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Wall of deaf issues, Mesa/EVM content

Discussion in 'Amps and Cabs [BG]' started by FC Bass, May 26, 2012.


  1. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    I have encountered a weird problem with my Wall of deaf (Mesa Bass 400, Strategy 400, 2x10 and 1x15 Diesel cabs)

    I bought 4 EVM ten inch speakers a while ago to replace the Eden speakers (in one cab) and the blown up EVM in the other cab (+ the good one in that cab because they're 16 ohm speakers)

    When I play the 2x10's through the Bass 400 (6x6550 tubes) the cones go in and out violently, with a nasty distorted sound.
    When played through the Strategy 400 (6x6L6 tubes/channel) they sound awesome, no excessive cone movement. Slap tones come out clear at high volumes and it handles the low B extremely well... :confused:

    The Bass 400 sounds great through the 1x15's, no problems at all (same results as the 2x10/Strategy combi)

    In this clip: Youtube link the stack is cranked up to deafening volumes (we had a gig the day before which I did with less cabs, forgot to put the volume down on the Strategy and there was no time for a line/soundcheck :D)
    Most of the sound you hear comes from the 2x10's, there was a mic in front of one 1x15 (no DI)

    15 inch speakers are EVM15L 8 Ohm 400 watt
    10 Inch Speakers are EVM10M 8 ohm 200 Watt (2x10 cab specs 4ohm 400Watt)

    Can anyone here give give an possible explanation for this weird amp/cab behaviour?


    stayin' ahead of the "no pic no stack" crowd:

    The stack with the old 10 speakers (with cheap substitute for the blown up EVM)
    [​IMG]

    "New" 10 inch speakers
    [​IMG]

    EVM 15L:
    [​IMG]

    The other EVM15L:
    [​IMG]

    Eden 1060F 16 ohm 150Watt (retired, keeping them as spares)
    [​IMG]

    EVM 10 16 ohm 200 watt, will be reconed to 8 ohm and also kept as spares.
    [​IMG]
     
  2. bongomania

    bongomania Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    All I can say is the fact that any one of those combinations doesn't blat out badly when cranked to "deafening" volume is a flippin miracle.

    Edit: I may have misunderstood, are you using the whole wall of four cabs at once? That would make sense. My initial response, I thought you were saying you saw problems when using just one 115 or just one 210.
     
  3. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Think you have just learned about why you can't just sling drivers in a box, or mix them. Sounds like they are unloading due to cabinet tuning and only one of your amps has content that low
     
  4. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    Could that be some kind of malfunction in the amp? (which the 1x15's seems to can handle)
    The 2x10 cabs were designed for the EVM speakers, they're both identical. (I think the Eden speakers were an option in the same cabs)
     
  5. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    +1. No matter what box you put them in EVM 10s are midbass drivers, and won't put out deep lows no matter how much they may try. If the amp isn't pushing a lot of lows they'll work well enough. If it is the cones will move in response to the signal but that movement won't result in deep bass output. It will eventually result in driver failure.
    Only because the voicing of the amp is filtering out the lower fundamentals.
     
  6. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    The EVM 10's were used in most Mesa Diesel cabs, these were in the PH1000 I sold some time ago:

    [​IMG]

    Sounded great with the Bass 400, also used it a lot with an Ampeg SVT III pro. So I guess the EVM10's should be able to handle any "normal" bass tones, which would mean either the Amp or the speakers have something weird going on...


    Edit: Sorry, thanx for the input btw. I'll discuss it with the local amp guru when it's tech time.
     
  7. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    Yep, in the vid its all cabs.
    The day before that gig, I had a 3 cab setup: Bass 400 - 2x10 cab, Strategy - two 1x15 cabs
    The 2x10 started acting weird (as described in the first post) so I turned it way down and cranked the Strategy. (Youtube link to the "3 cab" gig)

    I think I had the master of the Bass 400 somewhere between 3 and 4, hardly audible but no ugly cone action.
    If you come anywhere near "loud" with the Bass 400 and 2x10 combi, the violent cone action starts...

    The Bass 400 has had a major checkup some years ago, output was tested at 180 Watt sinus (I guess that's clean power?) and 340 Watt block max output (max overdrive)
    The 2x10 cabs are 400 Watt each, shouldn't they be able to handle about anything the Bass 400 puts out?
    I don't have a heavy distorted sound (gain at 6, output between 5-7 on the Bass 400, channel 2) and use no heavy bass boost.
    Most drive from the first vid comes from the Strategy, sounded awesome but comes with lethal sound levels :)
     
  8. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Thermal watts are irrelevant. What matters is displacement limited power. EVM10s are only able to take about 80 watts each in the lows.
     
