Good driver for small volume cabinet

Discussion in 'Amps and Cabs [BG]' started by Remus_Redbone, Jul 13, 2013.

  1. Remus_Redbone


    Dec 27, 2010
    Western AR
    I have an old 2x15" cabinet with which I've been experimenting. I first blocked and sealed the original shelf ports. Then I added a couple round ports to each compartment to tune each to approximately 42 Hz to match the Fs of the drivers I had on hand.

    Each compartment in the cab is 3.09 cubic feet, and I used 2.95 cubic feet (allowing for the speaker frame) as the volume to calculate the port length. I think the cabinet sounds as good as it's going to sound with the drivers I have. The lacking component in the performance is low end. I like the old cabinet for its retro look and the "one cabinet" rig, so I'd like to improve it and put it to use.

    The drivers I had on hand (EV 15B) have a relatively small XMax (3.1mm is what I find on the web).

    My question(s): is there a driver known to perform well in a a small volume, OR, what T/S parameter(s) indicate a driver will perform well in a small volume? I can change port lengths to re-tune the cabinet or seal it up, either one, I'm just looking for recommendations for a good 15" driver to use in a 3.0 cu. ft. volume enclosure.
  2. There is an excellent data sheet for the EV 15B (,d.cGE&fp=58c87a31b81c96ba&biw=1366&bih=574). EV recommended a vented enclosure of 3.2 cf (Fb=42Hz) for bass guitar use. The response graph in the data sheet shows -3db at 78Hz, -5db at 62Hz and about -12db at 40 Hz. They point out that with appropriate EQ, response can be brought up to about -3db at 40Hz. a 9db boost at 40 Hz will eat up a lot of power.

    Before abandoning the excellent EV drivers, double check the tuning. You might also try running them with the stock tuning.

    Assuming you want to use these drivers 'full range', here are a few suggestions.

    The Faital Pro 15PR400 ($230 each) in 3cf (Fb=40Hz) models at about -3db at 53Hz, -5db at 46Hz and -7.5db at 40Hz.

    The Dayton PA380-8 ($75) in 3cf (Fb=40Hz) models at about -3db at 50Hz and -6db at 40Hz.

    Both these drivers will give you more low end power than the 15B. The Faital is significantly (around 3-4db) more sensitive, smoother and more extended in the HF than the Dayton. The Dayton is good to about 3.2kHz (on axis), responds well to a little treble boost, and is a great value.

    The Eminence Kappalite 3015 (non-LF) performs well as a full range driver. A search on this forum will turn up plenty of information on its performance.
  3. ScottTunes

    ScottTunes Gear-A-Holic Supporting Member

    Feb 7, 2011
    So Cal
    I'll second the Kappalite 3015 in small cab... I replaced the EVM15L in a "stock" TL606 cab, and the 3015 is outstanding!

    I'm also using a pair of 3015s in a sealed cab (similar in size to JohnK's DIY 215, but sealed, and as much as 10% smaller). It too sounds fab!

    The 3015 is truly a killer speaker!
  4. Remus_Redbone


    Dec 27, 2010
    Western AR
    Excellent & thanks. I knew there was a better suited driver for this cabinet.

    Astro; thanks for the info on the EV drivers. I've done no less than 50 searches and still haven't seen some of the information you provided. The specific level @ the given frequencies is so very telling what is going on with my EV drivers. Open strings sound great until open "E" and it's obvious from the data that the EV being -12 db at 40 Hz is what I'm experiencing. The "E" is obviously weak out of my cab equipped with the EV's

    While looking at the suggested drivers, I ended up on a site selling Eminence speakers that had comments about each. One caught my eye, the Legend CB15, with the comment of punchy low end in a TWO cubic foot cabinet, so it also makes my list to consider.

    As for re-tuning, I've actually confirmed port size and length as well as cabinet volume a couple times. I initially had one of the compartments tuned to 35Hz for a JBL that I had, but that speaker ended up having some issues. I'm using an online port length calculator rather than performing the math as I did in the past, but the equation displayed looks correct (I've got an old Radio Shack speaker building book & I've done the calculations on paper in the past).

    I think the answer is a driver that will stay up around -6db or better @ 40Hz as you both have recommended & thanks again.
  5. iualum


    Apr 9, 2004
    Seconded :eek: .

    There are plenty of fellas who prefer the 15PR400. Know it doesn't take a back seat to any 15, the 3015 included, but neither does the Eminence take a back seat to the Faital. Both are the creme de la creme. I happen to like the 3015 a smidge better overall.
  6. OscarJr

    OscarJr Kneel before Zod!

    Feb 20, 2013
    Laredo, Tx
    You can always model the responses to get a better (yet rough) view of two different speakers and play around with the tuning.
  7. The CB-15 in 3cf (Fb=40Hz) models at -10db at 40Hz, and has a broad peak (+1db) centered at about 120Hz. HF extends to about 2kHz before falling steeply.

