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RCF crossover


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#1 Rik (ESA)

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Posted 06 September 2016 - 11:43 AM

Hi all, looking for suggestions...

We've just finished the upgrade to our PA (for now) to using 2 X RCF 712a tops and a 905as sub. We run the left and right channels into the sub, and deploy the built in crossover to send the signal to the tops. My question is, with only a 80 or 120hz choice for the crossover point, which is likely to be most suitable and why...?

We did the first gig with it set at 120, and it was ok if a tad muddy (even with sub set on 10% volume and tops on about 70%)... But I suspect with more tweaking the lows could be tightened, though I've no idea where to start.

For reference we use a soundcraft ui12 desk.

All help appreciated!

Thanks
Rick

#2 EBS_freak

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Posted 18 October 2016 - 09:18 AM

I would wager the problem is not with your speakers. Are you utilising high pass filters to curb the lows on your desk? I don't know what desk you have but if it's digital, you probably want to be shelving everything under 40 hz on all channels... then the same at 100Hz for vocals, guitars (maybe even higher for guitars), drum kit apart from kick... etc. That should help keep the crap out of the mix before it even hits your speakers.

The crossover on your system depends on how well the tops interact with the sub. As a starting point, I would probably crossover at 80 so the tops are doing more work than the sub as you only have one sub... but above all, use your ears... if your ears tell you otherwise, go with that.

#3 Rik (ESA)

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Posted 31 October 2016 - 10:32 AM

That's really helpful, many thanks.

It's a Soundcraft ui12 "desk", so has the option for HPF, but I'll need to play about with it...

Thanks again, will give it a go.

Rick

#4 EBS_freak

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Posted 31 October 2016 - 05:38 PM

Ah yes - my mistake. You did tell me your desk. Yes- start HPFing things, that should clear stuff up pretty quickly. Don't be afraid to bring those HPFs right up - especially on things like guitars.

#5 moonbass

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Posted 31 October 2016 - 06:33 PM

That sounds about the right ratio to me. I find that in smaller venues a tiny bit of sub goes a long way. As an experiment try setting the tops up with an MP3 playing before eq, and then bring the sub in until you get the sound you're after. The 905 is pretty powerful so you won't need much. Do a gig outside though and it will be a whole different story. The 712 is full range and goes down to 50 Hz, so you might not need subs for most venues; save you back and car space! If you want more punch you might be better off sending the sub on an aux channel that you can eq as you want it, and then set a high pass filter at 80 or 120 on the tops. Then send only bass, keys and kick to the sub. More fiddly but more likely to get the sound you're after.

#6 Rik (ESA)

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Posted 01 November 2016 - 10:06 PM

That's very helpful both thank you. Good to know there isn't anything drastically wrong with the volume settings!

It's interesting as I've recently done away with my bass amp live (using in ears following a lot of studying of your posts ebs, thanks!), and even without my amp there is still low end by the bucket load.

HPF seems to be the order of the day, I'll see how it goes!

Thanks again.

Rick

#7 EBS_freak

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Posted 02 November 2016 - 10:23 AM

Glad to help. That 905 should be a good match for those tops - so it defo sounds like a HPF issue to me. You never said what instrument you are putting through your PA - if you haven't put any HPF on your bass, along with compression, things will sound pretty swampy in the lows.

#8 Rik (ESA)

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Posted 06 November 2016 - 09:45 PM

Might as well give the full tail here and see if you guys have anymore quick fixes!

So, 4 piece function band (singer, guitar, bass (me) and drums, and me and the guitarist also do backing vocals). We play about a 50/50 split of weddings / parties and pub gigs, and play everything from Bruno mars to Kinks to rage against the machine (by request!), the idea being we offer something for everyone. We've been going for 2 years and slowly funded our PA and other gear "organically", so started with some really quite awful old desk, amps and passive peavey cabs. There was never any complaints about the sound but it always felt like something could break at a moments notice, and the system itself was on the cusp of maxing on many occasions, so we splashed some money on the gear referenced in my earlier posts (Soundcraft desk and rcf speakers), and are in the main absolutely delighted. The issue we have really is that I do the sound... and I'm not a sound man! Thankfully there are many built in presets to the mixer so I can largely set those and button mash (not quite) to get a sound we like, however I do feel we could get a punchier drum sound and a more rounded bass tone (which was primarily why we introduced the 905 sub). The HPF technique sounds a life saver so I'm looking forward to giving this a go, but are there any "basic" tips and tricks to look at / avoid? I've had a scan over the readily available YouTube videos but they all tend to get into detail that would only really be understood by a sound techie!

