Subwoofer Crossover set to AV?

Discussion in 'Audio Hardware' started by Vaughan, Apr 4, 2021.

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  1. Vaughan

    Vaughan Forum Resident Thread Starter

    Location:
    Essex, UK
    Not that I think it's terribly important, but I'm using a Q Acoustics 3070s (subwoofer).

    As you may know, I bought this subwoofer some time ago. I tried to integrate it into my system for music, but just became frustrated and put it on the cupboard. A long weekend meant it was time to dust it off and try again.

    The good news is, I think it's finally working quite well. The main issue previously was the Crossover, I believe. As it is right now, I think it's in the sweet spot. The frustrating thing is, the "fix" was not to mess with the cross over at all. The farthest turn of the dial is simple "AV", which I assume takes its lead from the AVR (which allows you to set crossover for Fronts, rears, and center speaker separately (I've put it at 80Hz).

    My speakers are Q Acoustics Concept 40's.
    • Frequency Response: 53Hz - 22kHz
    • Nominal Impedance: 8ohm
    • Minimum Impedance: 4ohm
    • Sensitivity: 90dB
    • Recommended Power: 25 - 150w
    • Crossover Frequency: 2.3kHz
    I have two questions:

    1) Does 80hz seem about right? Is there a magic formula, or is it always down to "trust your ears"?
    2) What does the "AV" setting actually do? The manual says virtually nothing other than acknowledging it's there......
     
  2. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
    AV is for effects. iirc it's called LFE now.
    Personally, I would not use it for music.
    Perhaps you can hook both up and it senses the active signal.

    if your speaker is -3 dB at 53 Hz it likely goes lower in a room. So I would start at 50 and listen. If muddy lower it.

    Typically people set xover too hi and gain too low. You should not be able to localize the sub when listening.

    I looked at the manual:
    The sub only has line inputs
    L/mono and right
    xover 50-150 plus AV
    I would not use AV for music

    set phase first
    Set gain at 2 o'clock
    Xover 100
    Play heavy bass music
    Switch phase back and forth, leave it where loudest

    set gain 12 o'clock
    Xover at 50
    Gradually adjust to taste
     
    Last edited: Apr 4, 2021
    Vaughan likes this.
  3. Vaughan

    Vaughan Forum Resident Thread Starter

    Location:
    Essex, UK

    I've seen LFE mentioned, but the amp only has a "Subwoofer Out L/R" (Sony STRDN1080.CEK). I will play around. I must say though, today was one of those days, and I've spent 12 hours straight today sitting in my chair listening to music, and to my ears it seems to be working well. Whicvh is not to say it couldn't be better - who knows?

    I guess I am curious about the settings on the AVR though. Obviously speakers get set to "Small", but I then can set the crossover there. I assume (sorry for the stupid questions), that I should set that at the same Hz as I have dialed in on the sub?
     
  4. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
    I don't think you can set anything on the AVR relating to the sub other than enabling it.
    Which is good, do all adjustments on the sub.
     
  5. Sterling1

    Sterling1 Forum Resident

    Location:
    Louisville, KY
    I don't know what control your AVR has over the sub; but, typically the sub preout will have a low pass adjustment, and you can set mains, center, and surround high pass filtered output to some degree. In addition, you can set volume of the sub to match mains or perhaps all speakers for equalized output. Your AVR may have a test tone which, when used with a Sound Pressure Level meter can integrate the sub nicely to your mains, surrounds, and center channel speakers. I have two systems one is 2.1 stereo and the other is 5.1 multi-channel. My 2.1 Parasound P6 controls sub volume, high pass (50Hz) and low pass (63Hz). My OPPO-205 provides bass management for 5.1. It controls speaker trim, distance, low pass (60Hz) and high pass (80Hz).
     
    Last edited: Apr 4, 2021
  6. Bingo Bongo

    Bingo Bongo Music gives me Eargasms

    Location:
    Ottawa, Canada
    I have my Sub set at 80Hz, works for me.

    I agree with @Ingenieur, You should not be able to localize the sub when listening. It should just enhance your speakers.
     
    Last edited: Apr 4, 2021
    Tim 2 likes this.
  7. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
  8. Vaughan

    Vaughan Forum Resident Thread Starter

    Location:
    Essex, UK
    The option is called "Crossover Frequency" (Adjust the bass crossover). It has a level for FRONT, CENTER and SURROUND in Hz. It's currently at 80. I can adjust the volume individually if I want to, but that's a whole other option.

