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cab question

Discussion in 'Amps and Cabs [BG]' started by nasaldischarges, Jul 7, 2005.

  1. nasaldischarges


    Jun 11, 2005
    i have a BX3000T (300 watt solid-state head) and a BA115 (1x15 8-ohm 600 watt handling). I want to get another 8-ohm cab, but I dont know if a 2x10 or a 4x10 would be better, or if a high quality but cheap ($150-$300) exists.

    If anyone wants to offer their two cents, i would like to hear it. please.
  2. That amp's 300W at 4 ohms. Meaning it probably only puts out 200W at 8 ohms into your 600W cabinet. Very much underpowered.

    If you get another cab to get 300W total out of your amp, it'll split between the cabs, you'll only get 150W into your 600W cab, 150W into the other cab. Even more underpowered.

    I think you need more power, not another cab. The extra speaker will look cool, but won't help much.

    Its like upgrading a yugo with racing slicks. Won't win races, cause the tires aren't the problem. The engine is.

    Money would be better spent getting a bigger amp. Hopefully the 600W speaker is honest RMS measurement, not some "music power" hokum.

  3. Blues Bass 2

    Blues Bass 2 Supporting Member

    Oct 3, 2001
    Davenport Iowa
    Sorry,I don't agree with this need a bigger engine instead of speakers.Adding speaker area will get you more volume than more power every time.Although 300 watts doesn't seem like much when divided through two cabinets many people gig with that much power and get along fine.Down the line when you can afford it more power would be nice for the headroom.A 410 might be pushing it power wise but a 210 or another 115 would help considerably volume wise.The power rating on cabinets is the most the cabinet will take for for a long period,not what the cabinet needs to sound good.Most cabinets will soun good way below their power rating.
  4. nasaldischarges


    Jun 11, 2005
    thanks...ill take both of your opinions into consideration
  5. Lots easier carrying a bigger amp up the stairs rather than an additional cab.

    Normally its a bit of a tossup whether another cab or more power is the answer. Both help, obviously.

    In your case, you've got 1/3 the rated power for the cab, which is about 1/6 what you should have. Add another cab and you're at 1/4 the rated power, 1/8 what you should have.

    Sure they sound good, they just don't sound loud.

    I mean, really, exactly how far do you have to be underpowered before the answer is get more power instead of add more speakers? Really need to look at the individual situation intead of always picking your favorite answer no matter what. You think 50 watts and a dozen speakers is going to get the job done? You need a really efficient cab to get any kind of reasonable volume with only a couple hundred watts.

  6. ESP-LTD


    Sep 9, 2001
    Probably a 2x10 given the power you have available; there are plenty that will take 150w. Whether you want lots of LOUD or lots of LOW would decide which 2x10 to get. Obviously used will save you a lot of money.

    Don't get too hung up on the power ratings of your speakers; it's become quite the marketing rage these days to quote how much power they can take before catching fire or dissolving into plasma. Even though I can buy a 4x10 that tolerates 1000w briefly, I'd much rather have a pair of 4x10's and give each 500w.
  7. Again, there's no such thing as underpowering a cab. Cabs don't care. You can, however, be underpowered for your playing situation, but the amp-cab power ratio, in itself, is irrelevant to that. All that matters is whether your amp is big enough to get you the volume and tone you want in your playing situation without being overtaxed (and whether your cab can handle *at least* the amount of power you're actually feeding it). If 300 W isn't enough, it doesn't matter whether his cabs are rated at 300 W total, or 600, or 1000 (asuming equal sensitivity). He's underpowered, by definition. Conversely, if 300 W is enough, it again doesn't matter what the cab capacity is. He's not underpowered, by definition.

    I agree that it's important to look at the poster's individual situation. But I don't think just looking at power ratings does that. I'd say that the kind of music played, the settings, the presence or absence of PA support, and the setups of the other musicians he plays with all are relevant. It's impossible to say X amount of power or Y number of speakers is or isn't enough unless you know how the gear is being used. It's like saying, is a top speed of 70 mph enough? The next question has to be, enough for what? Enough for driving 2 miles to the commuter train, sure. Enough for hanging on the German Autobahn, hell no.

    As for getting another cab, if he does do that, his amp will put out more power and he'll actually have more acoustic output. That makes him, if anything, *less* "underpowered", not more. Though the gain will likely not be earth-shattering.

    Personally, I'm a fan of getting as much power as you feasibly can. These days, watts are cheaper than speakers. But how much power you actually *need* to have is not determined by the cab's rated power handling but by your application.

    Also, there's the fact that speakers have practical limits on acoustic output. For a given driver--and I'm willing to bet that cabs in Behringer's range don't use tiptop drivers--there always comes a point at which it just won't give you any more output without malfunctioning or being damaged in some way.

    As you say, 50 W into a dozen speakers may not be the answer. But 1200 W into a single Behringer 12 may not be either.

