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"Maximum Power" winISD question

Discussion in 'Amps and Cabs [BG]' started by MikeyB, Sep 25, 2008.


  1. MikeyB

    MikeyB

    Aug 16, 2006
    Sykesville, MD
    Hello,

    Please help me understand a bit more about the Max Power graph in WinISD:

    I constructed a simple 5.5 cubic foot box, tuned to 41hz, and loaded with (4) DeltaLite-II 2510s. I run the Max Power graph and see the expected dip due to the ported design. HOWEVER, it shows that at approx 68hz the design will only handle 230w.

    I'm having a hard time believing that (4) 2510s in a fairly standard 410 type box would only handle 230w at that freq. I suspect I'm in a "don't know what I don't know" situation.

    Help?

    As usual... much appreciated... your experience is invaluable.

    Thanks,

    -Mike
     
  2. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    That's the sad fact of reality. Note that at the dip this is a plot of how much power it takes to exceed Xmax, which is usually defined as the point where speaker distortion exceeds 10%. So the speakers can handle more power than this but with ever increasing distortion.

    Alex
     
  3. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY
    Alex is right. That graph is all about how much power is required to hit Xmax at any given frequency. Like most drivers, the 2510 is Xmax limited. Just for kicks, look at the Max Power graph for a driver that is not Xmax limited like the 3015LF. It is much different.

    WinISD is assuming you are using a pure sine wave tone. The tones that your bass produces are somewhat different, and don't generate the same excursion that a sine wave would. So if you're using a 4 string bass, there is not as much going on down at 68Hz as you might think. Your 410 will still get very loud and you'll be able push more than 230W without much trouble. Heck, I'm probably pushing that into the 210 I built with 2510's. They sound fine.
     
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Now you do know. FWIW, your design will take roughly twice the power that the average 4x10 will.
    You'll also get a better result with 50 Hz tuning.
     
  5. MikeyB

    MikeyB

    Aug 16, 2006
    Sykesville, MD
    Thanks for the info.

    I was looking at the DeltaLite-II 2510s because I had an idea to construct a vertical 410 (I mentioned this in a thread a while back) and was considering using the hardware from an Avatar Neo 410. I know those are LF versions custom made for Dave, but I thought I'd just model up something rough to approximate his his cab and see what it would handle.

    Zac mentioned an alternate driver. Any other suggestions on a good driver for my project? I'd love to stay NEO if possible.

    And thanks for the tip on the tuning Bill.

    -Mike
     
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    IMO the 2510 is the best ten currently available. BTW, when Eminence comes up with a new driver they test a number of configurations of it. The one which in their opinion gives the best overall result is the one that goes into their lineup.
     
  7. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY

    BTW, the 3015 I mentioned is a 15" ant a 10".


    I've looked at a lot of 10" Neo before building my ZL210, and the 2510 was the best I could find. Another one that looks good on paper is the B&C 10 NW64. I has an 8mm xmax and good thermal handling too, but when I modeled it in WinISD I get less than impressive results. Not sure why. I recommend modeling some other drivers in WinISD and see what you get.
     
  8. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    Qts is rather low so choked off bass response due to the very strong magnet (which brings back up the sensitivity despite the high Xmax and low Vas). I suspect it's designed for use in very small subwoofers for small PA systems where they can compensate for the low Qts with EQ.

    Alex
     
  9. MikeyB

    MikeyB

    Aug 16, 2006
    Sykesville, MD
    Zac - I watched that thread on the Zaclite with great interest when it was ongoing! Very nice work.

    What was your interior volume and and porting? I'd like to model yours in WinISD to get a better feel of things as well.

    I recall you saying it is a "bright" cab - do you think that has more to do with the construction technique or the box design?
     
  10. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I suspect the brightness of any 2510-II loaded cab is due to the rising sensitivity through the midrange.

    Alex
     
  11. MikeyB

    MikeyB

    Aug 16, 2006
    Sykesville, MD
    Oh, one other question concerning interior volume. Is there any advantage is separate sealed compartments in a 410? I believe the Ampeg fridge 810 is sectioned off into separately sealed 210 compartments?

    -M
     
  12. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    It stiffens the enclosure and thus reduces detrimental resonances. However it's a rather heavy way of doing so.

    Alex
     
  13. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY
    Great explanation. Thanks. I knew there had to be something else to it.
     
