TOPIC:

I think I’m getting in over my head. I have learned that best results for subs happen when each is controlled by DSP individually. The SHD can do that for 2 subs, but not 3. So I got a 2x4HD and put the subs on that. Using REW, I set the volume and timing balance for all 3 on the 2x4HD. That part was fine.

Now I have a few problems:

1. Can I get the 2x4HD to stay at max volume all the time so it’s output is driven by the SHD? Now the remote adjusts both, not consistently.

2. I think I will have timing issues because I set timing form PC to 2x4HD directly. I could not get REW to talk to the 2x4HD through the SHD. I could see the meters reacting, but no sound.

3. Assuming #2 above isn’t solvable, I still have a timing issue. Since all the sub timing and volume adjustments were made talking directly to the 2x4HD, now, when I play music through the SHD, there is an extra delay while the signal now passes through both the SHD and the 2x4HD. Further, I understand that the timing delay depends on frequency and other factors., so maybe adding a blanket adjustment (delay) won’t work well. So, if I can’t get REW to measure the output from both the SHD and the 2x4HD operating in daisy-chain fashion, what is the best recourse?

4. Sometimes there is no sound coming from the subwoofers even though the 2x4HD plugin shows the meters moving. All connections have been triple-checked. I am going through analog. Would it help going digital?

Thanks for any help.

I know nothing about the 2x4HD so can't help much but...

1. Do you need to control anything on the 2x4HD after its set up? If not maybe cover the IR receiver so only the SHD responds to the remote control.

2. REW just sends an audio signal out. If your SHD and 2x4HD are set up properly the audio signal should pass through the SHD to the 2x4HD. Then assuming you are using REW to calculate delays of each speaker it will take account of the total series delay through both boxes. It will no doubt be confusing to select the correct speaker, at least I got confused with REW with just a 2.1 SHD system, there are far more ways of doing it wrong than right.

So yes, I think you've done it wrong. Direct calculation of 2x4HD separately won't take account of the series delays of both boxes.

4. I doubt digital will help, generally the minidsp boxes send exactly the same signals to analogue and digital outputs, if there's no analogue output it seems unlikely there will be digital output.

The series connection of SHD into 2x4HD should be able to bee seen as a black box with 2 inputs and 6 outputs. At least as far as the stereo input and the 6 outputs are concerned.

I don't know what delays 2x4HD incurs but assuming the SHD can compensate for it I see no reason using both boxes in series won't work. It just seems like you haven't quite got the 2x4HD under control yet, let alone the series connection from the SHD

If you have a soundcard with audio input or an audio interface you can measure the delay between the SHD and the 2X4HD.

I do not have a SHD but I do have a SHD Studio and I can say that the 2X4HD has a delay of 3.2 ms compared to the SHD Studio + Schiit Modius DAC when using the TOSLINK input on the 2X4HD, I imagine the SHD is similar. Adding a delay of 3.2 ms in the SHD Studio results in perfect sync between the Modius and the 2X4HD.

I would use the digital input on the 2X4HD (you will need a coaxial to TOSLINK converter). This will avoid quite a bid of noise and distortion introduced by the 2X4HD ADC. I think it will also result in a more consistent delay between the SHD and 2X4HD but to be honest I have not fully thought that through.

I see no reason why what you described will not work. The only limitation I am aware of is you cannot connect to the 2X4HD plugin and the SHD plugin at the same time.

Michael

Bottom-line, to your questions...Yes, you can daisy-chain a 2x4HD to your SHD. Concerning your specific questions.

1. Set the 2x4HD gain at 0dB for the 2-inputs and 4-outputs. Cover the IR receiver with duct tape. In my case, it required two layers of thick tape to do the trick.

2. My computer sends the REW signals to the SHD and onto the 2x4HD with no problems. Are your routing matrices appropriately set?

3. My system consists of KEF-LS50Ws, two Rythmik FM8 midbass units and two Rythmik G25HP units. The FM8s are located near the LS50Ws (symmetrically positioned) and configured as stereo. The G25HP units receive a summed L/R mono signal. HP/LP are at 165 Hz for the LS50Ws/FM8s and 65 Hz for the FM8s/G25PH (all Linkwitz Riley 24dB per octave). Signal delays are such that phase is aligned at the X-Over regions. The SHD passes full L/R signals from outputs 3/4. A suggestions if you sum L/R signals to "mono" at the 2x4HD, be sure to attenuate the associated outputs by -6dB.

The 2x4HD is very versatile and offers more than enough delay to manage virtually any situation. It is also possible to manage delay at the SHD for the outputs you send to your mains speakers. This is how I manage timing alignment between the LS50Ws and the FM8s (that is, add delays to the LS50s via the SHD outputs 1/2. Delays are also applied to the G25HPs via the 2x4HD to align with the FM8s. It sounds a bit complicated but is really quite straitforward.

