Power Amps and EQ's

Discussion in 'Amps and Cabs [BG]' started by martens-koop, Jun 1, 2003.

  1. martens-koop


    Oct 10, 2002
    hey there... I've been playing an old 1970's garnet tube combo unit (70 watts or so) for about 4 years now, and am thinking about upgrading. I've got a line on some equipment for a good price, and I'm wondering if anyone has any comments. please tell me if I'm completely out to lunch here:

    Acme Low B2 cabinet at 4 ohms
    1/3 octave graphic EQ (don't recall the make)
    Crest CPX 900 power amp (900W bridge mono 4 ohms)

    Basically, I'm looking for advice about whether this is a stupid setup.. I can't afford a rack preamp at this point, and thought maybe a year or two down the road gettng an Eden navigator...

    any comments? I'd really not like to spend close to 2 grand on this only to find out that I have blown a lot of dough!!! The reason that this appeals to me, is that each unit can be upgraded piece by piece, and I'm hoping to use the EQ for some tone control until the power amp gets around...

    or are rackmounted eq's used only to tweek the rig to the room (ie: RTA's, Pink Noise ala PA systems?)

    please, any comments would be awesome!!!

    Jeff martens-koop

    ps: if enough people comment, it might sway me into actually becoming a "contributing" member... something I've wanted to do for a while, as this place rocks.. just need an excuse...
  2. martens-koop


    Oct 10, 2002
    whoops.. I meant a "supporting" member...

  3. I would also consider, as a cheaper option, keeping your tube amp (maybe have a cap job done on it). Use it to power an efficient cab, but also use the line out to go to a power amp and second cab. Forego the graphic EQ, you've got a good tube tone going with the head you've got
  4. martens-koop


    Oct 10, 2002
    the tube amp I've got is an alright tone. but it's one big ugly box with the speaker underneath and control section in a little recessed pocket near the back. I'd have to pull it out and build an enclosure (I suppose if I racked it, it would'nt need to be such an intense job)

    but its not really a piece of equipment I'd like to keep around, except for really small sessions (like sunday school music with 100 kids etc)

    the tone section basically has a bass boost and a treble boost there's also a tremolo dial, which I have not yet been able to find a use for, except for fooling around by myself...

    anyways, If I modify it, I lose its use as a small combo unit...

  5. jokerjkny


    Jan 19, 2002
    NY / NJ / PA
    dont see how the EQ wouldnt work in driving a signal to the power amp.

    but, what's your app? why did you want the Acme?

    its very power hungry, and good to see you're feeding it lots of power. also, in a way, its a good thing you got the rackmount EQ, cause Acme cabs require lots of drastic tone shaping to stand out clearly in the mix.

    its flat response tends to keep it from cutting naturally thru the mix on its own. you gotta really tweak it, to get that same cutting tone, whereas most cabs that are already inherently voiced in their design to cut thru a mix.
  6. martens-koop


    Oct 10, 2002
    basicaaly the application will be the following:

    Dingwall Voodoo Prima 5 (not yet built but on the way) I'm going after the acme because I have heard great great things about its lowness!

    1 third of my playing will be probably 2 "retreats" a year where my bass has to be heard over a drum kit (not mic'ed) an electric guitar, and about 75-100 kids singing real loud. I want to make sure that I can be heard. Bleeding ears is usually a good indication for me!

    another third is once a month at church, for three songs. I won't be mic'ed and there's no option for DI... the piano however IS miked (people have dumb priorities eh?!) and there will be from 100 to 200 people singing. Ears bleeding would not be a good thing here...

    The other third is that I am desperately looking for a rock and roll, metal cover band to play in. small clubs with decently loud house systems where I can take a DI and mic the acme... I'd like to play a range of tunes including some David Bowie and Iron Maiden.... maybe a medley starting with Space Oddity and rolling into the Number of the Beast.... Okay, maybe I'm out to lunch, but I really want to do a lot of different things with this setup, but they don't neccessarilly have to be super super loud...

    ps: don't most house systems just want to take a DI straight from the bass? So in essence, you'r not really getting the same sound you get in rehearsal unless you demand otherwise... or am I wrong? its been about 6 or 7 years since I've played out...

  7. jokerjkny


    Jan 19, 2002
    NY / NJ / PA

    for your church gigs, the Acme would be perfect! when i owned my Acme B2, it was my small rig cab, and worked wonderfully, with my Sunday worship groups. hooked up, to either my old Eden WT400 or EA iAMP350, i had a killer rig that sounded great, and very portable.

