Subwoofer Placement

[Jeff R.]

I should be getting my new sub today when I arrive home from work. I am curious about how the size of a room or shape of a room affects the placement. For example is a large room easier to optimize vs a small; An asymetrical vs symetrical; etc. I have one sub arriving today, and have the second I will be ordering soon, but likely about 3 weeks out on delivery. Is there a way to get the placement planning for both done upfront with the single sub and then when the second arrives all I have to do is basically plug and play on that unit. Any help is appreciated. Thanks. My room is fairly odd shaped. I will try to repost a basic layout later today.

Thanks

Jeff

 

[MidnightSensi]

It sounds kinda nutty, but the best way to get an initial placement is to put the subwoofer in your listening chair and then crawl around on the floor while listening to some good bass content and listen for where it sounds best. Where it sounds best might be a bit of preference, but listen for where 'everything' sounds the best... not just the output, but the quality of the notes, the evenness of the sound. Once you find that spot, then put the subwoofer there.

You can later go through and use measuring tools to get it to sound even better, but when your super excited for your new subwoofer, this is the quickest way to get it up and running!

When your second subwoofer comes, measuring tools will make more sense because you can use the second subwoofer to flatten peaks and dips at the listening position.

 

[ParadigmDawg]

The best place for your new sub would be...my house...

 

[KASR]

What Midnight said.... "My Name is Mudd" by Primus is a good song for some dynamic bass.

 

[no. 5]

It sounds kinda nutty, but the best way to get an initial placement is to put the subwoofer in your listening chair and then crawl around on the floor while listening to some good bass content and listen for where it sounds best. Where it sounds best might be a bit of preference, but listen for where 'everything' sounds the best... not just the output, but the quality of the notes, the evenness of the sound. Once you find that spot, then put the subwoofer there.

You may find more than one spot where the bass sounds good, mark those spots with tape. Then when your second sub comes, those other spots should provide a good place to start for the second sub.

But remember that measurements will help a lot in getting it all 'right'.

 

[Jeff R.]

Excellent ideas, especially from P Dawg. Well my sub is on a Fed Ex Truck and will be waiting when I get home from work in a few hours. Can't wait to try it out.

 

[lsiberian]

The best place for your new sub would be...my house...

I must strong disagree. The best place would be mine where it would get properly tested and calibrated.

 

[Jeff R.]

Anybody that is close by can come and help me set it up and test it. That is not my specialty, unfortunately.

OK - I just spend my first 90 minutes getting it set up and positioned. I will say this think is big, which I like because I have plenty of room and it looks great. So I just ran through some LOTR battle scene and it is an impressive sub. It really digs down deep shakes my floor. I a very impressed with the increase in output and how smooth and clear it will play down deep.

I had to jack my gain on my reciever way up to like +10dB so I could get my gain control on the sub to hang in the 50% region. Right now I have it crossed over at 80 hz to keep it simple for now. I may drop it down to like 60 Hz later. My tower handle the low end quite well and are rated to play down in the 28 Hz range.

Placement worked out well I found using Midnight's suggestion that I really had a fairly even output along my side and front walls. Since I could not tell a major difference I went ahead and placed it right next to my front right tower and I will hopefully get my second in a few weeks and place it next to the other tower. This was where I had hoped I could place them originally.

So far so good. I will say I am having a bit of a tough time getting it to integrate very well on some music. It seems like my sub is on the quiet side compared to my speakers. However in movies they integrate very well. Now obviously I can go some fine tuning, but I was surprised to see the large difference between the two inputs.

I will keep updates coming as I get it dialed in.

 

[fredk]

I will say I am having a bit of a tough time getting it to integrate very well on some music.

That could be placement related or it could be your crossover. If either your mains or your sub are in a null in the crossover area, that might affect integration.

It seems like my sub is on the quiet side compared to my speakers

... or it could be SNS (sub newbie syndrome ). A lot of people like their sub really hot when they first set it up. I sure did.

It could also be that whatever you had before was boomy in the bass area and you are not used to a more natural bass sound.

 

[Jeff R.]

Right now I have my fronts crossed in my reciever at 80hz and my sub coming out of my reciever crossed at 80hz and my crossover on my sub turned up to the highest point so that the reciever is the one controlling the crossover point. So I have to assume that I do not have any gaps.

I do question whether I need my fronts to come down closer to 60 hz. I tried to get them to do that yesterday and for some reason my receiver would only allow me to crossover the sub at 80 hz or above. It would let me bring my mains down lower into the 40/50/60/70 hz mark, but not the sub. I am guessing that I have something selected in my Onkyo 805 that is restricting this crossover point. Still not sure what that is.

