Tuned percussion in MIDI?

[JohnG]

jazzcat said:

My concerns are not making an RCA to TS (unbalanced) or TRS (balanced) adapter. Soldering things like that is a snap. I do cord repair often. ( I don't do board soldering)

My concerns are the fact that the SD2 outs are Consumer Line Level ( -10dBu) and the line (instrument) inputs on my mixer are Pro Line Level (+4dBu) I don't know if the preamp in the board would bring it up to +4dBu and not cause a hefty noise floor increase, or cause the mixer to work too hard, or whatever. That's a dif in 14 dBu. I intend on asking my teacher about it if I can freakin' remember to do so. LOL! I'm a baby beginner to signal processing and it seems once I learn a little it brings up more worries and questions.

BTW the Paul White book is the text book in the class I am taking! Needless to say the class is barely srubbishing the surface of MIDI but, I am getting something out of it. It's forcing me out of the realm of GM as has ownership of the SD2.

Hi JazzCat,

Didn't think somehow that you'd have a problem wielding a soldering iron JazzCat! Depending on your mixer solder up an RCA to TRS and be prepared to cut the shield at just the RCA end.

Mmmm! If I were you I shouldn't worry too much about the difference in levels providing that you've got a half way decent mixer. I'm using a relatively low cost Mackie DFX12. The input gain on the channels seems to cater for whatever the input, whether mic, -10dBu, +4dBu etc. I honestly can't notice an increase in the noise floor. But at 61 it may be loss of high frequency sensitivity! Then, of course, if the Ketron is a bit noisy the extra gain may show it up. Trial and error I think is called for.

I'm very interested to know about the class you're taking. Please tell us more. The MIDI book I like most is "the new MIDI files" by Rob Young. Hard to find now though. It's got about 60 good examples on CD of how to create some interesting MIDI effects.

Best regards,
JohnG.

[shyamwestwind]

Jazzcat, you really are a genius !! What a simple solution and only you could've thought of it. AMAZING !!!! Thanks for being there for us, in the Forum !!

[JazzCat]

ha ha ha!! I seldom come up with ideas on my own. I come up with them by talking with one particular person I know. He is more adventurous with trying something in a non-traditional way with what features are available within a program. Although I think this is one I came up with myself. LOL

[JazzCat]

John G said:
I'm very interested to know about the class you're taking. Please tell us more. The MIDI book I like most is "the new MIDI files" by Rob Young. Hard to find now though. It's got about 60 good examples on CD of how to create some interesting MIDI effects.
============================


Now those effects I'd be interested in seeing or hearing about! Who knows, there might be some goodies there I haven't thought about!!

Awww Man! I wrote up a nice long post about my class, hit the 'post reply' button and got a message back saying I'm not allowed to post! My sign in time on the forum had lapsed and there is no way I was on for 6 hours! Grrrrrrrr !!! Before I hit the 'post reply' button again I'll copy and paste what I write to a document so if that happens again I won't lose an hour or two's time rewriting!

Anyway, back to class.
I guess the best way to show what class is about is to show the page for class:
www.channingbooth.com/classes/music202.html

The 3 homework examples for the first class are mine. Needless to say, my second weeks homework didn't cut the mustard. LOL

I took Music 190 last semester. It is the prerequisite to the rest of the recording arts classes.

The class uses Cubase SX3 & 4 (mostly 4 now) so I'm having to learn how to use it. Talk about one heavy learning curve! Gads!

[JohnG]

Hi JazzCat,

Thanks so much for the URL. It looks, on paper, a very interesting Course. I do hope you're enjoying it? Have great fun with Cubase, I didn't.

How many times have I lost what I was typing into a message? Too many to count. I now author them all in notepad then copy and paste them into the Message field and add smileys, field controls etc.

Here's a little techie stuff I looked up for you re. decibels. I've done it before but so long ago I couldn't remember the figures off the top of my head.

First dB is only a measure of relative levels on a logarithmic scale and unless it has a reference point is fairly meaningless. A 1000:1 ratio is 60dB.

So lets put those references in regarding the -10dB and +4dB we were talking about. -10dBV not dBu and +4dBu.
Oh-oh! Different units. Now lets convert the dBV into dBu and we get -7.8dBu. Aha, it's getting closer. I'd like to convert them both to voltages because it's probably more meaningful to most of us.

-10dbV = 0.32 Volts
+4dBu = 1.23 Volts.
Ah! Actually they're not as far apart as we first thought.
Just for reference:- 0dBu = 0.775 Volts.

Next let me have a look at the spec. for the line inputs of my mixer.