  14. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    True. Some don't care for a strong midrange, but that's why amps have tone controls and EQs. :D
    Never lose the opportunity to gain sensitivity anywhere you can. Compensating for it by cutting EQ saves power and reduces distortion. OTOH if a driver has weak mids and can only sound good by boosting EQ that costs power and increases distortion.
    +1. Also consider two 2x10s rather than one 4x10. It's a lot easier to haul, and you can't leave half of a 4x10 at home when you don't need it.
     
  15. Rune Bivrin

    Rune Bivrin Supporting Member

    Oct 2, 2006
    Huddinge, Sweden
    Another - albeit rather dubious - advantage is that if a driver fails and they are connected in series within the compartment, that compartment is out of the picture completely instead of acting as a poorly tuned passive radiator.
     
  16. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY
    Thanks. It was a really fun project, and my back and ears have been enjoying the results.

    V[SUB]b[/SUB] = 2.8 ft[SUP]3[/SUP]
    F[SUB]b[/SUB] = 46.25Hz (measured)

    The ZL210 sounds bright in a quiet setting compared to some commercial cabs, but in the mix on stage it actually sounds more even. The mids and highs don't seem to get lost. I think this is a really nice attribute of the 2510 drivers. For quieter or solo settings you might want to scoop some of this high midrange out with EQ, but it is great to have it there when you need it.

    As Alex mentioned, it is most likely the 2510's rising upper midrange response which gives the cab its bright character. I don't believe in magic or mojo, so I'm not going to claim that the composite construction does anything particularly special for the tone. It just makes it super light weight and stiff.

    I measured a 3dB peak at 500Hz and a slowly rising 5dB peak from 900Hz to 2.5kHz, and then a gradual roll off of the high end with smaller peaks at 4kHz and 10kHz. Eminence data sheet for the 2510 shows as much as a 1dB peak at 300Hz, and 9dB peak around 2.5kHz on the 2510, but I think that just beyond 2Khz the piezo tweeter array begins to take over and attenuates that 9db peak down a bit.

    Here's that data. I had to normalize the Eminence data since my readings are not in reference to any voltage/distance standard, but you should still be able to see the 2510's frequency response "signature".

    ZL210vs2510data.

    I must say that I find it pretty cool that the results I measured closely matched what Eminence published. I really gives me the "warm & fuzzy" about my own design and measurement processes, and better yet trust in the data that Eminence publishes. Good on you Eminence.

    Go and build your 410 with the 2510s. I think you'll like the results. I've been able to do small and medium sized gigs with the ZL210, although I did find its limits on a loud stage a few weeks ago. I'm confident that a properly built 410 with 2510's will be crushing on stage and sound great.
     
  17. zac2944

    zac2944

    Dec 28, 2004
    Rochester, NY
    +2
     
  18. Crockettnj

    Crockettnj

    Sep 2, 2005
    North NJ
    I used the avatar neo in a largish 1x10 tuned ** i think** to 50hz. Its a great little lightweight practice/small gig cab. I have pushed it and it does a great job for a 110.

    OTOH once the honeymoon period wore off, I do notice that it is not very strong through the upper mids, as some have described the stock 2510II and as the plots predict. At the expense of increased xmax and the potential (?) increased low end output is some midrange sensitivity.

    Also, bgavin published a spl measurement for a neo410 avatar and it doesnt, as i recall, show the rising midrange you'd expect.

    Something to consider.
     
  19. Nook

    Nook Commercial User

    Jan 6, 2008
    Usti nad Labem, Czech Rep.
    owner, designer and builder - www.soundelirium.com
    Very interesting talk! Regarding the B&C 10NW64...here you can find measurements made by the czech B&Cspeakers distributor:
    http://www.prodance.cz/protokoly/10NW64.pdf(made in 2005)
    http://www.prodance.cz/protokoly/B&C_10NW64.pdf (made in 2007)
    both differ quite a bit from published specs in a good way for a bass player. It made me think for a while about building a very small (~20liters) higher tuned cab for practice/small gigs, but had not enough courage (and money:smug:) to try it. And yes, my 30 liters Eminence Beta 10 loaded cab serves perfectly for that purposes.
    (See my "fullstack" (1x10 +1x15) :smug: here: ):
    http://ulozna.soulslavers.com/soubory/nook-220908-234657-dscn1289.jpg
     
  20. MikeyB

    MikeyB

    Aug 16, 2006
    Sykesville, MD
    Something to consider, indeed. Thanks much for that info.
    Do you have a link to those bgavin specs by any chance?

    Looks like what Bill alluded to - if it were "better", Eminence would make it that way.

    -M
     

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