Any ideas on this?

Thanks

Jeff

 

[jostenmeat]

It might be a good thing you can't lower the sub's xover, for otherwise you would certainly be truncating the LFE signal. Now, for music playback, it's a different thing (no LFE), and I'd play with settings at that point depending if you're doing stereo or not, or have mains that won't miss the sub for music.

The LFE is designated only for the subwoofer, unless you don't have one, and then it's rerouted to the mains with a considerably reduced signal to protect speakers and amp.

All of your other channels are actually recorded as "full-range", however it's best to reroute the lower freq's from the other 5/7 channels to the subwoofer in 99.999% of the cases. Sending this lower bass info from the other channels is called "summed bass" or "rerouted bass", and is a different thing than LFE. All of the above is FYI.

In the end, I just wanted to say you don't want to lower the sub's xover below 80hz for movies, for film tracks have plenty of LFE that goes that high. When you xover mains at 60hz, for instance, the sub still plays LFE up to 80hz, but also helps your mains out by taking over their signal below 60hz. Different things.

 

[DD66000]

I don't what kind of music you listen to, but most music doesn't have much content below 40htz. So when having a sub in the mix, it might only be playing the upper bass.

Also check the phase switch on the sub, while listening to music, flip the switch to see if it improves the bass, if it drops, then switch it back.

You mentioned you have the sub's XO point turned all the way up, so its out of the way. Does the AVR or sub have a switch or button labeled LFE? If so then you want it set to LFE and the sub's XO is out of the mix and you'll get the .1 channel, which is not the same as normal bass.

 

[Jeff R.]

It might be a good thing you can't lower the sub's xover, for otherwise you would certainly be truncating the LFE signal. Now, for music playback, it's a different thing (no LFE), and I'd play with settings at that point depending if you're doing stereo or not, or have mains that won't miss the sub for music.

The LFE is designated only for the subwoofer, unless you don't have one, and then it's rerouted to the mains with a considerably reduced signal to protect speakers and amp.

All of your other channels are actually recorded as "full-range", however it's best to reroute the lower freq's from the other 5/7 channels to the subwoofer in 99.999% of the cases. Sending this lower bass info from the other channels is called "summed bass" or "rerouted bass", and is a different thing than LFE. All of the above is FYI.

In the end, I just wanted to say you don't want to lower the sub's xover below 80hz for movies, for film tracks have plenty of LFE that goes that high. When you xover mains at 60hz, for instance, the sub still plays LFE up to 80hz, but also helps your mains out by taking over their signal below 60hz. Different things.

So if I understand the sub xover point at 80 hz is where I want to be. So what advantage is there of taking the front towers down to 60 hz?

To be sure I have this straight: Does that minimize the output from the sub in the 60-80 hz range, i.e. it is only playing the LFE in that range from my center and surrounds and the towers take over their own 60-80 hz. Then the sub plays all channels below the 60 hz. Now let's say I cross over my surrounds at 100 Hz, so that would imply that any frequency that is between 80 -100 hz is not being reproduced. Right????

Thanks for the clarification.

 

[jostenmeat]

So if I understand the sub xover point at 80 hz is where I want to be. So what advantage is there of taking the front towers down to 60 hz?

Get more bass from your mains. Mine are xover'd at 60hz atm. If your sub is located up front, you might not quite appreciate the difference as much. My sub is on the sidewall, and it's very easy to discern between different xover points. Then there's that whole pandora's box of speaker/room interaction. Try both, and pick what you like.

To be sure I have this straight: Does that minimize the output from the sub in the 60-80 hz range, i.e. it is only playing the LFE in that range from my center and surrounds and the towers take over their own 60-80 hz.

I suppose it might. Don't underestimate LFE energy though! Different soundtracks are mixed differently, so YMMV. LOTR has PLENTY of bass info for the main channels from what I remember. I used to have mains with a rolloff at 24hz, 4x 10" woofers, each woofer individually powered by 200w iceamps, and so I left them as large. I can tell you there is plenty of bass info, but LOTR has some of the most impressive action sound effects I've ever heard. With most movies, maybe there is very little bass info meant for the mains.

Then the sub plays all channels below the 60 hz. Now let's say I cross over my surrounds at 100 Hz, so that would imply that any frequency that is between 80 -100 hz is not being reproduced. Right????

The sub then would play everything below 100hz normally meant for the surrounds. At least that's what it's supposed* to do. I've read that some older receivers had funky issues when applying various xover points for the different speakers, but I don't think that's the case with modern Onkyo's.

Thanks for the clarification.

I hope I've helped.

