Can an Up2Stream Mini, drive an active SubWoofer?

DIY Products&Projects DIY Product Questions
1

This is my first time I might be doing a project with a subwoofer.
I have an active subwoofer, so the amp and filter are integrated into the speaker.

Questions

  1. Would it work to drive this sub woofer with an Up2Stream Mini? Would the subwoofer be functioning as a subwoofer but now wireless?
  2. Would this work in combination with two other, also wireless (Arylic inside), stereo speakers?
  3. Are there any things I should consider before starting this project?

I think both 1 and 2 = yes. As long as the sub-woofer is active and has its own low pass filter.

2

I am no expert and just set up my first system, but if the preamp line dash out is a full frequency range (which I imagine that it is unless there’s a good reason for it not to be) Then you are probably good with a low pass filter and an amplified sub for sure. You might even find their software helpful to smooth out any peaks

3

@mundmc
Thanks for your comments!

I guess you refer to APC Workbench software?
Unfortunately, I can’t use it. I only have Macs.

4

That’s what exactly what I did too. Line out to the active subwoofer from Upstream Mini, then adjust the crossover frequency at active subwoofer. Technically it works but I find the output level a little low on the subwoofer. Dunno why that is

5

Thnx @Decibelist

Concerning your remark about ‘output level being a little low’, that’s quite easy to solve.

Buy the ACPworkbench software from Arylic (only $20).
For this software you will need a Windows PC.

If you start the application and have an Up2Stream product connected:

  • Go to the 2nd tab ‘Audio-Effect’
  • Go to the ‘Pre-Gain’ slider (in red box)

Move the slider to your preference. If you have found the right level, you need to save this setting:

  • In the Menu click ‘Downloader’ > ‘Save configurations to Flash’ > ‘OK’

This will work.
For your reference, see a screenshot of ACPworkbench below.

Schermafbeelding 2023-03-30 140141
Schermafbeelding 2023-03-30 1401411031×809 200 KB

6

The analog output of MINI has 1Vrms level, and as I know active subwoofer might expect higher input level. That would be reason for not loud enough.

7

This might work. I’m using the Mini to output signal both the the stereo amp as well as the active sub. So, what I’ll probably do is to increase the gain at the intended crossover frequency for the subwoofer

8

Will increasing the gain as suggested by @KolfMAKER in ACP work?

9

Also, the active subwoofer I’m using us actually powered using Upstream Sub Amp

10

Just confirmed that the AMP SUB accept 2Vrms input, it’s not safe to increase gain on MINI, that won’t increase the output level as it’s limited by internal DAC, but cause distortion. If you won’t mind the final output power, could consider to decrease gain of stereo output, that would balance the sound.

And if you could modify the hardware, could try to remove the voltage dividing circuit. The ADC of MCU accept 1Vrms input actually.

Btw, I see the SUB board has reserved the USB port on board, so maybe I could build a firmware to make it support ACP, so you could adjust the input gain of LINE-IN.

11

Thanks for the suggestions. I can try reducing the gain via the Parametric EQ on ACP but wouldn’t reducing the gain on ACP reduce the gain overall, including the signal to the subwoofer. l Ideally I would like to implement a sub out on the MINI such that it’ll work with most active subwoofers.

Would having a more powerful sub amp help? At the moment, I’m using the the Upstream Sub Amp to power a 4ohm subwoofer driver with a power handling (RMS) of about 50W (max 100W). I’m not sure if the Upstream Sub Amp has enough power to drive the subwoofer. I know the Upstream Sub Amp is rated at 60W at 4ohm.

12

The SUB AMP board is using TPA3116 chipset, and working in PBTL mode, so it could support to drive 2Ohm speaker to get about approximate 100W output. You could connect 2 4Ohm speakers in parallel to get max power.

13

having a sub out option would be a great feature for the mini like you are suggesting.

although the pro (no amp) board is only $10 more. would it have the same problem of these output levels?

14

I did that with two small mini subwoofer connected in parallel. They sound fantastic. Packs a lot of punch for such small drivers. However, they were passive subwoofers connected to the Upstream 2.1 Amp.

Just wondering what would be the best way to increase the Vrms of the Upstream Mini output. Not sure if that’s even possible,

15

My portable system which I use outside uses a mini driving an amplifier via a gain pot, i tapped a sub out from the pot. This output drives my Jensen subwoofer with no issues, the sub is active with adjustable crossover and gain.

16

Thanks Steve. Likely the issue is with the Up2stream Sub Amp then. Let me try that with another active subwoofer

17

Hi Brian,
With regard to your comments about raising the output voltage of the mini, this is easily achieved by adding a preamp stage.
There are stacks of simple gain stage boards online, most just use a single NE5532 opamp but I’ve always liked the OPA2604, but both will equally do the job.
Steve