Cross-over frequency

chantrys

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Apologies if this is a dumb question, but could someone please give me some advice on a decent cross-over frequency setting.

I am just setting up my new Arcam AVR350. I am using Quad 22L fronts, Quad L Centre, and Quad 12L for the surrounds. I am using a Velodyne SPL1000 sub.

I can't find anywhere that tells what level to set the crossover frequency at to get the most out of the Quad's and sub. Can anyone suggest whether this should be 80Hz, 100Hz, 120Hz etc.

Many thanks,
Marcus
 
80Hz and set all speakers to small which should have the same effect. Set the Velo crossover to max/off/LFE, whatever it's called.

Russell
 
I'm not sure what russ.will's reasoning is, but neither the Velodyne nor the Quad 22's are performing at their best with a crossover set at 80Hz - you're asking the subwoofer to struggle with what the speakers can supply easily.

I think a lower setting would be better myself - eg 60Hz. You probably can set the crossover in 10Hz steps on the Arcam, so perhaps experiment between 50 and 80 with your favourite discs, and let real performance decide!
 
dingwall said:
I'm not sure what russ.will's reasoning is, but neither the Velodyne nor the Quad 22's are performing at their best with a crossover set at 80Hz - you're asking the subwoofer to struggle with what the speakers can supply easily.

I don't think THX would agree with you:D (and yes, I know these aren't THX certified components)

drago.d
 
Turn this on it's head, why make the speakers reproduce something that the sub can do easily. And is designed to do.

For music, the lower crossover may be preferable on a personal basis, but the sub is designed to do deep, clean, extended bass. Why use up valuable amplifier power, when the Velo is sitting on a 1000w RMS of the stuff in a package that can be tuned to suit the room in a way that the main speakers can't?

The Velo has built in, digital room equalisation and can be tuned for a smoother, flatter if you prefer, in room response and will comfortably work up to the frequencies where the room modes are likely to occur. The main speakers offer non of this.

Russell
 
I also have a query on this. I am going to be setting up my B&W M-1's (the MT series) with a BK Gemini sub. Any suggestions on crossover settings? Thanks.
 
First of all can I point out that the Velodyne SPL series subwoofers do not have any onboard digital room equalisation facilities. This is only found on the DD range.

As far as crossover settings go, 80hz would be the first choice in line with traditional Dolby labs and THX recommendations. However, I would also experiment with setting it a little lower as well to ensure that you have the cleanest integration.
Try listening to frequency sweeps and some music to hear what sounds the most natural. You are aiming to hear a constant sound accross the frequency without noticing the transition from your mains to your sub. However, this may be difficult if you happen to set the crossover at a point where your room happens to create a dip or trough in the frequency response. These are more likely to occur around 40hz to 60hz and much less likely around 80hz.
 
The new SPL-R range do have a very basic Room EQ function on there subs but it is not in the same league as the DD range or SMS-1..
 
Ah, ok. Only familiar with the series 2 personally, but Chantry's doesn't specify which one he has.
 
russ.will said:
Turn this on it's head, why make the speakers reproduce something that the sub can do easily. And is designed to do.

For music, the lower crossover may be preferable on a personal basis, but the sub is designed to do deep, clean, extended bass. Why use up valuable amplifier power, when the Velo is sitting on a 1000w RMS of the stuff in a package that can be tuned to suit the room in a way that the main speakers can't?

The Velo has built in, digital room equalisation and can be tuned for a smoother, flatter if you prefer, in room response and will comfortably work up to the frequencies where the room modes are likely to occur. The main speakers offer non of this.

Russell

This is an interesting argument. My setup is 2.1 and I use a Musical Fidelity Tri-Vista amp which is straight, unfiltered stereo. I would say in my case the opposite is true and that the more the stereo amp does the better, not that I can change it. It's significantly faster for a start. I think the sub works best producing low and restricted frequencies or it looses tightness in comparison to the stereo speakers. These go down to 34hz so the sub fills in around 38-17 (I have set it very tight with little overlap or it slows the bass above - nob is around 55-60hz) and has not a great deal to do on some music. But, I have different kit here. I tend to feel the more the sub does (I guess better ones will be faster!) the less tight the music becomes.

I guess it's just down to how well your front speakers/amp can handle bass in relation to your sub.
 
Cheers for your explanation russ.will! Reading my own post back, when I said "im not sure what your reasoning is" - it wasn't meant as criticism, rather that you must have your reasons. If that makes sense. Or if you found nothing wrong with it, just ignore me! I'm feeling a touch paranoid of late...

