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Elliot Thompson View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 6:19am

If you are not playing out on a constant basis, more so making enough money to pay off your investment, I would not over analyse the performance of your sound system in the eyes of others.  

 

Best Regards,

 



Edited by Elliot Thompson - 07 December 2017 at 6:23am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JonB67 Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 8:41am
I think anyone here asking how to get better may have the same desire to sound good and care about the opinion of their audience as anyone else. This is regardless of if they play one or 600 gigs a year.

Not all the little guys are happy to sound shit.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote charlysays Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 9:32am
Originally posted by Elliot Thompson Elliot Thompson wrote:

If you are not playing out on a constant basis, more so making enough money to pay off your investment, I would not over analyse the performance of your sound system in the eyes of others.  

 

Best Regards,

 

 
I've been keeping a tally of how much I've been paid over time and it's far from wasted money and it sounds good enough to be very satisfying for me and many others- compared to what else is around in my area it is one of the best sounding systems especially for bass heavy music. I can't really get my fix of stomach churning oldschool jungle bass anywhere else unless I go to London for nights out which soon gets very expensive if going regularly. It's also great for parties as a few of my mates have barns in valleys in the middle of nowhere.
 
So would there be nothing to be said for adding in a pair of 12" drivers or another pair of MP415s if only to add headroom on the full range section? Surely it would improve the mid- high balance?
They are affordable for me and easily transported and are loud at 130db. They are also a massive step up over JBL JRX etc. They are rare however but when they do come up they are not appreciable more expensive than JRX.
The seller who was selling the pair I bought kept getting very low offers as the buyers thought they were the same as JRX, so this makes them an affordable speaker with very good sound quality for the money in my country, if I can find another pair.
 
 


Edited by charlysays - 07 December 2017 at 9:35am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote charlysays Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 1:40pm
Just found these papers by rog mogale, interesting stuff.
He does not support splitting up the sub system for even coverage.
If I run two separate bass columns in the venue in question, judging by this paper, it will result in unsatisfactory sub SPL in the middle and rear part of the hall.
But this paper doesn't go into the issue of muddiness of the bass with a single stack of subs yet. Will keep reading these as they seem to be hitting the subject well.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote charlysays Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 1:44pm
"

Boundary Placement

In situations where bass enclosures are not installed in a DJ booth, boundary or on the floor against a wall placement has advantages. The bass array will now be radiating into one quarter space so an increase in efficiency can be expected and reflection cancellations will be minimised as the distance from the enclosure to rear wall is small. When an enclosure is placed at some distance from a rear wall cancellations and reinforcements take place at specific frequencies relative to the distance from the wall to enclosure. Positioning LF enclosures very near to a rear wall helps to reduce these reflection effects as cancellations will be at higher frequencies so out of band."

So this is exactly what I did at the venue in question, had my subs tight against the rear wall, yet apparently that was the wrong thing to do? I don't know who's wrong, void or you guys lol.


Edited by charlysays - 07 December 2017 at 1:46pm
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Sapro2 Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 3:14pm
I've done parties in big (echoey) warehouses.
The most important thing is to have your speakers at an angle from the wall. This will split up the sound and reduce (direct) reflections.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Hemisphere Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 5:23pm
There is no perfect 'colour by numbers' placement of stacks in a venue, as every venue is different and has eccentricities that would render rules of thumb useless (the slanted roof in the hall you used is bound to create some weird effects for example).

Void have given some guidelines which outline the basics/best practices, but to touch on every eventuality for the behaviour of sound in a room would take forever, and people wouldn't have the patience. It seems to be aimed at Void's customers: nightclub/venue owners, who in most cases will be starting with a room that has reasonable acoustics (as in the simulations offered), and in some cases will be designing/repurposing a room from scratch. (if you can afford a Void rig you probably have some budget knocking about). 

The room in the simulation is 25 metres wide. Your room looks about 10 metres wide with about 3.5 metres clearance on one side and 5 metres clearance on the other side of the stack. Acoustically that makes them completely different animals. In your case it means all the frequencies between 30 and 68Hz will have benefited from corner loading on both sides of the room, with a slightly less pronounced boost from 68 to 80Hz on one side of the room. With Cubos that could be something like a 10dB boost.

If you had had 12 metres each side of the stack (as in Mogale's 'optimum room' simulations), then you would have had no problems, because 12 metres is approximately 28Hz. That's why the room in the simulation is 25 metres across, and a good venue planner would (or should) consider something like this.

Since you're not a venue planner, you've got to be able to analyse each venue for it's own qualities, and weigh up what you would be prepared to sacrifice and which benefits are most important to you. Some of that will be subjective and dependent on taste and music genre.

In your case, the benefits of splitting the stack would have been to enhance your tuning options in a sub-optimal environment. If all your bass is in one place then there's not much you can do to tune it to the room besides EQ, but if the sound is totally different on one side of the room to the other, that's not much use, and as you mentioned, the DJs have their own control of the EQ, so unless you've got a very effective monitoring setup, some of the lower bass frequencies they're monitoring/adjusting will be coming straight from the rig.