    I'm guessing that our poster is being cautious with his cash. Given his price range, he may not be able to make a quantum jump in gear. Either a second cab or a bigger amp could help him in the near term, though.
  8. Getting another cab to get an extra 100W out of his power amp is less than 50% increase in volume. That's not even 2dB gain. That's worthless, a waste of money, there's no point in carrying around an extra 80 lbs of 4x10 cabinet for that kind of increase. A 600W cab coupled with a 200W amp isn't suffering from "not enough speakers". You can add more speakers and get < 2dB or you can add an appropriate amount of power and get > 5dB gain with virtually no extra weight to carry by getting a decent power amp. If THAT's not enough, by all means get more cabinet.

    What problem do you think he has? Not enough equipment to carry? Rig is too quiet? Too light? I'm assuming here, but if there's a problem with that setup, he's trying to get too loud for that combination. He's running out of amp power way before the speaker is being taxed. So he needs more power. Maybe it will turn out he also will need more speaker, in the end, but adding speaker when he can't even drive his existing speaker anywhere near its capacity is NOT the first thing he should try. Do you sell speakers or something? :D

    If you need more oomph, you need to ask yourself do I add power or add speakers. If you speakers are near the limit, they can't handle a big enough power increase to make much difference, you have to add speakers. As you say watts are cheaper than speakers, so what could possibly motivate you to suggest buying more expensive, heavy speakers to correct a problem that clearly needs more power FIRST before adding speakers makes any sense at all?

  9. Many people seem to leave out the fact that when adding a cab you are gaining dbs from added power "AND" increasing cone area.

    In this case a 2x10 cab would add 100w (nearly 2db) and roughly double the cone area. Assuming reasonable sensitivity of the 2x10 cab that adds another 3db to the equation bringing the total to roughly 5db. That is not too shabby and is well worth it. It would probably take a 1000w or more amp to accomplish the same thing.

    BTW check out avatarspeakers.com
  10. No, actually, he would get more output from adding more speakers even if power didn't go up. Couple that with the admittedly modest gain to be gotten from going from 200 W to 300 and there would be more of a gain than you say, even though, as I said, it likely wouldn't be earth-shattering. Still, probably a tad more than if he merely doubled his amp power and did nothing else.

    And where, exactly, did you see me telling him to buy a speaker?

    And remember the guy's price range: $150 to $300. Though as I said, watts are generally cheaper than speakers, that applies more to larger values--big watts are cheaper than big speakers. At the lower end, though, it's quite feasible to score a used 1-15 for $150-200. I sold one for $175 last year. But finding a decent amp in that price range--one that would have enough power to be worth it--IME is harder, though surely not impossible. Another speaker probably *is* the first thing he should try if he can afford a speaker and can't afford an amp.

    We'd no doubt agree that more amp *and* more speaker is probably ideal, but things aren't always ideal.
  11. nasaldischarges


    Jun 11, 2005
    heres my analysis of issues addressed as applied to my current situation. Im competing against a 100 watt guitar amp i believe its a 2x12 and its got tubes, if that matters, as well as an acoustic drum set, thats not microphoned. Transportation isnt much of a problem, as i only have to go up three stairs at most. Im interested more in quality of sound than loudness at this point. Im probably swinging towards buying a new cab, seeing as that automatically gets me more wattage as well as area of sound.
  12. I am running the same bass head, driving two 600 watt Kappa Pro LF speakers in a 4 ohm cab. The 3000T isn't the strongest amp, but capable of pushing my 15s quite well.

    I second the suggestions for a 2x10 cab. Just make sure it's an 8 ohm cab. Run both cabs together for 4 ohms, giving you the most out of the amp. The 10s would bring out more of the mids that 15s don't do as well, and this really helps to cut through guitars and loud drums. Probably the most important thing would be to pack your amp and cab down to a music shop, and try some cabs connected WITH your current cab. If you just run out and buy a cab, you won't know how it's gonna sound with your existing equipment.
    Good luck..

  13. I didn't suggest doubling his power, that would also be as worthless as adding another speaker to his existing amp. He could stand about 6x the power he's got, most recommend having 1200W available to cleanly run a 600W cab with adequate headroom.

    More speakers = more output at same power. Sure, but with 2 cabs to split that "same power", each cab is getting half what the original 1 cab was getting resulting in half the output each. Add them up, you get same output, assuming the efficiency is the same. Even with the 300W power at 4 ohms with 2 cabs, each cab gets 150W vs the 200W the one cab got previously. So you get less output out of the original cab when you add the 2nd cab. This cuts the gains you are expecting down a bit. All the extra cone area does is get less rolloff in the bass, so a lower freq response, since more cone area can reproduce a longer wavelength more efficiently. And you coax another 50% more power out of the amp. You're still only adding a couple of dB, similar result to doubling the power.

