1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

Why don't guitar amps use 3-way speaker arrangements?

Discussion in 'Amp Central Station' started by MrCoolGuy, Oct 29, 2020.

  1. enorbet2

    enorbet2 TDPRI Member

    Age:
    74
    Posts:
    31
    Joined:
    Nov 26, 2019
    Location:
    Viurginia, USA
    Guitar amps, unless you're including SIMs/Modelers with FRFR speakers, are NOT reproduction devices like HiFi amps are. Guitar amps are integral musical instruments... they have a "voice". The only moderately successful guitar amps that were anything even approaching HiFi were strictly for ultra clean Rhythm players and NONE of those are considered to have stood the test of time or musician's ears.
     
    Dukex and tubelectron like this.
  2. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    First, the guitar doesn't have that kind of range. Second, the original amps were all licensed designs from the likes of Western Electric, and there's a 'traditionalist' mentality.
    Also, the speaker is a prt of the sound. When the amp is miced through the PA, what you're asking about is what they're doing. A biamped or triamped setup would be better than a passive crossover. The guitar signal is a lot more dynamic in range than the compressed music on a CD or other digital recording, and it puts a lot of stress on the power supply filter caps and the crossover caps.
    I've done this with an effects unit run directly into my stereo, but it was a brute of an amp and the so were the speakers. More speakers get blown up by cheap and/or underpowered amps than overpowered amps, due to nasty responses from an overworked power supply.
    I haven't gotten around to messing with this yet, but I've got some old 2 way computer speakers and a bunch of electronics that I've been saving, just to do this.
    Passive crossovers eat a lot of power, so you generally don't see more than two way systems in lower end PA systems, and the more expensive ones use electronic crossovers and multi amp setups.
    So, I'd say it's mostly cost, tradition and not so much physical limitations, although a midrange or tweeter are not going to like being overdriven, like full range 12" driver.
     
  3. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    Other considerations include the speaker loading the power supply interation with the speaker. For most hi fi speakers, the cabinets are sealed or vented, not open back or infinite baffle. The cabinet is used to damp the backwave, which is what they call damping. In guitar cabinets, the cabinets aren't sealed as tight, with a lot of guitar speakers.
    Also, the impedance of the power supply damps cone vibrations in hi fi speakers, and that impedance is usually tenths of an ohm and lower. In a typical tube amp, the speaker impedance is reflected back through the output transformer.
    For clean sounds, the hi fi approach can sound great. However, remember the old saying, 'the best sound you're likely to get from your amp is the last half hour before it blows up'.
    If you've got a great sounding front end (sounds good through headphones, you should be able to just hook it up to a hi fi setup, as long as it's not a cheap amp powering the speakers.
     
  4. jaxjaxon

    jaxjaxon TDPRI Member

    Age:
    67
    Posts:
    39
    Joined:
    Apr 4, 2020
    Location:
    SanluisObispo CA.
    Any one hear a guitar plugged into a Leslie. They are full range speaker set ups. I think you could use different crossovers to get the frequency's you want. Why use a Bass amp to play guitar thru but many people do. Why put capacitor on your tone pot. And you should allways use a speaker that is rated 1/3 more watts then your amp puts out if you are going full volume.
     
  5. waynereed

    waynereed TDPRI Member

    Posts:
    43
    Joined:
    Apr 2, 2013
    Location:
    Central Ohio
    You can buy guitar sub woofer cabs. They make them. I'm thinking those who drop tune their guitars down 1/2, a whole, some even down to low C would appreciate them.
     
  6. fjblair

    fjblair Tele-Holic

    Posts:
    526
    Joined:
    Dec 29, 2010
    Location:
    NC High Country
    Yeah the guitar operates in a pretty narrow frequency spectrum.
     
