SabrinaX Sub-Crossover

I’ve felt that the bass has decreased the quality of the sound which is likely a reflection of both integration and how good the SabrinaX are. 

Putting in a sub and making it integrate well with main speakers and the room takes effort.  I wrote about the difference between expectations and measurements here:

https://speakermakersjourney.blogspot.com/2021/12/room-speakers-eq.html

One thing I should have mentioned, is that in-room performance of speakers has almost nothing to do with the specified or quasi-anechoic (Stereophile style) measurements.

Room gain is real, as are room modes which can move the bass output singificantly up or down.  Setting a sub or crossover by published specs is really tough compared to doing it by measurement.

My advice above assumes you will be using a high pass filter on the mains, if not, you’ll need to still seal your ports, and then use measurements to figure out the best integration point which will probably be around 40 to 60 Hz.

Undoubtedly someone will get huffy about my recommendation about sealing a speaker which is ported.  I say it as a speaker builder, and remind you that the procedure is easily reversible, depending on the condition of your socks.

Hey there!

First, try to optimize the placement of your main speakers and your subs.  I like to use the AM Acoustics room mode simulator.  Try to keep yourself and all of your speakers out of the lowest room modes.

I am of the school of thought that a higher crossover for subs is best, especially given all the feedback from listeners who started too low.  Up to 80 Hz is a good spot.  In your case, this will reduce the load on your amps significantly, hopefully making up for the low impedance around 2 Ohms for your mains.

Next, consider sealing your main speakers.  This will raise the -3dB point, but also severely reduce distortion and excursion in the lowest octaves.  Clean socks work great here.

Lastly, the DSP control over the subs will give you an unprecedented advantage over pure main speakers.  Leverage it, but instead of striving for flat, strive for a descending slope from 16 to 80 Hz, about 1.25 to 1.5 dB per octave.  Then set levels to taste.