Without the sharp edges. I may do something strange on the top now I have a bandsaw. Right now, testing different glues in MDF to see if that is actually the seam sink-in problem. PVA, Epoxy, Poly Resin, Superglue and a new Locktight glue called C06. Two sets. One set sealed with 50% poly varnish, the other sealed with Delft sanding sealer.
Attachments
Cut out larger cabinets. Doing the full matrix internal cross-bracing as it is cheaper than panel bracing with oak strips. Boxes are about 9 x 24 x 13. EDGE simulation wanted the woofer more centered that I would have guessed. Doing it his way to see. In theory, I can miss-match the ripple from baffle-step with the natural dip in the SilverFlute and smooth the 1K reagion just a tad. In theory.
Been a bit side-tracked on this. Mostly researching glue. Over in the woodworking world I got lots of conformation about PVA shrinkage. I am not waiting a year for the results, so I will be using WEST epoxy. I also got side-tracked in designing a solution to Delta planer snipe. ( I'll write it up over in in the techniques forum)
Just glueing up the internal matrix. I am trying an inside-out build process this time rather than fitting bracing inside a box. Sides are cut about 1/64 proud, so I will see if it glues square and can sand to fit.
Just glueing up the internal matrix. I am trying an inside-out build process this time rather than fitting bracing inside a box. Sides are cut about 1/64 proud, so I will see if it glues square and can sand to fit.
Attachments
Bi-amped Crossover measurements for Newbies
Though completed construction of my two-way speaker system is some months away, I want to become proficient on the software that can make tweaking the active crossover reasonably quick, easy and accurate.
Though crossovers can and should be adjusted by ear, says the First Watt B4 crossover manual http://www.firstwatt.com/pdf/prod_b4_man.pdf, p. 17 also says that by using a mic and preamp and software, one can generate graphics that will help get the task done a lot faster. See ATTACHED (A three pole filter is shown for clarity, though I'll be hoping to get away with using a two pole at most).
I know that ARTA is way too math-intensive. I am an old tech school grad, a B student in math, and never took calculus. Would TrueRTA be the best bet for me?
I need to learn how to measure and display the frequency response and phase response of the HP and LP filters-and their summed responses-of the chosen one or two pole crossovers. Presumably, this is done by using test input signals versus acoustic system recordings made via a mic and preamp, fed to my desktop pc's M-Audio card and stored as files in TrueRTA. Then, using TrueRTA's dual trace oscilloscope, do I compare a given "filtered" input signal (i.e. representing the chosen filter, slope and turnover frequency) to the "recorded live" acoustical result-that is, the output "into the room" response of the same chosen HF filter/slope/Fc from the B4 crossover, combined with the response of the HF/MF range driver that its feeding (via the power amp/per channel). Then the steps are repeated for the LF filter + midwoofer driver. Correct?
Is that the way Nelson Pass and probably everyone else does these measurements, and-together with their ears-tweaks the filter type, slope and/or Fc to get the flattest summed amplitude response between the HF & LF filters, versus their most time aligned phase response?
Again, I am pretty much a nube at doing this. Did I miss anything in my explanation about how I think this task all gets
correctly done?
And might RealRTA, or something else, be the easiest way to do this for a beginner?
Also, would you care to suggest a mic? And a preamp. My M-Audio card has no mic preamp.
Though completed construction of my two-way speaker system is some months away, I want to become proficient on the software that can make tweaking the active crossover reasonably quick, easy and accurate.
Though crossovers can and should be adjusted by ear, says the First Watt B4 crossover manual http://www.firstwatt.com/pdf/prod_b4_man.pdf, p. 17 also says that by using a mic and preamp and software, one can generate graphics that will help get the task done a lot faster. See ATTACHED (A three pole filter is shown for clarity, though I'll be hoping to get away with using a two pole at most).
I know that ARTA is way too math-intensive. I am an old tech school grad, a B student in math, and never took calculus. Would TrueRTA be the best bet for me?
I need to learn how to measure and display the frequency response and phase response of the HP and LP filters-and their summed responses-of the chosen one or two pole crossovers. Presumably, this is done by using test input signals versus acoustic system recordings made via a mic and preamp, fed to my desktop pc's M-Audio card and stored as files in TrueRTA. Then, using TrueRTA's dual trace oscilloscope, do I compare a given "filtered" input signal (i.e. representing the chosen filter, slope and turnover frequency) to the "recorded live" acoustical result-that is, the output "into the room" response of the same chosen HF filter/slope/Fc from the B4 crossover, combined with the response of the HF/MF range driver that its feeding (via the power amp/per channel). Then the steps are repeated for the LF filter + midwoofer driver. Correct?
Is that the way Nelson Pass and probably everyone else does these measurements, and-together with their ears-tweaks the filter type, slope and/or Fc to get the flattest summed amplitude response between the HF & LF filters, versus their most time aligned phase response?
Again, I am pretty much a nube at doing this. Did I miss anything in my explanation about how I think this task all gets
correctly done?
And might RealRTA, or something else, be the easiest way to do this for a beginner?
Also, would you care to suggest a mic? And a preamp. My M-Audio card has no mic preamp.
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