Subwoofer setting

I have a Yamaha A-S500 2.1 integrated amp. The speakers I'm using are Pioneer FS-52's and a Polk PSW10 subwoofer. The amp has a sub out, but there is no way to set the LFE from it. I'm driving my self nuts trying to find the right setting on the sub. The crossover is variable 80hz to 160 hz. I don't need (or want) chest thumping bass, but I would like CLEARLY audible clean bass. The Pioneers have a listed frequency response of 40Hz to 20kHz. Should I just leave the sub crossover at 80 since the Pioneers will (reportedly) go down to 40? What advantages would I get by setting it to 160? I've tried several combinations of volume (mostly turned up just enough to start to feel the vibration) and crossover. I just can't seem to find that "perfect" mix. Any suggestions?

 

First thing to make sure is that you have the sub in the right place in the room. Where is it in relationship to your mains? What's the room like? Where's your listening chair?

For adjusting the knobs, start by using a relatively high crossover frequency and a maybe too much gain on the sub. Play something that has a lot of bass. Switch the phase switch on the sub back and forth. You may need a helper to do this while you listen in the middle of the room. Whichever setting gives you the most bass is the right one.

Now turn the sub crossover way down. I like lower settings the best. I'd certainly be under 100 Hz. Adjust the gain until the sound seems roughly right. Listen to it for a while, at least for a few minutes.

After you get accustomed to that, dial in the sub by moving the two controls in the opposite directions. If you lower the crossover, raise the gain. Decreasing the gain would cause you to raise the crossover point. With a little fiddling, you should find a sweet spot.

 

One tip I learned in mobile audio is to reverse the phase of the subwoofer- you can use the phase switch on the back of the polk. this eliminates pressure wave competition. even in a home the pulse of the subwoofer can restrict the pulse of the speaker woofer.
reverse the sub and it should sound much better and more integrated.
as for crossover- turn it down! subs sound horrible above 80 hz or so.

 

The Pioneers while capable of sound at 40hz, won't put much out until about 75hz or so. I would put the sub at 80-90hz. Set the level at whatever sounds best.

 

Agreed on a low crossover setting. I like crossing over a sub low and goosing the snot out of it. Make it dance. I also learned that trick from car audio.

 

GGerm's advice is spot on. With your amp/speakers/sub combo I'd start at 80 hz and adjust the gain till you get the blend you deem balanced. Ideally you don't want to go higher than that if the sub is placed to the right or left of the mains (say in a corner, where it will render the more bass) because your ears might discern where the bass is coming from (directional bass).

Set the gain at the middle (12 o' clock) and go up or down until you get the right amount of bass. Take into account your Polk is only 100watts, so expect to crank it somewhat.

You can also place the sub center position or anywhere in between the mains.

Good thing is you want just reinforcement, not disco thump.

The Yammy outputs a full range signal from the sub out, so determining the crossover setting from the sub is mandatory. Bear in mind this setting may vary from record to record and even song to song, but dont go crazy and find a compromise and just vary the gain because continually varying the crossover point can drive the sanest person crazy.

Also with the mains running in ¨LARGE¨ as they are you can turn off the sub with bottom-end rich material.

Just my 2 cents and good luck. Just don't go OCD on it; lay back and enjoy the music.

 

This seems to work pretty well. Since I'm doing this alone, one thing that became pretty clear is that even though it may sound a bit too loud and thumpy standing over it, when I got to my listening position it loses some of the fluff and becomes clearer. Sounds pretty good. Thanks to all who contributed advice. Gotta love this forum!

 

Thanks for the help. You pretty much nailed my set up sight unseen! And you're right, no need to obsess, just sit back and enjoy the music!

 

Indeed. The bass will not sound the same on any two given points of the room. It is the listening position that counts. Sit as far away from walls as possible and/or get some room conditioning.

Glad to be of help

 

A couple of additional suggestions. Generally you want the subwoofer and monitors equidistant from your ears. Otherwise they will be out of phase and image poorly. I would pick music with just one bass instrument for testing. I used a jazz piece with a double bass and McEvoy "Did I Hurt You," which has a bass drum. It is easier to get the sound right with a single instrument. All of that said, at some point think about going to floor standing speakers. I used to have a system like yours, but was told stereo bass makes a big difference, so finally went to floor standing. Now I am a full convert. Stereo bass adds a lot more than I suspected.

