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Help me out - I almost never start threads!

Discussion in 'Amps and Cabs [BG]' started by Joe P, Apr 7, 2005.


  1. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    I'm thinking of investing in a cabinet; like - tomorrow!

    I know this is considered radical, but keep in mind that I was a sound man before I was a bassist!

    I listened to many 'bass bottoms', and nothing really grabbed me until I plugged into a JBL JRX125. Take a look for a sec here, will you?

    http://www.jblpro.com/JRX/JRX125.htm

    They're selling these things at a big local music store for $399 - now that seems like A-LOT of cab for four hundred bucks.

    D'dya see the specs?

    36Hz - 16kHz for -10dB points
    45Hz - 12KHz for -03dB points
    500W power capacity; 2000W peak!
    100dB efficiency
    133dB Max SPL
    Nominal Dispersion: 90º x 50º
    4-Ohm nominal impedance

    I spent about half an hour with my bass and pedals and a 300W Hartke HA3000 amp (Head is the same price as the speaker, bytheway: $399) plugged into one of these JRX125s. I was thrilled with the sound I was hearing - the mids were SO-so tight!

    That rig absolutely BARKED!! It was startling; it just pumped that big room with bass (most of the whole store is in one huge room with a concert stage on one wall -- Man! I was rattling the snares on every snare drum in the percussion department!). That thing just grabbed me by the lapels even at ten paces.

    Am I just spun, or what?? I'm used to hearing basses pumped direct through PA stacks; I just can't seem to get into the "bass bottom' sound, as compared to the PA-stack sound!

    Could I get some input here please? I'm very tempted to get this thing before this Saturday's gig. I listened to all sorts of bass guitar cabs - my salesman and I even ran back and forth between the 'bass room' and back out into the PA-room with my bass and pedals to A/B this setup with an SWR head with a 1X15 + 4X10 stack: there was no comparison to me, specially-especially off-axis to the front of the speakers; the JBL sounded great from all over the room!

    Help me out, will ya?

    Joe
     
  2. Mcrelly

    Mcrelly

    Jun 16, 2003
    Minnesota, USA
    best thing to do, if you can is borrow or buy the cab with the option of returning it UNDAMAGED OR BLOWN if it doesn't sound good at the gig. things usually sound better at the store, but the gig is where they HAVE to sound good, especially to you.

    also ask the band if they can hear you good with it.

    good luck!
     
  3. $399 for JBL...not bad at all!
    I would go for it
     
  4. James Hart

    James Hart

    Feb 1, 2002
    toms_river.nj.us
    Endorsing Artist: see profile

    JBL makes good stuff
    most boutique bass cabs have taken from the HiFi and PA fields
    Anthony Jackson uses PA cabinets for his bass
    I know guys running powered PA cabs with sansamps as bass rigs
    lots of pros tour via monitors only

    Do it if it sounds right to you!
     
  5. Rav

    Rav

    Dec 29, 2004
    Aurora, IL
    One of the specifications your ignoring is relative frequency response. Some PA cabinets are strong in the mid range and rolloff above 15khz. They still handle up to 20khz or 25khz but at reduced output levels. Also some PA cabinets rolloff below 100hz pretty steeply. Sometimes as much as -10db at 80hz.

    Point is if your going to go with a PA speaker try to make sure its response is as flat as possible in its entire reprodution range as possible.

    On the other side of the agenda many bass cabinets roll off everything above 2khz pretty sharply and almost completely attenuate everything above 10khz.

    Compared to most bass only cabinets a PA speaker is goign to seem to have a ton more midrange. This isn't necessarily a bad thing just keep it in mind that if you like mid's its a plus and if not your going to need to EQ them down some.

    -Rav
     
  6. Rav

    Rav

    Dec 29, 2004
    Aurora, IL
    Its getting late and I think my previous post made me come across anti PA cabinet.

    On the contrary I personally love the sound of a cabinet with a flat reposnse. I'ld love to get my hands on an Accugroove El whappo cabinet for instance. Or a monitor series JBL. I like the sound of mids/highs'.

    There is a lot of personal preference in the sound your gear makes. I was just trying to give some helpful information on how to know if a cabinet will sound like you want it to.

    -Rav
     
  7. emjazz

    emjazz Supporting Member

    Feb 23, 2003
    Boston, MA
    If you don't mind carrying that thing around I'd bet it'd sound fabulous. I was at a gig once where my poweramp crapped out on me. The only option was to go into a powered PA cab. It ended up sounding better than my bass rig. I personally think that bass guitar speakers are too hyped sounding. More companies should take a look at PA speakers.
     
  8. dood

    dood

    Dec 9, 2004
    sitting down,facingforward..UK
    Endorsements: Shuker Guitars, Dingwall Designer Guitars, D'Addario, Planet Waves, Barefaced Bass
    hmm, 42kilos, about the same weight as an average non NEO 4x10..
    looks good to me!
     
