I may have been a little hasty.

[Count Arthur]

I currently have a pair of Dynaudio 52SE which I use in combination with a REL Stampede subwoofer using the high level connection, where the subwoofer is connected to the speaker outputs on the power amp in parallel with the main speakers.

I've just bought a pair of Dynaudio Core 7 active monitors: https://www.dynaudio.com/professional-audio/core/core-7

Having bought them, I've realised I won't be able to use them with my existing subwoofer.

Other than getting a different sub with balanced pass-through, what can I do?

 

[Certainkindoffool]

You could use an active crossover and send an lfe signal to the sub. My Behringer dcx2496 can do that and they aren't expensive. I'm sure there are better and cheaper options as well - thats just the one I am familiar with.

If your preamp/source has both ballanced and unballanced out, you could also just connect an amp to the unbalanced out and create a high level signal for the time being.

 

[Soniclife]

Can the core do it's own high pass?

 

[andreasmaaan]

What's your signal chain prior to the power amp?

 

[NTK]

Can the core do it's own high pass?

Yes it does have an 80 Hz LR4 HP filter.
https://www.dynaudio.com/professional-audio/core/core-7/support/manual/en/dsp-settings

 

[TimW]

The REL Stampede has an LFE unbalanced RCA input. The Core 7 has a digital AES output that can be used for daisy-chaining the second monitor and adding the Dynaudio Core Sub. If you're using a digital source with the Core 7's then you may be able to add a device to the digital out with mono summing and an analog output for the sub. If I were you, I would consider getting a modern preamp with a subwoofer output and room correction.

 

[Soniclife]

Other than getting a different sub with balanced pass-through, what can I do?

As the core has a high pass, and I assume the sub a low pass, you should be able to split the analogue signal, or use 2 outputs from a DAC, and let them handle the filtering.

 

[Count Arthur]

The "front end" is a PC and an RME ADI-2 DAC FS, with analogue out via RCA or balanced XLR, there's no digital output.

The miniDSP Balanced 2x4 looks like it will do what I need:

However, could I get away with something simpler. As I understand it, I want a balanced pass through and a mono single ended/RCA output.

I currently run the main speakers "full range" and then set the upper frequency cut-off on the subwoofer, which is currently set to 45Hz, so it just fills in the lower frequencies below the main speakers.

 

[TimW]

Just about any miniDSP product will accomplish proper sub integration. The SHD series does it with higher performance and adds Dirac room correction.

It doesn't make a lot of sense to use an excellent DAC like the RME with the miniDSP 2x4. And the balanced 2x4 doesn't have a single ended output for your sub. The A/D and D/A of the 2x4 will degrade the performance of the signal, although that's what will happen inside the Dynaudio speakers as well since they use DSP. I would recommend taking a look at the SHD studio.

 

[Count Arthur]

The issue with the SHD studio is that it's not far short of the price of one of the Dynaudio subs.

 

[andreasmaaan]

@Count Arthur I'm not sure why you wouldn't just use the inbuilt high-pass filter on the Core 7s as @Soniclife and @NTK suggested? The Adi-2 can send signal via both the XLR and RCA outputs simultaneously, so you could send one signal to the Core 7s and the other to the REL (or your power amp). The REL has an adjustable crossover, so it would be relatively easy to integrate it with the Core 7's 80Hz/LR4 high-pass filter. And this would save you buying an additional piece of gear...

 

[Count Arthur]

The Adi-2 can send signal via both the XLR and RCA outputs simultaneously

Ah, that's interesting. The Rel Stampede doesn't actually have RCA in, only a high level input and an LFE:

Presumably, the LFE input needs to be mono, however, if I can safely connect the Core 7 speakers to the RME DACs analogue XLR outputs and a power amp to the RCA outputs simultaneously, I can still use the high level input for the sub.

I'll check with RME that this is OK to do.

 

[Count Arthur]

It occurs to me that the high level input may not work with an amp that doesn't have any speakers connected to it in parallel to the high level cable:

 

[CDMC]

All the high levels inputs do is take the speaker level and convert it to low level. It could be bypassed and RCA jacks installed. Easier would be get an inexpensive low power amp or an old amp and run your RCAs to it and the speaker out to the sub. Something like this would work great:

https://www.parts-express.com/smsl-sa-36a-pro-tpa3118d2dap-stereo-amplifier-2-x-20w--230-212

 

[Soniclife]

Ah, that's interesting. The Rel Stampede doesn't actually have RCA in, only a high level input and an LFE:

View attachment 85277

Presumably, the LFE input needs to be mono, however, if I can safely connect the Core 7 speakers to the RME DACs analogue XLR outputs and a power amp to the RCA outputs simultaneously, I can still use the high level input for the sub.

I'll check with RME that this is OK to do.

The LFE input is a phono input isn't it? Just use that from the RME phono output.

 

[Blumlein 88]

All the high levels inputs do is take the speaker level and convert it to low level. It could be bypassed and RCA jacks installed. Easier would be get an inexpensive low power amp or an old amp and run your RCAs to it and the speaker out to the sub. Something like this would work great:

https://www.parts-express.com/smsl-sa-36a-pro-tpa3118d2dap-stereo-amplifier-2-x-20w--230-212

I started to post this myself. But it would work just fine. I've done that for a couple people in the past. No problems.

 

[Count Arthur]

The LFE input is a phono input isn't it? Just use that from the RME phono output.

Yes, but it's only a single channel/input, so I assume it needs the stereo signal to be converted "downmixed"? to mono.

Would something like this work?: https://www.amazon.co.uk/Monacor-21...JJ7F5A0YXWH&psc=1&refRID=RER2FSWFSJJ7F5A0YXWH

Or perhaps?: https://www.instructables.com/id/Simple-Way-to-Convert-Stereo-to-Mono/

All the high levels inputs do is take the speaker level and convert it to low level. It could be bypassed and RCA jacks installed. Easier would be get an inexpensive low power amp or an old amp and run your RCAs to it and the speaker out to the sub. Something like this would work great:

The issue I see with using an amp, and if it works, I already have something suitable, is that without speakers attached, one of the outputs will have no negative connection. There are three conductors to the speakon connector, left +, right + and one -ve which is connected to one of the negative connections on the amp. If there is no negative connection to one of the amp outputs, surely there's no circuit and that channel, either left or right, whichever has no negative connection, will be innoperative:

 

[Soniclife]

Yes, but it's only a single channel/input, so I assume it needs the stereo signal to be converted "downmixed"? to mono.

Would something like this work?: https://www.amazon.co.uk/Monacor-21...JJ7F5A0YXWH&psc=1&refRID=RER2FSWFSJJ7F5A0YXWH

Or perhaps?: https://www.instructables.com/id/Simple-Way-to-Convert-Stereo-to-Mono/

Sending a single L or R channel will probably be very similar to proper summed mono, as most bass on recordings is mono, but either or those options should work. I kind of expect someone here to have an even better way.
The LFE input does offer a lowpass filter?

 

[Count Arthur]

Yes, the upper frequency roll off point can be set for the high level and LFE input:

I probably have a couple of suitable ~1k resiters in my box of bits.

I even have a neat little project box I could re-use:

This is actually a little crossfeed circuit I built to try it out. I didn't really like the effect, so it's been sat around unused for years.

 

[Fatsow]

Please let us know how those Core 7s sound, when you get a chance.