    If he's concerned about the "sound" not the volume, with a 200W head trying to compete with 100W guitar amps, sounds like he's at least short of headroom or more likely even clipping the amp frequently.

    Adding another spkr will, as you say, not make much difference at all with the existing amp. Neither will just doubling the power. So I say don't waste your money on either approach. Neither will result in noticeable improvement.

    If he can't afford to solve the problem with what he's got available now, he can't afford to waste money on another speaker, or a little more powerful amp that won't solve the problem either.

    In that case, the answer is to keep the money you want to spend today, save more over time until you CAN solve the problem. His existing speaker can handle way more power than he's got. Fix the power situation, the biggest deficiency first. If his existing speaker couldn't handle a massive increase in power, I'd agree with you, it'd be worthless getting a small increase in power then. Getting extra speaker capacity would be the ticket. If the Beringer cab is actually rated at 600W MUSIC power rather than RMS, it'd be closer, but I'd still go for more speaker.

    You're the one that said watts are cheaper than speakers anyway. He's has tons of excess speaker capacity RIGHT NOW he's not taking advantage of. Why get more cab when he's already got excess speaker capacity? The choice is clear. Watts now, cabs later if the power alone isn't enough.

  14. ESP-LTD


    Sep 9, 2001
    Another issue to consider is how you like the tone of your cabs. Personally, I prefer to to underrate my cabs by 50% and my amp as well.

    For example if I have a 1000w amp, I only want to push it to 50% volume and leave some headroom. Likewise if my speakers are rated for 500w I only push them to 250w. I like the tone better; it sounds more open to me. You will find also that as a speaker voice coil heats up, the speaker parameters change from their nominal value in a phenomenon knows as 'power compression'.
  15. Actually, you don't get the same output. That would imply that if you send 100 watts into a 1-12, it's the same volume as if you send 100 W into a 2-12, when the same 12" drivers are being used. A Marshall head would then sound as loud into a single Celestion V30 as it does into a full stack containing eight V30s. Clearly, this is not the case; no one would use multiple drivers if this were true. I think you're ignoring the effects of acoustic coupling.
  16. You're trying to turn acoustic coupling into some kind of perpetual motion machine.
    See? Its not going to make a significant difference. You're not seriously suggesting that an extra cab with a 200-300W boost in power from the lower impedance will produce nearly the same effect as going from 200W to 1200W are you? It'd be a different story if the cab wasn't able to handle that much of an increase.
    I'm not ignoring acoustic coupling, I'm just saying its not equivalent to a 6 fold increase in power. Its a fine solution when you already have a reasonable amount of power available. If he had a 100W amp would you suggest getting 4 extra 4x10's to make up the difference? I suppose with all those speakers they use at concerts they can get by with 50 watt amps, you know, with the acoustic coupling.

  17. Show me where you think I suggested that.

    Never said it was. You've set up a straw man there. What I said about acoustic coupling was specifically to do with this statement of yours:

    "Sure, but with 2 cabs to split that "same power", each cab is getting half what the original 1 cab was getting resulting in half the output each. Add them up, you get same output, assuming the efficiency is the same."

    Which is factually wrong. 100 W into two identical cabs does not yield the same total output as 100 W into one such cab.

    But regarding the rest, I certainly think a 1200 W amp would be cool and would help, but I don't know if he can get one for $150-300.
  18. Jazzin'

    Jazzin' ...Bluesin' and Funkin'

    This is a very interesting thread. I, myself, am in the same situation. I have a 300W(@4ohms) Ashdown along with an 8ohm Avatar 212 cab(which handles up to 1000W). I'm looking to upgrade in the near future. Maybe I'd get a stronger amp and a second cab at the same time. I'd think that's the best solution.
  19. DavePlaysBass


    Mar 31, 2004
    I started out with an EBS HD 350 and a 8-ohm Aggie GS-112. Getting around 250W max into a single 12"speaker. Not a bad setup. With drums I found myself running the amp on 5 or 6. With the addition of keyboards and a second guitar player, I found myself a little underpowered when everything went full up. Then I added an 8-ohm Avatar B210 Neo cabinet. Now I have 350W into 3 speakers. Big difference. Run the amp on about 3 to get where I was at with 5 or 6. I buy into the add more cone area argument. YMMV.

  20. Blues Bass 2

    Blues Bass 2 Supporting Member

    Oct 3, 2001
    Davenport Iowa
    A few years ago I had a Trace Elliot RAH 200 head that put out 200 watts into 4 ohms and 130 watts into 8 ohms pushing a 8 ohm 15"Black Widow.I started working with a band that was louder than I was used to and the 15"cabinet couldn't keep up so I added another 15" cabinet and then didn't have any more trouble keeping up volume wise.I must have imagined that I was louder because according to the information all the newbies are getting in this thread they all need 1000 watts and one 15" speaker and adding more speakers won't help at all unless they have mondo power.I feel sorry for the new guys that take this as gospel.

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