  7. LightningPhil

    LightningPhil Tele-Meister

    Posts:
    354
    Joined:
    Dec 1, 2018
    Location:
    Nottingham, UK
    To go against the grain, I rather like playing distorted guitar through bass PA drivers, direct from the amp - without crossovers. Rounds off the highs nicely. And for clean tones, a guitar speaker that’s been forcibly broken in to lower its resonance into the 40Hz range. This gets the resonance peak of the driver away from the lowest notes and, to me, sounds less boxy.

    HiFi drivers aren’t efficient enough and as mentioned above by many, don’t add to and shape the sound - they just present it clearly.

    5” mid/bass speakers can be fun though - when played through on their own in a suitable cab. Ones with similar frequency range as a guitar driver can be found, but much less efficient. Gives the effect of an attenuator without having to have one.
     
    PhredE likes this.
  8. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    Hi fi drivers can be plenty efficient. A 100 watt amp through a Klipschhorn will literally blow the windows out of a living room. Even my Heresy model was so loud with my 110 watt amp that it made my ears distort. The more efficient horn loaded drivers will have a sensitivity of 108 dB/1 watt. I think my Heresies were rated at 96 dB/1 Watt. You're going to be hard pressed to find an instrument driver with that much output. The 5 inch drivers mostly don't have trhe excursion to move a lot of air. A 12" Jensen instrument speaker won't make a very good woofer, however, due to it's construction.
     
  9. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    The Leslies don't get used for massive overdrive, but your point is well made. I had a Leslie that was taken from an organ and it was basically just a 10" Jensens, firing into a rotating deflector.
    As for power, a big key for solid state amps is the filter capacity. Many more blown speakers from underpowered amps, where the filter caps get drained, causing a lot of nasty transients that take out midrange drivers, tweeters or crossover components. My buddy blew the midrange drivers on a pair of JBL Centuries (12" woofers) with a 60 watt Pioneer amp.
     
  10. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    Les Paul played the Recording model, which has low impedance wide range pickups, and he went right into the board. There's plenty of sweet sounding tones way brighter than most electric guitars that the Recording model produces, even through their matching transformer, into a standard guitar amp. And it doesn't sound anything like an acoustic.
     
  11. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    A lot of it has to do with signal level. Take that same amp through a typical speaker, record it properly, and play it back. There really shouldn't be too much difference. Also, the guitar amp's output impedance is going to affect the movement of the cone. A typical solid state amp is going to have a different damping ratio than a tube guitar amp.
     
  12. LightningPhil

    LightningPhil Tele-Meister

    Posts:
    354
    Joined:
    Dec 1, 2018
    Location:
    Nottingham, UK
    A horn loaded guitar speaker would be fun. Tried transmission line. Added a little to the low end and sounded nice, but was bulky.

    So ok, I was referring to the more general, less imaginative and inexpensive speakers.
     
  13. Boreas

    Boreas Friend of Leo's Silver Supporter

    Age:
    65
    Posts:
    2,025
    Joined:
    Nov 3, 2019
    Location:
    Adirondack Coast, NY
    Probably nothing worse than crystal-clear, hi-fidelity distortion...
     
    PhredE likes this.
  14. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    It will definitely sound different. Tube guitar amps have output transformers, and solid state do not. The output impedance is much lower, and this controls the damping factor. If you try this with a solid state amp, make sure it's got a very good power supply, or you'll blow a tweeter, midrange or a crossover component. Cheap amps blow more speaker components than overpowered amps do.
     
    Last edited: Nov 4, 2020
    MrCoolGuy likes this.
  15. Sparky2

    Sparky2 Friend of Leo's

    Age:
    61
    Posts:
    3,460
    Joined:
    Apr 15, 2017
    Location:
    Harvest, Alabama
  16. W.L.Weller

    W.L.Weller Tele-Holic

    Posts:
    817
    Joined:
    May 20, 2014
    Location:
    Queens
    My Eminence Red White & Blues is 101 dB and I don't think that's the most efficient speaker Eminence makes.
     