Just to clarify, I'm generally really pleased with what the new equipment has done for our sound, and that I am now amp free makes me smile, but just looking to tap into the basschat wealth of knowledge for anything I can look to incorporate, or indeed research further.

Many thanks
Rick

#9 moonbass

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Posted 07 November 2016 - 06:37 AM

(I should caveat the following with the fact I am no expert!)
I think it is fairly simple to set a vocal/keys/acoustic guitar mix up that will do for a whole set, and so can be done while also playing an instrument (usually bass as we all know... why do singers never seem to want to do the PA..?) But, adding bass and kick to this adds massively to the complexity. The levels of these vary considerably depending on the material, and throughout a song, so any set level will be a compromise. That being said getting a sound guy is not always possible for most bands, so my thoughts would be:
1) don't underestimate how extreme kick drum eq needs to be. Even with a specific kick mic you're likely going to need to cut a fair amount at around 200-400hz to get rid of boxiness, and boost a lot of high end if you want to hear any click (sometimes best to look at the damping and beater head on the kick drum first)
2) use compression on kick with an attack time that lets the initial transient come through, and if you have a gate with a quick attack that will help too (I don't think the Soundcraft does (?) but the Behringer XR18 is pretty good for this)
3) in most smaller venues where you can hear the bass amp on its own the PA might just be adding some low end around 50-80Hz, with a bit of high end (depending on material). I generally find getting the bass quieter on stage ends up with a better result out front.
4) when everything is set on the channels use the mix bus to shape things overall. A little compression and eq here can make a massive change to the overall punchiness of the mix. Remember to check again when punters are in as the sound will have changed from soundcheck.
At this point the Bar Manager usually comes over and tells me to turn it down, so not sure what happens after this :)


#10 FuNkShUi

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Posted 07 November 2016 - 08:39 AM

View PostEBS_freak, on 02 November 2016 - 10:23 AM, said:

Glad to help. That 905 should be a good match for those tops - so it defo sounds like a HPF issue to me. You never said what instrument you are putting through your PA - if you haven't put any HPF on your bass, along with compression, things will sound pretty swampy in the lows.

Sorry to hijack this thread a little, but do you recommend putting a HPF on everything?
We run vocals,keys,sax,drums and bass through our PA. Should we put a HPF on all of them?

#11 EBS_freak

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Posted 07 November 2016 - 11:47 AM

View PostFuNkShUi, on 07 November 2016 - 08:39 AM, said:

Sorry to hijack this thread a little, but do you recommend putting a HPF on everything?
We run vocals,keys,sax,drums and bass through our PA. Should we put a HPF on all of them?

Depends on how good your subs are... but probably yes - but it depends if you can specify at which point the HPF is set. For an analogue desk with a fixed HPF of say 100hz... well, that isn't going to help your kick drum... but if you can HPF your kick at say 40-50hz, given your chest thumping fundamental happens at about 65Hz, you'll suddenly start tightening up your subs and making them more efficient.

#12 EBS_freak

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Posted 07 November 2016 - 12:10 PM

In addition to what has already been said on the thread, I would actually advise against using presets. I've yet to find a digital desk where the presets are anywhere near where I would want them to be. Desk manufacturers cannot begin to guess what mics are going to be in play, so it seems more of a selling point to con people into thinking that they are simple "push the button" solutions - which of course they aren't.

The key to getting a good mix is spending some time to getting your ears used to frequencies. Don't be afraid to experiment - again, I would say it's worth hiring a room for the day just to play and get your sound as tight as it can be.

