Large speakers, small speakers.....

[Dave964]

Although I posted last night saying I'd got my new sub configured well - I changed my mind a bit later.

As per the setup instructions on here, I initially set my front speakers to small. However - this seems to cause me some problems.

If I want the sub to work with explosion type things (e.g. Sauron imploding at the start of the first LOTR) then the frequency has to be high-ish (100Hz or so), and I have reasonable gain set. However, this causes other problems - in other parts of a film, where there is deep bass music etc. it rumbles far too much. It also loses detail - a couple of scenes in LOTR has loud heart beat sounds - and this just comes out as a rumble from the sub. If I adjust the sub so I get clear (deep) heartbeats - then there is no effect from the sub at all with bits like Sauron imploding.

My amp manual recommends that the front speakers are set to large (even if they are small) and also recommends that the frequency is set to max on the sub. If I set the speakers to large, it does seem to work much better - the Sauron implosion shakes the room, and I still get clear heartbeats. The gain has to be set quite high when the fronts are set to large though.

I am going to experiment a bit tonight to see whether I've lost any detail by setting the fronts to large. But at the moment, it looks like that's how I'm going to have them set.

However - this seems wrong, since it goes against all the advice on the forum. Does it mean that I've got the setting fundamentally wrong when I've got the speakers set to small? I can't find a setting that works in all cases if I do that!

It seems my sub might keep me entertained for a long time - just trying to set it up!

[Badger0-0]

Nothing is set in stone when it comes to audio
There are too many variables eg your room.
Experimentation is the name of the game.
It may well be that setting them to large just works better for your particular application
Don't forget, it's your ears that count, as you're going to be the one listening to it


I'd certainly be looking to try different postions for your sub, if at all possible, though.

[Dave964]

Originally Posted by Badger0-0

I'd certainly be looking to try different postions for your sub, if at all possible, though.

I'm a bit limited there. There are only about two places I can try - and both seemed to show the same problems when the speakers were set to small.

[iainsilvester]

Practically all "bass moments" cover a very wide frequency range, ie a gun shot is a complex wave form that will use a very large part of the audio spectrum. Many bassy moments crack and snap as well as the lower stuff you feel. And how your speakers interface to the sub will be key in hearing this as intended.

In theory it should make no difference with a sub based array where you set the crossover, provided each speaker can work with that crossover slope. With large speakers you have more flexibility than small in this regard. But setting a crossover too high will localise sub bass, hence 80Hz is regarded as the norm.

Sounds to me you are responding to the quality of your sub bass, it has poor definition and you prefer critical lower bass to be handled by the larger speakers (but note your centre and any surrounds will likely not be large, accoustically). I also wonder whether you are over cooking the sub, is there actually as much sub bass as you think there should be?? Your problem is probably one of sub set up which is invariably room induced issues.

[Badger0-0]

Trying to set up a system is extremely difficult, just using your ears.
I'd get a SPL meter to do a proper job, TBH.

[Peter Galbavy]

One of the reasons I have my fronts set to small even though Auddessey on the Denon sets them to Large and crossover of 40Hz (for LFE+Main) is that the amp cannot drive them at volume unless I divert the bass to the sub. The speakers are AE EVO 3's which seem to need lots of omph to work - and I am bi-amping already.

So, if you can find an audiably acceptable compromise then you get the benefit of letting the sub amp take some load off your primary.

[Andori]

Originally Posted by Badger0-0

Trying to set up a system is extremely difficult, just using your ears.
I'd get a SPL meter to do a proper job, TBH.

I'd agree with that

You might want to try using test tones and plotting your room response or if you can get a PC in the same room that has a line input (not Mic) you might want to try using REW.

From other posts your room is about 11ft square. I think this will give you gain at around 51 Hz (someone will no doubt correct me if I'm wrong), so it may be that this is influencing what you are hearing.

[avanzato]

Does the Sony amp have variable crossover points for the bass management?
If it does you could try setting the fronts crossover to something around 30-40hz and the rest of the speakers to 80-100. Then the sub will be coming in on the low 'bass' moments and shouldn't just rumble.