    I guess I'm a little confused at this point. I'm still not 100% sure what setting the Subwoofer to AV does. Or what the outcome of having the Sub set to say, 100, and the amp settings at 80, would do. I assume they're supposed to have the same setting, but it seems a little strange.
     
  9. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
    Your speakers have a very low bass.
    Can you set the AVR lower than 80 or turn it off altogether.

    The more adjustment in the mix, the harder it will be to get it right.

    I'm assuming if AVR is set to 80
    Below 80 will go to sub
    And only above 80 will go to the speakers?

    Is that in the manual I linked?
    Page?
     
    McLover likes this.
  10. McLover

    McLover Senior Member

    For music, I prefer no subwoofer most of the time. And for Sony, I prefer the STR-6120 and their pre-1973 receivers for music.
     
  11. Erik Tracy

    Erik Tracy Meet me at the Green Dragon for an ale

    Location:
    San Diego, CA, USA
    The Yamaha AVR I have has multiple memory settings - I have one for movies set at fronts=small, bass for sub and xover set to 80Hz for 'scary low' LFE levels and omg loads on power.

    I have another memory setting for multichannel music with fronts=large and bass for both fronts/sub for music because it sounds better.
     
  12. Ilusndweller

    Ilusndweller S.H.M.F.=>Reely kewl.

    Location:
    Columbus, Ohio
    80 Hz low pass to sub(s) (B&K AVP-1030 5.1 pre from 1996) is what I have used with speakers with similar low end frequency response (and generally similar) to your speakers. Those speakers are B&W CDM-1SE and NHT 1.5. Works well. If you can send a high pass @50 Hz or thereabouts to your mains and have the amp power, then you will be able to turn things up a bit more.
     
  13. head_unit

    head_unit Senior Member

    Location:
    Los Angeles CA USA
    Best would be to call Q Acoustics and ask. My *assumption* is it bypasses the subwoofer's internal crossover and so yes relies on the AVR. IIRC on an SVS we got, that is labeled "LFE" which is kind of conflating a different concept but that's how it is.
    - 80 Hz became somewhat of a default crossover because experiments showed the subwoofer could not be localized. That presumes the sub is of good quality and low distortion and no port noise, probably the crossover was steep, and room peaks above the 80 Hz not huge.
    - Set the sub also to 80, play some pink or better yet brown noise. Switch the phase between 0 and 180. One position should have much stronger bass; use that.
    - I think experimenting by ear with crossovers is rather futile. I think it makes more sense to do some measurement and then let your ears be the final arbiter. At least some smartphone app for crude measurement, or you can go all the way to REW room acoustics and audio device measurement and analysis and a UMIK.
    - Highpass and lowpass frequencies don't have to be the same. Many times response may be better if they are not.
     
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  14. Sterling1

    Sterling1 Forum Resident

    Location:
    Louisville, KY
    Turn the AVR's sub preout to on. Set the AVR's sub low pass filter to 60Hz. Set AVR's speaker crossover to Small (80Hz). Play AVRs test tone and adjust sub, center, and surround speakers to match volume level of front left/right speakers using a SPL meter, which you can download to your phone. Using the SPL meter rather than ears is important since ears cannot discern proper adjustment of bass volume to match mains volume. That's it.
     
  15. Tim 2

    Tim 2 MORE MUSIC PLEASE

    Location:
    Alberta Canada
    Set your sub at 10Hz above your speakers low frequency limit.
     
  16. Sterling1

    Sterling1 Forum Resident

    Location:
    Louisville, KY
    That may not be possible if the low pass filtering is limited.
     
  17. Vaughan

    Vaughan Forum Resident Thread Starter

    Location:
    Essex, UK
    Hey guys - I've not been avoiding this thread, I just wanted to get a response back from Q Acoustics before replying further, and we just had a long 4-day public holiday so it took some time..............

    So, they have confirmed what my ears are telling me:

    "Thank you for contacting Q Acoustics. The 'AV' setting on the crossover when set to this it passes the crossover setup to the AV Receiver rather than setting it up on the subwoofer itself, this is the better setting to use when you have a connected amplifier with the ability to set the crossover point of low frequencies."

    It seems in this case at least, setting it to AV simply accept what the Amp is configured at.

    Thoughts?
     
  18. Sterling1

    Sterling1 Forum Resident

    Location:
    Louisville, KY
    My thought is not to have your active sub's sub management and sub management from your AVR both engaged. Use the AVR's sub management, beginning with basic settings as I last posted.
     
    jeffmackwood likes this.
  19. Vaughan

    Vaughan Forum Resident Thread Starter

    Location:
    Essex, UK
    Agreed. I think this is, essentially, what setting the sub to AV is doing, it's turning off the management on the Sub itself.
     
