No rim on pd125 one td10and tdw chart - Roland PD125 VPad (VPad 12 DualTrig Mesh Pad)

Your answer is in the link provided below. The chart shown is for a 50 ohm circuit but in the paragraph below the chart they address other characteristic impedences and describe the z factor and how to compute.

http://www.radio-electronics.com/info/rf-technology-design/attenuators/attenuator-resistor-values.php

Here is a flute chart. It is downloadable as well from the same site.

Modern Flute Piccolo Alto Flute

Try;
www.kenmahood.com/free/index.htm

I just found this website, so sorry for the delay. sometimes the heads (especially plastic or composite) come partially unrolled from the rim to which they are attached. since by tuning it, you are pulling the head tighter only because it's firmly attached to the rim, if the rim is loose at even a little spot, that place will sound funny. you might get a crackle or buzz where the fit just isn't right. plus, in this case, if you keep tightening the rest of the head, this portion will just warp or fold since it's not tight enough to lay flat and stretch, which will just increase your noise.
Now, if the head's leather, the buzz might be a fly trapped inside. no really, check for splinters or separations on the rim of the body which the head is stretched over. if there is a split in the actual drum body, you'll hear it more when the head next to it is vibrating.

It MAY require the flashcard to be left in... in other words they may NOT download and transfer the flash update card to internal memory.

The card MAY be the wrong format for the unit. Also the maximum size for a CF card in this unit is 4Gb. Check that yours is not bigger than that. There has been SOME compatibility problems of flash drives... try a different brand.

The subs are rated at 133 Db peak... that IS loud. Note that the crossover is 90Hz so ONLY the very low frequencies will pass through these... possibly your input frequencies are above this? Everything above F2 will be attenuated and will have to go through other speakers. From this chart:

http://www.google.com/imgres?imgurl=http://ehartmusic.info/wp-content/uploads/2010/12/frequency_chart_lg.gif&imgrefurl=http://ehartmusic.info/music/music-frequency-chart/&h=709&w=1026&sz=61&tbnid=lLcM8uGqj673QM:&tbnh=104&tbnw=150&prev=/search%3Fq%3Dmusic%2Bfrequency%2Bchart%26tbm%3Disch%26tbo%3Du&zoom=1&q=music+frequency+chart&hl=en&usg=__TpgHSTWoL_Wg1Q0T8gadkn8o_gE=&sa=X&ei=sZWzTdLqOcrjiAKrrf2uBg&sqi=2&ved=0CBsQ9QEwAQ

You will notice that ONLY the LOW END portion of a bass guitar and a few other instruments will oass through this unit. It is up to your mains to handle things above 90 Hz. These subs are truly subs. Make sure you use balanced lines to drive these. (XLR)

How they expect you to find the information is beyond me!!! I downloaded the manual and it appears that the information you want is on page 57.

Near the bottom, and the only way I spotted the parameter of MIDI channel number setting is seeing the range as 1 to 16.

They list this as L part and R part channel/track setting... these will be for the left and right parts of the split keyboard... that is you can set a MIDI channel to between 1 and 16 for both the left and right division of the split keyboard.

I don't think many people would find this... AND shame on Yamaha, there doesn't seem to be a MIDI implementation chart, which you should get familiar with for any MIDI devices you might have... the chart is a quick access to the MIDI capability of MIDI devices and they didn't include one in the documentation for this unit...

Yes there is a rim shot trigger. Your electronic generator has to be set correctely to use it. Refer to the manual. Usually the trigger is carried on the same cable and has a "different waveform characteristic" which your Roland sound generator recognizes and reacts to.

ALWAYS to answer your question, refer to the "MIDI IMPLEMENTATION CHART" for your MIDI instrument.

This chart can be found USUALLY near the end of your user's manual.

This chart, among other things, will tell what can be transmitted and received by the MIDI device.

Refering to the chart for your DX21 it shows that the DX21 can both receive and transmit program changes.

If you don't have a user manual, download one here:

http://www.maths.abdn.ac.uk/~bensondj/dx7/manuals/dx21-man.pdf