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Post by soundmanjim on Nov 21, 2005 23:50:36 GMT 1
ok, heres a good one.
had the sultans of ping here the other night; just wondered why
A/the engineer miked the bass AND di' - d it?
b/ does putting a mike above and below the snare really sound that much better?
The actual sound on the night was awesome so it must make some difference; esp the bass, you could actually feel your trousers vibrating.
one other thing; some engineers that have been here roll the bass off on the foh graphic; others leave everything flat and dip the problem frequencies. i mean, you cant really hear any difference if the very top fader and the very bottom faders on the graph are pulled down; or is it the fact that they actually DO have an effect on the other frequencies even though they are out of your hearing range?
discuss!
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Post by John Bell on Nov 22, 2005 10:11:35 GMT 1
Hi Jim, By DI'ing and Mic'ing the bass, you get the tight punch of the DI and the "growl" of the speaker. By mic'ing the snare head and reversing the polarity, ( to prevent both mics being out of phase with each other) the bright snap of the snares can be accentuated. As for the FOH, I always roll-off 20 & 25 Hz to prevent the sub's being destroyed. If you drive a sub below it's resonant frequency, serious physical damage will occur to the cone, as well as a likelihood of over-heating the voice coil. You will then get a reduction in efficiency and less output for more power being applied.
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Simon Ryder
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Bringing out the best through sound
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Post by Simon Ryder on Nov 22, 2005 13:20:35 GMT 1
Funnily enough you will find egineers who only single mic snares and engineers who double mic snares. With me it is as much a time factor as anything else, I often find that with the mic on the underside of the snare the gate setting needed to remove the snare rattle (just want the crack) is very extreme and remove much of the actual snare sound from that mic. It also uses up an additional channel of gating. I personally tend to single mic he snare and use a combination of good EQ and accurate gating to shape the full and punchy sound that I am looking for. Many engineers I know who ALWAYS mic top and bottom comment on my snare sound and ask me how I got it - they often look slightly puzzled that I just used one mic! Incidentally I place that mic around 2-3 inchs in and 2-3 inches up, pointing at the centre of the snare. Conversely, I often double mic bass cabinets (if they are good enough - I like trace elliot metal 10" drivers, very punchy) and very often don't bother with the DI at all. I use a small diaphragm condenser pointed at the inside of the driver and a kick drum mic pointed at the outside, being sure to align the capsules so that the signals are in phase with each other. Sometimes it works well to mix in the DI'd signal as well and sometimes not, depends on the exact tone that I am looking for and how many channels of compression I have available. As for rolling off the low EQ, it is better practice to leave extreme low end of the EQ flat due to phase shifts that occur every time you apply a process. It is better practice to use a high pass filter on the crossover and just prevent infrabass from reaching the amps. Incidentally, I often put 2 FOH GEQs in installs, one set using pink noise and an RTA and tuned to within +/- .1dB of a perfect response curve and locked away in the amp rack. The other is their for guest engineers to play with and is located in the FOH rack. This unit is best left on bypass unless the music requires a certain sound, dub reggae perhaps. The upshot is that a well tuned room stays a well tuned room and the venue continues to have good sounding system without the house engineer having to re tune it every day or so. Of course it does mean that guest engineers are free to make a complete balls up of it and some insist on laying some very strange looking curves over a tuned system. S
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Post by soundmanjim on Nov 22, 2005 21:13:54 GMT 1
blimey thats a good idea!
personally i have always di'd bass guitars as its just one less channel of feedback to worry about; but then that was a long time ago when i was a bit green and the acoustics of the hall were worse as were the speakers; so i might have an experiment myself this friday.
miking snare, i point the 57 at the centre about 2-3" up and 2-3" back as you do, as close as i dare but far enough away to prevent the drummer striking it. i then put that channel thru a gate and a compressor but i find that in normal use i dont really need either.
I was wondering about phase shifts; i mean the amps have the 20hz cut on most of the time anyway so no signal that low is going to get thru to the speaker so i leave it flat.
this is really interesting, thanks guys!
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Post by allongsounddesigns on Nov 23, 2005 8:19:25 GMT 1
Generally double micing anything is a studio technique, just gives you that little bit more control over what the instrument sounds like.
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Simon Ryder
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Bringing out the best through sound
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Post by Simon Ryder on Nov 28, 2005 22:52:39 GMT 1
These days with the quality of live sound systems available there are fewer and fewer differences between studio and live sound techniques. OK, using omni capsules on anything other than a lavalier is never normally going to be a good idea at a gig, but things like near-coincident miking techniques, M&S drum kits, double miking instruments are all becoming more common. Ribbon mics are in regular use on stages all around the world from small to large. I even see Pro Tools used live in the form of the Venue system and in its standard HD platform to record shows. As for live techniques used in the studio - I use them every time I record. Bono from U2 only ever sings through a standard SM58 whether live or in the studio (admittedly patched through a ludicrously excpensive preamp and compressor) When he records he stands in the control room facing the studio monitors and uses those to monitor his performance and cues. He doesn't use headphones. (This is correct as of a couple of albums ago, I don't know about their latest - I haven't worked with him but I have hobnobbed with his engineers). The gap between studio and live is decreasing in terms of possible sound quality, though in terms of job satisfaction I really do love live..... Regards, Simon
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Post by soundmanjim on Nov 29, 2005 20:44:11 GMT 1
so what were actually looking at is to increase the shine of a live performance to almost studio quality; it seems that more and more punters are demanding the most perfect sound they can get at a live gig; this is going to make things more difficult for the live engineer; i see the next generation of Midas live desks are now in digital format! will this be the way forward and will we all have to 'toe the line' and move over to more digital/pc routes for live work? 'Shudders'
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Simon Ryder
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Bringing out the best through sound
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Post by Simon Ryder on Nov 30, 2005 16:55:19 GMT 1
Digital is great but then again so is analogue. They have their different uses, if Midas can honestly say that their forthcoming digital desks give you all the flexibility of digital AND sound as good as the XL4 then, oh boy are they on to a winner! The difference between live and the studio is not in the quality of the equipment or the actual sounds generated ( with todays digital boards you can program the cues and produce track for track what was done on the album). No, the difference is the quality of the listening environment. How many venues were designed for that purpose? How many are acoustically treated? The majority of venues I work in sound appalling with standing waves, massive RT60 times, hideous reflections, slap back and general mush smeared over the music by the venue's acoustics. To work in a venue that has been built with acoustics in mind is a dream that few of us (except some of the theater guys) get to realise. The standard of kit has improved, now we need to improve the standard of live sound engineers and the standard of venues. We need to encourage venue owners to care about the quality of service they provide and get past the minimum spend per drinking person through door equation. A happy punter relaxes and drinks more, you also get a better reputation, your clientele improves, you get less trouble and generally everyone enjoys themselves more. S
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Post by soundmanjim on Dec 1, 2005 1:38:45 GMT 1
i wonder how long it will be before they start building venues that are 'acoustically flat' then?