Also set the sub up using music as it's much easier to get right and be prepared to tweak the levels a bit. I've setup subs successfully without a SPL meter that way.

[iainsilvester]

Agree with everything above but still mantain the problem has to be sub/room interface. There's nothing clever about a sub, it just handles the bass and will extend deeper than your average large speaker. Sure it has an on-board amp which will probably afford greater dynamic bass headroom than your typical speaker/amp combo but that's it.

So whether you have a crossover at 100Hz or 40Hz should make no difference to percieved sound provided the speaker can handle a 40Hz cross over point. The only difference is which bass driver, speaker or sub, is handling whatever frequencies.

So I suspect the issue is poor sub set up and liklely over use of gain, just because you can because you want the impressive LFE effects but not the unimpressive muddying of mid bass.

[Dave964]

I played about with it last night and tried a range of settings, including having the main speakers set to large and small.

I found that using the sub amp for LFE (which I was when I posted this thread) seems to make the situation worse - sounds better with it off, and just relying on the Sony amp.

Varying the crossover frequency didn't seem to make a huge difference (unless it's set too low).

With small speaker settings, I did find one combination that was OK - but it still seemed to lack bass a bit in some of the heavier moments. Whereas, with large speaker settings I seemed to have the same clarity when I wanted it - but got better deep base when needed.

I'm now 99% happy with it. I ran out of time last night - I think the gain is just a touch too high now - at one or two points there was a very slight rumble which shouldn't have been there. But I'm confident that reducing the sub output from the amp by 1dB or so will cure this, without sacrificing bass elsewhere.

I also played 5 mins of Warhawk on the PS3 last night for the first time since buying the sub - and that was quite amazing. Explosions really do sound like explosions!

[russ.will]

Dave, there are couple of things that are worth bearing in mind and between them can result in some seriously variable results.

1. The sub needs to run in and the passive radiator type may take longer because the PR only moves at the lowest frequencies - it's not permanently working like the main driver. Until it's loosened up a bit, the lowest frequencies will be noticably absent. I've had an XLS300 for a three weeks and it took a couple of weeks to loosen up with general use.

2. The character of the bass from a good sub is significantly different to that which you have been used to. Even good speakers (which yours are) do not have the driver area, cabinet volume (and yours don't) or amplifier power to deliver deep bass cleanly. This isn't unusual, it's what most people get.

As such, the first quality subwoofer tends to be a bit underwhelming as it does not deliver a deeper or louder version of the bass that up until that point, has been the norm. Shorn of the harmonic distortion you have been listening to, bass will sound surprisingly quiet, prompting you to keep turning the thing up. Of course, when a real bass 'moment' arrives, all hell breaks loose. Equally sounds that were there, now aren't, as they were simply the more clearly audible harmonic distortions of a much lower note. Remove the distortion and certain sounds quite literally disappear.

Frustration ensues as the fine line between not enough and too much, is apparently hard to find. So, the sub has to run in and as importantly so do you! You have to get used to what bass should sound like, rather than what you've been expecting.

This process is complicated further by the subs far superior LF output, interacting with the room in a way that no stand-mount speaker can, but to find out more about that you'll have to get an SPL meter. The Radio Shack new analogue meter is by far the most universal supported and can be found here or at any good auction website (and some crap ones).

For the mean time, you need to separate out the use of the sub as AV sub and hifi sub as I assume you're running CD into the MF and out to the GS10s ful range.

Try and position the sub as near the front of the room as possible, as this will generally (but certainly not always) give the easiest position to integrate. Set the phase control and the low level gain to zero.

Connect the sub via low level only and switch the low level input on the sub to LFE to bypass the crossover. You do not need, or even want, the sub and the amp to be handling crossovers at the same time. With the amp alone handling the crossovers, your speakers will roll off at 12dB/octave, the sub will roll in at 24dB/octave and they will cross at -3db at 80Hz.

In the amplifiers menus, set the sub to 'on' or 'yes' and the speakers to 'small'. If there are any other options, set them all to 80Hz and if there is an 'LFE+Main' option, turn that on too!

