Options for Routing Audio to Powered Speakers vs DP-24SD

[Old No7]

Ahoy the forum from the coast of Maine... It was 64 degrees here today -- and light well past 7PM! Ayuh!

I could use some advice on options or how best to route the audio output from my analog mixer to my 12" powered speakers (for live/loud playing) versus (or is it "and"?) to my new DP-24SD with 5" monitors connected.

Before I got the DP-24:
- My 3 keyboards -- MODX6 synth, Mojo 61 clonewheel & RD-88 stage piano -- all go into an analog mixer.
- The "Main Out" goes to the (2) 12" powered speakers (L & R), Mackie Thump 12As.
- This rocks the house (when the bride is away) and I love it.

Now with the DP-24 added:
- I used "Control Room Out" (L & R) from the mixer to go into Source A & B on the DP-24.
- With that, I can assign source A & B to any tracks and get mono or stereo as needed.
- The "Monitor Out" from the DP then goes to (2) 5" JBL 305 Mk II monitors (L & R).
- I know the DP has no "mute" on the output, and both the headphones & the 305s are controlled by the "Monitor Level" knob of the DP-24.

But... (And here's the rub...)
--> Sound is still coming out of the 2 powered speakers too.
--> Turning down the "Main Mix" to mute the powered speakers -- also mutes the "Control Room Out".

One option?
So I was wondering whether I should...
* Add a Mackie Big Knob Passive Studio Monitor Controller ($70)
* Use the "Main Out" audio from the analog mixer, as Inputs A to the Big Knob.
* Then I'd put the powered Thump 12As as Outputs A on the Big Knob.
* Then the DP-24SD would get their audio from Outputs B on the Big Knob.
(No Input B is needed... Yet...)

That way, I'd be able to play and jam along using the bigger Thumps (A to A), and when the inspiration hits or I really liked the groove I was in -- I could dial down the Big Knob's volume, switch over to Output B and now have the sound going through the DP-24SD (A to B)

Q1: Are there any issues with this idea?

Q2: Or are there any other options to consider?

I'd admit that I do have GAS (Gear Acquisition Syndrome); but between all the balanced cables I got, the DP-24SD, (4) decent 32 gb SD cards, the (2) JBL 305s, plus a decent microphone and a Gator heavy-duty mixer stand (which works really well for the DP!) -- I am pretty well tapped out...........

So the Mackie Big Knob for $70 seems like a reasonable and inexpensive approach.

Thanks in advance for any advice!

Old No7

 

[-mjk-]

@Old No7 hands down, this is the best studio monitor controller there is (and I have owned 3, including the Big Knob Studio):

https://www.thomannmusic.com/behringer_studio_xl.htm

Any controller that puts audio on the variable resistor has issues with stereo imaging. My Big Knob studio was driving me crazy because every time I moved the knob, the imaging would shift. In fact, when bringing up the level from infinity, only one side would come up first!

The Behringer design uses a VCA circuit, so the only thing the knob is controlling is the voltage that controls the amplifier.

I have done nulling tests on both the Mackie (which lead me to replace it) and on the Behringer. The Studio XL has no issues whatsoever nulling reversed polarity white noise across the entire volume range.

Put the outputs of the devices you want to control and feed to the monitors separately into the inputs on the device. Use the 2-track outs to feed whatever inputs you need. Also, that model very conveniently has 2 mic pres in addition to the line inputs.

Beware of feedback if you are monitoring a device you are also feeding from the 2-track outputs. Each input has an On/Off switch. There are also outputs and On/Off switches for 3 sets of studio monitors. Plus, if you hook it up to your PC you can use the USB interface for a 2 channel in/4 channel out device. Very convenient.

 

[Old No7]

Thanks MJK, I do understand that you have much more experience than I do, and I appreciate you taking the time to reply, but I did go ahead and get the Mackie Big Knob Passive...

Before pulling the trigger, I'd reviewed numerous online videos and read dozens of online reviews and hadn't heard or seen of that issue you mention. For the price point, and for what I want it to do, it seems to work just fine for me. I've run numerous tests with my gear -- and my ears -- and I'm not hearing the stereo shifting.

I don't know, either I got lucky or my ears or gear just aren't sophisticated enough to detect any issues? Well, I have it in my setup, so I will have to hope my luck (if that's what it was...) continues, as it seems to work fine.

Here's how it's setup for me now:
* "Main Outs" from the analog mixer go to Source A & B on the DP-24.
* "Monitor Out" from the DP goes to Inputs A on the Big Knob.
* The 1/8" phono cord that came with the Big Knob (with a Lightning adapter added) is Input B, so I can play tunes off my iPhone over either speaker system when learning new material.
* The powered Thump 12As are Outputs A on the Big Knob.
* The 5" JBL 305 Mk II monitors are Outputs B.

