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SWR SM400

Discussion in 'Amps and Cabs [BG]' started by rjl1160, Jan 1, 2005.


  1. rjl1160

    rjl1160

    Jan 1, 2005
    I have a SWR SM400 I bought used and took to a respected music store chain to check out to make sure all is ok with the amp (and it is). I have this hooked in stereo to a SWR Triad (4 ohm) (400 watt) and a SWR Goliath Jr. (4 ohm) (350 watt) combination, (should be 300 watts per side @ 2 ohms according to the SWR website). My problem is that I am not at all happy with the volume and sound quality this combo puts out, I can hardly be heard and what I hear is flat (no low end punch). I go to a music store yesterday, pick my bass off the wall, plug into a SWR Super Redhead and THAT is the sound quality I am looking for, i've tried all kinds of settings with this SM400 but can't get anywhere near that Super Redhead, I play in a very loud rock band and want that Super Redhead sound but louder, what should I do? :help:
     
  2. tornadobass

    tornadobass Supporting Member

    Nov 20, 2000
    Iowa City, Iowa
    Endorsing Artist: Black Diamond & SuperSensitive strings
    With a 4 ohm cab on each side of the amp, you'd be getting 240 watts per side...it will get fairly loud if you set up the amp okay. I've found that these SM-400 amps need to have the input gain set somewhere in the vicinity of noon to have a hot enough signal.

    Play with your normal attack and turn up the gain until the clip light flashes occasionally, then turn it down a tiny bit. The master volume will probably be set at about 1 o'clock, maybe a bit higher, for decent volume.

    Note that the clip light senses all the gain stages before the master, so that a boost of an EQ knob will increase the overall gain, too. Set the limiter after you're dialed in, because it also follows the overall gain.

    You might also try running the amp bridged and using just your Triad. You'd be able to put 420 watts into it, which should be a good match. If you put the amp in a rack, be sure to leave an empty space above it to allow for air movement to cool it...the amp normally runs hot as it is.

    BTW, I have both an SM-400 and SM-400S...you can find their owner's manuals on the swrsound.com site in the vintage products section of the manuals page.
     
  3. iammr2

    iammr2

    Jun 10, 2002
    Tejas
    Make sure the switch on the back panel is set to stereo mode. Also use it with 8 ohm cabs. That amp is not optimally designed to run at 2 ohms. It will run really hot and shorten the lifespan of the amp. I run mine with 2 8 ohm cabs at 148 watts a side and it's pretty darn loud and sounds great. Or you can daisy-chain the cabs together and run the amp in bridge mode for 400-420 watts, of course using 8 ohm cabs. Make sure you are using high efficiency cabs and have sufficient mids turned up.

    If a Redhead's sound is the sound you like, you really should buy a Redhead and an extension cab for it to get more volume. Can't buy a Chevy and expect to get a Cadillac's ride.

    Might also want to consider getting your bandmates to turn it down and let the PA do more of the work. The loud ringing in your ears that you'll have later in life might not be as bad as some some of us have it.
     
  4. Doesn't the Bass 750 have the same preamp section as the Redhead?
     
  5. Fred312b

    Fred312b What if I want to play jazz precisely? Supporting Member

    Apr 23, 2002
    Chicago, IL
    yeah, the bass 350 and 750 were supposedly made to be similar to the redhead/ super redhead preamp.
     
  6. Then he can just get an SWR 750x or 550x or a used Bass 750. and get the Redhead sound but "louder".
     
  7. rjl1160

    rjl1160

    Jan 1, 2005
    I have the switch on stereo mode, I did try the settings suggested and others all over the map, it still sounds flat and not loud enough. All the speakers are moving so I know the power is getting there. At 240 watts per cabinet am I pushing the speakers hard enough? - like I said i'm playing in a loud rock band and need to be audible. I play quite fast with my fingers (no pick) with a light touch, maybe this light touch requires more power?, I can get a SWR Mo'Bass amp that will take me to 400 watts per side, what do you think guys? - I thought of the SWR 550X AND 750X series but I want to use both the 4 ohm cabinets I have and supposedly you can't load those 350X/550X amps that much (2 ohms), with the Mo' Bass you can.

    Great Site, didn't think i'd get responses so fast, Thanks all!
     
  8. Finger Blister

    Finger Blister

    Jul 8, 2003
    Always run bridged mono.

    Stereo can sound sweet at lower volumes,
    but the SM 400 & (S) seem to "wake up"
    when ran in bridged mode with either an 8 or 4 ohm cab.

    I get much more volume out of a 400 and a 8 ohm G JR. III
    then a Redhead.
    And it's easier to load and carry.

    Or use the 4 ohm Tri as the bridged cab for a little more headroom and wattage.

    Magic setting (other then Flat) seems to be 1:30.

    My pre gain is always set to 1:30
    A.E. 1:30
    Bass 1:30
    Max. Master Volume 1:30.

    Freq #1 set to 35Hz with a 10db cut
    will get you a lot more volume,
    as will an extra gain stage in the serial FX loop (compressor, etc...)

    BTW: The SWR SM 220, 400, 400S, 500, & 900
    all have preamps that smoke any SWR "X" series crap.
    Mo Bass is discontinued because it's proven crap.
     