All I can say is I understand the theory, but you clearly have never dealt with a Velodyne SPL! It's just not up to the task you think it can do. I'd let it provide clean, deep bass when required and leave it at that. Those 1000W are all used up EQing the tiny box to the max to get ultimate extension, as this was its primary design in fact. The main speakers should do an infintely better job for the region under discussion, and the receiver's power is more than adequate to drive a speaker crossovered at 60Hz! It's those low, low frequencies at high SPLs which sap up the power...
 
I'm not trying to start a pointless techie arguement like 'the forum that can't be mentioned' or AVS, take a mo to refer back to the original post. The OP wants somewhere to start with setting up his NEW kit.

80Hz IMHO and a few others besides, is pretty much the industry standard place for a crossover. To get him up and running and familiar with his gear, I felt this was a reasonable place to start, whereby he can quickly get on, adjust his levels and watch some movies.

The refining of the crossover and further integration of the sub was not asked about and is probably best left for a later post, once he's comfortable with what he's dealing with.

I am well aware of the limitations of small box subs (I've had a few) and you're quite right, aside from a couple of demos I've sat in on some while ago, my experience of the SPL-Rs is limited and I thought the built in EQ was a little more comprehensive than it's turned out to be. But I feel that unless either of us possess an SPL-R AND the Quads AND the AVR-350, it's just a good place to start.

I stand by my original recommendation as a good starting point, but that's all. :)

Russell

PS. I didn't have a problem with your post and I'm not ignoring you, but you may be paranoid.:smashin:
 
Cool.

The OP asked for the best settings, you gave a definite answer as though it was fact, with no mention of it just being a starting point or trying anything else to fine tune.

That's why I asked for a bit of explanation, and pointed out that IMO it was better to suck and see at 50, 60, 70 and 80Hz. I didn't think this was pointless argument myself.

See yas. :thumbsup:
 
KingKrell said:
This is an interesting argument. My setup is 2.1 and I use a Musical Fidelity Tri-Vista amp which is straight, unfiltered stereo. I would say in my case the opposite is true and that the more the stereo amp does the better, not that I can change it. It's significantly faster for a start. I think the sub works best producing low and restricted frequencies or it looses tightness in comparison to the stereo speakers. These go down to 34hz so the sub fills in around 38-17 (I have set it very tight with little overlap or it slows the bass above - nob is around 55-60hz) and has not a great deal to do on some music. But, I have different kit here. I tend to feel the more the sub does (I guess better ones will be faster!) the less tight the music becomes.

I guess it's just down to how well your front speakers/amp can handle bass in relation to your sub.
Not being familiar with your system, it's a little hard to comment much. But one point worth noting is that where the integration of the sub relies on the natural roll off of the speakers, the speakers, especially if they're sealed could roll off slower than would normally be the case with a bass managed AV amp. This maintains more output down into the subs territory and requires the sub to be run at lower levels to prevent excessive bass.

I've also seen it said that really deep bass sounds slow full stop. It quite literally doesn't start and stop on a sixpence. To my ears at least, there is a ring of truth about this.

I too, wasn't a great fan of subs when a reasonable size floorstander is present. My Kefs, whilst hardly cutting edge, reach down to a good solid 35-38Hz in room and I'd never managed to achieve a balance of speed/tightness v depth that I was happy with. So for music the sub stayed off.

I am quite happy to admit to a total u-turn since I got involved in room EQ for the sub. It moves bass quality onto a whole new playing field.

Just a few thoughts, none gospel.

Russell
 
thanks for all the advice and comments. So far, I've come to the conclusion that the 22L fronts do a fine job by themselves for listening to stereo music and at the moment I'm running the Velodyne at 60Hz for home theatre use, but I'll continue to experiment for a while.

The Quad 22L's have a range of 30Hz to 24K and I read on another site that for a smooth transition between speaker & sub that you should set the sub at 10Hz higher than the bottom range of the speaker, meaning I should be runing the sub at 40Hz. Does anyone else agree with this?

By the way, the Velodyne is the current version of the SP-L 1000, which has the inbuilt room equalisation feature.
 
It is almost impossible to make hard and fast rules.

When my 37Hz (-3dB) speakers were used full range with high level connections they had the best combined response with the SVS 16-46 rolled off at 60Hz.

Now I have the speakers biamped and rolled off at 80Hz. Most subs can manage 80Hz with far lower distortion than most speakers. Just because the speakers go lower doesn't mean you want them to. Distortion will be rising extremely rapidly somewhere around the tuning point or even much higher. Remember Ilkka's distortion graphs for small boxes trying to do bass? Well imagine the even smaller box in your speakers trying to do the same!

I have previously illustrated (in another thread) that even with a 24dB/octave crossover @ 80Hz the speakers are still playing quite loudly at 40Hz even at normal listening levels. 84dB -24dB = 60dB @ 40Hz. (80 - 40Hz is 1 octave difference)

In my own experience the perfomance of the speaker is markedly improved by being lightened of the full bass load. It just takes some getting used to after listening full range for a while.