Input gain control range.
Line in (mono channel): -15 to +30dB. e.g. guitar after effects unit.
So I can reduce the signal, if it's too loud (sorry techies), by 15dB (about the same as a tone control on a hi-fi amp does) and amplify it by 30dB if it's too quiet. That's quite a bit.

Line in (stereo channel): -20 to +20dB. e.g. a -10dBV or a +4dBu sound module. i.e. plenty of cut but, most importantly, gain for a semi-pro unit.
In other words taking the 0.32V to 0.775v (or even to 1.23v) shouldn't be any problem at all. Often you'll find you have to cut the input from a pro unit (to 0dBu) but amplify the input from a semi-pro one (again to 0dBu). Many mixers work at the 0dBu level internally.

Then my mixer spec. says maximum Voltage Gain, Line in to Main Out 56dB. Blimey that should be enough!

Of course that's my mixer not yours.

Lessons learned =
Understand the units you're measuring
Don't confuse different units
get familiar with your mixer specification.

And for JohnG? Get off your high horse and stop being a geek, nerd, whatever.
Too late for that now!

And for JazzCat, a little gem, what are the standard connector types at each end of the cable connecting pro mixer to active loudspeaker? And what kind of, off the shelf, terminated cable could you use?

Hope this helps if you've ever been confused about these things.
Best regards,
JohnG.

[JohnG]

P.S. I'll take the MIDI effects and use them for some of my postings in my MIDI thread.
With fresh examples and reworded text, that should keep me busy for a year or so!
No plagiarism here please.
JohnG.

[JazzCat]

what are the standard connector types at each end of the cable connecting pro mixer to active loudspeaker? And what kind of, off the shelf, terminated cable could you use?

I don't understand the term 'terminated' in regards to a cable.
I do know that speakers use unshield cable, instruments used shielded.

As for standard connector types, I believe you are looking for me to say, 1/4" TS Phono plug.

It seems that is changing on an awful lot of newer equipment, to speakon connectors, for 2 reasons.
1. Too many people have accidently grabbed a phonojack from the back of a PA and plugged it into their instrument. Instruments fry.
2. Speakons lock into place and can't be easily yanked out like a 1/4 phono plug can.

[themd21]

Don't know of any active speakers that use either speakon or 1/4 jack. Any I've come across use a standard mike cable, female end to the active speaker and male end or 1/4 jack connect to the mixer depending what output connections are available.

[levi2]

i have a active sub speaker and as themd says theyre just standard xlr mic cables
go to this link click on the pic right of speaker it shows you the back panel

www.stagebeat.co.uk/P/4159/PRO+SUB+P+POWERED+SUB+BASS+SPEAKER+400w+RMS
dunno if this one has dual xlr and the 1/4 inch jack

[JohnG]

Well done Levi2 and themd21, sorry JazzCat the answer's XLR male and XLR female as in a microphone cable. So the correct answer is a standard, off the shelf, microphone cable will connect a pro mixer to
an active LS.

Why? Because we're carrying a "line level signal" of just a volt or two unlike a standard speaker cable which is carrying many volts, 40 or 50 is not uncommon in PA use and Mucho amperes. The signal for active LSs needs shielding from external noise as it's the amplifier built into the loudspeaker that will do the power amplifying. So shielded cable is preferable.

I would have accepted XLR to TRS jack or even TRS to TRS too, as connectors do vary from LS to LS and mixer to mixer, but XLR each end has become the norm. BTW my mixer has XLR(f) and TRS main outs.

I have a strong liking for Mackie mixers.

"Terminated" is a term used when a cable has connectors soldered to the ends i.e. terminated not open at the ends. In this case when you buy a cable already made up with the appropriate connectors. Or, for example, "terminated" at one end with XLR female and at the other with a TRS jack plug.

Terminators is a term more specifically used when the plug that is on the end of the cable has a resistor within it to make the transmission line (cable) have a characteristic impedance. The old 10 base 5 and 10 base 2 Etherenet standards come to mind.

However Speakon "terminators" (plugs) are the best for passive speakers as you say JazzCat. 1/4 inch TS pose a health and safety hazard if live and unplugged.

Here are some references BTW for the -10dBV and +4dBu.
en.wikipedia.org/wiki/Nominal_level or this one
en.wikipedia.org/wiki/Line_level
or, of course, the IEEE or AES.

Again, I hope this helps those who don't have a pro audio background.

For those with a couple of weeks spare to read some really good documentation on compact mixers you could do a lot worse than downloading some of the pdfs on this site:
www.mackie.com/support/compactmixer/index.html
Happy reading,
Best regards,
JohnG.