 

[DD66000]

So if I understand the sub xover point at 80 hz is where I want to be. So what advantage is there of taking the front towers down to 60 hz?

To be sure I have this straight: Does that minimize the output from the sub in the 60-80 hz range, i.e. it is only playing the LFE in that range from my center and surrounds and the towers take over their own 60-80 hz. Then the sub plays all channels below the 60 hz. Now let's say I cross over my surrounds at 100 Hz, so that would imply that any frequency that is between 80 -100 hz is not being reproduced. Right????

Thanks for the clarification.

Not sure about Onkyo, but my HK you can have bass from both the sub and mains together.
If the mains are at 40 and the sub at 80 then both are playing the 40~80 range.

The LFE is a separate setting from the bass XOs, once again, not sure about Onkyo, but the HK has separate XO point for the LFE. I've got mine set to 120, which is what HK recommends. But the XO points for the bass is at 80 for all channels and sub.

If you cross sats @ 100 then the sub needs to be @100. but then you're into the region of the sub being localized. Subs need to be crossed @ 80 or lower so you can't tell where they are.

 

[Jeff R.]

Ok I have been able to get it dialed in a little better by just playing with the gains on my reciever I have backed it down some.

I am getting a very strange noise from it every so often in some sound scenes. I noticed in a few scenes from LOTR and The Matrix movies. It sounds like some odd distortion. The weird part is it sounds like it is distorting in upper bass area. I at first could not tell if it was my towers or my sub. So I replayed some scenes with the sub off an it ran find with no issues. I then turned sub back on turned down the gain and also turned the volume down (-18 db on the read out on the receiver which is not all that loud on my system, I used to wat most movies in hte -15 to -13 range). and it did it again but not nearly as bad The odd part is that the sub is hammering out some great low end at much higher volumes with out any issue or distortion and then all of a sudden it will make have the issue again. I can not tell whether it is just really low LFE coming as a real quick hit and the sub can't handle it or if something else is going on.

Any ideas......

 

[lsiberian]

It might be a good thing you can't lower the sub's xover, for otherwise you would certainly be truncating the LFE signal. Now, for music playback, it's a different thing (no LFE), and I'd play with settings at that point depending if you're doing stereo or not, or have mains that won't miss the sub for music.

The LFE is designated only for the subwoofer, unless you don't have one, and then it's rerouted to the mains with a considerably reduced signal to protect speakers and amp.

All of your other channels are actually recorded as "full-range", however it's best to reroute the lower freq's from the other 5/7 channels to the subwoofer in 99.999% of the cases. Sending this lower bass info from the other channels is called "summed bass" or "rerouted bass", and is a different thing than LFE. All of the above is FYI.

In the end, I just wanted to say you don't want to lower the sub's xover below 80hz for movies, for film tracks have plenty of LFE that goes that high. When you xover mains at 60hz, for instance, the sub still plays LFE up to 80hz, but also helps your mains out by taking over their signal below 60hz. Different things.

I suppose you are talking direct signals. Which may pose some interesting challenges in my design and setup.

 

[no. 5]

In the end, I just wanted to say you don't want to lower the sub's xover below 80hz for movies, for film tracks have plenty of LFE that goes that high.

A valid point. As the purpose of the LFE channel is to allow the filmmaker the ability to add extra impact to the soundtrack (the channel itself is low passed, brick wall filtered at 120Hz, and allows up to 10dB higher levels than any of the other channel), it's good to remember that the AVR will effective be throwing away anything in the LFE channel above the crossover point.

Of course, most LFE content is below 80Hz, and a crossover is a slope not a wall, but it's something to consider when you set up your system.

 

[DD66000]

A valid point. As the purpose of the LFE channel is to allow the filmmaker the ability to add extra impact to the soundtrack (the channel itself is low passed, brick wall filtered at 120Hz, and allows up to 10dB higher levels than any of the other channel), it's good to remember that the AVR will effective be throwing away anything in the LFE channel above the crossover point.

Of course, most LFE content is below 80Hz, and a crossover is a slope not a wall, but it's something to consider when you set up your system.

The LFE will go up to the point of the LFE setting, not the XO point of the sats/sub settings. They're independent of each other. At least that's how HK does it, and I would think other manufacturers.

 

[AVRat]

Jeff, it sounds like the sub may be bottoming out. Which is understandable if you’re trying for more output in your ~5800 cu ft space. This is why I suggested an upper level sub for your initial sub purchase inquiry. In this case, you should probably run your L/R with a 60Hz x-over. The gain control should be no more than half-way on the sub and no more than ~4db in the receiver’s level settings. Hopefully, the second sub will help.