    The Kappalite 3015 in 3cf (Fb=43Hz) models at -8.5db at 40Hz (Fb much above or below 43Hz results in lower output at 40Hz). F3=65Hz, F5=52Hz and F10=37Hz. Its HF does not extend as high as the Faital (3.5kHz vs 4.7kHz), but it has a more aggressive tone due to peaking between 1.2 and 2.3 kHz. The Faital is audibly smoother and more extended in the HF, with greater harmonic content in the higher notes - more than the measured (on-axis) HF extension would indicate.
  8. Remus_Redbone


    Dec 27, 2010
    Western AR
    So Astro, if i'm seeing things correctly from this post and your earlier post, the Dayton PA 380 - 8 performs down to 40hz in a 3cf box as good as anything mentioned so far and still gets up to around 3200 Hz? Is it really outperforming the much higher priced drivers as the data indicates or am I missing something?
  9. froghat


    Jun 14, 2009
    Rhinebeck, NY
    You'll be missing 3-4 dB of sensitivity with the Dayton. That is, it will require roughly double the power of the Faital to produce the same SPL. Not a bad tradeoff if you can reach the volume you need before hitting the Dayton's power limit.
  10. The Dayton outperforms the more expensive drivers in deep bass extension, and does pretty well on the high end. However, the expensive drivers outperform it (the Dayton) in sensitivity (as Froghat said), and the Faital significantly outperforms it on the high end. Both expensive drivers are substantially lighter: about 10 lbs. per driver, so the cab loaded with the Daytons will be about 20 lbs. heavier than with the 3015's or Faitals. OTOH, the Daytons will weigh about the same as the current EV's. All three are good candidates for your application. Each is a mix of advantages and compromises. You will have to decide which characteristics are most important to you: deep bass extension, mid-band sensitivity, smooth or aggressive upper mids and lower highs, weight, and high frequency extension. Hey, it's a great time to be a bass player!
  11. If E is weak it's not from lack of 40hz. An SVT 8x10 makes almost no 40hz.

    To get big bass shoot for your lowest 2nd harmonic, just like an SVT drops off response below 70hz.
  12. OscarJr

    OscarJr Kneel before Zod!

    Feb 20, 2013
    Laredo, Tx
    Don't you mean 1st harmonic? :confused:
  13. will33


    May 22, 2006
    Technically 2 horses of the same colour depending on language. If you consider them all harmonics, 82hz would be the 2nd. If you think root/fundemental + harmonics, 82hz would be the 1st.

    Good points here so far about all these drivers. Depending on how much topend you wish, I'd take a second look at the CB158. Good blend of LF extensiin and power handling vs. sensitivity. They are a warmer driver, not bright by any means, but do provide enough upper harmonics to not be muddy. Their treble end (which pretty much ends in what we would call uppermids), does provide enough definition for very good fingerstyle playing, plenty for anything with flats on it, but may leave some wanting who play a good deal of slap, or are looking for a brighter clean tone, or higher pitched grindy tone. In other words, warm and fat, but not mud. Can take a good deal of power but also play plenty loud without high power amps.
  14. OscarJr

    OscarJr Kneel before Zod!

    Feb 20, 2013
    Laredo, Tx
    Not for me, I have formal training in physics. For me personally , the fundamental is not really a harmonic of itself, therefore 41.2Hz is strictly the fundamental, and the harmonics start at 2xFundamental. They are all modes of vibration of a string (inc. fund.) , but none the less the fundamental has a special place. :)
  15. will33


    May 22, 2006
    Well, you're right. :)

    Just for purposes of communication and all that....some folks say 1st harmonic they mean fundamental x 2, etc. Understood to mean the 82hz here.

    I sort of liken it to saying "driver" or "speaker". Not the same but the point gets across. :)
  16. will33


    May 22, 2006
    Should've added a " ;) " up there for spelling "color" "colour". ;)
  17. Matthijs

    Matthijs Supporting Member

    Jul 3, 2006
    +1 Don't give up on the EV just yet. If you want bass don't focus to much on 40hz and on the computer model. Experiment with a slightly higher tuning frequency first. It might get you the right balance between fundamental and first harmonic.
  18. Whatever, yes, 80hz needs to be produced strongly to get a "solid" E. Modern cabs have almost erased the collective memory of weak E's it seems. Meanwhile, another new generation of bassists needs wising up about which frequencies they are feeling when a bass rig pounds them in the kidneys. Not fundamentals!
  19. Arjank


    Oct 9, 2007
    Above Amsterdam
    As far as "harmonics"go, in the world of loudspeakers and other audio equipemnt the 2nd order harmonic is 2xfundamental (check the internet for "harmonic distortion").

    As far as tuning cabs go, I mostly tune them somewheren between 45 and 50hz so I'm sure the cab also plays a low B with some authority. But if you only play 4-string somewhere between 50 and 60hz will do the trick ;)
  20. Have a look at the original TL606 alignment, no fundamental there but a good low E from the EV'B.