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Importance of Speakers/Cabinet?


I hope the guitar amp community considers the question, what does "speaker distortion" sound like?I've been listening to 60s bands and think I can identify the distinct distortion artifacts contributed by speaker breakup. My first speaker isolation cabinet experiment, around 1988, led to a blown speaker very quickly, from a 30-watt solid-state amp, so I am reluctant to experiment with speaker distortion.


My current hypothesis is that a guitar speaker sounds the same whether played at the level of an unplugged solidbody guitar, all the way up to the point where it explicitly distorts -- only then does it sound different. When people suppose that speakers have to be pushed to smooth out, I suspect that it's really the power-tube saturation (subtle and gradual) they are hearing, not a change of speaker response between, say, 100 mW, 1 watt, and 5 watts.


I have no evidence that a guitar speaker sounds any different at 100mW versus 5 watts, but I think I do have evidence of a 15-watt tube power amp sounding subtly more compressed when moving from 100mW to 1, 5, then 10 watts.I also wanted to find, but failed to find, any difference in response -- dynamic or EQ response -- between the next-to-lowest and next-to-highest setting of the Hot Plate, Power Brake, or Power Soak; I only notice explicit changes when jumping to the most extreme settings.


An amp system sounds different louder, but why?It is the ear, the speaker, the power tubes, the pot's frequency response (like the pot in the lowest Hot Plate setting)?The ear and the power tubes definely respond differently at different levels, but aside from out-and-out speaker breakup, as far as I can tell, the notion of "speaker smoothing" and "having to push the speakers so they kick in" is incorrect.


I believe this is what a certain tech was trying to convince me, online, about guitar speakers.Such speaker smoothing is elusively subtle, or nonexistent, though explicit speaker breakup -- a kind of "thrumming" sound -- is another matter.


Guitar Player magazine mentioned speaker distortion in a shoot-out that included the Celestion Blue and the Blue Dog.


TripMind wrote:
>I was interested in hearing different opinions on how certain speakers or guitar cabinets influence the sound and how important they actually are in the overall tonal picture. I know they're a lot of things that influence the guitar's sound: strings, pickups, woods, amplifier, etc, and I was wondering how much of a difference the speakers actually make. Another issue, I notice most guitarists use "vintage" 25 watt speakers or usually some type of low wattage speakers; why? I know you can get 100 or even in some cases 300 watt 12" speakers, why not a higher wattage? thanks for any input.

Scott Colborn replied:

>Through the speakers, the guitarist (first) and then anyone else (audience, etc.) "hears" his/her music. As guitarists we begin (through a process that may take years) to have a "sound" or "tone" we think of as "our" sound or tone - a really individual thing with very subtle nuances. In the days of old, "clean" sound and tone was what most guitarists sought. Others may disagree, but I think the 60's saw many of the guitarists trying new sounds and tone possibilities, and one of the byproducts of that era that lives on is the "edge" (overdriven amps or distorted amps/speakers) or "cranked" sound and tone. Lower wattage speakers break up easier than high wattage speakers - and this is a trait that many guitarists want. No less an amp authority than Jim Marshall has said something to the effect that the Celestion speakers (25 watt per speaker) were an integral part of the "Marshall" sound. The 4 x 12 cab (half stack) or the two cabs (a "stack") were equated first with the Marshall sound (although as a guitarist that still has pretty good hearing, I never stacked my cabs - didn't want that big sound hitting my ears full throttle, so I ran them side by side). The 4 x 12 cab has a bigger bottom end and a fuller sound compared to a 2 x 12 cab, but it may be easier to move a 2 x 12 cab around in cars, up stairs, etc. Also, most clubs and small halls may not require more than a 2 x 12 cab.

>I play at a local club and I take a 15 watt combo (with a 12" Celestion Vintage 30 speaker) and sometimes a 2 x 12 extension speaker cab (Weber Blue Dog and Celestion V30 speakers) and crank the amp and get fabulous tone and sound - and it's easier on my back. But if the chips were down, I'd take my 4 x 12 cab - no question.

>The bottom line for "any" guitarist is to listen to a lot of music (recorded and live) and start getting a sense of what tone and sound you are aiming for. Then through experimentation and trial and error by actually trying various amps and speaker cabs and guitars, you begin to move closer to what you "hear" in your head as "your sound and tone."

>Lower wattage speakers that break up easier, combined with an overdriven amp and a good overdrive pedal, and the "right" guitar (insert your fav guitar and pickup combination here...) will give you an edgey sound that many of us really like. Some amps/speaker cabs can give you some "clean" headroom before the breakup starts - how much clean headroom and where the breakup starts in the volume and tonal range is an individual thing.