The other issue which enters the mix is that a lot of the 'bite' of the bass, what we perceive musically, is coming from the harmonics or through overdubbed samples/synth notes, and those will be coming to the DJ through the monitors, while the true bass will mostly be coming from the rig..but they'll be adjusting the lower bands on the EQ anyway. How well they're able to handle that discrepancy will depend on how skilled and experienced they are.

Edit: Talking of which, do you have any monitoring setup for the DJ? I can't see any in the pictures..

I didn't give much consideration to cancellations but you're bound to have had a bunch of these as well. Short of running test tones and measuring at different points in the room during set up (or modelling the room and running it through software as Mogale did) it would be very difficult to say exactly what to expect, other than 'not good'!

That's all the more reason to advocate for split stacks in this case imo, as you're going to get a mess whichever way you slice it, but if you take two erratic messes and mix them together, and you have independent EQ control over each mess, theoretically that offers the greatest chance of even coverage of a flat response (or the Fletcher-Munson equal loudness contour adjusted response as you mentioned on the other page - great find btw!)


Edited by Hemisphere - 07 December 2017 at 5:37pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote charlysays Quote  Post ReplyReply Direct Link To This Post Posted: 07 December 2017 at 10:14pm
Cheers man, nice explanations of what the corners and wonky roof are doing :) Will defo try separate stacks then with EQ on each.

I would assert though that the whole thing of "move the boxes 6ft or even more away from the wall" should be ignored though- surely it cannot be good to add even more reflections and cancellations from the rear wall in to the mix by doing this. As Rog says, placement close up against the rear wall moves rear wall reflections out of the sub band and into a band which is easier to massage.

I did bring a 150w thomann 1X15 active monitor but the DJs didn't want it. I don't think either of them have played much on PA systems. I have a bit but I wouldn't say I'm skilled. This was part of the reason that the fussy promoter/ DJ would either be giving me thumbs up or requesting me to alter something almost on a tune by tune basis.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote charlysays Quote  Post ReplyReply Direct Link To This Post Posted: 30 December 2017 at 3:43pm
Originally posted by Elliot Thompson Elliot Thompson wrote:

Your loudspeaker setup looks as if you stepping up from smaller events to larger events in which, you are adding larger bass bins but have not upgraded the tops. The JBL two-way full range will perform well with the JBL subs below. Such a setup is common with many Wedding/Corporate DJs in the States with an additional pole mount to elevate the tops.

 

However once you add an additional four Cubos in the equation, those JBL two-way speakers will have great difficulty offering the same quality in terms of midrange at high sound pressure levels.

 

 

 

 

Best Regards,

 






I've read a couple of rog mogales papers on setting up dance music playback systems and he says that the best sounding venues in the world all have a significant increase in SPL below 100hz, up to a 10db boost under 100hz. They also have a significant dip in SPL in the mid range. Why should I not try to emulate this system response if I am playing very sub heavy music?

I'm not sure if you have ever used any JBL MP418 subs but I can assure you that there is no way that I could get +10DB boost below 100hz just using one pair of MP418s underneath my MP415 full range speakers, unless I ran the tops at something like -20db. Furthermore the response of the MP418 drops off steeply below 50hz- you just can't feel or hear the lowest notes at all. Sure I could boost the EQ and hammer the voice coil into the back plate. Cubo subs are much better in terms of output below 50hz which I why I choose to use them.

Over the last few years I tried using one, two or even three pairs of JBL 2241 loaded single 18" reflex subs with these MP415 tops and the output of the lowest bass notes and "feel" of the bass at these frequencies was always disappointing even when running the subs flat out and the tops at around -6db. Due to this I built cubo subs and have been slowly selling off the JBL subs apart from one pair of MP418 which I find useful for general use and playback of music which is not sub heavy. I also use them for extra kick over the cubos.

I'm also confused as to how running a pair of speakers at -6 or even -10db is in any way asking too much from them?




Edited by charlysays - 30 December 2017 at 3:51pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2018 at 10:34am

When the SPL increases, we (Humans) become more conscientious on the midrange frequencies. The intelligence of the music is lost when the Bass and Treble overrides the Midrange at high sound pressure levels. The above method is known as the smiley face equalisation method. Using such a method will also be problematic for Dance Music that offers any means of vocals and/or percussion.

 

Larger sound systems use Double Eighteen Inch Reflex Subs. Only small sound systems will focus on Single Eighteen Inch Reflex Subs. The logic behind each method is based on transport when using quantity.

 

Larger sounds systems will use two Double Eighteens for one top minimum. So it is not surprising you are not getting enough bass using, three Single Eighteen Reflex bins to two Full-range tops.

 

You need understand how the frequencies work on the type of music you are reinforcing from a dB standpoint. I would suggest finding someone reinforcing the same type of music as yourself, utilising a larger sound system than yours, in order to get a better understanding what is needed to get the job done properly while, achieving the fidelity you are seeking.

 

When a loudspeaker system offers a frequency response of shall we say 40 Hz – 100 Hz (-10 dB @ 40Hz) it means, you need 10 decibels of amplitude @ 40 Hz to equate the same amount of SPL @ 100 Hz (100 Hz being 0 dB).

