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

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?

 

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.

 

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?

 

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.

 

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.

Good Luck

 

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.

 

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.

 

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.

 

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.

 

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.