>Some folks like a higher wattage amp that allows more clean headroom, combined with higher wattage speakers, and then get their overdriven sound by overdrive pedals, etc. I have moved away from the higher wattage amps personally to smaller amps that I can crank up more to hit the "sweet spot" of the amp and get the overdrive sound I'm after. I combine this with lower wattage speakers that offer more breakup. This range of amps might run from a hotrodded SF Fender Champ putting out 12-14 watts into a `72 Marshall 2 x 12 cab up to a Marshall Super Lead running two power tubes and using a choice of either a 4 x 12 cab or a 2 x 12 cab, and using a Marshall Power Brake to attenuate or lower the volume the speakers get. Ted Weber makes great speakers that are lower wattage and sound great, and so does Celestion. What is best is up to each guitarist to come to.

>In the final analysis, each guitarist must pursue his/her signature "sound and tone" and the speakers and cabs used are a big part of the equation. I can never understand why a lot of guitarists spend big money on guitars, pedals, and amps, but try to skimp by on speakers and cabs. A great-sounding amp through poor speakers and bad cab will sound mediocre at best. A mediocre amp through great speakers and good cab will give the mediocre amp the best chance it's ever had to sound good. Never skimp on speakers or cabs - it means too much to your tone and sound that you and the audience will hear.

May 1, 2000
To: WeberVST, Celestion:


Which guitar speaker provides the lowest volume, with the best sound?

I want to buy some 8", and maybe 6" and 10" speakers, to experiment with for quiet cranked-amp tone. Which 3 speakers should I buy for best sound with least volume?

Details below.


People assume that "small amps" sound quieter because of their lower power (15 vs. 50 watts). But actually, there is little difference in volume between these levels. The real cause of a "small amp" being quieter than a "big amp" is the smaller speaker system. Therefore, a guitarist at home can reduce the volume of a saturated tube power amp by deliberately driving an undersized speaker setup. How about a 2x12 cabinet with only a 50 watt 8" speaker in it? This would be much quieter than 2 12" speakers, driven by the same saturating tube power amp.

What is the best sounding 8" speaker for this application?

This enables a multiple-technique approach:

o Tube convertor sockets to use 2-watt preamp tubes as power tubes
o 8" speaker in a full-sized cabinet
o Isolation closet/box/booth

This approach uses essentially a standard studio gear setup but with slight variations, less radical than using 99% power attenuation after the output transformer.

There are many alternatives! You could do 3 coneless speakers (pushing foam) with one 8" speaker.

I have become interested in speaker selection, to compensate for the tonal compromise of using a speaker isolation cabinet, isolation closet, or isolation booth. I am asking Folded Space the following.



Which 8" or 10" speakers will sound best for such applications (an iso cab or a 2x12 cab in a closet)? How about 6" speakers? The goal is to get extremely quiet, but have excellent Tone. Using the digital auto-loop re-amp technique, it could free both hands to dial in the best tone, swap speakers out, and aim the mics. You can use every possible Tone technique together, to achieve this goal without the tonal compromise of a power attenuator at 99% attenuation, which would sound like a dummy load.

Does anyone have experience with a range of 6", 8", or 10" speakers to recommend a model that will sound good in a small space in a standard cabinet? I am least interested in using an 8" speaker mounted in a combo amp case. I am most interested in these points along the spectrum of possibilities:

o Micro Room type cab: very small. 2 cubic feet. 6" or 8" speaker. (most portable and likely quietest)
o Silent Speaker Chamber type cab: medium-small. 6" or 8" speaker, or possibly 10" (Demeter offers 12" standard, or smaller custom mounting size). (reasonably portable and quiet).
o Large isolation box over, or containing, a standard 2x12 cabinet but loaded with 6" or 8" speaker (least portable).
o Custom-built isolation booth (closet sized) containing a 2x12 or 4x12 cabinet with a single 6" or 8" speaker.

Which 6" or 8" speaker to use? I am defining a range of power and enclosure approaches here, but the main idea is "Which undersized, inefficient speakers should I have in my collection?"

Possible assumptions about power: o 1 1/2 watt amp (http://www.amptone.com/g232.htm Tiny Tone) to 5 watt amp (most any 6" guitar speaker can handle this level)
o 5-15 watt amp (almost all 6" or 8" speakers can handle this, unless doing what I plan: endless power-tube saturation directly driving the speaker hard.
o 16-50 watt amp -- are there good sounding 6" or 8" speakers that can handle this much power?

