as comes out of the front, no tweeters but plenty of highs, they don't like too much bottom end so you need a sub bass unit, I've gigged with them on foldback.


G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#50
hye man, just the other day i had a ****load of quesrtions about building a cab. and you just answered al my questions. great work
#51
^^ Thx.

Speaker/cabinet design is probably the most important element to consider in your tone simply because this is the weakest part of the chain. Traditional speakers pale in comparison with amps, mics, effects, pretty much everything. Add the acoustics of the room in there, and you can get some unbelievably bad sound.

I just saw a show at a warehouse, and what a pile of crap! It's not even worth playing amplified music in there.

I'm currently thinking about frequency-specific phase cancelling speaker systems - manipulating room acoustics by adding energy from speakers. You could do something like that very cheap: a parametric EQ, delay box and an amp/speaker placed at the right location, simply wired backwards. Work with that EQ and the delay time, you could "tune" the room with unbelievable flexibility.

...ah, the thoughts of a lowly acoustician attending a very unpleasant concert.
"Virtually no one who is taught Relativity continues to read the Bible."

#53
Originally posted by pooch0072
is it normal for a closed back bass cab to have cotton batting inside? Also, what are good ways of getting rid of tweeter his ( even if you have an L-pad)?

Most manufacturers put some form of accoustic wadding inside bass & PA cabs. On bass it cuts down unwanted resonance, if you go too near a PA cab with a mike and the cab has no wadding inside you will notice bass boom /feedback.
If you fill a bass cab (without blocking the tuning ports) with accoustic wadding you theoretically increase the internal volume of the cab therefore lowering the resonant point, the only drawback is that you lose some effeciency.
Boosting high frequencies excessively can cause tweeter hiss having the master set too high can also make your rig noisy.
Just fine tune your settings, even the top range amps are noisy if used improperly.

G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#54
Hi Bubonic,

I loved reading your thread, there is some great information in here! I was just wondering if you could answer one question. I have a VOX AD30VT of the valvetronix series. I'm very happy with it, though the only thing I miss is the real bite, and the aggression. It all sounds a little bit to smooth, if you know what I mean. So I was wondering if I could change the speaker in my amp, but I decided I didn't want to fool around with my amp, since it's fairly new, and I didn't want to screw anything up.

So then I decided it might be cool to make my own cab, for under the combo. My amp doesn't have socket to connect with a cab, but it does have a line-out. So I thought I would connect the cab that I'm going to build, with my combo, by connecting the line-out of my combo and the line in of the cab, with an audiocable. Would this be possible?

I understand that the combo wouldnt't have enough power for the speaker in the combo itself AND the speaker(s) in my cab, so I thought that if I wanted a very smooth sound, I would unfasten the cable from the back of my combo, enabling the speaker in my combo to work. And when I would want a more aggresive tone, I would fasten the audiocable back, thus enabling only the speaker(s) in my cab to work. This way they wouldn't ever work simultaneously, os I wouldn't need a different amplifier.



Here is a picture I made to illustrate my idea. I would love to get some feedback on the plan, and to hear any critical points that I have missed in my idea.

Thanks,

Peter
#56
About the VOX, you will have to hook up a speaker output.

The important thing is to get the same wattage, but most importantly the same ohms speaker as the one in there.

To hook up a speaker out, you're correct, you need to disconnect the existing speaker. Understand, though, that any alteration to your current cab is a deviation from its original design and the original sound - and VOX is very sought after - will not be available anymore.

What I would recommend is to install a speaker out after disconnecting the current speaker. Then, install a standard 1/4" connector to the speaker so you can plug it back in if you want and have option of using the original cabinet very close to its original design. Unplug that speaker, plug the new one in, etc.

Don't worry about porting or anything on the guitar cab. There are some ways to work with resonance to boost the low end, etc., but they are very tricky, and I doubt you'll need them. Just buy a nice 12". 12"s are good all-around speakers for attack.

The main thing about this job, though, is that you will probably never get the kind of attack you want out of a VOX amp because they just are not designed to give you that kind of sound. Can you improve the sound for attack by using different speakers? Definitely. Will it sound like a Marshall, or better yet, a Mesa/Boogie? No.

The nice thing is, though, you can always just pick up a head later, Marshall, Peavey 5150, Mesa, Laney, whatever you want and hook it up to your speaker. I give you my blessing in doing this, but warn you in advance that modifying the speakers will only get you so far. The amp itself has the biggest influence on the attack.
"Virtually no one who is taught Relativity continues to read the Bible."