    Sterling1 likes this.
  20. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
    Yes
    It is basically setting the xover very high, above 150. That way the AV xover is the limiting factor and the sub is out of the picture.

    For music I do not agree with this:
    Your speakers roll off at <50
    AV xover at 80, ie, sub will roll off at >80
    sub and speakers will add (reinforce) 50-80
    This will result in a 'hump', "boomy"

    I would disable AV or set as high as possible, 80 should work.
    Set sub at 50 and gain at midpoint
    Listen to music and adjust sub up in very small increments until satisfied.
    If you exceed 80 it will start to add again
     
    Last edited: Apr 6, 2021
  21. Sterling1

    Sterling1 Forum Resident

    Location:
    Louisville, KY
    I'd set sub output low pass to 60 Hz, crossover from mains/surrounds/center to small or 80 Hz, and I'd set sub volume from AVR from the sub amp's mid gain setting using a SPL meter from full frequency tone. That's it for starters. In my stereo system which has full range mains to about 35 Hz +/-3 db. I have my sub output low pass filter set for 63 Hz (as recommended by JBL) and my left/right output high pass filter set for 50 Hz. it makes the double bass in my Diana Krall SACDs sound just left and in back of Diana Krall on piano. At any rate, as low pass and high pass are set my sub integrates nicely.
     
    Ingenieur likes this.
  22. Vaughan

    Vaughan Forum Resident Thread Starter

    Location:
    Essex, UK
    I thought this was a good video, albeit a couple years old.

     
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  23. Ilusndweller

    Ilusndweller S.H.M.F.=>Reely kewl.

    Location:
    Columbus, Ohio
    You need to see what sounds best to you. I was watching a PS Audio vid a while back and was surprised to learn Paul preferred a 100 Hz low pass filter to sub(s). May have even been 120 Hz. Seemed high to me, but if it sounds good it sounds good.

    When (Ive only been living here 8 months now lol) I get around to setting up my bedroom system (which was my former main system) it will be the following.

    B&K AVP-1030 5.1 pre (1996, used for stereo mode only, used for its 80 Hz low pass filter (12 dB/octave if memory serves?)

    Sub 1 out (80 Hz low pass) to one channel of Forte Model 3 (200W@8 Ohm/400W@4Ohm) to 1999ish 12" Kicker Comp VR (400W) in sealed MTX box (both car stereo, ousted Velodyne).
    Sub 2 out to other channel of Forte Model 3 to NHT SW2Si 10" 200W sub

    NHT SA-2 sub amp gets a pre out from B&K but is used only for its 50 Hz high pass filter to Counterpoint NPS-100A to B&W CDM-1SE.

    The Forte powers those subs just fine (I simplified from running a bridged NAD 2700 @400W for the Kicker and a bridged Sony TA-N55ES@300W for the NHT SW2Si)and I get independent remote control of each sub with the B&K remote. If you need a pre and bass management(the B&K also has a high pass filter, but I like the 50 Hz of the NHT SA-2 for the B&W speakers), mid/late90s/early 2000s B&K 5.1 pres work excellent in stereo mode and can be found for pennies on the dollar.

    I prefer the overlap from 50 Hz to 80 Hz. I have also played around with the variable low pass of the NHT SA-2 (which can also power 2 subs but is not nearly as powerful as the Forte) and still prefer having about a 50-80 Hz overlap. I do like my bass so ymmv of course.
     
    Last edited: Apr 6, 2021
  24. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
    When an AV receiver low pass is set to 80 Hz does it work like this?
    Sub gets below 80 Hz
    Main speakers only get ABOVE 80 Hz?
     
  25. Sterling1

    Sterling1 Forum Resident

    Location:
    Louisville, KY
    Yes, that's how it works; and the 80 Hz scenario might be ideal when front left and right speakers have woofers 6.5 inches in diameter or less; but, the scenario might be more ideal if the low and high pass are set to 50 Hz if your front left and right woofers are a greater diameter than 6.5 inches. This is according to Parasound recommendations for a 2.1 system. In multi-channel systems, low pass might be 60 Hz, while mains high pass might be set at 60 Hz wiyh center and surrounds high pass set at 80 Hz. And, of course, after crossovers are set, sub, center, and surround volume settings must be made, and perhaps speaker distance/delay settings.
     
    Last edited: Apr 6, 2021
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