what do you reckon the worst place is to do sound in? and whats the best place?
i wonder what the albert halls like to set up in!
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Simon Ryder
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Bringing out the best through sound
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Post by Simon Ryder on Dec 1, 2005 10:59:27 GMT 1
Worst places would be stadiums, Earl's Court, Wembley Arena, Excel and many more. Any place that is big, concrete and resonant. Best places would be somewhere like the National Theatre or indead any theatre (lots of absorptive material in the shape of seats, carpet etc and in an auditorium built to carry sound to the back. Irregular shaped rooms can also be a real problem if the system has not been set up with the right coverage angles. I like doing big outdoor gigs for the reason of no building acoustics to worry about - just coverage, wind speed and direction, temperature gradients etc. The ALbert Hall is supposed to be an interesting one, mostly due to the fact that you can't hang speakers where you would want to due to TV camera sight lines. Using line arrays however, they seem to have gotten a lot closer to solving that problem. S
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Post by soundmanjim on Dec 2, 2005 6:39:44 GMT 1
ah! very interesting. while were on the subject; what effect does ambient temperature have on sound? Only i was soundchecking a band in he hall last friday and it was freezing becuase someone had forgotten to turn the heaters on, and everything sounded really tinny and reverb-heavy, the like i'd not heard before. as the heaters came on and the temperature increased, the sound improved until it was back at its normal loveliness. Even in a small building, can temperature really have that much effect?
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Simon Ryder
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Bringing out the best through sound
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Post by Simon Ryder on Dec 2, 2005 12:27:51 GMT 1
In short, air temperature affects the speed of sound. The warmer the air, the faster the sound travels. Sound moves at aprox. 344m/s at 20 degrees C and this is the basic assumption of most sound theory. However, sound moves at 355m/s at 40 degrees C and 337m/s at 10 degrees C. When you feed these constants into the simple equation V=f/L (this forum does not have a Lambda character) You will notice that for a given speed of sound (select at appropriate temperature) the wavelength will change for a given frequency, or, the frequency will change for a given wavelength. Needless to say, this drastically alters the sound.
The real problems come when you are working out doors and set up during the day when it is warm and then the gig starts at night when it is colder and suddenly you find that your carefully tuned settings are meaningless and you need to retune the system. The next problem is that in the cold night air, the air immediately surrounding your audience will be much warmer creating a temperature gradient. This temperature gradient will refract the sound upwards! this meeans that if your speakers are just above the crowd, you will be in effect bouncing the sound off the temperature layer above the audience's heads causing extreme loss of inteligibility. The way round this is to fly your speakers high in the air and point them downwards (still at an angle towards the back of the audience) You will of course need more delay speakers to then cover the same audience.
Wind speed also refracts sound. If the wind is blowing against the sound waves, it will refract the sound downwards and then up, probably covering your audience quite well, though for a shorter distance than on a calm day. If the wind is blowing in the same direction as the sound waves, it will refract the sound waves up, then down. This lifts the sound above the audience's heads and then drops it down much further back. It means that sound can "leap" over objects to reach a listener (or a farm house the other side of the hill, who will then complain about noise) S
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Post by John Bell on Dec 2, 2005 14:46:02 GMT 1
Hi Simon, Does the air humidity have just as much effect as the air temperature, as when a venue is very cold, like Jim's place was, I expect it could feel damp as well?
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Simon Ryder
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Bringing out the best through sound
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Post by Simon Ryder on Dec 3, 2005 13:47:05 GMT 1
Hi John, Yes, humidity affects the speed of sound. The denser the object that sound is travelling through, the faster sound travels. Sound travels faster through liquids than it does in air, so the more fluid content that the air has, the faster sound will travel. In short hot, sweaty rooms tend to sound better than cold, dry ones. Of course you then have other factors to worry about such as heat dissipation from speaker voice coils (or rather the lack of it which causes thermal compression and therefore a loss of volume and transient response) and moisture affecting the speaker cones, depending on what material they are made from. S
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Post by Apollo on Dec 20, 2005 13:54:08 GMT 1
i wonder how long it will be before they start building venues that are 'acoustically flat' then? what do you reckon the worst place is to do sound in? and whats the best place? i wonder what the albert halls like to set up in! I've read that The Albert hall is "renowned for being a tricky venue." Source = www.eaw.com/news/?id=440It's in the last 2 or so paragraphs before the section called " About EAW" (at the bottom of the page)
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