XSP-1 bass management using XLR cables

[widmer]

I have an XSP-1 (gen 2) and two UPA-1s. I just switched from RCA to XLR cables. I read the user manual and am inquiring about using the XSP's bass management features with the UPA-1s and XLR calbes.

I want to use XSP-1 high-pass filter at 60 Hz for my bookshelf speakers (mains) and set the XSP-1 low-pass filter (also at 60 Hz) for my subwoofer. I have the set them at the same value as instructed in the user manual on page 17:

"Note: Typically, when bass management is enabled, the selectors are set to Low Pass and High Pass (respectively) and both Crossover Frequency adjustments are set to the same frequency. A commonly recommended frequency is 80 Hz, which works well with smaller satellite speakers. With these settings, the crossover control in the subwoofer (if it has one) should be set to 'flat' or 'direct'."

However, later in the user manual on page 20, it appears to say that if I use XLRs to the UPA-1s, then I cannot use the low/high-pass filters - that they are disabled automatically and a full-range signal is sent to my bookshelf speakers. Is this true?

"The internal circuitry in the XSP-1 is designed to provide a balanced fully differential signal path from input to output. This is the default operating mode for the XSP-1 when balanced inputs and outputs are used, the Frequency Trims are disengaged (Direct mode), and bass management is disabled (Main Outputs are set to Full Range)."

Please advise. I definitely would like to use the hi/low pass filters for mains and subwoofer.

Thank you!

[emotimmo]

I had this exact setup. I think this statement is a little ambiguous. Differential Reference Mode is more when a series of settings have to be in place rather than putting it in this mode would disable these other settings. It's not like a Denon where you put it in pure direct mode and Audyssey and base management are disabled. On the XSP-1 you have you disable the bass management and be in Direct mode along with using balanced in/outputs to qualify as "Differential Reference Mode". If you leave bass management, you technically won't be fully differential through the whole signal path.

One thing to note is if you are using balanced outputs to your UPA-1s and RCA to your sub your mains and sub will be 180* out of phase. This is an Emo thing. I just swap polarity on my speaker wires at the amp to compensate.

[widmer]

Thanks for the very helpful reply. Regarding your note at the end: I am currently using an RCA from the summed output of the XSP to the LFE input of the SVS 2000 Pro, so instead of reversing polarity, I will change the phase of the SVS to 180 degrees per your advice.

[emotimmo]

Used a PB 1000 Pro as well. Yes, I originally did this, but then I actually changed the "polarity setting" to "negative" within the app and kept the phase default. I have a UMIK1 and saw better starting results in REW from this and then I tweaked the phase. You would think they are effectively the same, but I saw differences.

I ultimately went to reversing speaker polarity since this is absolute phase and keeping the sub default. If you search for "emotive phase" you will see the back story, but it probably doesn't matter in the long run: emotivalounge.proboards.com/thread/55385/phase-outs-sources-speakers-important

tldr: most balanced signals are inverted and Emotiva leaves out the piece that other manufacturers add in to flip it for sound quality reasons. If you use RCAs on their amps no issues.

The first time I hooked it all up and wasn't aware, I thought my sub went to sh**.

[leonski]

Why the SAME frequency? Crossover filter settings are not brick wall, but at a slope which you don't mention.
HIgher numbers of slope are steeper. And are usually in 6db increments from 6db per octave to as high as 48db per octave.
The 'per octave' part is what's important. If you et a crossover at 60hz for both speaker and sub, they will both have useful
output in a very large overlap...even if a more aggressive 12db or in the case of my sub, a 24db slope....
By crossing at the same freuquency? You'll make a 'bubble' at that point. Both speakers are 'on' across a small but important band.

My solution in my setup was to cross the mains and sub at 15hz or so apart. In your case? Maybe 80 for the main speakers and
60hz for the sub....

you can test this by Ear. My setup was a little 'tubby' until I did as I suggest.

You should be able to determine the phase relation of the sub to main speakers easily and by EAR, also. One way the bass just sounds 'thin'
while the correct setting is the most rubust bass.... A few lucky types have a variable control on the sub, while the rest of us have
a simple '0 degree or 180 degree' switch....
See the above answer from emotimmo. He noted exactly what I mention you should note. His fix was simple. The swap of speaker polarity?
That'll work, too, I suspect. TEST and LISTEN......

NOTE: 6db is 4x the power. And an 'octave' is double or 1/2 the frequency. So? If set at 60hz, your output will be 1/4th at 30hz. Speaker
outputs can Add or Subtract from one another. that's why that pesky phase thing is important. You can have a 'hole' or 'peak' in response.
That's the main reason to keep crossover point of mains and sub apart.....