  9. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    Thanx for the input, but I have a hard time believing the Bass 400 and EVM10's do not match (in my case it doesn't work at all)
    Mesa has been selling these sets for years (from late 80's), that would imply that I'm the first one that notices it does not work... (in 2012)

    Also I've never had problems with other EVM 10's (in the PH1000 and the 16 ohm versions) Sounded great with the Bass 400

    The "new" speakers look identical to the 16 ohm versions I pulled out, it looks like the ones in the PH1000 have a slightly smaller magnet.
    Through the Strategy the "new" EVM's -to me- sound like they should, nice crystal clear clean sound -also at high levels- (not the extreme high settings from the first vid)
    I liked the sound at the extreme levels, but it was way to loud and normally I have a much cleaner sound ('till I press the Big Muff) :bassist:
    The cabs handled the power well and sounded awesome to me, I have no output report for the Strategy but that would be way over 150 Watt/channel I guess?
    Manual says: 1 led lit: 12,5 Watt, 2 leds lit 50 Watt (is loud) 3 leds lit 200 watt. During the gig the third led was on a lot, normally I see two leds lit.
     
  10. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Mesa sell a lot of things that don't work. They can do it because people keep buying them.
     
  11. No one else sees the possibility of self oscillation in the Bass 400? Remember Mesa does not use diodes between B+ and ground on the plate side of the OT. Could have a fault in the feedback circuit causing oscillation.
     
  12. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    I'll retube the Bass 400 next week, noticed the 15 inch speakers struggle also tonight at high power with lots of Bass from the EQ.

    If that doesn't work, I guess it's techtime for the amp...
    (I'll mention the possible oscillation/diode issue, thanx!)

    Last checkup was about 4 years ago (tubes are older than that) so that's not too bad.

    Mesa earned it's name and fame by selling stuff that doesn't work? :eyebrow: Didn't know that, you always learn something new on TB. Thanx! :D

    For the picture hungry crowd (myself included)

    [​IMG]

    [​IMG]
    (those are the =C= 6550 tubes that are still in it)

    Inside:

    [​IMG]
     
  13. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That's also to be expected. EVM15s only have a moderate excursion capacity, and for every 6dB of bass EQ added excursion demands on the drivers are doubled, just as it is with every 6dB of additional power. If you must have high output in the lows EVs are not the drivers to be using.
     
  14. You have an incredible amount of bass dialed in on your amp...I'm pretty sure that's what's causing a lot of the damage.

    2 on the bass is considered flat if I recall correctly...
     
  15. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    The "base" sound of the amp has a high mid level, I use these settings approximately: Middle at 4, bass between 6/7, Treble between 7/8, Graphic EQ: 40 and 100 sliders in the middle, 250 and 625 cut and a slight boost on the 1560 and 3000 sliders.
    After a lot of tweaking, these settings sounded best to me.

    I think my basses (Alembics) require a bit more bass from the amp?
    I don't have/need an extremely heavy bass sound, there's plenty of low coming from the cabs for my likings (sometimes even a bit too much) I mainly use the graphic eq to compensate when needed.

    I never had problems with any of the EVM speakers I used (even got paid by the guy who blew the crippled 10 inch speaker with his amp) or felt they were lacking lows, I don't think that's the problem here (me requiring too much lows from these speakers)

    Btw: There's no trace of the "ugly distorted sound" coming through the Strategy, the 10 inch speakers perform extremely well at high levels
    Isn't that a bit strange if there would be a malfunction in the output of the Bass 400? (since the Strategy gets its signal from the post OT slave out?)
     
  16. Not really as the oscillation could be quashed in the slaved amp, being a very low frequency.
     
  17. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Different amps have different voicings.
     
  18. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    Thanx!
     
  19. FC Bass

    FC Bass Alembic and Mesa/Boogie junkie

    Jun 9, 2006
    Holland
    Most simple fix ever, new tubes :)

    Retubed with EH 6550 tubes and amp is back on track. :hyper:

    Low end got a lot better, had to back up the bass controls quite a bit. For midrange speakers these have a massive solid bass sound, I guess that's mostly because of the cab design?

    These EH's are not so bright sounding as the old tubes (=C=) Combines great (I think better than the =C=) with my super bright Alembics, I used to back up the filters on the basses quite a bit.
    Happy camper here! :)

    Just in time for the next festival where we will share the stage with Obituary :)bassist:) Moonspel, Death Angel, Pro-Pain + many others.
    Too bad Exciter is not on the bill, I would have loved to see the ultimate Metal bass in person (and it's owner of course)
    (they have a Marshall VBA 400 as standard backline, Clammy would have been happy)

    Mesa will kick some butt!
     
  20. Alex1984

    Alex1984

    Jan 16, 2010
    Vancouver
    I thought the Mesa used the glittery EV drivers, 10BX or something.
     

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