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[Ionescu Florin Gabriel]

[Ionescu Florin Gabriel]

[Martin Morris]

Those drivers won't last long in the DJ world with
out grills ... just saying

Cheers
Martin

[Ionescu Florin Gabriel]

I manipulated the enclosures without the protective grille for the speakers, with care and attention nothing will happen.

Anyway, they are not definitive, they were only made for testing, soon I will make them from mdf painted with orange tuffcab ral 2003 with the protective grid and everything you need to look flawless as a finish.

Have a great day! 🤗🔊🔊🔊 🔊

[Art Welter]

I want to use it for now for mobile dj in groups of 4 and my question is if with the 4 pieces I can handle a maximum of 300 people inside or outside?

Or how many pieces would I need for outside for a maximum of 500 people, even for live?

Ionescu,

How many people your subs can handle depends on how many are in the area of coverage, and what SPL your target is.

I have used four similar volume and Fb (36Hz tuning) dual Lab 12" subs outdoors with 3000 to 5000 people attending for live and playback events.

Each of the dual LAB 12" cabinets can produce around 125dB SPL, or 128dB peak at one meter within the 400 watt per driver thermal limits and not exceed Xmax, linear displacement limits 30-100Hz.
The cabinets with the additional front resonator would have more upper (60-120Hz) output.
The small voice coils of the LAB 12" are not very good at getting rid of heat, as they heat impedance rises, creating thermal compression as voltage amplifiers deliver less power into higher impedance.

If the dynamic range of your program material is large (>+12dB) there will be little thermal compression, if very low, < 6dB, the voice coil heating could reduce output by -3 dB or more, especially if the bass line is near the 35Hz Fb, where displacement (and cooling) is minimized.
If closely coupled, adding a pair gives +6dB, going to four cabinets, +12dB, for a total of around 140dB peak level at one meter.
Outdoors, each doubling of distance reduces level by 6dB.
140dB at one meter would drop to about 120dB at 10meters, 100dB at 100 meters.
Depending on whether the people are jammed shoulder to shoulder, dancing, or seated on lawn chairs, you could expect a range from 5 per square meter to as little as 0.5 per square meter.

Indoors, room modes and location of the cabinets will create areas with more or less output at different frequencies, but in general the level won't drop as much with distance as outdoors.
 
Nice looking cabinets, but definitely add grill covers unless you enjoy cleaning trash out of the ports and repairing holes in cones and surrounds.
Also, MDF does not hold up well on the road, especially if conditions are wet or humid, and weighs far more than plywood for a given stiffness.

Art

[Ionescu Florin Gabriel]

Ionescu,

How many people your subs can handle depends on how many are in the area of coverage, and what SPL your target is.

I have used four similar volume and Fb (36Hz tuning) dual Lab 12" subs outdoors with 3000 to 5000 people attending for live and playback events.

Each of the dual LAB 12" cabinets can produce around 125dB SPL, or 128dB peak at one meter within the 400 watt per driver thermal limits and not exceed Xmax, linear displacement limits 30-100Hz.
The cabinets with the additional front resonator would have more upper (60-120Hz) output.
The small voice coils of the LAB 12" are not very good at getting rid of heat, as they heat impedance rises, creating thermal compression as voltage amplifiers deliver less power into higher impedance.

If the dynamic range of your program material is large (>+12dB) there will be little thermal compression, if very low, < 6dB, the voice coil heating could reduce output by -3 dB or more, especially if the bass line is near the 35Hz Fb, where displacement (and cooling) is minimized.
If closely coupled, adding a pair gives +6dB, going to four cabinets, +12dB, for a total of around 140dB peak level at one meter.
Outdoors, each doubling of distance reduces level by 6dB.
140dB at one meter would drop to about 120dB at 10meters, 100dB at 100 meters.
Depending on whether the people are jammed shoulder to shoulder, dancing, or seated on lawn chairs, you could expect a range from 5 per square meter to as little as 0.5 per square meter.

Indoors, room modes and location of the cabinets will create areas with more or less output at different frequencies, but in general the level won't drop as much with distance as outdoors.
 
Nice looking cabinets, but definitely add grill covers unless you enjoy cleaning trash out of the ports and repairing holes in cones and surrounds.
Also, MDF does not hold up well on the road, especially if conditions are wet or humid, and weighs far more than plywood for a given stiffness.

Art

Thank you very much for the answer and for the appreciation, finally someone who appreciates my work!

 Although here at my place all my friends are against me and they tell me that even with 4 double LAB 12 I can't cope with even 250 people.

I made some measurements in the 35-60 hz band with an RTA SPL LAB PRO microphone. Amplification CROWN XLS 1502 CU 516 W RMS.


 I WANT TO GET TO 4 BOXES, BUT TO GET THE 4 AT A CONSTANT SPL OF 136-137dB. IF I CAN GET A MINIMUM OF 300 PEOPLE UP TO A MAXIMUM OF 500 TO COVER THEM, IT MEANS THAT MY PROJECT IN MY HEAD WILL GIVE RESULTS.

 https://youtu.be/Kmw5QB1fLOU

[Art Welter]

Although here at my place all my friends are against me and they tell me that even with 4 double LAB 12 I can't cope with even 250 people.

Ionescu,

The XLS 1502 is a little light for peak power, but still more than enough to burn the 2.5" LAB12 voice coils if driven with "CONSTANT" signal like a sine wave with only 3dB crest factor. Power handling is not the LAB12 strong point..

