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Setting up a Sub Woofer???

S

strummer

pfm Member
I've had a BK XLS200 sat unused for years. I'm just trying to set it up now & not having much luck.

My speakers, Impulse H2 are not bass light. They go pretty low, but when I add the XLS200, it is clearly adding something. The problem is tuning it. At the moment I've got a rumbling mess.

The sub goes from 120Hz to 40Hz. Nobody would use a Sub at anything near 120hz, would they??? I'm sure the Impulse go down to 40ishHz, so should I just be setting the thing at 40Hz? seems like a waste to have a piece of kit working at a fraction of it's capability! Am I missing something??


I've got a Linkwitz toneburst CD & a pro Db Metre, so I can do some measuring. It would be useful to get some pointers first.


Thanks
 
If the Impulse are -3db at 40hz set the sub between 50-60hz. You're probably better off with a frequency sweep sample, then just dial the level on the sub in until you barely know it's there. Everyone sets them up too loud, way too loud, for music you shouldn't know it's there until its turned off.
 
Thanks SQ.... what do you mean by "-3db at 40hz"? Do you mean if I play the toneburst CD & 40hz is 3db less than 50hz or 45hz??
 
I measured my H2s to be 3dB down around 26hz at home. I suspect you'll want the crossover set at the low end of the scale.
 
martin clark said:
I measured my H2s to be 3dB down around 26hz at home. I suspect you'll want the crossover set at the low end of the scale.
Click to expand...


Wow, really! I'll try to get my dB metre out tomorrow.

Soooo, that being the case, I wonder if this XLS200 Sub is actually any use to me whatsoever? It's range is 120-40hz
 
Well it will add more energy to the bass / punch region, so if you like it loud and punchy, and can settle the integration, why not :)
 
Strummer, if Martin's measurements are correct then the short answer is yes, it's next to no use to you. The ref1 on the other hand....
 
sq225917 said:
Strummer, if Martin's measurements are correct then the short answer is yes, it's next to no use to you. The ref1 on the other hand....
Click to expand...


I'm sure what Martin says is correct. I'm sure the XLS200 goes lower than 40hz though, that's just the lowest crossover setting. That said though, I'm not sure it's up to the job. My room is 6.5M x 5.5M & I've noticed on some notes the thing is rattling.


I just searched MJ Acoustics Ref 1. How would that compare with a BK Monolith?
 
They are broadly similar, the Monolith would be my choice, more watts bigger driver= less effort. The Mj uses a 10" and less watts in a larger cabinet and is way more expensive. The MJ does have variable phase as opposed to 0/180 on the Monolith, this could make a difference in a tricky room. if you are putting the sub between the speakers then it's not likely to be an issue.
 
Thanks again SQ.

I've got the XLS200 sounding a lot better now, although not 100% convinced it's adding much to the music.

I'm looking into going down an Active Monitor route. That might be where a Monolith (or pair of) might be of interest.

I'll continue playing & get the db metre out later.
 
The peerless XLS driver in the BK sub takes a lot of use to reach it's final compliance. To start with they are quite stiff and may not be giving all their bass. As sq says you need to try the 0/180 deg swich to see if this helps as it could be 'fighting' your speakers.
 
Strummer,

I’m not familiar with Impulse H2s but I’ve used a REL 201E, which is roughly the same size and spec as the BK XLS200, with a variety of speakers including small monitors like Rogers LS3/5As and Harbeth HLP3-ESRs.

While I got generally good results, high energy bass notes could sometimes excite room modes and cause excessive boom which no amount of fiddling with the sub cross-over frequency, output level or phase could ever entirely remove.

After reading a favourable review I bought a DSP Anti-Mode 8033 from BK Electronics. To my ears it is one of the most cost-effective upgrades I’ve made and well worth the £220 asking price. The REL output sounds tighter and faster, and I find I can run it at a slightly higher level. In my experience, the DSP also makes room placement much less critical.

J
 
I was reading recently that to avoid room effects at these low frequencies, two or three subs placed unsummetrically around the room will give a smoother result because they will excite different room modes and largely smooth out the lumpy response at LF.
A great idea but getting one sub in the living room was enough of a challenge for me.

