Why is this

Discussion in 'Amps and Cabs [BG]' started by cb56, Mar 4, 2001.

  1. cb56


    Jul 2, 2000
    Central Illinois
    I usually stack my Ampeg 410 cab(rated 500 watts) on my Ampeg 118 cab (rated 175 watts) and use my 350 watt amp sending 175 watts to each cab. Last night the stage I played on had a drum riser that ran the lenght of the stage left to right so I put both of my cabs on it side by side about 3 feet apart. I noticed that my 118 cab seemed alot louder than the 410. Is this because the 118 cabs reproduces lows better or is it because I'm under powering the 410 cab? or is it some other reason
  2. JimM


    Jan 13, 2000
    Northern California
    Is the 1x18 a 4 ohm or 8 ohm ?

    If it's a 4 ohm it will draw more watts than the 4x10 if the 4 is an 8 ohm.Also,bigger,more efficient cabs are louder than less efficient ones.
  3. cb56


    Jul 2, 2000
    Central Illinois
    both are 8 ohm cabs
  4. cb56, it sounds that the 18 cab is just more efficient to me. If you're sending 175 watts to both
    cabs, the 18 is getting its max power rating, while
    the 4x10 cab isn't halfway there. Also, the more
    power a cab can handle usually, but, not always
    means it's not as efficient as a lower rated cab; it
    needs more power to reach its cruise level. Kinda
    like a hot car, most of them only show their real
    performance when the pedal's to the metal. It's
    a pain in the butt, but, you can buy a crossover and Bi-amp your rig. Only the real lows will go to the
    18, while everything above goes to the 4x10 cab.
    It's much more efficient; this way the two cabs
    aren't competing with each other for the same

    Just a thought,
    Mike J.
  5. cb56


    Jul 2, 2000
    Central Illinois
    That's kind of what I thought. Just so happens I have a biampable head coming tomorrow. A Hartke 7000. It's in a 210 combo amp(believe it or not) but I think I might pull it out and rack mount it. I'm not sure I will like the sound of the Hartke head over my solid state Ampeg but I'll give it a try. At what frequency do you recommend setting the crossover?
  6. Ah yes, this is one of my favorite subjects.
    As for the crossover frequency, that'll depend on two things: your taste, and the size of the room.
    The first one is naturally up to you, the second I'll
    explain here.

    The lower a frequency is, the longer it is; literally.
    The lowest note of a four string bass is about 40hz. I'm not sure of the exact length of it, but,
    let's say it's ten feet long. This means from the time that note leaves the speaker, it needs ten
    feet to fully develop, and sound full to human ears. As you go higher on the neck, the frequency of the
    note is higher(vibrations per second) and its length
    gets shorter and shorter. This is why a bigger
    woofer can produce a deeper sounding bass note
    than a smaller woofer. The note has more time to
    develop before it hits the free air. Conversely, it
    doesn't produce as crisp a mid-range tone as a smaller woofer, because the notes have fully developed, but, must still travel down the extra cone material before reaching free air. When you
    put the two together with a crossover, you get
    near optimum performance.

    As for the room size, the larger a room, the more it
    will enhance lower frequencies, because there's
    more room within the room for the lower notes to develop after leaving the speaker enclosure. A smaller room will do the opposite, enhancing mid and
    high end notes. This is why you'll have to experiment with the crossover setting on your new amp. I'd suggest setting it to 200hz at first, then
    just see how it sounds to you. The larger the room, the lower you can set it because the room will allow the low notes to really bloom. In a very small
    room, you may not even need the 18 at all; again
    this is up to you.

    As for the crossover frequency, this is not the point where the bigger speaker cuts out and the
    smaller ones take over, but, rather the pont at which they're both radiating 50% of the crossover
    frequency. If you set the crossover at 200hz for
    example, the 18 is prodicing half the signal, and the 4x10 cab the other half. As the notes go higher, the
    4x10 produces a higher percentage of the signal,
    and the 18 less; as you go lower, the opposite happens. A lot of guys think that just adding another bottom will make an amp sound better.
    It will make it sound louder and fuller, most of the
    time, but, not necessarily better. A lot of people
    also ignore room size and acoustics which affects
    the sound a lot more than you can believe. A bare room simply bounces the sound all over the place.
    You can have the best amp in the world, but, if it's
    in an acoustically bad room, it will never sound good.