#57
hey, great article its sparked my imagination for building a cab. I was just wondering, since i love Cerwin Vega's speakers so much, why aren't Cerwin Vega's used in cabinets. I would like to try and would love input on how good they woud sound. thanks
#58
Originally posted by russiaininvader
hey, great article its sparked my imagination for building a cab. I was just wondering, since i love Cerwin Vega's speakers so much, why aren't Cerwin Vega's used in cabinets. I would like to try and would love input on how good they woud sound. thanks
They are not designed for instrument use.

They are designed (if I'm not mistaken) to be used for music that is already produced, meaning there are no sudden impulses of high decibel sound coming through.

It's kind of like the difference between a pickup truck and a sports car. A Cerwin Vega is kind of like a sports car, but if you need to haul 1,500 lbs of junk, you're pretty much screwed. The pickup truck is not as fast or comfy, but when you need to move your shit, you're glad you have it.

Know what I mean?

Two different kinds of speakers for different kinds of tasks.

Instruments put out a lot of juice, and it's really hard on speakers. That's why you need something that's specifically designed to be rugged, that can handle funk bass, or heavy metal chunk. You would probably tear your CV's to pieces in an instrument cab.
"Virtually no one who is taught Relativity continues to read the Bible."

#59
hey thanks alot for the Cerwin Vega explanation you saved me like 400$$ but ive got another 2 questions concerning speakers. Why do so many speakers (guitar) cut off the frequency at about 5khz when our hearing goes up to almost 20khz for some people? As well, what does it mean when a speaker has 100db sensitivity? thanks in advance, and keep up the great work=D
#60
Originally posted by russiaininvader
hey thanks alot for the Cerwin Vega explanation you saved me like 400$$ but ive got another 2 questions concerning speakers. Why do so many speakers (guitar) cut off the frequency at about 5khz when our hearing goes up to almost 20khz for some people? As well, what does it mean when a speaker has 100db sensitivity? thanks in advance, and keep up the great work=D

There are speakers around that go up to 20khz, these are co-axial speakers that take an added HF unit as well as the basic speaker, also available are 'Dual Concentric' or twin cone speakers, these speakers have a tapered cone fitted where the dust cover goes in the centre of the speaker cone, they can extend response up 14/15khz.
The above mentioned speakers are very rarely used on instrument amplification they are normaly used for public address (PA). The twin cone speakers aren't much more expensive than standard speakers
The 100db sensitivity figure is very often a waste of time as it usualy is '100db @ 1 watt @ 1khz @ 1metre, the point that I am making is that 1khz has little meaning for guitars bass or vocals.
Many manufacturers now give a performance graph printout which is much more relevant to requirements. Bubonic actualy wrote earlier in this thread about higher frequncies, look it up and you will see what I mean.
As an after thought why don't you start experimenting with add on HF units yourself, I was using horns in my bass cabs way back in the 70s, you can experiment by altering the value of the capacitors and getting attenuation by using high power handling resistors.

Regards
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
Last edited by John Swift at Jan 19, 2005,
#61
I'd just like to say this is a sweet thread. I have a question of my own now, im thinking about making an extension cabinet for my amp, but i was wondering - how hard would it be to make a leslie - type cabinet. In case you dont know, but you probably do, in a leslie cabinet the speakers rotate, giving a sort of swerly-type sound. So back to the question, how hard would it be for someone like me who is new to amp making but wants to build one of these?
Orange Rockerverb 100 + Orange PPC412
Fernandes Dragonfly Elite
Ibanez RG1570 Prestige
Ibanez RGA121 Prestige
Fender Road Worn Player's Telecaster
#62
Originally posted by ~Rock~Guitarist
I'd just like to say this is a sweet thread. I have a question of my own now, im thinking about making an extension cabinet for my amp, but i was wondering - how hard would it be to make a leslie - type cabinet. In case you dont know, but you probably do, in a leslie cabinet the speakers rotate, giving a sort of swerly-type sound. So back to the question, how hard would it be for someone like me who is new to amp making but wants to build one of these?


The Leslie cabs speakers rotated a varying speeds that's where the unique sound came from, but on some multi effects units there is a Leslie simulation I believe that the 'Alesis Quadraverb' had such an effect in its presets.
To build one yourself would be pretty nigh on impossible, but, if you live in the UK there are hundreds sittng unused, on stages, in 'Working Mens Clubs' (for those of you in the colonies someone else can explain what these establishments are) and I do know for a fact that many band have manged to talk some of these places into selling them.