The goal is to treat a saturating tube power amp, guitar speaker, and mics exactly like just another effects pedal halfway along the processing chain all the way to "tape" or monitor speakers. I absolutely do not want to hear the speaker directly, not even the low-bass leakage. I only want to use the mic output. This is specifically for a home recording studio setup, not for merely casual jamming. The only thing that matters and the only thing I want to hear in the mixing space, literally, is the sound that hits the tape -- I am monitoring with near-field monitors, not with headphones, so the mixing room must be silent with respect to the hard-driven guitar speaker. I will definitely use multi-mic phasing or EQ, and electronic reverb, after the miked speaker.

I think anyone using these approaches will want to have at least 3 speakers to swap around for different tone. You could mount two different models in a 2x12 cab and electronically switch between them. In fact, that's really my question. I want to buy some 8", and maybe 6" and 10" speakers, to experiment with for quiet cranked-amp tone. Which 3 speakers should I buy for best sound with least volume?



Marshall cab specs at Blame


Speaker talk at WeberVST

Why is it that some speakers sound great in a closed back or sealed cabinet, but sound terrible in an open back cabinet, and why is the opposite true with other speakers?

Chris, excellent question. When a person designs a speaker, one of the considerations is how much the cone will move and the subsequent loudness for a given amount of power driving it. If the designer uses a loose spider and fairly flexible surround on the cone, the voice coil will have an easier time moving the cone and the speaker will be loud with a small amount of power. The problem with a loose spider and surround is that as the power is increased, it takes the cone to its mechanical limit of movement and it gets harsh. This is an underdamped system and can also sound ringy. If you put this speaker in a sealed or closed back cabinet, the air that is trapped in the cabinet acts as a spring or big balloon that the back of the cone pushes against. This air mass helps control the movement of the cone and also affects the damping of the system, making the speaker sound more in control. A designer who uses a big magnet, tight surround and tight spider is designing for a low system Q, good damping, and good transient response. In other words, when you hit it with a sharp attack note, it responds and then stops very quickly rather than ringing on and on. This speaker would work well in an open back. However, in a sealed or closed back, the air mass spring we discussed earlier would add to the damping, potentially causing the speaker to be overdamped, compressed, and lifeless. It's a difficult design task to design a speaker that is a good compromise for all shapes, sizes and types of cabinets.


Mesa offers 21 different guitar cabinets, each with a specific voice and application. By combining any of these choices, you can arrive at a sound that's all your own.

They range in speaker design and impedance, from the tiny 1x10 Rocket Extension to the mighty Recto 4x12. From bedroom to coliseum stage, they provide the full array of sound style and venue coverage.


Speaker cabinet design and speaker response

How far can you scale down the speaker and the cabinet and the isolation booth? We know that a 4x12" cabinet in a large isolation booth (20'x17') sounds great. It seems that a 6" speaker in a 12"x12"x22" [can you say "resonant peak"?] sounds bad for some reason. Perhaps there's a knee past which we should not reduce the speaker size or isolation booth cubic feet size. The hard rock guitarists seem very pleased with their jumbo flight cases over a 4x12 cabinet -- this implies you just need an isolation booth that's a little larger than a 4x12 cabinet, called supposedly a "doghouse". That's really an isolation box, not an isolation booth - since there's not enough room for a musician inside; these are unmanned spacecraft. You couldn't put a drummer in it.

A very small space around a cab does not sound small mainly because the close mic picks up room resonance. The actual motion of the speaker itself is severely messed with when you front-load it with a sealed tiny airspace as in the Demeter Silent Speaker Chamber or the Folded Space: MicroRoom. The doghouse approach only puts, say, 1/4 of the front-loading pressure on the speaker compared to a full-blown compact isolation cabinet.

It would require major research to try to get great tone from a 6" speaker in an open-room cabinet, then even more research to produce this in a totally sealed small box. Why doesn't Folded Space try a folded port inside their box? Surely the trick is just a clever, balanced tuned cavity -- probably not a symmetric 12"x12" chamber.

I want to build the $300 1 1/2 watt Tiny Tone head (small shoebox size). Buy the Folded Space cabinet or Silent Speaker Chamber cabinet. Buy several small, low-wattage speakers. Buy several mics. Try all combinations of speakers, miking, multimiking, insulation, and cabinet divisions to reach the best possible tone. There's a good chance that when optimally tuned, a 6" speaker in a small sealed cabinet could sound as good as good headphones. It is hard to find good headphones. This is like a headphone design problem, or a bookshelf speaker design problem, except with the possibility of active parametric eq after the mic.