4. I experienced this same thing. I contacted miniDSP tech support and they were very helpful -- they pointed out that I needed to toggle the 2x4HD to the appropriate input choice (found at the "Input and Routing" tab). I'm currently using a digital out from the SHD into the Toslink digital input of the 2x4HD. As the SHD has SPDIF-RCA outputs and I'm using the Toslink input on the 2x4HD, an inexpensive converter was required.

Have to say I'm extremely pleased with the results. I've found the best DSP solutions using REW generated filters (2x4HD) for the FM8s and G25HP and limiting Dirac to ~2,000 Hz and above for the LS50Ws.

Thanks to entripy, mdsimon2, and Randy0223!!!

Thank you so much for replying to my plea for help. By chance I have the coax digital to toslink converter ($9!) so I’ll try that ASAP. I’m hoping that will help with communications between the two MiniDSP devices.

Randy, I found out the hard way that you do, in fact, need 3 layers of tape over the sensor. I’m glad you paved the way for me. Seems like i want to do exactly what you accomplished, so this is very gratifying.

For some reason, even though the “meters” on the 2x4HD jump up and down to the music when attached to the SHD, I get no sound out. I’ve double-checked every setup and link I can think of. As soon as I connect directly to the 2x4HD, the subs start pounding. I’ll keep looking. And, hopefully going to the digital path will help.

If anybody has any other ideas for getting the sound to come out of the 2x4HD from the SHD, I’m all ears.

Thanks again for all your feedback. I’m most encouraged.

alanhuth wrote:

Thanks to entripy, mdsimon2, and Randy0223!!!

Thank you so much for replying to my plea for help. By chance I have the coax digital to toslink converter ($9!) so I’ll try that ASAP. I’m hoping that will help with communications between the two MiniDSP devices.

Randy, I found out the hard way that you do, in fact, need 3 layers of tape over the sensor. I’m glad you paved the way for me. Seems like i want to do exactly what you accomplished, so this is very gratifying.

For some reason, even though the “meters” on the 2x4HD jump up and down to the music when attached to the SHD, I get no sound out. I’ve double-checked every setup and link I can think of. As soon as I connect directly to the 2x4HD, the subs start pounding. I’ll keep looking. And, hopefully going to the digital path will help.

If anybody has any other ideas for getting the sound to come out of the 2x4HD from the SHD, I’m all ears.

Thanks again for all your feedback. I’m most encouraged.

Concerning your 2x4HD not outputting a REW signal. How do you have the respective "Plugins" installed. I determined each Pluggin requires an independent computer. In my case I manage the SHD pluggin via a Mac (macOS Catalina) and the 2x4HD via a Windows 7 machine.

When you say the meters jump up and down are these the input meters only or the input AND output meters? What levels are you seeing on the meters?

When you say connect directly to the 2X4HD I assume this means you are changing to the USB input?

At least on mac you can have multiple plugins installed but it will only allow you to connect to one at a time. Might be different on windows.

Michael

I had both plugins running on my MacBook Pro. One was attached through WIFI to the SHD via the WI-DG WiFi bridge. The other one was connected via USB directly to the 2x4HD. I had no problem switching back and forth between them. But when I ran REW, I think only the SHD plugin was still connected. No sound. Same problem now, with neither plugin running. I can connect to either one and produce sound, but I cannot get it to send sound from SHD to the 2x4HD and produce sound.

The input meters were bouncing halfway up the scale, while the output meters only showed activity when large bass notes were playing, and then they bounced up maybe 20%.

Hmm...20% is quite a low level (-50 to -60 dB) but I would think you would still hear/feel something at that level.

Would you mind saving the .xml configuration files and posting them on here for both the SHD and 2X4HD? I could try them with my SHD Studio + 2X4HD and see if there are any obvious issues.

Michael

alanhuth wrote:

I had both plugins running on my MacBook Pro. One was attached through WIFI to the SHD via the WI-DG WiFi bridge. The other one was connected via USB directly to the 2x4HD. I had no problem switching back and forth between them. But when I ran REW, I think only the SHD plugin was still connected. No sound. Same problem now, with neither plugin running. I can connect to either one and produce sound, but I cannot get it to send sound from SHD to the 2x4HD and produce sound.

The input meters were bouncing halfway up the scale, while the output meters only showed activity when large bass notes were playing, and then they bounced up maybe 20%.

The MiniDSP Development Team advised me to never have Both SHD and 2x4HD connected to the same PC while configuring (see following screen shot). Again, I connect to the SHD Plugin via a MacBook and to the 2x4HD Plugin via a Windows 7 machine. Not saying your current approach accounts for your problem. But it may raise issues at some point.