    BUT, for a loud metal gig, i dunno if one, let alone two, Acmes are gonna cut it. a few gents werent too thrilled at how they didnt cut thru too well. also, they're very power hungry, so be prepared to push MORE wattage than what you already have to sufficiently get the volume you need.

    if you dont mind having your bass come back to you via stage monitors, then i guess you'd be ok.

    and yea, for the most part, soundguys usually just take a direct line to the house. BUT, a rig onstage is mostly about hearing yourself properly onstage, when battling against a heavy hitting drummer, or an obnoxiously loud guitarist.

    give 'em a try regardless. Andy at Acme offers a 2 week trial, so you can really see how they work for you, at your next rehearsal.
  8. The rig you are looking at will work for the church gig no problem. Rock and Roll, Metal, etc. is another thing entirely. You'll be lucky to hear yourself on stage with a B2 let alone cut through the mix. That full range hi-fi sound the B2 makes that sounds so sweet in a quiet setting won't make it past the edge of the stage in a loud rock band. You can't depend on the house PA either, sometimes they create more problems than they solve. Is there a speaker that can work well in both situations? I think I'd look into that Accugroove El-somethingOrOther, they are reported to have a great full range sound but enough punch for R&R. I don't know how much you're paying for the guitar, but, for a custom made Dingwall it can't be cheap. The amp and speaker you choose will have as much effect on your sound as your guitar. Better get something you know will do the job. (jmho)
  9. martens-koop


    Oct 10, 2002
    Mr jokerjkny

    when you say be prepared to push more wattage, do you mean push more wattage than the 900 watts? into ONE 210 cab thats rated for 350 watts? that seems totally insane to me?!!!!!!! are you serious!????????

    yeah, I know it'll suffer for rock and roll, but its got to be better than what i've got right now, and I don't mind monitors I suppose... I mean I'd have to use them right now anyways, and the trade off for awesome sound in a quiet setting is what makes it worth it (to me)

  10. martens-koop


    Oct 10, 2002
    ps everyone: thanks for the comments... It feels great to have so many people with so many idea's out there...

    well, I've got a 1yr old daughter who needs a bath, and it aint gonna happen by itself...

  11. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I'd have thought that the Dingwall would match up very well with the Acme - big bottom and plenty of top end growl to make sure that this (relatively) subdued cab cuts through. I use two Acme Low-B2II cabs myself and with the attenuators cranked (which gives you a 5dB mid boost and 2dB high boost) I find there's sufficient cut.

    If you do find that the Low-B2 is too polite in your potential heavy band, you could always run your valve combo in parallel with the lows cut and mids/high mids cranked to give you a bit of growl/grind (depending on how hard you push it). I bet that would sound awesome, big tight bottom and clear top from the Acmes and characterful cutting mids from the valve combo.

    Rather than get a graphic eq I'd pick up a cheap secondhand preamp like an SWR GP.

  12. jondog


    Mar 14, 2002
    NYC metro area
    Yes, if he stuck w/ just the eq, wouldn't he need some kind of DI to get the signal up to line level? You can get a decent used bass preamp for around $100.
  13. Use your 1/3 octave EQ to simulate a honking cabinet, if you desire this tone for cutting through.

    I have a Rane GE30 in my rack, and find it very useful for this purpose. A simple push up +6 of the sliders between 80 ~ 120 Hz will give you the Eden/Carvin/BagEnd honk.

    Be sure to cut the 31 ~ 50 Hz sliders to further simulate the honking tone. Cutting the nuts off the low end lets you safely drive the cab harder without farting. By itself, the sound is pretty crappy, but it will cut through very well.

    If you have access to a honking cab, A/B compare it and the HiFi cab using program (CD) music. Program material will quickly reveal the sonic character of the honker. EQ the HiFi cab until it sounds like the honker. Your ears will get you awfully close just by tweaking the EQ sliders.

    The nice thing about HiFi cabs is, they can be EQ'ed to simulate a honking cab. It is much harder to make a honker cab sound HiFi.
  14. martens-koop


    Oct 10, 2002
    not sure what You mean by "honking" cab, but my boss has an Eden 210 with a tweeter hooked up to an eden wt300. I suspect I could probably dial in a cabinet from that...

    another question: by itself, I'd be running the acme in a bridged mono form. I'm thinking that down the road I could get another not so polite cab, and a splitter, then run the acme on channel A and the other one on channel b. if I spend a little extra money now and get a dual channel eq, in theory I could have endless possibilities here... but in reality, I'm probably never going to get another cabinet, or at least not in the next 3 or 5 years...

    so does anyone here have any thoughts on what would be better in the short run:

    a fairly good EQ (possibly a digital programmable one that I could pick up for about $200)


    a fairly cheap preamp at around the $100 to $200 level?

  15. Lonnybass


    Jul 19, 2000
    Minneapolis by way of Chicago
    Endorsing Artist: Pedulla Basses
    Ok, this thread seems to have wavered a bit, but from what I can tell, I'd definitely suggest putting some extra $$ into a good preamp. If you're going to use an Acme enclosure, don't forget that it's going to precisely replicate exactly what you put into it.

    Essentially, I think it would be kind of a shame to have a killer Crest/Acme rig and then skimp on the preamp - after your bass, that's the heart of your sound! You could probably get away with using a good DI (Sansamp, etc) into the power amp also.

    Feel free to ask me any questions. My system, for your reference...