Now carefully measure the distance from the middle of the baffle on all of the speakers, to where the middle of your head would normally be. Channel level is trickier because you don't have an SPL meter, but try by ear to equalise the front three - hint, the centre speaker has more driver area and may be more efficient. It is likely to need 1-2dB less than the stereo pair.

Now, set you AV amp to stereo, pop in a familiar CD with a strong bassline, preferably with lots of notes. Simply get a handy minion to very slowly turn the sub up until the bass line sounds strong enough (for you), but doesn't stand out as noticeably separate from the speakers. Look for kick drums becomming too thumpy and check with female vocal for thickening chestiness.

Until you get that SPL meter (do you see a theme here?) there's not a lot to you can easily fine tune further. It may be worth a punt to twiddle the sub's phase knob to see if one position is noticeably louder than another, but it's as likely to make thing worse rather than better.

Then what I'd honestly do, is leave it alone and get used to each other and worry about hifi integration (if you're bothered) at a later date.

Russell

[seagill]

I will be getting an xls300/pr for xmas but will be using kef floorstanders 55.2 should these also be set to 80hz on my amp(onkyo 705).

Also sorry to go off topic but you say you have had the xls300 for a few weeks. What do you think of it and how does it compare to other subs you have had?

Thanks

[Dave964]

I spent Thursday night annoying my neighbours yet again with more sub testing, but concentrated more on moving the sub between the (few) positions I can use in the room. I also configured two settings in the amp - one with large speakers and one with small. I could then switch between the two quite easily and vary the sub gain from the amp for each one (but using the same sub gain settings).

I found that the room position was making more difference than I thought, and the rumbling I'd been getting was mostly caused by the sub being in a corner.

After much tweaking, I do now have the speakers set to small and am very happy with the results. I tweaked the gain down a bit last night (War of the Worlds sounded astounding but there was clearly a bit much bass when the first alien came out of the ground), and again a little more this morning.

I agree the sub needs to loosen up - I've turned the sub output down by 5dB since Thursday night - but the same LOTR scenes actually sound like they have heavier bass than they did on Thursday!

I am going to order a meter and will use that to tweak the settings a bit more. At the moment, it sounds pretty fantastic - and it does seem to get better as the sub loosens up. Even without having the gain high, the room shakes when it needs to.

I think my neighbour hates me.

[Neil Hawkes]

Originally Posted by Dave964

I spent Thursday night annoying my neighbours yet again with more sub testing, but concentrated more on moving the sub between the (few) positions I can use in the room. I also configured two settings in the amp - one with large speakers and one with small. I could then switch between the two quite easily and vary the sub gain from the amp for each one (but using the same sub gain settings).

I found that the room position was making more difference than I thought, and the rumbling I'd been getting was mostly caused by the sub being in a corner.

After much tweaking, I do now have the speakers set to small and am very happy with the results. I tweaked the gain down a bit last night (War of the Worlds sounded astounding but there was clearly a bit much bass when the first alien came out of the ground), and again a little more this morning.

I agree the sub needs to loosen up - I've turned the sub output down by 5dB since Thursday night - but the same LOTR scenes actually sound like they have heavier bass than they did on Thursday!

I am going to order a meter and will use that to tweak the settings a bit more. At the moment, it sounds pretty fantastic - and it does seem to get better as the sub loosens up. Even without having the gain high, the room shakes when it needs to.

I think my neighbour hates me.

Another recommendation for an SPL meter from me as although the EQ in my amp did the room acoustics well, I found the level settings and distances to be inaccurrate (which surprised me), just balancing the levels made the overall sound change from good to awesome............it only took 10 mins of my time and all!

Good luck and Merry Christmas,
Neil.

[Dave964]

Have just ordered one, although the BK order page says they are on holiday until the 2nd now, so I guess it won't turn up for a couple of weeks.

I need to stop visiting their page - I noticed the pic of the Monolith, and I'm now thinking I could have squeezed that in. Considering I've only had the XLS300 for a week, that's not really a good thing!