G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#63
On Leslie - check Ebay.

You probably won't be able to find exactly the right parts to build a true leslie yourself, but doing something similar to that has always been a dream of mine, but..

I'm married.

I love her to death, but I doubt she would appreciate even more big ass speakers in our humble abode.
"Virtually no one who is taught Relativity continues to read the Bible."

#64
Thanks. I searchd ebay and found quite a few parts for them, including several motors, rotary horns, and speakers from actual leslie cabinets. do you think i would be able to do it?

edit: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3275&item=5744665390&rd=1 these speakers are from a hammond organ, could i make a guitar cabinet with them?

im seriously starting to consider this project... i just dont want to start on it and then halfway through i realize i have to spend $500 on special extra parts or to see an expert on it.
Orange Rockerverb 100 + Orange PPC412
Fernandes Dragonfly Elite
Ibanez RG1570 Prestige
Ibanez RGA121 Prestige
Fender Road Worn Player's Telecaster
Last edited by ~Rock~Guitarist at Jan 20, 2005,
#65
Originally posted by ~Rock~Guitarist
Thanks. I searchd ebay and found quite a few parts for them, including several motors, rotary horns, and speakers from actual leslie cabinets. do you think i would be able to do it?
edit: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3275&item=5744665390&rd=1 these speakers are from a hammond organ, could i make a guitar cabinet with them?

im seriously starting to consider this project... i just dont want to start on it and then halfway through i realize i have to spend $500 on special extra parts or to see an expert on it.

Looking at those speakers wouldn't encourage me to buy them, and looking at the dust cover I would say that the voice coil would be 1" max and as they appear to be well used they will have taken some hammer from the bass pedals.
They don't even look to be decent speakers either so you would be better off with a pair of 'Eminence 12" 200 watt GP speakers.
What you must remember is that the 'Leslie' cab was a complex piece of gear, the variable speed motor must have had some kind of controle system, maybe you could get hold of a 'Leslie' manual before you start spending your money.
Have you thought about buying a complete 'Leslie' cab and then using the parts to build smaller separate units?, but I would try and get hold of a manual first, I'm am not trying to put you off I'm just trying to point you in the right direction
G&L L2500
Squier Affinity Jazz Bass 5
Ashdown RPM pre-amp
Ashdown Little Giant 1000
300 watt 15" powered cab
450 watt 15" powered sub bass cab
2x10 + horn
1x15x10 + horn
#66
Well thanks. I'm going to do my best to find a manual but I'm probably just going to build a regular 212 extension cabinet for my Fender Hot Rod Deville.

as far as the hot rod deville goes - if i plug a cabinet into the extension speaker jack will it also play out of the deville or will it just work like a head in a half stack and not make any noise?

also, im looking for a very vintage bluesy-rock tone so im looking at the celestion vintage 30. would this be a good choice? thanks.
Orange Rockerverb 100 + Orange PPC412
Fernandes Dragonfly Elite
Ibanez RG1570 Prestige
Ibanez RGA121 Prestige
Fender Road Worn Player's Telecaster
#68
Originally posted by Bubonic Chronic
^^ Of course.

The photo will take a bit of time, though, as I'm working with a disposable camera and a scanner. Usually turns out better than digi anyway, though.


wow. amasing u guys know your ****! I build myself an 8 watt amp, but not just the cab. Do any of these things apply?
www.myspace.com/funkmecrazy
Stevie Ray Vaughan and John Bonham's number one fan

"how do you make a 15 watt solid state amp sound good?"
Quote by p o e
step one, insert screwdriver into speaker
step two buy a good amp
#69
Originally posted by Robbieeggo
wow. amasing u guys know your ****! I build myself an 8 watt amp, but not just the cab. Do any of these things apply?
For eight watts, you really don't need to worry about anything. Just stick it in a box and go. The reason for all the science is because (generally) you're putting out large amounts of bass frequencies, which are difficult.

For a small project, there's not a whole lot you can do to improve upon the standard practice amp design, although the sky is the limit as far as circuit design.
"Virtually no one who is taught Relativity continues to read the Bible."

#70
im back again, and ive decided im going to make an extension cabinet for my fender hot rod deville. im gonna put in 2 12 inch vintage celestion 30 speakers in, and ive got two questions.