    Furman power conditioner
    Korg DTR-2 tuner
    Aphex Parametric EQ
    Alembic F-1X preamp
    Behringer compressor
    BBE sonic maximizer
    Crown CE2000 power amp
    2 x Acme Low B2's

  16. jokerjkny


    Jan 19, 2002
    NY / NJ / PA

    lets just say, tho its rated for just 350 watts, i'd say pushing a good 500-600 watts really opens it up, and makes it sing. so, if you needed two, which i heartily recommend if you're gonna be in a loud rock context, you might not have enough power to properly drive both at the same time to be loud enough.

    also, if you pair it up with another "more rude" cab, the Acme will literally be drown out, despite equalizing the wattage on your power amp. the specs speak for themselves. if pushed to maximum loudness, the Acme only hits 93 dB. thus, the Acme will have a hard time competing with a 102 dB rated Eden. in theory, you need twice the wattage, just to rise another 3 dB. in this case, you'd need 3x the wattage pumped into the Acme, just so it can be as loud as the Eden!!!

    why are the Acme's rated so low? this is in part cause it takes much more wattage to properly reproduce the low low frequencies it claims it can reach. so, if you're going down to 30hz to properly reproduce a Low B string, you'll need lots of power to do accomplish it.

    somebody correct me if i'm wrong, but if i'm not mistaken, most amps reproduce the upper harmonic partials of the Low B, which is what you hear in bass cabs that only reach 45hz, thusly you're not actually hearing the real Low B fundamental itself. the Acme cabs stand apart, cause they are claimed to be able to reach down that far, and hit the low B fundamental.

    also, to add to this conumdrum, like we've been saying, the Acme's response is very flat. no voicing or specific frequencies are boosted. the purity of your bass, pickups, and preamp shine thru without any coloration. great for moderate volume use, where you can really appreciate the beautiful tone of whatever you're using.

    the downside is that, they're not really optimised or voiced for really loud use. most other bass cabs like the Edens are specifically voiced and engineered to help the tone of the bass cut and slice thru a dense/loud mix.

    but, the good news in all this is that you have a very flexible EQ. if you follow Bgavin's advice on which frequencies to bump up on your EQ, you'll be able to simulate the more cutting (aka "honking") qualities of the other rock 'n roll bass cabs.

    later, when you get a real nice preamp, you can run the preamp thru the EQ, so you can both the very nice sounds the preamp affords, as well, as the EQ to help your tone cut thru.
  17. martens-koop


    Oct 10, 2002
    wow man. thanks. Your last messzage was really inspirational, and it totally helped me make up my mind...

    I think I'm gonna go with the EQ over the preamp, as I will be doing only moderate gigs for the time being... it might be quite some time before I get the hard rock metal thing happening, and possibly never if work keeps on being so hectic!

    any idea's on digital EQ versus analog EQ? I got the following email from an aquaintance who owns a company that installs and sells PA gear:

    Several ways to go here:
    a/ 15 or 31 band EQ: $220
    b/ digital effects unit with flange, EQ, phase or other: $200 - 300 range.

    he doesn't really mention the benefits of one over the other.. just ballparks a cost (in Canadian dollars)

    I guess the manual eq has this going for it: you can change settings really quick... the other one though seems like it would be a little more versatile if you set it all up beforehand...

    any ideas?
  18. Buy used from eBay. Rane EQ boxes are cheap and very plentiful on eBay. Rane is top quality pro audio equipment and very well built. For the record, I also would spend the money first on a good quality preamp, then add EQ later.

    A "honking" cab is one that has a significant hump in the response in the mid-bass region (80 ~ 125 Hz).

    The primary cause is putting too large a driver (acoustically) into too-small cabinet space. The Carvin PS10 driver is a good example of this. This driver likes 2.26 ~ 6.36 cubic feet, but it is stuffed into about 1.6 cubic feet (net) in the RL210 cabinet. This results in a noticeable honk in the midbass which is sold to the buyer as "big bottom". Carvins are gutless in the bottom range, but they do cut through quite nicely.

    The downside to over stuffing is the very rapid rolloff below the hump. The bottom end is about zilch. The secondary cause of midbass humping :D is a high Qts driver, with its characteristic hump and fast rolloff below the tuning frequency.

    The Acme is a low efficiency cabinet designed to produce more accurate lows. Loss of efficiency is the trade off to get the extended lows. My subs are worse than the Acme by a long shot, so I use multiple drivers and high power to make up the difference.
  19. Phat Ham

    Phat Ham

    Feb 13, 2000
    I also suggest getting a preamp over an EQ. Most EQ's out there are designed more for line level, low impedance applications. If you feed the signal from your instrument directly into the EQ you may get some loading of the pickups, resulting in a loss of tone. I'm also worried the EQ may not have enough gain, leaving you with too weak a signal to properly drive the power amp. If you're really set on getting the EQ, I suggest picking up a cheap preamp such as an ART TubeMP (I think that's what it's called) or something similar. They are in the $100 range and sound surprisingly good for the price.
  20. Petebass


    Dec 22, 2002
    QLD Australia
    I must admit that I have been thinking the same thing. I love EQ - it's my favourite effect because you can do so much with it. I find that most EQ's start to sound "un-musical" when you try to use them as gain boosters.