The sub kicks in at 120 Hz because that is where the LFE output on surround sound decoders starts.
 
demotivated said:
The peerless XLS driver in the BK sub takes a lot of use to reach it's final compliance. To start with they are quite stiff and may not be giving all their bass. As sq says you need to try the 0/180 deg swich to see if this helps as it could be 'fighting' your speakers.
Click to expand...


Hmmm, I wonder if this sub isn't run in then. I've had it a few years, but not sure I had it on for more than a few hours.

At the moment it's set on the lowest x-over point (40hz) & turned up just 1/4 volume. Anything above that has the thing making nasty rattling noises. The 0/180 deg has some effect, but not a lot.



JADISMAN said:
Strummer,

I’m not familiar with Impulse H2s but I’ve used a REL 201E, which is roughly the same size and spec as the BK XLS200, with a variety of speakers including small monitors like Rogers LS3/5As and Harbeth HLP3-ESRs.

While I got generally good results, high energy bass notes could sometimes excite room modes and cause excessive boom which no amount of fiddling with the sub cross-over frequency, output level or phase could ever entirely remove.

After reading a favourable review I bought a DSP Anti-Mode 8033 from BK Electronics. To my ears it is one of the most cost-effective upgrades I’ve made and well worth the £220 asking price. The REL output sounds tighter and faster, and I find I can run it at a slightly higher level. In my experience, the DSP also makes room placement much less critical.

J
Click to expand...


The Impulse H2 have a folded horn on the bass so they do go Low.

That's interesting. I'll have a read up on that device. I've actually got a Behringer device with mic for the same thing. I never got it out of the box :confused:
 
Check driver bolts...

1/4 of the way up, mmm your speakers are sensitive so that could be about right. Just don't expect stunt bass, a sub should underpin the music nothing more.
 
sq225917 said:
Check driver bolts...

1/4 of the way up, mmm your speakers are sensitive so that could be about right. Just don't expect stunt bass, a sub should underpin the music nothing more.
Click to expand...


Aha! Just checked the bolts & was able to give them all 1/2 a turn. Can't test if it's made a difference yet as the room's being used for footy.

So the sensitivity of speakers effects the Sub? how does that work?

Yes, not looking for Booming bass. just like to feel the kick drum though. I think most hifi enthusiasts never hear a kick drum, yet claim their system sounds like Live music...how does that work?
 
strummer said:
That's interesting. I'll have a read up on that device. I've actually got a Behringer device with mic for the same thing. I never got it out of the box :confused:
Click to expand...

Here's a link:

http://www.dspeaker.com/

I use the most basic version with one sub. Its about the size of a paperback and tucks away nicely. I've no idea how it compares with the Behringer, but I wouldn't be without it.
 
Today I reset my BK sub. I had to do this because my new TeddyPre is putting out a lot more in the bass dept than the previous Naim pre did.

I pretty much did it as per the manual.

Get a piece of music that you know well with good bass on it; not really deep bass but just good tight tuneful bass.

Play the piece a couple of time with the sub connected but turned off; gauge the sound…

Now turn on the sub with the xo point to maximum of 120 Hz and the gain to zero. Now dial in the gain till the bass on the sub pretty much matches the bass from your speakers. This is why you need a piece of music with tight tuneful bass rather than very deep bass.

Now turn down the XO point to where it integrates with the main speaker, keeping the gain as set re above.

Now adjust that 0-180 degree thing so that it gives you the tightest sound. This made a big difference once you get this right. Mine sounds tightest at about 150 FWIW.

Sit back and enjoy. Tweak a very little bit here or there only if you are more often than not getting something you don’t like coming from the sub. I would leave for about a couple of days between any tweaks.

My IBL’s are now integrated perfectly again.
 
Thanks very much chaps. I'm going to have a go at this tomorrow. My system is in the main living room & the family are glued to the tele..

SQ, the bolt tightening definitely improved things, thanks :D Still work to do though.
 
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