- as far as ohms go, my amp says the external speaker output should be used with 8 ohms, so should i buy two 8 ohm vintage celestions?
- also, in the product descriptions it says my amp is 60 watts, but on the specifications on the back of the amp it says "180W" will this be too much for the vintage celestions because they say they handle 60w.
Orange Rockerverb 100 + Orange PPC412
Fernandes Dragonfly Elite
Ibanez RG1570 Prestige
Ibanez RGA121 Prestige
Fender Road Worn Player's Telecaster
#71
I have a Peavey Basic 112 with an internal 8 ohm 12" speaker and an external speaker jack for an 8 Ohm speaker. I need the extra 25 watts that I could get by having 4 ohms of speakers hooked up, but this cabinet building is looking to be complicated for bass, and out of my budget. Would it be possible to just replace the internal speaker with a 4 Ohm speaker so i could get 75 watts instead of 50?
Winslow
#72
Originally posted by rockbassguitar
I have a Peavey Basic 112 with an internal 8 ohm 12" speaker and an external speaker jack for an 8 Ohm speaker. I need the extra 25 watts that I could get by having 4 ohms of speakers hooked up, but this cabinet building is looking to be complicated for bass, and out of my budget. Would it be possible to just replace the internal speaker with a 4 Ohm speaker so i could get 75 watts instead of 50?


If you cut the impedence in half (the ohms) the wattage should double.

Doing so, you run the risk of frying your amp. Plus, you might clip a gain stage, which could fry your speaker as well.

If you have no money and need more bass juice, stick the cabinet in a corner with concrete walls. You can get some acoustic gain this way.

And to Rock Guitarist: don't worry so much about what speakers will handle. Impedence (ohms) is the important thing. Never mess with ohms unless you know absolutely what you're doing.

If you overdo it on wattage, you will hear it before anything bad happens. When they start farting (you'll know what I mean) you probably have 10-15 minutes to turn it down before your speakers are fried. If you hook up low ohm speakers to a high ohm amp, you'll get a sudden death...followed by a mysterious hot smell, like burnt toast.
"Virtually no one who is taught Relativity continues to read the Bible."

#73
Originally posted by Bubonic Chronic


If you cut the impedence in half (the ohms) the wattage should double.

Doing so, you run the risk of frying your amp. Plus, you might clip a gain stage, which could fry your speaker as well.

If you have no money and need more bass juice, stick the cabinet in a corner with concrete walls. You can get some acoustic gain this way.

And to Rock Guitarist: don't worry so much about what speakers will handle. Impedence (ohms) is the important thing. Never mess with ohms unless you know absolutely what you're doing.

If you overdo it on wattage, you will hear it before anything bad happens. When they start farting (you'll know what I mean) you probably have 10-15 minutes to turn it down before your speakers are fried. If you hook up low ohm speakers to a high ohm amp, you'll get a sudden death...followed by a mysterious hot smell, like burnt toast.

No, the amp has an external speaker jack, and it will take 4 Ohms impedance. It has an 8 Ohm internal speaker, and it can take an 8 Ohm extentsion. I was just going to put one 4 Ohm speaker inside of it instead of building an extra cab for another 8 Ohm.
Winslow
#74
If you did that, I'd wire a plug to the leads and put it into 4 ohm speaker out, just to make sure ... and make sure that plugging in an extension speaker overrides the original speaker, or you may have a problem
Alexander Eagle--> Morley M. T. Power Wah--> Hot-Rod DS-1--> Phase 90--> EHX Small Clone--> Peavey Delta Blues 2x10
#75
Originally posted by Bubonic Chronic


And to Rock Guitarist: don't worry so much about what speakers will handle. Impedence (ohms) is the important thing. Never mess with ohms unless you know absolutely what you're doing.

If you overdo it on wattage, you will hear it before anything bad happens. When they start farting (you'll know what I mean) you probably have 10-15 minutes to turn it down before your speakers are fried. If you hook up low ohm speakers to a high ohm amp, you'll get a sudden death...followed by a mysterious hot smell, like burnt toast.


thanks. in your examples you showed how to wire 2 4 ohm speakers to make an 8 ohm cabinet... how would you wire 2 8 ohm speakers to make an 8 ohm cabinet, because the external speaker jack on my amp says to go to an 8ohm cabinet, and i cannot find the kind of speakers i want in 4ohms.
Orange Rockerverb 100 + Orange PPC412
Fernandes Dragonfly Elite
Ibanez RG1570 Prestige
Ibanez RGA121 Prestige
Fender Road Worn Player's Telecaster
#76
^^ Hmm, that's tough. If you had four 8-ohm speakers, you could do a series-parallell thing and get a single 8-ohm system, but with two 8's you're pretty much stuck with a 16-ohm or a 4-ohm system, depending on if you wire them in series or in parallell.