 

The OP's are Pioneer RF-52s. They're floor-standing speakers.

 

Set your sub to 35-40 hz. That should work nicely.

 

Doesn't sound like his internal xover lets him go below 80Hz. I always set my subs to the lowest they'll go for lowpass, generally in the 40Hz range. *Maybe* his receiver/integrated can set a lower subout frequency. Personally, I do not like subs that play up to 80, but that's just me. I'm firmly in the camp as said above, lowest crossover, then goose the gain. Even if I have mains that don't go down to 40 Hz, I still keep my subs there, best practice or not.

 

I did not realize that. Perhaps I should have said full range, floor standing speakers.

 

One thing I do is put a couple of good reference tracks on, both different styles. Sit in the sweet spot with the receiver at a decent volume. Have a helper turn the sub gain to 0 and with your eyes closed, slowly have them turn it up until it sounds as if the bookshelfs are producing the bass simpatico with the sub. Use the thumbs up or down to have them adjust it. Short of using a SPL meter or receiver with a mic to set the level, this works for me.

 

Doesn't that create a hole in the frequencies?

 

There is an old acoustic trick which is to stick the subwoofer where your head would be-literally-and stick your head in possible subwoofer locations. BASS-ically laugh the strongest sound means the most reinforcement from the room, and a good spot for the sub.

Your Pioneers may be towers, but have mercy, there are just three 5" woofers. 40 Hz? Not without strain I think. I'd have the crossover higher. There was a lot of testing (Harman? THX? I forget) which showed that subwoofers were not localizable if crossed over at 80 Hz. A few caveats:
- 18 dB lowpass (many circuits might be just 12 dB)
- Low distortion-this is not a trivial consideration, and probably doesn't apply to many cheap subs. Otherwise, the higher frequencies of the distortion ARE audible and let you localize the sub
- Port noise and/or response peaks in the port can also be localizable

The high pass and low pass frequencies don't necessarily have to be the same.

Your power ratio is off: your amp is 85W and your sub apparently 50W. A sub should really have MORE power than the amp, because it takes a lot of power to move a cone in a small box enough to generate audible sound pressure. Plus, 50 watts is just really low for a subwoofer and I'd expect frequent clipping if turned up. I think you'll be happier either with a beefier sub or another of the same sub to reinforce the one you have. Or 3 more of the same! Or a bakers dozen, hung randomly from the ceiling! OK, maybe that last is not a good idea, though it would look interesting. Looks like your model sub are down to $100 each.

 

Absolutely. That's why I said it's not considered best practice but, the human brain is pretty amazing in that it can "fill in" the gap for us. It's not perfect, of course, but to me, I prefer the sound of that gap over one with overlap in the sound. With that said, I didn't realize OP's speakers had 3 5" "woofers" in them, so that gap may be a bit much to compensate for. And lastly, it's been a long while since I've had a setup which would create such a gap, so my memory is admittedly fuzzy to how much I liked that type of setup.

 

Ah, I see what you're saying.

 

Another thing I did was hear how bass sounded on a given CD on a system a lot better than mine, and then used that as the (admittedly unachievable) lodestar for my system.

 

The OP would indeed be better off with a beefier sub, but if he uses the Polk he has with restraint and at 80 hz he may achieve adequate reinforcement of the lower frequencies without excessive localization issues provided he doesn't expect concert-level volumes.

 

A beefier sub will have to wait a little....even with the modest system I have the wife thinks I'm nuts for investing in audio equipment. I'm trying to be covert about how I add to the system, while I ever so gently convince her that this is a very worthwhile endeavor. So, a new sub right now is not an option. However, with the suggestions I've received so far, I think the system is sounding pretty good. I have no intention of creating a hip-hop or disco club in my listening room, so the volume will not be house rattling by any stretch. I have goosed it a bit, and so far the sub is keeping up and seems pretty clean and clear. I'm having fun with it! At some point in the future I can definitely see making some upgrades, but for now, I think this will get me by!