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DIY 210 using PAudio neo 10's. Volume & tuning?

Discussion in 'Amps and Cabs [BG]' started by Krit, Nov 20, 2005.


  1. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Hi guys,

    I've had a read through various threads about DIY cabs and thought I'd post a specific question. I've got 4 PAudio SN-10MB's (200w @8 Neo) to use in 2 210 cabs (to be used as a 410 or one cab with my 15). T/S info below. I'd appreciate any input into the cab volume and tuning frequency. I've been fiddling around in WinISD too.

    Am i right in saying that 66l (Vas x2) would be an ok cab volume?

    Tuning frequency should be same as FS (59Hz) or should i make it closer to 41Hz to ensure E string is supported ok? Thanks again for you input! :D

    fs: 59Hz
    Re: 5.4 Ohm
    Le: 0.71 mH
    Qms: 5.82
    Qes: 0.24
    Qts: 0.23
    Vas: 33L
    Cms: 198.4 uM/N
    BL: 17.12 Tm
    Mms: 35.72 gm
    Sd: 0.0346 Sq.m
    EBP: 210
    X-max: 3.5mm

    Cheers
    Krit
     
  2. I'd personally tune to 40Hz, especially if you use 5 strings.
    When you enter the speakers stats in winISD, the program should give you the ultimate setting as far as volume goes - just adjust it after that to get the sweet size you're after. The "Usable Low Frequency" (-10dB) should be the one you're mostly concerned with, but look at the Freq. Range (-3dB) as well.
    66 litres does sound a little small......the last thing you want to do is compromise on low end, but it could work with some efficient port(s).
    Have you thought about porting?
     
  3. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Have you already bought the speakers? I ask because I've actually got 2 of those speakers and here's my honest evaluation.

    I got them before they changed them. Mine have slightly different T/S specs. I initially had them in a 2x10 bass wedge. They don't produce much below 100Hz, so I had to mate them with a seperate 15". Together it's pretty good bass rig.

    I later transfered them into two 1x10 PA speakers. Again, they're not perfect for this job because they have a bit of a hump at 4K that is more noticable when playing recorded music than when they were in the bass cab. Again, the lows are handled to a 15".

    Mine are each in a 15 litre cab that's tuned to 75Hz for a -3dB point of 100Hz. I've also got a passive High-pass filter in ot to stop the lows from making it fart.

    A Couple of years later, I contemplated using them on another bass cab I was designing and found the T/S specs had changed. The new version made it even worse for bass. The cab size is down to a mere 7 litres, tuned to 59Hz, with a -3dB point of 160Hz.

    I've found that a lot of the P.Audio stuff is designed this way. They've clearly picked the PA market as their target. I haven't come across any yet that are suitable for bass. That said, I haven't yet done the math on the new Hexagonal framed speakers. Perhaps I should.
     
  4. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Thanks for the replies guys.

    When I enter the data and open a project with 2 10's winISD first shows a volume of 10.3L!! Does this mean that putting these into a cab of 90L will cause major problems?

    With a cab size of 90L, tuning at 40Hz and 2 8.5cm diam and 17cm long ports the cab is showing a usable low end (- 10db is ok?) down to around 36Hz. The -3db point is 220Hz which obviously isnt ideal but should be ok with a 15 as well?

    Pete: Yes i have already bought these speakers. I've also noticed that the specs on their site are diff to the ones on the boxes. Not sure if mine are new ones or old! I will usually be running 1 210 and 1 15 so hopefully this will help with the roll off in low freq.

    Thanks again for you input guys.

    Cheers
    Krit
     
  5. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Big time problems. I'm not sure which version of WinISD you're using. Winisd Pro has a graph called the "Maximum power" graph which shows how many watts the speaker can take before it hits the limit of it's suspension travel. The unfortunate thing about making your box too large is that while it creates a great looking frequency response graph, it also causes yout speaker to hit X-max MUCH earlier. It also creates a huge hole in the low mids, and there's a lot of audible energy in those low mids.


    I see a potential problem. What is the impedance of the speakers you bought? And what is the minimum impedance of the amp you'll be using? And have you selected which 15 you'll be using?
     
  6. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    I've found at least three sets of specs on the SN10MB, and mine measured different from any of them. They are a great driver whem horn loaded for full range or in a small sealed cab for midrange, but I wouldn't use them for bass full range in a direct radiator.
     
  7. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    OK so basically these speakers wont be usable in a decent size box? As you said it seems like they really are designed to be in little tiny PA speakers. :( I havent got the pro version on the beta version. I probably should update.