16-ohm would be the safest:

+____+(Speaker)-_____+(Speaker)-____-

That's just like lining up batteries in a flashlight.

Trouble is, 16-ohm would be awful quiet.

You did say you have an 8-ohm speaker in it already, though, right? And it can drive an additional 8-ohm speaker?

If that's the case, you can just build the cab with two 8-ohm inputs. Then convert the output to the internal speaker into a male 1/4" jack. If you do that, you'll have to solder new lead wires directly from the circuit board. I'd go with 10-guage or fatter wire.

As for the external speaker output, you could either plug a regular guitar cable into that and then into the other input of your cabinet or conver that to a male 1/4" as well. That's not the usual way of doing things at the factory, but there's no reason why you can't do it that way. In fact, eliminating a female/male connection will strengthen your signal and give you better tone. The only drawback is physical stress that loose wires might place on the circuit board, but there is a quick fix for this, too.

Pull the wires to the side of the amp's chassy, leaving a bit of slack. Now take an industrial staple gun (not your mother's Swingline!) and put a big-ass staple into the chassy to hold the loose wires in place. Then if you happen to step on the wires and lift the cabinet you will rip the staple out of the chassy, but your circuit board should be ok.

I don't know what you call that, technically, but it's generally a good idea to relocate your physical stress point away from fragile circuitry. Connect those wires (physically) to some wood, and your circuitry will last a lot longer.
"Virtually no one who is taught Relativity continues to read the Bible."

#77
Mr. Bubonic Chronic, what are the dimensions for the old school marshall cabs? the really long ones that looked like bass cabinets.
do those dimensions create "modes"?? and how do you cover cabinets, in general?
#78
Upon Request from Bubonic:

I'll post the questions I have been having.

Q: Would someone who builds subwoofer cabinets be qualified for making guitar cabinets?

A: Not a bad question.

Guitar cabs are a whole lot more simple to build than subwoofer cabinets. It's different technology. I'm assuming he builds subs for automotive applications?

I don't touch that stuff, lol.


Q: What kind of speakers should I choose. Also, what things should I buy to make the cab?

A: Anyway, you pretty much have to choose among the major speaker manufacturers that make guitar speakers:

Peavey and Celestion come immediately to mind. To me, it is somewhat like Ford/Chevy - it depends on who you ask. I use Peavey myself. They are rugged.

Crate builds some, but they're not that great.

There is also Laney, which Opeth uses, and a ton of British bands.

But guitar speakers generally come in 10", 12" and 15". I don't know who makes a 14".

For gigging, a 2X12" should be fine, assuming your venues provide monitors. Realistically, you don't even need a cab at all these days if you're gigging at clubs with a good sound system.

4X12 is only 3 dB louder than 2X12", that's more for the vintage look than anything.

For practical purposes, 2X12" should do you fine.

Celestion is the Marshall sound, Peavey is the 5150, Van Halen sound, Laney is the AC/DC, Motorhead sound (British)...I'm really not too sure about that, but what else would you expect the brit bands to use? lol

Wood, cones and wires is all you'll need. You also need a poweramp.

Just tune the port for something below 160 Hz and you should be ok (try 100, that's a nice, square number for your calculations, that'll make it easy.)

Of course you don't have to port, you can always just bust a hole in the back. Guitar doesn't have the same problem with the cancellation that bass has. Bass is truly an art.

The best way to go is to just buy a guitar head. If you're a soloist, the 5150 (Peavey) has a great sound, but lacks a bit if you're into the hardcore metal. Marshall is great for classic rock/80's metal. Mesa/Boogie is like the lamborghini of amps. They sound like a woman's tits in your mouth covered in strawberry syrup, but then they also cost at least $1500 new, so there you go. Marshall is probably more versatile.

2X12" Celestion cab would probably be the best for general applications. I went with Peavey because I did a hybrid job (1X15" and 2X10"). Celestion may or may not make 15"s, but I know that Peavey's Black Widow is a good speaker, that's my 15". I'm also not too familiar with Celestion's availability of 10"s, so again I went with Peavey as they offer a good product, the Scorpion in that size.