Try all the settings you have at your disposal. Hopefully you will find something you can live with. If you want to see the response curve you are actually listening to then download REW from the HT Shack. You'll need an SPL meter though.
 
Nimby,

Excellent info. But the speakers in this case are 2.76 times the volume of the subwoofer, and are not trying to produce all the other sub-bass frequencies either. IMO they will distort a LOT less than the subwoofer for real material at 80Hz.

I apologise for the pointless tech argument, but this is a forum, not a shop or helpline (though sometimes it's hard to tell :D).
 
dingwall said:
Nimby,

Excellent info. But the speakers in this case are 2.76 times the volume of the subwoofer, and are not trying to produce all the other sub-bass frequencies either. IMO they will distort a LOT less than the subwoofer for real material at 80Hz.

2.76 eh? :D

Now what about all the other frequencies the speaker bass drivers are playing? :)

If you remove the need for those speaker cones to flap about quite so much then wont you reduce distortion in the vital upper bass to midrange?
(Which is likely to be far more audible than a little distortion in the bass) ;)
 
Ah, yes excellent point.

But with two high-quality 6" drivers dedicated up to 150Hz only, those frequencies and that distortion isn't as much as one may think, and are masked by the high SPLs and amplifier limitations at which it will occur. At that point, I'd prefer this scenario to a struggling Velo SPL1000.

Maybe?

Great looking installation btw!
 
Eltee said:
I also have a query on this. I am going to be setting up my B&W M-1's (the MT series) with a BK Gemini sub. Any suggestions on crossover settings? Thanks.
Sorry, you got lost in the discussion.

All of the above points are valid as reasons for choosing a crossover point. With small satellites you'll just find that the range of crossovers in question are higher, or at least don't start as low.

I'd suggest the highest crossover you can manage without the sub becoming aurally locatable. In other words, if you can hear where the bass is comming from, try the next crossover point down.

The higher crossover (100-120Hz) will relieve the speakers of bass responsibilities, allowing higher volume levels, but a lower crossover (80-100Hz) may prove more satisfactory in terms of making the bass less obviously localised.

I used to run my Kef Eggs at 120Hz, because the sub was at the front of the room between the main three, so the localisation wasn't a problem. If your sub isn't co-located in the same way a lower crossover may be preferable. At the risk of upsetting dingwall :))), start at 80Hz and work upwards until you hear the sub and then down until you find where you're happy.

Russell
 
dingwall said:
Ah, yes excellent point.

But with two high-quality 6" drivers dedicated up to 150Hz only, those frequencies and that distortion isn't as much as one may think, and are masked by the high SPLs and amplifier limitations at which it will occur. At that point, I'd prefer this scenario to a struggling Velo SPL1000.

Maybe?

Great looking installation btw!
A pedants point:

What makes the Quad drivers better quality than the Velodynes'?

Russell
 
russ.will said:
Sorry, you got lost in the discussion.

Russell. Thnaks for getting back to me. My sub is co-located so I'll give your advice a shot this weekend. Cheers! :smashin:
 
I also agree with the argument for a higher crossover and usually run a good 50hz above the lower spec for the speakers. A decent sub will go upto 200hz, so I can't see a problem, myself. My SVS setup is currently set at 110hz, but then that's my ears doing the listening.
I'd personally start at the highest setting and keep dropping until it doesn't sound too much, but each to their own :smashin:
Just goes to show, you have to try all settings and find what suits you :smashin:
 
Nimby said:
I have previously illustrated (in another thread) that even with a 24dB/octave crossover @ 80Hz the speakers are still playing quite loudly at 40Hz even at normal listening levels. 84dB -24dB = 60dB @ 40Hz. (80 - 40Hz is 1 octave difference)

Hmmm.. fair point, but 24 dB is still a huge reduction in level, and a very steep filter at that.

With 22L's toying with anything between 80 & 40hz would be good. 80hz is the plug & play THX standard which, as russ.will states, is a good starting point.
 
Just wondering how do I set up a system where the sub only goes up to 120hz (BK XLS200) and the speakers only go down to 140hz (Tannoy fx 5.1 - don't laugh), the amp also doesn't have a crossover frequency option (Yammy RX-V440). Should I just set the frequency on the sub to 120hz and be done with it? I also have a pair of GR10s that I could add for the fronts but then it'd be a complete mis-match with the rest of the speakers, although would setting the amp bass option to "both" instead of "sub" take the burden of the rest of the speakers if I added the GR10s and set them to large...hmmm not sure.
 

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