Hey, mshilarious! New Product Idea!

[kojdogg]

...
I have to say, I am pretty embarassed at charging money to put resistors in a cable, but other people don't seem embarassed by charging five times as much to put them in a box (OK, with pretty switches, etc) . . . and then you'd still need to buy the cables!

Also, does your method require make-up gain (i.e. running the summed XLR outputs to pres then to the A/D)? That would be cool.

edit-- I see; you need to use either a BTA or some inline pads if you want to run them into mic pres? So, if you were summing four stereo stems/busses, you'd need two Mix-4's, which could be run directly into a converter (with an XLR to TRS cable or adapter if required) and if you wanted to run the Mix-4's into mic pres to color the sound, you'd need either the BTA's or a pair of 12dB pads. Is there a loss of fidelity or increased noise by doing that? It sounds like the BTA might be less noisy?

 

[dgatwood]

Unfortunately it's the harmonics that are troublesome!

True. True.

 

[SRR]

Let's collaborate!

I really need a pair of voices-in-my-head cancelling headphones!

I'll be glad to buy the parts and be the crash test dummy if you'd figure out how to rig them up.

Geodon, worked for me, and I am serious.

 

[mshilarious]

Also, does your method require make-up gain (i.e. running the summed XLR outputs to pres then to the A/D)? That would be cool.

Any passive summing network loss will be dB=20*log(1/n), where n is number of channels. Whether or not makeup gain is required depends on your setup. With 4 channels, the loss is -12dB, so for example I can run my D/A at +4dBu, and A/D at -10dBV, and no makeup is required. Also if you are running into a compressor, it shouldn't be an issue.

edit-- I see; you need to use either a BTA or some inline pads if you want to run them into mic pres?

Maybe; depends on the pre's ability to take high levels. But I wouldn't select a transformer over a pad unless you want the transformer's sound (and it will muck with your audio a bit, it is not transparent nor intended to be), or unless you are doing a balanced/unbalanced conversion.

So, if you were summing four stereo stems/busses, you'd need two Mix-4's, which could be run directly into a converter (with an XLR to TRS cable or adapter if required)

If you have 8 channels of D/A, one thing to consider is whether you want to run 4 stereo stems or 8 mono stems, and do left and right separately. If you are strictly doing summing, or even going to a mic preamp, you should be able to sample-align left and right sums done individually. If you are going to a stereo-linked compressor, obviously that doesn't work as well.

and if you wanted to run the Mix-4's into mic pres to color the sound, you'd need either the BTA's or a pair of 12dB pads. Is there a loss of fidelity or increased noise by doing that? It sounds like the BTA might be less noisy?

If you add more stems, then you have greater network loss (24dB for eight channels), and that might low be enough to feed the preamp.

With passive devices the only noise is thermal, which is down in the -130dBV range. You can also pick up some transmission line noise, and of course the self-noise of the outboard gear (you should be hitting it pretty hot though) but I presume these are the desired qualities of OTB summing

 

[mshilarious]

Presenting my latest product, the MDF-1 mshilarious Dog Frightener, v1!

A friend has a dog that keeps getting in their trash, so they wanted a loud noise they could operate remotely. At first I figured they wanted some sort of motion detector or something, but no, they were happy triggering it manually.

So I built this thing to connect to a 2-way radio. Basically when you send a signal, like the call button, this thing triggers. I used two buzzers, 3kHz and 3.5kHz, and best of all, I didn't bother to rectify or filter the incoming signal, so you get the half-rectified amplitude of the incoming signal as a combination 3kHz and 3.5kHz tone. It sounds like ASS

 

[kojdogg]

... It sounds like ASS

I bet Harvey Gerst will be able to make a hit record with it

 

[mshilarious]

Today I did the Extreme Sony TV mod! I am committed to a single remote control lifestyle, but I wanted to add external speakers (which I am building using 5" Fostex full range drivers), and my TV doesn't have an audio output. Sure, the DVD player does, but then I'd have to change channels using the DVD's tuner which isn't as good as the TV's (yes, I am still on broadcast! I have a 10' VHF antenna and 5' UHF antenna to pull in signals from the transmitters which are 70 miles away!), plus I wouldn't have volume control via remote. Not good enough!

So I tapped the speaker wires for a line output, with nicely mounted RCA jacks in the TV case.

While I was in there, I swapped in some Tang Band speakers. PartsX has a $20 TB 2x3 or whatever those mini TV speaker size is, clever little upgrade. Nothing brilliant, but the TV will make its own center channel not that I have surround upstairs, just in the studio. Well, I have the studio wired for surround. I haven't finished those boxes either