How do YOU set your sub volume and XO point?

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I thought it would be good for the newbies to have a thread where they can learn to set their subwoofer up properly, so advice on positioning, XO and volume would be appreciated. (Perhaps get a moderator to sticky it.)

My advice - set the sub Xo to around 10Hz lower than where your mains roll off this means they will both be playing quieter, but their combined efforts will bring this to equal.
This all depends on the steepness of the XO and main speakers.

I also found a strange way of setting the volume - make the excursion of the sub and the mains equal while playing some music (I usually do it by touch). This is provided the mains have no high-pass filter.

I also favour the sub being near a wall, but not a corner, as it means there is no corner-related boominess, but the subwoofer is not protruding into the room.

Everyone is different, so if you have some advice for people who are new to this, post it here.

Thanks for reading.
 
I just use my ears, actually, for both my home and auto subs. And it's different for home theater.

For the car, I generally set the xo to the lowest point possible, but I give it a fair amount of volume. When stopped, the bass should be a little overwhelming, as road noise obscures it when driving.

For home music, I just have to listen to a lot of music and do a fair amount of fiddling.

Home theater is a bit easier, because you don't have to mess with the xo- the DVD is already encoded with the sub information, so it's just a matter of volume.

I don't like to have the sub in a corner either, but it's a big (3 ft. cube) box, and that's the only place the wife will let me put it.
 
in HT (or any setup where the sats are HP filtered) it is best in my experience (both the HT and my 2.1 in the living) that the x-over is at least half an octave above where the sats would roll off. in this way the integration is a lot better

with volume I set it using my ears, at a level that at first would be just too thin.. for HT there are some test DVD's where you can set the level of the sub, I used one of those on my HT and found that my ears had done an excelent job :D
 
At the moment, I am just using my ears, with the goal of being flat. I'm going to borrow a db meter and test CD later on. After a weekend of being really picky, I think I got really close, if not set up as optimal as it can be.

If you want to be flat, then the sub shouldn't stick out at all. I had to turn the crossover higher then I thought I would need to, to blend in because I heard a distinctive low rumble that sounded apart from the rest of the music. If you hear the sub over the main, or stick out, then it is too loud and if you hear a huge gap, turn up the crossover.

As far as placement, I have it in the middle of the mains, for music anyway. For HT, I'll hide it, put it away. I don't care if it is more boomy, or not 100% optimal.
 
i have 2 set of speakers : 1st - JBL lX 400 (90´s model) cabinet with Seas woofer and tweeter and JBL midrange.

Seas L18RNX/P 6.5" woofer

2nd - Epos els 3 as midrange and tweeter and Visaton GF200 woofer in a separate cabinet

and JBL ES250P Sub woofer

I use the sub crossover at around 110hz , and the subwoofer volume at around 60% , this is a active sub.

i try to set the sub so it will blend with the rest of the speakers , not to loud nor to low , to loud it will sound boomy , to low well...no need of a sub for that.

In your place i would go with my ears and forget rules.
 
I did that once. Stuffed the port of a older Infinity sub with a towel. It was a pretty sloppy sub though. All it could do is make boomy noise.

What kind do you have? Plugging the port might make it sound tighter, but if you heard a lot of port noise, it might have also been too loud.

If you like it sealed, you could always make a new box for it. I think a quality driver can be ported and sound good. I made a baby sub with 4 tang band subs. Sub being below a woofer, not infrasonic sound. Anyway, it is ported and sounds pretty tight. Turned up even a little too loud and the port rumble gets louder then the mains and sticks out too much. Backed off, it adds to the music, instead of over powering it.

Try and integrate it port open. If it's a decent sub (not sloppy) then the port can really add more low end. If you can't you can't, but I bet it was just too loud.
 
i´m using it from 25 to 110 hz +- , i think it sounds more even in that range with the port covered.
it does sound good with the port uncovered , just a matter of taste.
i dont like the sound if the low end stands out .
cant wait to try it with my cambridge audio 740C cd player , coming tomorrow...

This is the link to my JBL sub:
http://www.jbl.com/home/products/pr...e=ENG&Country=PT&Region=EUROPE&cat=CLA&ser=ES
 
The problem is probably actually with the port tune. It's impossible to know what they did. Too many commercial subs have port tune in the 50-60hz range. It makes for a nasty db peak because too many customers want that boomy sound.

Just play around in Win ISD and see what happens when you play with the port tune. If you really wanted to, you could port tune a sub with a 15-20db gain (or more) around 60hz.

The right driver and amp should be sealed. If I had more cash, I'd probably get the dayton audio reference sub and bash amp. My current sub was built for HT, but it turned out cleaner then I thought, so I might just keep it integrated in my stereo. For now anyway.

Looks like you got pro jbl suff. Maybe a sealed box would be the fix for a much better sub.
 
I use pink noise and an RTA. The xo's are LR 24dB/oct so are matched at their -6dB point.

In the old days I used to guesstimate the xo on the low side and slowly increase it until it blended without muddying the sound.

I used to use a Leftfield track (one more hit) off the 'Trainspotting' soundtrack which has a bass line that seems to roll between the mains and the subs, adjusting until it sounded correct.

Rob.
 
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