I always dial the Big Knob down all the way before switching from A to B or back. I can really hear the change when the "Mono" button is pressed, so that's another indication I am getting a good stereo signal.

To practice or play live, the DP must be on, with Source A & B assigned to Tracks 1 & 2, and the faders and recording set (but "Record" button not pressed). In case I really like what I'm doing and want to save it, I have followed Phil's guideline and always start with a new song template, and then create a "new song" file to use that evening.

I will keep you posted if anything changes, but I like the fact that my DP is always there, ready to capture a moment of inspiration; and when I am doing tracking or mixes, I can listen over the headphones and/or both speaker systems to monitor the audio.

Cheers from Maine.

Old No7

 

[-mjk-]

@Old No7 what matters is the outcome, the results. I'm very happy to hear that you have things setup how you need them to be in order to get the results you need. Excellent.

I don't know, either I got lucky or my ears or gear just aren't sophisticated enough to detect any issues? Well, I have it in my setup, so I will have to hope my luck (if that's what it was...) continues, as it seems to work fine.

I don't think its your ears though. Fresh from the factory the BK will be fine. The potentiometer will eventually wear out and then you'll hear the imaging shift. You can help with a spray of Deoxit but replacement is the solution. Both my JBL M-Patch and Big Knob Studio did that.

An easy way of testing would be to do the following with your DP machine:

1. Record white noise on 2 mono tracks. A minute or 2 is enough and you can loop it if you need to.
2. Pan the tracks to Center.
3. Reverse the polarity (called Phase on the mixer screen) of 1 of the channels.
4. Adjust the faders so that the signal cancels and you don't hear it (or it will be extremely low level).
5. Leaving the faders where they are, pan the channels L/R.
6. Do not touch the Monitor control on the DP-24 (see below).
7. You now have white noise on 2 channels on the DP-24 that will cancel when summed into mono. The reason you panned them L/R is to check the mono summing in the Big Knob.
8. Press the mono button on the Big Knob, press Play on the DP-24 and observe what happens. In a perfect world, you should get the same level of signal cancellation that you did when you used the DP-24 to sum in mono (by panning the tracks in the Center).
9. Move the Big Knob and observe any changes to the audio. Any leakage or change in sound is the result of differences between the 2 channels in the Big Knob.

In my case, both my JBL and Mackie controllers would allow white noise to leak though at various points along the range of the knob.

Notes:

1. The Monitor knob of the DP-24 uses the same technology and therefore is another source of image shift for the same reason. Therefore:
2. When testing the Big Knob do not move the Monitor control on the DP-24.
3. When you find a spot on the Big Knob that has the lowest null of the signal, you can then turn the Monitor control on the DP-24 and find the point in the range of that control that gives you the best null and leave it there, using only the Big Knob to control the monitoring level.
4. Working between both the Big Knob and the Monitor controls you can find the position where they like to remain for the best null (and therefore the best L/R imaging balance). You can then set your studio monitor output levels for a comfortable setting so you don't have to move the knob all that much.
5. You can always mark it with a grease pencil for critical mixing.

Or, you can ignore all that and just have fun! lol

 

[Old No7]

Thank you for the info above -- I won't ignore it, but will have some fun too.

I'm pretty sure I can generate white noise from my MODX6, so I will run that test to check. (I have to admit -- I am really curious now!) Then I'll plan to run it again in a year after more much use of the Big Knob -- and it will be interesting to see the results. I'll report back here with any results worth mentioning...

Thanks for taking the time to share your expertise on this -- much appreciated!

Old No7

 

[-mjk-]

@Old No7 that would be great. I would be very interested to find out what you discover. Doing that test to find out where to set the DP's Monitor control for the best null is probably worth it for that alone. Then you can use the BK for all the wear and tear. I haven't used the native control room knob on my console since I started using monitor controllers (which was very soon after I got my console).

 

[Old No7]

I haven't used the native control room knob on my console since I started using monitor controllers (which was very soon after I got my console).

Interesting...

There is no "unity gain" setting on the Tascam "Monitor Level" -- where would you set it? 12:00? 3:00 or max clockwise?

Old No7

 

[-mjk-]

Unless I was going to set it using the null test as described above, I would just put it in the middle of the range somewhere to start. You'll have 3 different level controls: 1. DP-24SD monitor level; 2. Big Knob; 3. Powered monitor level control. Its normally a good idea to put things in the center of the operating range to begin with. As you work you will figure out what needs to be set to what level.