Celestions, though, are standard in Marshall cabs and in tons of other manufacturers' amps, too. They are great. Each will cost you about $100, and you want to wire them with at least 8 gauge wire, if not thicker. The thicker the better. Don't let anyone tell you that Monster cable (cryogenically treated and special alloys and junk) is better, it's a waste of money. Sure, maybe it's a bit better, but for the extra cash, just go down a gauge or two - lower gauge is thicker. You'll get farther with 5 gauge cheap wire from a hardware store than with 12 gauge Monster. It's just a scientific fact.

They will do perfectly. The reason I went with Peavey is they offered me more flexibility as far as speaker diameters.

I could use a 15" and 2 10"s that way.

If you're going with 12"s, then Celestions are your best option by far.

The thing to remember is you want to oversize your amp (your head) rather than your speakers. Here's the reasoning:

If you put a 50W head on 100W speakers, the speakers are going to "ask" for 100W. Since the amp can't produce that wattage, it will "clip", or send out a straight voltage with no frequency, like hooking up a car battery to your speakers, basically. A speaker coil (the coil of wire that surrounds the magnet) then becomes a highly effective toaster.

A very expensive toaster at that.

So you're much better off hooking up a 300W amp to a 100W speaker cabinet because the amp is not going to clip, and the speakers are not going to become a toaster. Instead, you'll be forcing the speakers to the limits of their design. Like a car or any other machine, they can handle a little bit of punishment. The thing is, though, you probably won't turn the amp up all the way, and your speakers will warn you that they are reaching their limits by "farting," and you will know when this happens. It's an ugly thing, but it's not doing permanent damage (probably.)

When you hear your cones farting, turn it down. You still have speakers!



To recap:

Small amp + Big speakers = TOAST!

Big amp + Smaller speakers = you'll get a warning, use your noggin and turn it down

A power amp is called a head. Good ones cost between $800 and $1500 new, but you can often find used ones as low as $150 or $200. It all depends on age, condition and what you want.

There are tube amps and solid state amps. Tube are generally considered to be better, but solid state technology is getting better and better. The tubes "flavor" your sound.

Some good heads:

Marshall
Peavey
Laney
Fender

I would go to a guitar store (such as Guitar Center) and try some out. Get a nice guitar off the wall and plug into a variety of amps. Try out all four of those above if you can. See what you like best.

Then go home and look on Ebay, or even look in the "Musician Ads" here at UG.

Fender stuff is generally consistent and all sounds good. It is definitely blues or classic rock sounding, though. Marshall is very hard rock/metal sounding. Great if you're into that heavier stuff.
Laney, like Marshall, is excellent for heavier stuff, but different. It's like vanilla or chocolate,which is better? It's up to you.

Peavey makes some crappy heads. I wouldn't waste my time unless it is comparable to a 5150.

You can also rent, too. Look into that. It would be $20 a month or so, and you'll build your credit. I rented to own literally thousands of dollars in equipment and my credit is great now for a guy my age. I could buy a house if I wanted (and will soon.) You just have to be serious about making those payments for 2 years or so...if you want a top-notch amp that will last a lifetime.

As for the one speaker idea, that will work fine. I would recommend an 8-Ohm speaker. That is going to be the safest way to go and will work fine. There are 4-Ohm and 2-Ohm models, but that's for when you are more experienced and know you won't fry your gear. At this point, 8-Ohm will be a perfect fit.

If you wanted to double that speaker up, just wire it parallel with another 8-ohm job (I explained in the thread) and it will be a 4-Ohm pair. You're still safe with that. Just make sure to flip the switch on your head to 4 instead of 8 ohms.


Bubonic Chronic, You've been a huge help!
Last edited by metallicaman80 at Apr 6, 2005,
#79
Originally posted by FlyingFuc!<
Mr. Bubonic Chronic, what are the dimensions for the old school marshall cabs? the really long ones that looked like bass cabinets.
do those dimensions create "modes"?? and how do you cover cabinets, in general?
Hmm...I'm not sure of the dimensions.

You can cover cabs in anything you want, but I recommend something cheap as you'll probably spill beer on it at least once.
"Virtually no one who is taught Relativity continues to read the Bible."

#80
If i were to compare two guitar speakers that had almost the same specs, but made from 2 different companies, could they still sound totally different?

Also, its possible to mix two different 12" speakers in a 2X12 cab to give a unique sound? thanks

lastly, for what was talked about trying to get the speaker rating close to what your amp is, how close do you have to be, is 60 close enough to 50, also, should i be trying to match the speakers RMS to my amp, or the max handling? thanks again