    Congratulations on your new amp, and let me know
    how everything turns out.

    Good luck,
    Mike J.
  7. Ehrr, I'm gonna bug again here. Sorry about that.

    That's simply not true. It IS true that a large speaker needs more space to develop its lowest frequencies, but no one on this board, including Mike D, who has done extensive study on this subject, has been able to determine why. It certainly is untrue that the speaker needs one wavelength to develop its low end. It's WAY more complicated than that. The midrange drop is because the cone of a larger speaker is heavier, and therfor unable to make swift movements of several hunderds cycles per second. Sound waves don't travel down the cone. A good speaker has an almost infinitely stiff cone, and what the coil puts onto it, comes out. Heavier cone means less mid and high.
    Well, sorta like the opposite. A small room will enhance low bass, a large room will cut it away. Ever wondered why a very small subwoofer in a car can sound so good? Because a car is a VERY small room. Lower freqencies will bounce around the room far more often so each time they will amplify themselves. But it is true that a large speaker will sound better in a large room, because of this "throw" issue mentioned above. The low end needs room to fully develop, but sound pressure drops.

    Food for discussion. Let's have it!
  8. Joris, without copying the entire book here, see if you can get a copy of a book entitled " Good Sound" by Dr. Laura Dearborn. This is where I got
    a good deal of my info, also from issues of a magazine called "Speaker Builder". I'll see if I can find mine to back up what you've called into question.

    Mike J.
  9. Hey Joris, you were right! After I read, and re-read
    your criticism of my post on speaker theory, I enlisted the help of another poster at this forum
    who read my post and pretty much had the same
    response as you did. I was wrong on a couple of things and hazy on another. I better get back to my books and make sure I have rock solid proof
    before I give any more speaker theory advice.

    Can you imagine if this was a discussion on defusing bombs, and I'd given the wrong advice?


    Thanks for pointing out my error, I shall be much
    more careful in the future.

    Mike J.

    P.S. If you want his entire response, e-mail me, and I'll forward it on to you.
  10. Gabu


    Jan 2, 2001
    Woodland Hills, CA
    Hey MJ.

    Cool beans on your reply. I always dig it when a dude learns he made a mistake and goes with it rather than slinking off into the night or fighting a losing battle. :)

    We all make mistakes, but cool people learn, and rock on. I didn't know any of that stuff... I am learning alot from this board too.
  11. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    OK - I read Michael's post and thought it sounded reasonable, because it matched up with my experience. I don't know anything about the physics of speakers apart from what I've read on this forum, but I have played bass in a lot of different rooms, halls or outside.

    Now my experience (my ears)and what people have confirmed in the audience area, is that in a large room with a high ceiling, the same bass setup sounds "boomy", bassy and very overpowering; but in a small room with a low ceiling, it sounds tight, focused and you can actually hear the mid-range, not just the extreme low end.

    So what is going on - why does this sound contradictory to what you are saying?
  12. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    Come on Joris - I thought you wanted a discussion on this! ;)

    Seriously, I would be interested in learning more about this and applying it improving my live sound - I just tend to use my ears, but if there is any theory I am interested to know more.
  13. MikeyD


    Sep 9, 2000
    I would participate in this thread, but I've been having nothing but headaches with the new TB forum software, so I'm not posting much anymore. Maybe we could take up this thread under the Fender forum instead. I'll check there if you make the topic obvious.
    - Mike
  14. cb56


    Jul 2, 2000
    Central Illinois
    So what was the answer to my question???
  15. To cb56, sorry for all this confusion, but, my first
    response to you about the 18 cab probably being
    more efficient was correct. My statements which
    came into question were all in the speaker theory
    follow up post. As for the crossover point, as I stated originally, start at 200hz, then try different settings to see how your amp sounds to you. The
    other member (I don't know if he wants me to drag
    him into this ) said he'd recommend 800hz. In the end, it's up to your individual taste. It's just like
    stereo speakers; what sounds too trebley to you
    may sound *open* to me. When it comes to speakers, there's theory and there's practice.
    Discussing speaker theory is almost like disscussing
    religion. As Joris said, there's a few things we know that speakers do, but can't easily explain. I don't
    want to give any more advice on theory until I've
    re-read some of my source material, and perhaps
    researched some new ones.