  9. tornadobass

    tornadobass Supporting Member

    Nov 20, 2000
    Iowa City, Iowa
    Endorsing Artist: Black Diamond & SuperSensitive strings
    Good details on the setup. Note that with the Aural Enhancer all the way off, the amp's gain is noticeably lower, too.

     
  10. rjl1160

    rjl1160

    Jan 1, 2005
    I want to use both cabinets, and i'll buy what I have to to get it to work, how about a SM900 run in stereo, will that suite me better?
     
  11. Finger Blister

    Finger Blister

    Jul 8, 2003
    I want one.

    with two SWR 8x8's!
     
  12. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    one of the problems might be the triad. they sound really good in lower volume setting but don't seem to be all that good for aggressive rock. I think you might be happier running another 2x10 or a 4x10. FWIW, an SM-400 might not be the loudest amp out there, but running bridged into an 8 ohm or 4 ohm 4x10 seems to be their forte'
     
  13. Fred312b

    Fred312b What if I want to play jazz precisely? Supporting Member

    Apr 23, 2002
    Chicago, IL
    yeah, i've heard that the triad is not the loudest/most efficient(?) cabinet in the world... i've run my sm500 (same idea, a few more watts) bridged mono into my 8 ohm goliath 3 (400 watts) and it was hella' loud- i didn't even have to go past 10 o'clock... :bassist:
     
  14. iammr2

    iammr2

    Jun 10, 2002
    Tejas
    Try the amp with JUST ONE cabinet and see what the volume is like. If it's loud, the problem is not the amp. Could be a phasing problem between the two cabs. From SWR's website:

    "This means that while the speaker cones of one cabinet are moving out, the cones of the second cabinet are moving in. The net result is little or no sound at all. To check for this situation, get out that 9-volt battery again. Turn off the amp and unplug the speaker cable from the amp, leaving the other end still connected to the cabinet. As shown in Fig. 1, touch the plus (+) side of the battery to the tip of the phone plug and the minus (-) side of the battery to the sleeve of the phone plug. When you do this, the cone(s) in the cabinet should move out. When the battery is disconnected, the cone(s) will go back to their original position. Now repeat the procedure with the second cabinet; chances are, the cone(s) will move in the opposite direction—in. If so, the speakers are wired out of phase."

    Take YOUR bass to the store and try out the Redhead. See if the same thing happens.

    If a tech(a good one) has checked it out and ok'd it, then it's the settings and you'll probably do the same thing with even a larger amp.

    Are you trying to drive frequencies under 50hz?
     
  15. TCube

    TCube

    Sep 1, 2007
    Eugene, Oregon
    Hi folks,

    I was wondering if anyone would be kind enough to email (terry@uoregon.edu) a pdf of the SM400 manual. I've gone to the webpages of the SWR website for vintage-gear manuals, but the download for the SM400 is "blanked out". Thanks a million in advance!

    Keep walkin'!
    Terry
     
  16. Ah, the elusive RedHead mystique!

    I bought a Goliath Jr II as an extender cabinet for my RedHead and was never really happy with the volume.

    I may be wrong, but I believe that the ideal match for an SWR SM400 head is a pair of Goliath II cabinets.

    When I upraded the RedHead to a Grand Prix + Stereo 800 and bought a Goliath II, I added a Triad I to round out the sound with a 15" speaker but, again, I was not really happy.
    I tried two stacked Goliath IIs and got all the warmth and punch I was hearing in my head (and yes, the sound was a perfect complement to the little voices in my head! :)

    I know: Goliath Jr and Triad I are a joy to lift and setup, whereas Goliaths are HEAVY; however, I always felt that the Goliath sound was worth it. Once I got handy with a simple luggage trolley, handling the Goliaths was not that taxing on my back... and my ears were most grateful!
     
  17. iammr2

    iammr2

    Jun 10, 2002
    Tejas
  18. maggbass

    maggbass Supporting Member

    Jan 7, 2007
    new jersey
    I have been using an SM400S in bridge mono into epifani T310 for a few years now and I have no problem cutting through a loud drummer and two guitars, but this amp has a very powerfull eq and you got to be careful dialing in the lows to get the most volume out of it. what I do on a gig is that I set the slider 1 all the way down and turn the freq knob and the bass knob until I have decent lows without to much cone movement
     
  19. z4string

    z4string

    Dec 23, 2008
    New England
    Had a 400S for 9 years......... try this.
    Always run bridged mono... always. Gain until LED blinks, then back off a tad. No Limiter... ever. Aural enhancer never past 10 o-clock or it's complete tone suck. Bass ~ 2 o-clock. Boost the two left slders to +5 and +4 then dial in the freq. knobs for whatever cab you are using to get lows and low mids. This is where the head lacks and will need tweaking. Third slider at zero. Right slider +3, knob at 3 o-clock. Treble to taste. Zero is good. With an 8 ohm Eden 410xlt I never had to go past 11:00 on the master, even in some loud situations. The SM400 is not an amp that you can set flat and immediatley get a good tone. It's very hi fi. All the settings posted here are an attempt to put more "hair" on it. The SM400s are great and bullet proof heads but I finally gave in to an all tube amp. The "hair" is there right away. Hope it works for you.

    TTBB