  9. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Oooaah - I've been thinking about this thing all night!

    This'll be my first pro rig since highschool (1979)! One thing I promised my wife before I got back into music a couple years ago was that I'd borrow equipment until I was playing out; that I wouldn't buy anything except with gig-money. Now the band's playing out regularly (most Saturdays), so it's time. There are indications - because of some personal problems with OTHER band members - that The Mole Patrol band might not be together for all-that-long, so I have to be ready to audition for another group!! I'll be nervous until I have a complete setup of my own!

    This cab doesn't have earth-shaking low-bass, but when I was running my bridge pup with the bass' tone control rolled-off, the CS-3 workin' pretty hard, and just a little-little bit of grind from the ODB- overdrive unit (drive way-down and blend control mostly to the clean-side) - staccato notes on the low-side of the B and E strings just BURPED with such startling authority -- oh Baby. ..and that's driven with only a 300W, $399 Hartke head - and NOT just straight in front of the cab. This thing has nice, even dispersion; it just smacked you full-range everywhere in the room, even way off-axis - you certainly can't say that about the BEST 4X10 or 8X10!

    This investment is a pretty big deal to me; I'm still really, really thinking I should do it.

    Joe
     
  10. The JRX125 cabinet is made from compressed poo poo, better known as MDF. For small boxes like home stereo speakers and floor monitors MDF is OK if you treat it with care, but boxes that weigh 90+ lbs tend to get banged around a lot and MDF just doesn't hold up well in my experience.
     
  11. emjazz

    emjazz Supporting Member

    Feb 23, 2003
    Boston, MA
    This is a good point to be made.
     
  12. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    I had noticed this, but only thought to myself that it probably contributes to the weight - that plywood would probably be lighter. But are you guys saying that it would... what? -warp? fall apart? What would happen to it? You mean that its performance would be compromized, or it would be rendered useless in... what? - three years? five? TWO?!!

    I'm not planning on dropping it or tipping it over, but I'd expect to smack into tavern door frames, and clunking'er down steps and off of tailgates. You guys are saying it would actually loose its structural integrity, and go loose or wobbly on me?

    I mean seriously: I appreciate you bringing it up, but I just can't see it falling apart or whatever for several years from hauling it to a tavern and back every weekend!

    Is this reason NOT to go through with it you think?

    Joe
     
  13. emjazz

    emjazz Supporting Member

    Feb 23, 2003
    Boston, MA
    Nah. Just thought that it being a bigger cab it would be more prone to getting banged around a bit. The wood for this cab will dent easier is all. Other than that you should be fine.
     
  14. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Dents are no problem - besides it's covered in nice, black "rat fur" (as Dr. Bass calls it). I'll bet the material does add to the weight, compared to if it were made of plywood.

    Eesch - this thing's ninety-four pounds! I'd have to get a dolly or something...

    Sheesh - originally I was thinking of two avatar 1X12s on the floor, with a PA-horn suspended above it on a stand (time-aligned, of course); then I was thinking of either one or two Avatar NEO15s with the horn above. I was thinking of crossing-over real low, like 500Hz or 800Hz - I like mids, I like horns, and I like even, controlled dispersion! The horn I was thinking of is a Selenium that would cost me about $220 for the driver and horn; the Avatars would be about the same for ONE twelve, or like almost $300-shipped for ONE 1X15; then I'd need at least a passive crossover for something like $50 minimum...

    See how this is tempting? ..and I've actually TRIED this setup!

    Oh, Man - work is almost over for the week. I'm really, really thinking of going down and buying this thing today.

    Joe
     
  15. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Well - work's almost over for the day. If I'm going to get any more thought-provoking info or opinions before I make a decision, it'd be about now...

    ..So I checked the stats, and this thread has had 226 views (I realize that at least 50 were MINE), and 13 replies (and three of those were mine - sigh..) I appreciate all of you who chimed-in to help; Mcrelly, LoveThat', Mr. Hart, Rav, Emjazz, Dood, Mud': thank you all much!

    Joe
     
  16. Passinwind

    Passinwind I Know Nothing Supporting Member

    Joe,

    I'd suggest you do a test load-in into your car, at least. That sounds crushingly heavy to me, but then I'm a geezer. :cool:

    Best of luck, and have fun with your new cab.
     
  17. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    "Have fun... New cab... With your new cab... MY NEW CAB..."

    I sure like the sound of that Mr. Wind; yes in-deedy-do.

    OK: as I tally-in the final piece of data that has been input to this thread - that being "have fun with your new cab" - I'm finally ready to make a decision.

    I'm buying it!

    I'm gonna go punch that timeclock, and burn rubber down to the music store now...

    Good by -

    Joe
     
  18. Passinwind

    Passinwind I Know Nothing Supporting Member

    Somehow, I didn't think you'd do the test load-out until you get it home. :cool:
     
  19. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Thanks, guys!