    Yeah I'm using a 15 from PAudio too. Was already assembled into a ported cab. It's 8 ohms and the 10's are 8 too. I'll be using a QSC PLX so no problems down to 2ohm.

    Thanks for your help so far!!
    Cheers
    Krit
     
  8. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    So you're agreeing that these are really only suitable for a small fullrange PA speaker? Any ideas of how i could use these in a decent 210 bass cab? Looks like i should've posted here b4 i bought anything!!

    Thanks for your help Bill
    Cheers
    Krit
     
  9. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Hi again guys.

    I just got hold of WinISD Pro and after entering the driver specs it initially shows 56L cab size and 50Hz tuning so things look a little better. No idea why it was showing so small in the beta version of WinISD. I've also contacted the PAudio dealers for their opinion of cab volume. Will keep ya'll posted! Thanks for your help to guys.

    Cheers
    Krit
     
  10. When you enter in the info, and winISD first gets going, the curve it shows should be like an exponential curve,
    ie. Sharp incline, then flattening out to a plateau before the 400Hz range. If the curve has large bumps and looks more like a ECG line if you're getting your heart checked out, then the box will have a fair whack of boom at certain frequencies, and be quieter for others. :crying:

    Good Luck
     
  11. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    No, I use one in my own bass rig, but it's horn loaded. But since you have a fifteen why are you trying to run them so low? Put them into 30L each tuned to 70 Hz, high-pass them with a cap at 100 Hz and let them do what they do best.
     
  12. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    I suspect you've made a mistake entering in the T/S data. The specs posted above don't lend themselves to a 56L cab.

    I presume you bought these through Cannon Sound? Dan and Roscoe are good guys, but they knows nothing about loudspeaker design. Most salesmen dont. So asking them about cab volume isn't going to help I'm affraid.
     
  13. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Thanks again Bill. This makes a huge amount of sense. I guess i was hoping to be able to use the 2 210 boxes as a quad that would give great bottom end. Looks like the 15 and 210 combo will be the go though.

    Cheers
    Krit
     
  14. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Just checked data and it seems to ok. Shrug. What size do you think would be ideal?

    Yeah they were through Cannon. I presumed they'd have data/software from PAudio that would be pretty close to the money but maybe not.

    Thanks again guys. Really is a huge help!!

    Cheers
    Krit
     
  15. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    It's all too easy in WinISD to input the numbers correctly, but to have the unit of measurement wrong. For example, check you didn't accidentally put in a VAS of 33cu.ft instead of 33 litres, or an X-max of 3.5m instead of 3.5mm.

    I often make this exact same error, which is why I also to manual calcs to double check.
     
  16. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Thanks Petebass. I double checked and all appears to well for the data entry. I can see what you mean by the maximum power having a big dip. This appears to be "fixed" by either using smaller volume or tuning the cab higher. Eg At 60L and tuned at 87 Hz max power is a flat 400w from 78Hz up. This should be ok with a 100Hz high pass filter in place? Or would be better to make smaller cab and lower the tuning a little too?

    Thanks again guys! :D
    Cheers
    Krit
     
  17. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    I'd tune at 70 Hz, unless you plan on using at least a 12dB HP filter, and that would get pricey. With 70Hz tuning that gives a 1st order 100 Hz filter the opportunity to kick in before the drivers unload; tuning at 87 Hz gives far less wiggle-room, especially since between driver and cap tolerances a 100 Hz filter could end up with an actual f3 down around 80 Hz anyway.
     
  18. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Thanks again bill. So a simple cap high pass filter has a relatively low roll off in db/oct terms? I'll keep fiddling and try to find a cab size that works nicely with tuning at around 70 Hz.

    Cheers
    Krit
     
  19. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    A two dollar cap will give you a 6dB rolloff. Adding a proper inductor to get to 12dB/octave will cost another $20. US. Probably $50 Aus, if you can get them at all.
     
  20. Krit

    Krit

    Nov 20, 2005
    NSW Australia
    Thanks Bill.

    One quick question to any of the speaker guru's. What 10" speakers are suitaible/ideal for building a fullrange 210 or 410 cab?

    Will any of them allow you to tune down to 40Hz or so and not get the massive dip in Maximum Power between say 50 Hz and 100Hz that seems to occur with a lot of speakers when modeled in WinISD?

    Do the 40 Hz - 16Hz 210 commercial cabs also exhibit this Max Power dip?

    Thanks again everyone who's helping me get my head around a few things!! :D

    Cheers
    Krit