Looking at moonbass response, theres a couple of things that you can do to make life easier. First is, look at your mic. If you want a mic that will instantly get you in the ballpark, check out the Audix D6... its the most dishonest drum mic out there, with a response that is pretty much where you would want your EQ to be. I understand that quite a considerable investment, especially if you have a drum mic already. So here's the key frequencies... Boost 65Hz with quite a wide bandwidth (check the "q" setting on your eq) - but for your subs, HPF at about 45-50 Hz (Again must stress that this is not a formula - you must use your ears). Moonbass is right about the boxiness- so follow those tips. For click, you've got a couple of good options - 1 find the click using the eq... but you can artificially enhance the click using the credit card trick - which is literally taping a credit card loosely to the the area where the beater hits... so you'll get the natural click and the click of the credit card. I'm not a big click fan but plenty of people are - so this may get you where you want to be with minimal hassle... especially if you are having difficulty picking out the frequencies.

Mic placement is key - a lot of people simply chuck a bass drum mic in the bass drum and expect a great sound. Unlikely to happen. Your sound is going to be a lot tighter if you aren't picking up all the sound bounding around inside the drum... so you may want to invest in a bass drum mic stand if you haven't already, and place it closer to the exterior of the drum. Again, the exact positioning depends upon the mic and the drum itself. Oh yeah, make sure your bass drum is tuned - thats going to be a helpful start!

Compressing the hell and above all (this is the number one) applying a gate to the kick is where you are really going to start tightening up your drum sound. I've looked into the gate thing briefly and it would appear your mixer has a gate available on all channels - but it may require a firmware update if it hasn't. Again, literally just a quick read on my phone. I'd be very surprised if a gate has been overlooked as it's pretty much an essential tool when micing up a drum kit. Oh - worth mentioning... don't go to crazy on the compression or you may get a lock where you pretty much get instant feedback... and the floor tom may trigger that.

As for me micing the bass drum now? Well... I'm quite anal about getting the perfect bass drum sound... so I went into a studio, recorded the bass drum in various situations using different mics. Then I played with the EQ, sub bass, enhancers and everything to get my perfect bass drum sample. I set up my PA in a dead room and fine tuned til I got it where I wanted to be. From venue to venue now, the tweaks are minimal if anything at all. What do I do with this sample? I simply trigger that. None of the problems associated with micing up a bass drum, an open mic removed off stage and nobody can understand why I can get get peoples bass drums sounding so mentally good. So now you know. Again, this is probably over kill for most people - as it's a lot more expensive to do this than but a bass drum mic!

The rest of the kit is miced up traditionally.

And no, you can't have my bass drum sample! :P

Edited by EBS_freak, 07 November 2016 - 12:11 PM.


#13 FuNkShUi

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Posted 07 November 2016 - 12:31 PM

View PostEBS_freak, on 07 November 2016 - 11:47 AM, said:

Depends on how good your subs are... but probably yes - but it depends if you can specify at which point the HPF is set. For an analogue desk with a fixed HPF of say 100hz... well, that isn't going to help your kick drum... but if you can HPF your kick at say 40-50hz, given your chest thumping fundamental happens at about 65Hz, you'll suddenly start tightening up your subs and making them more efficient.

Thank you!

#14 JPJ

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Posted 07 November 2016 - 05:04 PM

I like the op look after our live sound, but I'm not a sound engineer. For a good drum sound, I've found a good hard gate to get rid of any after ring, followed by running the drums through a little bit of reverb just to warm them back up a little gives me the best result in 95% of the venues we play.
As to crossover points, I prefer something in the 100-120 area, but as I use a pseudo crossover on our Behringer X-Air (combination of a high pass and a low pass on the mains and one aux, running the subs from the low passed aux out) I have the best control over the balance of the rig, much better imho than when we used a dedicated crossover.

As with all these things, you have to first know what your gear can/cant do, and then experiment until you find something that works for you.
JPJ

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#15 EBS_freak

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Posted 07 November 2016 - 05:21 PM

View PostJPJ, on 07 November 2016 - 05:04 PM, said:

I like the op look after our live sound, but I'm not a sound engineer. For a good drum sound, I've found a good hard gate to get rid of any after ring, followed by running the drums through a little bit of reverb just to warm them back up a little gives me the best result in 95% of the venues we play.
As to crossover points, I prefer something in the 100-120 area, but as I use a pseudo crossover on our Behringer X-Air (combination of a high pass and a low pass on the mains and one aux, running the subs from the low passed aux out) I have the best control over the balance of the rig, much better imho than when we used a dedicated crossover.