 

The above passage means if you are feeding the loudspeaker system 1000 watts @ 100 Hz, you are going to require 10,000 watts @ 40 Hz to achieve the same SPL.

 

Those who study the fundamentals on how everything works together as a team, usually achieve the frequency response, the sound pressure level in addition to, the fidelity they are seeking.

Then there are those who find themselves constantly damaging speakers, living off of heavy equalisation and, still looking for that special magic black box in order to achieve great Fidelity.

Those who fall into the above category usually tend to become perplexed on why they are not achieving a sound which is pleasing to the ear while others are not facing the same issues. The answer is quite obvious... focusing only on one thing and disregarding everything else. 

 

Best Regards,

 



Edited by Elliot Thompson - 01 January 2018 at 10:58am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote charlysays Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2018 at 11:31am
Originally posted by Elliot Thompson Elliot Thompson wrote:

When the SPL increases, we (Humans) become more conscientious on the midrange frequencies. The intelligence of the music is lost when the Bass and Treble overrides the Midrange at high sound pressure levels. The above method is known as the smiley face equalisation method. Using such a method will also be problematic for Dance Music that offers any means of vocals and/or percussion.

 

Larger sound systems use Double Eighteen Inch Reflex Subs. Only small sound systems will focus on Single Eighteen Inch Reflex Subs. The logic behind each method is based on transport when using quantity.

 

Larger sounds systems will use two Double Eighteens for one top minimum. So it is not surprising you are not getting enough bass using, three Single Eighteen Reflex bins to two Full-range tops.

 

You need understand how the frequencies work on the type of music you are reinforcing from a dB standpoint. I would suggest finding someone reinforcing the same type of music as yourself, utilising a larger sound system than yours, in order to get a better understanding what is needed to get the job done properly while, achieving the fidelity you are seeking.

 

When a loudspeaker system offers a frequency response of shall we say 40 Hz – 100 Hz (-10 dB @ 40Hz) it means, you need 10 decibels of amplitude @ 40 Hz to equate the same amount of SPL @ 100 Hz (100 Hz being 0 dB).

 

The above passage means if you are feeding the loudspeaker system 1000 watts @ 100 Hz, you are going to require 10,000 watts @ 40 Hz to achieve the same SPL.

 

Those who study the fundamentals on how everything works together as a team, usually achieve the frequency response, the sound pressure level in addition to, the fidelity they are seeking. Those who find themselves constantly damaging speakers, living off of heavy equalisation and, still looking for that special magic black box in order to achieve great Fidelity, tend to become perplexed on why they are not achieving a sound which is pleasing to the ear.

 

Best Regards,

 



I see what you're saying, however it doesn't explain why MP415 tops will have trouble with midrange running at moderate SPL (their response graph looks pretty smooth from 90hz up to 18khz) so much so that you advocate that I only run one pair of JBL reflex subs with these tops, like a typical disco setup.

That is just woefully inadequate for playing bass heavy music and something which I have tried and was very disappointed with. As I said I was even disappointed with the low sub from 6X single 18" JBLs with these tops, though the upper bass was very powerful with the 6X18" drivers. Not only is there just not enough bass from each cabinet but the enclosures are too small and tuned too high.

With the best dance systems being +10db under 100hz I surely do need a few cubo subs to achieve this and not just one pair of MP418 subs. If I feed 10kw to a couple of JBL2241s at 40hz there will be death lol. So instead I use cubo subs which has a lower tuning and will still have good output at 40hz.

To add more midrange headroom though (and have some spare speakers for more monitors at smaller events) how about adding in something like the JBL SP212 which have 1.75" CD VCs? As I said I rarely run all my bass bins so can't be doing with a massive pair of very expensive tops which I pretty much never use. Using two pairs of smaller tops has surely got to result in better midrange headroom than just one pair and a similar effect to two large tops.

I've never damaged/ blown a speaker in 4 years so I'm doing fine there. I did once hear my 18nlw9400 cubo subs sounding a bit fruity with 1300w into each with the DJ pushing hard into the limiter- going over xmax I imagine but nowhere near x-lim. As I've said, I'm happy with the fidelity and the majority of customers are too. Generally the sub is eyeball rattling, with vocals clear and the tops not sounding harsh or ringing ears. I started this thread to devise ways of keeping the minority of customers/ punters with a negative opinion of my sound happier and I have some strategies now thanks to you and hemisphere- having two stacks with separate EQ for each and ideally more midrange headroom.










Edited by charlysays - 01 January 2018 at 11:31am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hemisphere Quote  Post ReplyReply Direct Link To This Post Posted: 01 January 2018 at 1:43pm
Do let us know if the split stack idea actually helps - I would recommend running a test with a single pair of subs on long cables and shift them to all the viable location combinations with a flat EQ as a baseline before tuning. You could even play band limited pink noise and wander round the venue with a measurement mic/netbook/usb interface and see exactly what's helping and what isn't, and 'tune' the locations accordingly. Some split stack arrangements will be even worse than mono.
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