Pass xvr -1 problem in the setup
- Thread starter tdh888
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I can't say what to expect with the 48 Hz setting. I based the crossover frequency suggestions on the specs and capabilities of your speakers and my experience "playing" with my XVR1 crossover. There is no formula. That's what makes it so much fun=frustratingand time consuming. You have to test it out! (...)
It can help if you have room dimensions and know about the speaker and listener positions - you can have a guess of what will be the critical zone, and can exclude some tests. But as you say, experience is a must to have success. And I insist that some form of measuring system can be also of great help, specially if comes with an experienced expert.
It would be great if we could built a list of WBF officially approved CD recordings easily available to tune the subwoofers in systems, stating the specific aspects to listen and the time at which they happen. We could even ask people who have properly integrated subs to detune them slightly and report on the effect!
When I work with people on electronic crossovers, I really encourage them to learn and understand graphing.
If you graph, things become very obvious. For example, with a turnover frequency identical for low-pass and high-pass there is considerable overlap between frequencies and considerable opportunity for drivers to argue. More typical to stagger the turn over points for low-pass to high-pass
Specific to the Pass Labs XVR-1, there is no requirement to for example set both poles in a two pole filter to say 48 HZ. One could be set to 36 Hz, the other to 48 Hz. The resultant 2nd order slope intermediate to the two selected values.
Cyclotronguy
If you graph, things become very obvious. For example, with a turnover frequency identical for low-pass and high-pass there is considerable overlap between frequencies and considerable opportunity for drivers to argue. More typical to stagger the turn over points for low-pass to high-pass
Specific to the Pass Labs XVR-1, there is no requirement to for example set both poles in a two pole filter to say 48 HZ. One could be set to 36 Hz, the other to 48 Hz. The resultant 2nd order slope intermediate to the two selected values.
Cyclotronguy
When I work with people on electronic crossovers, I really encourage them to learn and understand graphing.
If you graph, things become very obvious. For example, with a turnover frequency identical for low-pass and high-pass there is considerable overlap between frequencies and considerable opportunity for drivers to argue. More typical to stagger the turn over points for low-pass to high-pass
Specific to the Pass Labs XVR-1, there is no requirement to for example set both poles in a two pole filter to say 48 HZ. One could be set to 36 Hz, the other to 48 Hz. The resultant 2nd order slope intermediate to the two selected values.
Cyclotronguy
Cyclotronguy: do you own and use an XVR1 crossover or are these your assumptions about it?
I was thinking of another factor here.
Each of the control modules (one power supply and two control modules for a three-way, more of each for a "more-way") you can cascade the control modules OR you can use one control box for midrange bandpass and the other for lowpass and highpass to the woofers and tweeters respectively, which is what I do with my XVR1 three-way.
Here are my thoughts. The four poles in each control module ARE cascaded. So, if you set the first pole at 36 Hz low pass and the second pole at 48 Hz as low pass, DO YOU actually get an intermediate frequency? It seems you would get an altered slope and the ultimate crossover frequency at the output would be determined by the order of the frequencies you select for the poles. I ask this because if you set the first pole at 36 Hz lowpass and the second pole at 48 Hz lowpass, the 48 Hz and above would be largely gone at (6dB/octave per pole). On the other hand, if you used the 48 Hz in the first pole and 36 Hz in the second pole for low pass (keeping in mind there are up to four poles per channel you can use) I can see that would tend to widen (flatten) the now summed 12 dB/octave slope somewhat (6dB/octave at 48 Hz plus the 6 dB/octave at 36 Hz).
Therefore, it appears that if you use different crossover points on each pole, it matters what pole order you place the crossover points.
I've owned an XVR-1-3 for the past 6 years and have tri-amped with a few other units. There are lots of XO options in set-up with it and it's easy to make a mistake unless you are careful. One of the manual recommendations is to have some kind of measurement capabilities. You can get reasonably good results without it, but great results if you can measure in-room acoustic response. Using a room calibration tool, I ended up setting my Subs LP at 18dB @ 53Hz, MQ setting, and the mains HP at 18 dB @ 48 Hz, MQ, overlapped, to take care of some room anomolies. I wouldn't have tried this unless I saw the acoustic response of the room. Also, I was forever tweeking the subwoofer output on different material which stopped once I could measure. Note that while you can "twiddle" all 4 or 8 of the gain dials on the front of the XVR unit(s), you will not achieve exact electrical matching of left and right ouputs by lining up the dial cursors. The PEC pots are good (and sonically great), but they don't match exactly. Exact electrical matching of XO/amp output is less critical for subs but is absolutely imperative if you are employing XOs at higher frequencies and want any semblance of a soundstage. It's like a night and day difference and if you haven't tried it, you have no idea what I'm talking about.
He's the guy that talked to me about it on the phone when I called Pass Labs. I was just verifying the bandpass function jumper/output pair as it's not mentioned in the manual, but I bet he has a few more tricks up his sleeve.
I too, am using the bandpass function for my midrange. The woofer and tweeter use the low pass, high pass functions.
The manual does need to be more complete. At least half of the XVR1 capabilities aren't in the manual. Actually, bandpass IS mentioned, but it doesn't tell you how to use it.
When I have called Pass about setting up my crossover, I spoke with Kent English and he was great. Is he Cyclotronguy?
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