A pair of 12" have similar SD to a single 18".
The LAB12 have 13mm excursion, about double that of a budget-price 18", so you can expect as much as 6dB more LF output from a dual LAB12 than a single cheap old 18".
That said, there are relatively low cost 18" available now with displacement similar or even greater to a pair of LAB12 that can also handle far more power, so are capable of more output, especially in the upper sub range where front loaded LAB12 performance is not great.

I don't know what type of systems "all your friends" are used to, but it would be interesting to hear what they think after hearing your system outdoors or at the usual nightclub venues.

Art

[Ionescu Florin Gabriel]

Ionescu,

The XLS 1502 is a little light for peak power, but still more than enough to burn the 2.5" LAB12 voice coils if driven with "CONSTANT" signal like a sine wave with only 3dB crest factor. Power handling is not the LAB12 strong point..

A pair of 12" have similar SD to a single 18".
The LAB12 have 13mm excursion, about double that of a budget-price 18", so you can expect as much as 6dB more LF output from a dual LAB12 than a single cheap old 18".
That said, there are relatively low cost 18" available now with displacement similar or even greater to a pair of LAB12 that can also handle far more power, so are capable of more output, especially in the upper sub range where front loaded LAB12 performance is not great.

I don't know what type of systems "all your friends" are used to, but it would be interesting to hear what they think after hearing your system outdoors or at the usual nightclub venues.

Art
[/quote
Thanks for the reply !

I own the Labs since 2016, until this year when I bought LD SYSTEMS I did my work with CROWN XLS 1502, but he did not see a -10dB signal at any event, not even a clip.

 I now attack the subs with an LD SYSTEMS DEEP2 2400X AMPLIFIER POWER:

2X1200 W RMS 2 OHMS
 2X950W RMS 4 OHMS
 2X600 RMS 8 OHMS

DAMPING FACTOR 450 /20-500 HZ 8 OHMS.

In 3 ohms it would be about 2x800 w rms, which would be ideal for LABs I don't want to exceed the power of 800 rms on each subwoofer even if it would carry the speakers, I prefer power equal to that of the speakers with a clean signal from the mixer but also from the amplifier.

The respective LD SYSTEMS has this on the front panel:

 protection
limited
 -5dB
 -10dB
-15dB
SIGNAL

 At a single event, I went with light blinking up to -10dB, and anyway I decided not to exceed the -10dB signal regardless of how big the event is and how many people there are.

For example, if I attack the amplifier with -15 dB (this being the gain from the mixer until around 9:30-10:00) and apply a 27 hz sine I have a travel of almost 10 mm, if I reduce the gain a little the travel decreases about 6-7 mm, HOWEVER, I AM VERY CAREFUL ABOUT THE PARTS I PUT THAT HAVE FREQUENCIES UNDER 30 HZ AND I ADJUST THE GAIN SO THAT I DO NOT EXCEED XMAX AT 27 HZ, AND ANYWAY NOT ON THE PARTS THAT HAVE FREQUENCIES FROM 35 HZ ABOVE I HAVEN'T REACHED XMAX, I'LL PROBABLY HAVE TO GO FROM THE -10dB TO THE -5dB TO REACH OR EXCEED XMAX, HOWEVER I WILL NOT ATTEMPT THAT.

For extra spl, WE ALWAYS MULTIPLY THE SUBWOOFERES, BUT WE DON'T GO WITH THE SIGNAL TO LIMITATION OR PROTECTION, I LIKE TO SEE GREEN ON BOTH THE MIXER AND THE AMPLIFIERS, SO NO ONE WILL SUFFER, NOT THE SPEAKERS, NOT ME.

[Spenser Hamilton]

I own four cabs based on Art's design, I've used them in bars with 300ish loud, drunk, dancing attendees for both DJ and live bands and they worked great in that scenario.

Outdoors, I would want a lot more depending on the program material.

[Art Welter]

I now attack the subs with an LD SYSTEMS DEEP2 2400X AMPLIFIER POWER:

2X1200 W RMS 2 OHMS
 2X950W RMS 4 OHMS

In 3 ohms it would be about 2x800 w rms, which would be ideal for LABs I don't want to exceed the power of 800 rms on each subwoofer even if it would carry the speakers, I prefer power equal to that of the speakers with a clean signal from the mixer but also from the amplifier.

The respective LD SYSTEMS has this on the front panel:

 protection
limited
 -5dB
 -10dB
-15dB
SIGNAL

 At a single event, I went with light blinking up to -10dB, and anyway I decided not to exceed the -10dB signal regardless of how big the event is and how many people there are.

Ionescu,

If the 2400X can do around 1000 watts into 3 ohms, -10 dB is only 100 watts.
One cabinet can only put out around 115dB at that level, if you're reading much more, your SPL calibration is probably off.

With dynamic music, reaching Xmax on peaks is no problem.
The LAB12 Xmax is 13mm, 26mm peak to peak of linear (clean) travel.
I set the grill cloth just a bit beyond that point on my cabinets, made it easy to see when Xmax was reached.

Xlim/Xmech is 22mm, 44mm peak to peak. At that excursion, the LAB12 suspension is pulled tight, past that may rip.

Using a BW24 30Hz HPF for a 35Hz Fb (excursion minima) would keep excursion roughly equal at 45Hz and 30 Hz. Below 30Hz the port unloads, excursion rises with little output increase- trying to get much output at 27Hz is a waste of power.

Art

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