As with all these things, you have to first know what your gear can/cant do, and then experiment until you find something that works for you.
Reverb on snare is cool - but I would never advocate reverb on a bass drum! - one way ticket to mushville! Funnily enough - with most digital desks, you can see the higher and lower thresholds of reverb frequencies - so for example, on a snare, you'd get reverb on the mid to high end for the nice "airy" reverb, but can cut it so that the bassier elements of the snare don't get any 'verb applied. So yeah, same thoughts apply to floor tom with reverb - don't go mad! Hats especially, you actually want some definition in all those hits!

#16 Rik (ESA)

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Posted 07 November 2016 - 10:15 PM

I LOVE THIS FORUM! Thanks all for the tips, plenty to have a play about with here. I've been looking at an audix d6 for a while as it happens, but want to give the mic we have a shot before discarding it too hastily because of my lack of knowledge. That said though, it's one of those all in one cheapy drum mic sets, and tha gets what tha pays for more often than not!

Thanks again.

Rick

#17 EBS_freak

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Posted 08 November 2016 - 12:44 PM

View PostRik (ESA), on 07 November 2016 - 10:15 PM, said:

I LOVE THIS FORUM! Thanks all for the tips, plenty to have a play about with here. I've been looking at an audix d6 for a while as it happens, but want to give the mic we have a shot before discarding it too hastily because of my lack of knowledge. That said though, it's one of those all in one cheapy drum mic sets, and tha gets what tha pays for more often than not!
You should be able to get some good results from the bass drum mic that you are using because you have some fairly powerful eq at your fingertips. The D6 is great because even through mixing consoles with limited EQ at your fingertips, it'll will get you in the ballpark with zero/minimal twiddling. It's defo worthwhile sticking with your exiting mic until you can at least get something in the ballpark - because you do have the flexible EQ available to you.

The thing with kick drum though - is to nail that gate setting.

#18 Rik (ESA)

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Posted 13 November 2016 - 12:42 PM

Well, last night we had the best drum sound we've ever had, and I'd like to say it's entirely down to the HPF and eq tips shared above... however the drummer has "misplaced" his cheapo drum mics, and we had to borrow another cheapo set, but managed to get hold of an AKG D112 for the night, so it's impossible to know if it's just because of the better mic! In truth I suspect it's a mixture of the two, however, in the absence of being able to quite afford the Audix D6, how much worse is the D112, as they seem to go for around 70 second hand...?

Thanks!

#19 moonbass

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Posted 13 November 2016 - 03:06 PM

One of the best kick sound I ever heard was with an sm57 on a tipped over floor tom; there are lots of ways to skin this cat! The D112 always seems a bit big to get through a kick port to me, and the unprocessed sound is a bit more flat than the d6 or the shure beta 52a, but it's massively popular; people just get used to using what they use.

#20 Rik (ESA)

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Posted 13 November 2016 - 03:17 PM

Haha that's novel, no way I'll be able to convince the drummer to try that though... we actually had the mic just at the port edge so inside my maybe 1cm-2cm.

Not considered the Shure mic, I'll take a look, thanks!

#21 EBS_freak

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Posted 14 November 2016 - 10:29 AM

I would wager that the HPF has done the trick over the choice of mic. The mics are important but it's actually quite difficult to buy an unusable bass drum mic nowadays. Yes, something like the D6 will get you a desirable eq pretty much out the box... but with a digital desk with the powerful eqs available to you, you can make pretty much any mic and kick drum sound pretty fat and pleasing to the ear. You may have more issues if you are using an analogue desk where you haven't got as much flexibility in the EQ (e.g. fixed frequency point, fixed q :-/ )

#22 Rik (ESA)

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Posted 31 March 2017 - 06:46 PM

So, a quick update... all the tricks and tips above have been used in some form - the HPF and gate proving the best tips. I've since bought an audix d6 which is as great as everyone suggested.

I am however experiencing issues with the sub (RCF 905 AS) farting when the bass guitar is played at volume. EQ is pretty much flat, I've used different DI boxes, and the bass sounds fine through a bass amp. The kick sounds great, as does recorded music, so wondering what it could be from the bass that's causing this?