    Now, if you read Bruce L.'s post, he seems to agree
    with me in a practcal sense. Again, I know what sounds good, proving it, in theory is a horse of a different color. I was wrong on some theory, and not on some others. This whole theory thing can be like a dark forest; just make sure you leave a trail
    of bread crumbs behind you.

    Talk to you guys soon,
    Mike J.
  16. I'm sorry for not replying sooner, I've been away & busy & engaged in other threads & all.

    I have several remarks.

    1. I don't know everything. Everything I say is only my opinion. Though I think I have a good understanding of the physics of sound.

    2. Micheal, though remarks 1 stands, I think you're really cool dude! You got guts to admit you're (a bit) off. And I would like you to forward that message to me, with consent of the original sender.

    3. Bruce, what you refer to as boomy low end, is usually a mid-bass boom, on other words a (fairly) midrange-peak. IMO, it is caused by lack of low end to "balance" the total sound. What you refer to as "tight" I think is that balance. Low end can't be boomy, by the simple fact that it's hardly audible. It can rather be felt. But it can make or break the total sound.

    The meaning of "low end" could be explained in two ways: the lowest part of YOUR sound, or the lowest part of SOUND. When I talk about low end, I mean 20-60 (roughly) Hertz, a spectrum which is hardly reproduced by even the most expensive speaker cabinets (Hifi excluded).

    Last Saturday, I took my bass rig with me to the club I work at as a volunteer. It was a dance/cafe night with just the bar and loud music, so there was no band. I was doing the lightshow, and next to me I had set up my rig as a subwoofer to test if it would do any good to the sound in this high ceiling, large room. I programmed a sub filter into my preamp/effect unit, so only 20-60 Hz came out. While standing next to it, it was unbelievably loud, but IMO far from boomy. And down at the dance floor, there was this "Hey where does THAT come from?"-feeling. The DJ, a guy I play with in one of my bands, comes up to me and says: "I don't have to crank up the PA to make it sound good! The room is filled with sound as it is"

    Which brings me to this: in a large room, there's less low bass (room eats it away) so you tend to turn up the volume knob to compensate for that. But in addition to more low bass, you get more mid bass too, making it sound boomy. Does that make any sense to you guys?

    Those subwoofers I mentioned above each have 1 12" hifi driver capable of 8mm swing (back and forth) without distortion and a usable frequency range down to 24 Hz. I know low end :D. I mean: I do believe I think what I'm talking about. But as always, I could be wrong. And everything I said above is only my opinion.

    Rock (or jazz) on,
  17. Joris what's up?
    I don't have time for a long reply right now(e-mail
    and Internet service are at my job) but, as I said,
    I thought you were wrong on a lot of stuff, I went
    to a third party, and he told me that you were
    more right than me! Remember this is speaker theory, and I cosider this almost as hard as nuclear
    theory. Ha! The explanation you just gave on the low part of sound made very good sense. I'll write
    a longer message when I get a chance.

    What is this forum for? To try to be right all the time, or to learn from one another?

    Good talkin to you. Hey I hope we didn't lose the rest of you guys out there. Stay tuned.

    Mike J.
  18. another reason for the 118 sounding louder could be the stage (inc. drum riser)'s resonance ie. reacting to the low frequencies which would be most prevalent in the 118's output.
  19. Bruce Lindfield

    Bruce Lindfield Unprofessional TalkBass Contributor Gold Supporting Member

    Thanks for the reply Joris - I am going to think about this more and see if I can actually "experience" what you are talking about - It does make sense, but I suppose there are always other factors affecting the sound - as has just been mentioned. You are usually playing on a stage which can often be a hollow wooden resonating box which must also add to the "boominess"?

    The worst sound I can remember was on a polished wood dance floor in a medium-sized venue - but this was bad for everything, not just bass.
  20. Phat Ham

    Phat Ham

    Feb 13, 2000
    Joris, so if I was playing in a large room and had to turn up do you recommend maybe turning down around 100-200hz?