It would be nice to offer a single small box containing the Tone Engine: a 1 1/2 watt tube power amp, a 6" guitar speaker, a small sealed cabinet, and a mic, and a preset parametric eq. The basic model is not adjustable -- the idea is to provide a guaranteed standard single constant transform function. Has a jack for line-level input, and a jack for line-level output. This is a tube amp in a box - the holy grail of guitar gear for a pedal-chain approach. Speaker can be swapped out in 15 seconds. Mic is permanently mounted and cannot slip. Parametric settings are fixed in DSP. All variation is via your preamp and your post-processing, which can be MIDI-linked together.

If a tiny speaker, tiny wattage tube power amp, and tiny sealed-front isolation cabinet cannot sound great, then go with more like a 20-watt amp, 2x12 cabinet, 12" speakers, and a BFB (Big Funking Box) to put over the 2x12 cabinet -- *that* is pretty much guaranteed to work to full satisfaction.

[spk] For the power half of the chain, try:

tube power amp - wattage irrelevant
dummy load with line-level trim pot
linear amp
1 12" guitar speaker in a dedicated cab pushed above 2 watts into rounding

If a cab has 2 speakers connected, then you have to play at 4 watts SPL minimum: 2 watts per speaker. How you use gobos or isolation box/hood/booth is up to you, but you must have an actual guitar speaker, pushed past the wimpy zone, which can be done by 1-2 watts.


Celestion speakers

Celestion speaker samples


Guitar World speaker reviews


Design a cabinet system enabling A/B comparison of 4 speakers at once, as well as the WinAmp approach for A/Bing in non-realtime.


Budda Switchmaster technology - "Do you like the sound of a 15 and two 10" drivers? How about the combination of 10's and 12's? No problem. The Budda SwitchMaster cab allows you to access any combination of speaker with our new Dual Stage 30 and Superdrive 30 heads and combos. The new Dual Stage and Superdrive 30 amps incorporate a speaker/cabinet switching system that routes your main and auxiliary speaker outs to your choice of speaker or cabinet, simply by pressing a footswitch. For over the top sonic possibilities, we developed our Lead Link switching system, which allows you to simultaneously switch speakers or speaker cabinets at the same time you channel switch to the hi gain mode of either the Dual Stage or Superdrive 30. What it means; Using a Dual Stage or Superdrive 30 head or combo as your tone source, you can pick and choose any of our fine cabinets and access your favorite speaker for your rhythm and lead tone. Whether it be an open back 1x12 or a 2x12/2x10 half back cab, you can nail the best of both Vintage and Modern tones for today's diverse musical styles. Why limit yourself to one speaker box or one type of speaker. Now you can obtain the ideal rig, a Dual Stage 30 or Superdrive 30 amp and one of our SwitchMaster cabs."

Guitar speakers vs. full-range speakers

>Why is it that while audio speakers have tweeters and woofers, guitar amps only have one size speaker? The range of the instrument isn't that great, but I would think that a lot must get lost in the one size fits all speakers.

Some guitar amps have full-range speakers.

����� Amps for bass guitar

����� Amps for acoustic guitar -- try Rock guitar with distortion pedal such as Big Muff Pi through this.

����� Keyboard amps used for guitar -- I always thought Rock keyboards are being mis-processed through full-range "keyboard amps"; in the 60s you played Farfisa organ through a guitar amp.

����� Roland Jazz-Chorus amps -- can be used for hi-fi amplification of a CD player with cymbals audible. Electro-Voice speakers are more full-range than Celestion.

����� Amps for use with a guitar synth for reproducing any instrument (Roland VG-8 synth)

http://www.amptone.com/ - isocab - some speaker articles
http://www.amptone.com/g156.htm - some speaker specs inclu. freq response.
http://www.google.com/search?q=guitar+speaker+full-range - Web pages about full-range speakers used with guitar amps





>ive always loved the sound of full range guitar(particularly clean)but needed the grime of the 4X12 for distortion etc... im also doing alot of full range looping stuff and to top that off i also got a vg8 recently
>i want to know if anyone out there has midified their 4X12 with something like a tweeter or throwing some bass 10s in there instead of 2 12's
i.e. left side=a 10(bass) 12(mids) and a tweeter(highs) same for right crosover, no crosover?
>At PARADIS we proposed this in the eighties. We added a small cabinet with a mid-high 8' speaker and a cap (as crossover, otherwhies it does not
survive!) and a footswitch so you can use it for clear piezo sounds and switch it off for heavy solos...

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