Hardware high pass filter for DAC output suitable for powered monitors

[Scrutable]

Hello all. I have a problem that I thought would be common and easy to solve but it turns out it's not so obvious. I just scavenged together a surprisingly good sounding 2.1 nearfield desktop system using Y connectors to feed duplicate signals to the monitors and sub. This works well at most volumes, but when I turn it up the small woofers strain. So I am now am trying to offload the low and low-mid bass to a subwoofer. The configuration is as follows:

Macbook Air 2020 source
Meizu Lifeme Mblu headphone/DAC
1 stereo in/2 stereo out Y connector
Yamaha MSP-5 5" 2 way powered monitors
Dayton SUB1000L low profile 10" powered subwoofer

The speakers have meaningful output down to only about 80 Hz, so ideally I would like a high pass filter with a cut at about 80-100 Hz. The sub has all the settings for bass management so it just needs to be set.

So, my questions: Is there a little box somewhere that will take full bandwidth stereo in and put out high pass signals? Is there another inexpensive solution?

Many thanks in advance for the help.

 

[staticV3]

Harrison labs makes these: https://www.hlabs.com/products/crossovers/

Feasible would be:

-FMOD hi pass 70Hz
-FMOD hi pass 100Hz
-FMOD hi pass 150Hz
-FMOD CABLE 70/100Hz high pass
-PFMOD HP-1

Amir has measured one before:

Harrison Labs In-line Crossover Review (RCA)

This is a review and measurements of the HLabs in-line RCA 50 Hz crossover. It was kindly sent to me by a member and costs US $27.95. I understand these are popular with car audio folks. Company sells many variations of this and also a custom version. The sample I received was "New Old...

www.audiosciencereview.com

The PFMOD would likely be smartest, as it is Stereo so only one unit required, and it has all HPF frequencies in one unit.

You can even replace the Y-split with it, as the PFMOD HP-1 has one HPFed output for your Mains and one full-range output for the Sub.

 

[Sokel]

Can you DIY a little?
If so, here is a dead cheap solution with decent measurements:

Cheap analog electronic crossover

I've been playing lately with a very cheap analog 2-in/4-out analog crossover. Is somehow DIY but very easy to fix. To my surprise it measures very decently! (note that has been measured with the worst possible conditions,long cables soldered just to see,adapters,noisy PSU and by someone totally...

www.audiosciencereview.com

 

[voodooless]

A few other solutions:

Introducing DSPi | A powerful, user friendly and open source DSP for less than a cup of coffee

For the longest time, I have been in search of the “perfect” inexpensive audio DSP device. Something with user friendly control software that could accept a USB input, apply PEQ, delays and other essential processing and then produce a digital output. Over the holidays, I was (un)fortunate...

www.audiosciencereview.com

Or, you can use an aggregate device and use the DAC for the main speakers, and the headphone output for the sub, and use some software DSP to do the filtering. CamilaDSP should work, or something like Element.

 

[Scrutable]

Man, those solutions are all awesome. (Not so awesome: The websites for ordering and support.)

@staticV3 - The PFMODS look like the cheapest and fastest solution. Only $40 for a plug and play. But I can't get my cart to process. Will attack this more thoroughly today.

@Sokel - Another cool box, it is unclear from the site what DIY needs to be done. You just need to solder in the input jacks and put it in a project box?

@voodooless - I thought of that but also thought it might be subtly out of sync. I will look into this for sure because it is something I can do with my collection of adapters without more purchases. The downside is that my Air is in a Bridge dock and I would need to manually plug in the 3.5mm sub cable.

The other thing that this suggests is a DAC with bass management/sub output.

Regardless, I will be implementing one of the above shortly and will report back! Many thanks for the quick and helpful responses!

 

[Scrutable]

Update: Spoke to Stan at Harrison and he also recommended the PFMOD. I got the 2W-1 which has both high and low pass. Hopefully it will be here in a week or so.

 

[staticV3]

The PFMODS look like the cheapest and fastest solution. Only $40 for a plug and play. But I can't get my cart to process. Will attack this more thoroughly today.

Here's one on eBay, even cheaper: https://www.ebay.com/itm/134824420534

 

[staticV3]

I got the 2W-1 which has both high and low pass.

Your Sub has a better Low pass already.

Could've saved a few bucks with the HP-1 and not lost anything.

 

[Scrutable]

That is true but I was curious about the device and for an extra $20 I figured there was little to lose. Even that cheap system was about $600 when new.

Amir's review that you mentioned was kind of funny - so disdainful, with its lonely single graph.

 

[NTK]

That is true but I was curious about the device and for an extra $20 I figured there was little to lose. Even that cheap system was about $600 when new.

Amir's review that you mentioned was kind of funny - so disdainful, with its lonely single graph.

It is a first order filter, which is highly inadequate. The are good reasons why first order filters are rarely used in loudspeaker cross-overs. (With a first order high pass filter, the driver excursion with still be increasing inversely proportional to frequency below cut-off.) The exceptions are of course speakers catered to audiophools.

 

[voodooless]

It is a first order filter, which is highly inadequate. The are good reasons why first order filters are rarely used in loudspeaker cross-overs. (With a first order high pass filter, the driver excursion with still be increasing inversely proportional to frequency below cut-off.) The exceptions are of course speakers catered to audiophools.

I think these are actually 2nd-order crossovers. For a sub, that is generally also on the low side of things, but better than nothing.

 

[NTK]

I think these are actually 2nd-order crossovers. For a sub, that is generally also on the low side of things, but better than nothing.

Measurement said otherwise. 50 Hz cutoff, -6 dB at 100 Hz (and -13 dB, close enough to -12 dB, at 200 Hz). Therefore first order.

 

[Scrutable]

I don't have the unit yet so can't speak to actuals, but the specs give good expectations.

First or second order are both fine for this very specific application, and this is high-pass: It is just to ensure the 5" woofers don't get abused when my eardrums do. At LP 100Hz, the 50 Hz level in the graph will result in calm woofers. Amir's review thread shows several members are using it for this exact purpose.

(The subwoofer has full bass management built in, and it is fed full frequency stereo, so the low pass of the 2W-1 is not needed.)