As always hints and suggestions welcomed, my initial thought was there is something wrong with the sub (amp or driver) at higher volumes (even then only at 3 or 4 out of 10 on the subs amp).

Thanks in advance,

Rick

#23 EBS_freak

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Posted 03 April 2017 - 10:47 AM

Been having a think about this - the only thing I can think of is that your bass signal is actually distorting at the desk (or prior to getting to the desk) or you have a problem with the driver in your sub.

Alternatively Is your bass active? It could be the case that you are driving the DI to hard? Are the batteries in your bass on the way out - a lot of onboard bass preamps will go into distortion before giving up completely...

What is the exact signal path between your bass and the desk?

#24 mrtcat

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Posted 04 April 2017 - 02:49 PM

I think EBS freak is probably absolutely right here. I use the 905s and they are really solid subs. It's very unlikely that you will make them fart out with the bass especially with all your HPFs in place and the subs crossed over at 80hz unless you are really hammering it hard. Are you able to run a test tone through the sub to check that the driver is ok? If it is then the built in protection shouldnt allow the sub to fart out unless you are putting in a distorted signal.

#25 Rik (ESA)

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Posted 05 April 2017 - 10:29 AM

Thanks a lot both for the replies!

I use a Sterling Ray 34, which has an active 3 band EQ. Battery v recently changed. Signal path is bass into a smooth hound wireless (or cable when I tested that) into a tech 21 bass fly rig (or a standard Di box when I was eating to ensure that wasn't the cause) and into the soundcraft desk. The gain isn't close to peaking so shouldn't be a problem with the desk hopefully.

I took a look at the driver and there's no obvious rips or similar, but could always be something non visible I guess?

I tried my bass through a bass amp and no issues there, but I will try another bass through the sub to see if that returns the same issue.

Cheers
Rick


#26 EBS_freak

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Posted 05 April 2017 - 12:31 PM

OK - just checking - you've gone through steps to eliminate the problems...

plug your bass into the desk directly via a cable
plug your bass into the DI and from that into the desk... all using cables
plug your bass into the Wireless and from that into the desk... all using cables (apart from the wireless bit obviously)

Have you tried plugging into different channels on your desk? Hi-Z vs Lo-Z etc - I see the UI has different sockets - that could influence things.

Have you tried different cables? Are you using instrument cable? Are you using mic cable or balanced TRS from your Bass Fly to the mixer?

#27 Rik (ESA)

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Posted 06 April 2017 - 11:27 AM

Thanks mate.

I'm using an EBS patch lead from smooth hound to flyrig, and as far as I know a generic (but good quality) mic xlr cable from flyrig to desk. I'll try the different channel approach and perhaps a different xlr.

Thanks again.

Rick

#28 Rik (ESA)

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Posted 27 July 2017 - 01:58 PM

Just resurrecting this one again! Managed to avoid the "farting" by dropping the sub volume and increasing my amp volume. Had a thought though, and I've had a scour online for info, but is it possible I'm putting too much gain on the bass before it hits the sub? I'm running the sub on volume as 1 of 10 (8 o'clock), and anything above that presents issue. As you'll have gathered from this thread, I'm a real FOH sound novice, so never really considered I could be driving the sub too hard at source. That said, on the mixer (iPad) the sound isn't clipping. Could the volume nobs on the soundcraft itself influence things? I run those on full...

Thanks again,

Rick

#29 moonbass

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Posted 27 July 2017 - 02:25 PM

I don't think this has been mentioned above yet, but you might want to try sending subs on fader. This means using your main left and right outs of the Ui12 for the PA tops, and then sending an entirely different feed off an aux out to the sub(s). This way you need only put the actual bass instruments (kick, bass, and possibly keys and guitar depending on genre) through the subs. You can then control,the sub independently with gain, filters, compression etc. I don't know about the RCF sub but certainly my Mackie 1501s don't turn all the way off even with the volume at '0', so doing it this way gives me much better control in smaller venues.
To be fair it does take a bit of getting used to having a whole extra send to balance with the mains, but I instantly got better definition and punch in my mix. With digital mixers in this way you can control your own crossover, and not be limited to your sub's presets.

Edited by moonbass, 27 July 2017 - 02:26 PM.






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