  17. tubelectron

    tubelectron Tele-Afflicted

    Posts:
    1,690
    Joined:
    Nov 25, 2010
    Location:
    France
    Speaking about the Klipsch Heresy speakers, which are and still stay amazing speakers :cool: :

    When I measured them, my Heresy I HBR had a loud bump in the frequency response that was 12 to 15dB in the Mid-Hi range due to the extra-efficiency of the K-77 and K-53 horn drivers... I made a correction on the E2 crossover to achieve a "normal" response curve and posted this on the Klipsch forum in 2005, as an alternative :

    [​IMG]

    I even made first the quick test to damp the horn with cotton pads to tame them :confused:...

    [​IMG]

    Later on, investigating about the reason (and normality) of that bump in the response and impedance, I discovered that the Heresy speakers were more or less "designed as satellite speakers for a center Klipschhorn or Belle Klipsch", according to the Klipsch Forum.

    So obviously, the poor 12" K-22 woofer in sealed enclosure could not match the 104-108dB efficiency of the bass section of the K-H or B-K ! My little correction was welcome - at least on my pair of Heresy I HBR.

    That's also the reason why many Heresy owners complained that those speakers "did not have a satisfactory bass extension" when used as standalone speakers, even placed on the floor and in room corners, as specified by Klipsch... De facto, treble and midrange were rather "in your face" !

    So it's not really surprising that you had your ears distorted with your Heresy, @Robert Graf ... At any loudness, should I even say !

    Just for an experiment, many years ago, I connected one of my Heresy I to my late 70s SF PR. Why ? Just because the K-22 looked like a guitar speaker :rolleyes: :

    [​IMG]

    Sure, at low volume, I had a nice, unusual clean guitar tone, but when entering the overdrive mode, the tone went in an awfull "mud-and-fizz" distortion.

    Speaking about "Hi-Fi speakers for guitar" - if I can say so - I would mention the Electro-Voice EVM12L and the ALTEC 417-8H Series II. I have both in my amps, and I'm personally very satisfied by their tone :

    [​IMG]
    [​IMG]

    [​IMG]
    [​IMG]

    But how does it comes that many people do not like them too much ?

    This, despite their efficiency at circa 100dB/W/m, their broad response, their ability to whidstand that response at high loudness, where most of the other speakers are already distorting ?

    Often, the answer is "too heavy and too Hi-Fi" ! :)

    Again, IMHO, apart for reproducing acoustic instruments (guitar or other), using a 3-way enclosure is indeed doable, but wouldn't show great interest as a guitar amp speaker.

    But it's me, OK ? :D

    -tbln.
     
    Last edited: Nov 4, 2020
    MrCoolGuy likes this.
  18. Robert Graf

    Robert Graf TDPRI Member

    Age:
    63
    Posts:
    44
    Joined:
    Mar 20, 2016
    Location:
    Broadview Heights, OH
    108 dB is over twice as loud as 101. And the point is that hifi drivers are not inherently less efficient.
     
  19. LightningPhil

    LightningPhil Tele-Meister

    Posts:
    354
    Joined:
    Dec 1, 2018
    Location:
    Nottingham, UK
    That’d be the average efficiency over some weighted band.

    Guitar speakers have nice lumpy responses, often with excess output somewhere between 2 to 4 kHz. Pretty sure some spike above 105 dB. Though this is based on looking at graphs. Most of my drivers are Celestion, and some of the graphs on their website look suspiciously similar, despite quite different sounds, resonances and whatnot.

    Anyhow, an AC30 with blues certainly doesn’t need any more efficiency than it has. Can only crank it with hearing protection and an empty house. Much fun.
     
  20. MrCoolGuy

    MrCoolGuy Tele-Holic Silver Supporter

    Age:
    37
    Posts:
    544
    Joined:
    Jun 16, 2020
    Location:
    Fort Worth, TX
    It's a tube stereo in question
    No worries about ss.
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.