    I went and bought it. Now I've only half-upgraded my rig, so I'm runing this monster (500W continuous; 2000W peak; 4-Ohms) with my little Hartke 1400 (140W into 4-Ohms). Boy, is this thing efficient (rated 100dB @ 1W, 1m) - The authorative punch that emminates from this mis-matched combination is surprising.

    I've only tested it so far in out little basement studio, which is too small and under-damped to support low-freqs well, but when I stand with my back right up against one of our big broadband absorbers (2'X5'X7"), the low-end is very strong and tight! Not the earth-shaking subs that you feel in your feet, but the 45-50-60-70Hz that you feel in your CHEST; Ohhhhhh, Baby.

    Tonight we play at one of the bigger hall-type rooms that we do - there I'll have enough room volume to let this thing breath a little!

    ~~~~~~~~~~~~~~~~~
    I'll just briefly bring this up now.... but I ran into another instance of this insane superstition about "underpowering". I had salesmen and even one store-customer just imploring me to NOT use me 140W head with this speaker because of this 'underpower' myth - this is really driving me nuts.

    The 500W power handling spec on this speaker is derived with a 100-hour - one-hundred hours, people!! - 500W random noise test. This noise signal is set up with a 6dB crest factor - that means that the input to the speaker contained regular, frequent TWO-THOUSAND WATT PEAKS. 2000W peaks with 500W average, for ONE-HUNDRED HOURS. This little head of mine can put out NO MORE THAN 300W - that's the theoretical absolute max IF I cranked-up every knob all the way, and sent a horrendously-clipped square wave to the speaker!!

    I hope we all at least know that there is absolutely no way that this could blow two crossover-filtered JBL concert-fifteens with edge-wound voice coils - right? - but the horn could possibly be a concern - right? This IEC random noise test is BRUTAL on horns; brutal. One-hundred hours, people. ..And need I say that I'm NOT going to turn every knob on the amp up all the way, and play square-waves?

    Can we remember that this is a very efficient speaker, and 100W will be fine - just fine?? Y'all understand that 100W at 100dB efficiency will result in 121dB at one meter? I'm only going to be standing at-max two or three meters from the cab - I think that'll do...

    This is just insane. This is like Dark-ages mysticism or something. I'm running into this like everywhere I go lately, it seems. I'm starting to feel a little mystical myself - like I'm getting some kind of calling from God to fight and dispel this myth.

    Joe
     
  20. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    I played a regular four-hour show in a medium-sized hall last night with my new cab. It was being driven with my little Hartke1400 140W head (that's the next thing to be upgraded, of course).

    The cabinet performed beautifully. I still want to come up with a little riser for it (which someday may be a subwoofer, but for now I'll build some 'silent' platform for it to stand up on), so at least the horn will be over my head for a straight shot out into the room. The horn in the JRX125 is crossed-over at 2000Hz. JBL advertizes a 'quasi-three-way' design, wherein the two 15" drivers both produce the lowest freqs, but the bottom one is crossed over lower than the 2KHz that the top one is. This lets the two 15s work together for authorative low-bass, while the top one produces the mids up to 2KHz by itself for more focused mids. This seems like a good idea to me, and my ears tell me that somethin's working right!

    I put it as far to the back of the stage as I could; Besides wanting the two other musicians to be fully within its 90-degree dispersion pattern and able to hear it well for goove's-sake (and to maximumly-impress them, of course), I wanted to be out away from it a-ways. My main thought with keeping it as far from me as possible was that I would like for my rig to replace our little PA for the bass guitar as much as possible, but that means there's a good chance it'll be too loud on the stage for a nice mix with the audience (we usually use electric drums that go to the mains and monitors, so in those cases I don't have to overcome the usual ham-fisted drumming on an acoustic set. When we do use an acoustic set, we're sort-of forced to have most of the instrument sound come from the stage, so then everything's way too loud up there anyway). With the square-law of sound volume falloff with distance, if I were to move it from four feet to eight feet away from me, the power that reaches ME from it will be down to approximately one-quarter the power (4/8 squared = .25), but to an audience member out there the cab would have moved from, say twenty feet to twenty-four feet - this would make much less difference in THEIR volume level (20/24 squared is .7).

    This thing sounds great. I should mention that at least in last night's situation, that little 140W-capable head had MORE power than I needed - I tried going back and turning it up a couple times, got a dirty look from the guitarist way over on the other side of the stage, and had to agree that it was too loud!

    So far, I'm very glad that I made this $400 investment.

    I can't wait to see what it's capable of with a two-foot riser and a 500-watt head! I'm also considering trying to incorporate some extended baffle-boards into the riser - that may help augment the low-bass a little, considering the cab's front baffle board is only barely wider than the 15" drivers the way it is (I still have to find out how huge of an extended baffle I'd need to move the 'baffle-step' down below 40Hz - this might be impractically huge).

    Thanks agian to all that helped me with my decision.

    Joe