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project bass reflex 2x12 with eminence lab 12
Art Welter:
--- Quote from: Ionescu Florin Gabriel on March 24, 2023, 01:44:32 AM ---
If in the long term I need below 400w for each speaker, this would mean that I should not go with the volumes at the maximum on the xti4002 to go with them in the long term, or keep them at the maximum but not give the gain from the mixer at all, because events like weddings, will they have to go 8-10 hours continuously?
I have learned that the xmax of the speakers should not be exceeded, once this is done the life of the speakers will tend to infinity.
--- End quote ---
Ionescu,
Reaching or slightly exceeding the LAB12's Xmax of 13mm is no problem, it's Xlim (mechanical limit) is 22mm.
With a BW24HP at 30-35 Hz, excursion shouldn't be a problem, but long term average (RMS) power still can be.
"Long term" can be a matter of seconds or minutes, hours are not needed to cook voice coils.
As an example, the RMS power of dynamic music when reaching peaks of 1600 watts may be under 200 watts.
If the sub content is highly compressed, it may have as little as 3dB dynamic range, (same as a sine wave) and 200 watts RMS would be reached at 9dB below the peak power.
Gain or volume settings don't limit average power, limiters do that. The Crown XTi 4002 has peak limiters, but not RMS limiters.
Art
Ionescu Florin Gabriel:
--- Quote from: Art Welter on March 25, 2023, 01:43:53 PM ---Ionescu,
Reaching or slightly exceeding the LAB12's Xmax of 13mm is no problem, it's Xlim (mechanical limit) is 22mm.
With a BW24HP at 30-35 Hz, excursion shouldn't be a problem, but long term average (RMS) power still can be.
"Long term" can be a matter of seconds or minutes, hours are not needed to cook voice coils.
As an example, the RMS power of dynamic music when reaching peaks of 1600 watts may be under 200 watts.
If the sub content is highly compressed, it may have as little as 3dB dynamic range, (same as a sine wave) and 200 watts RMS would be reached at 9dB below the peak power.
Gain or volume settings don't limit average power, limiters do that. The Crown XTi 4002 has peak limiters, but not RMS limiters.
Art
--- End quote ---
From what you tell me, now I don't know which amplifier to have, I also gave up on the xti 4002 and decided 100% on the PKN XE2500 because this series shows the impedance as well as the power in real time on the screen.
This way I can set a power of 700-750w from the menu.
I was told by the guys at that shop that the power into 3 ohms won't drop much over 4 ohms, and I might have a little over 4 ohms in 3 ohms.
BUT I WANT A VERDICT FROM YOU IF I CAN SAFELY AMPLIFY THE BASS WITH THESE AMPLIFIERS.
https://www.poweraudio.ro/amplifier_PKN_XE2500
With respect, Florin.
Art Welter:
--- Quote from: Ionescu Florin Gabriel on March 26, 2023, 03:29:31 AM ---I was told by the guys at that shop that the power into 3 ohms won't drop much over 4 ohms, and I might have a little over 4 ohms in 3 ohms.
BUT I WANT A VERDICT FROM YOU IF I CAN SAFELY AMPLIFY THE BASS WITH THESE AMPLIFIERS.
--- End quote ---
YOU CAN SAFELY AMPLIFY THE BASS WITH THE CROWN XTi 4002 AMPLIFIERS PEAK OUTPUT OF AROUND 1400 WATTS INTO A 3 OHM LOAD, BUT THE SPEAKERS WILL BURN UP IF YOU USE THE FULL RMS POWER.
Ionescu Florin Gabriel:
--- Quote from: Art Welter on March 27, 2023, 08:03:39 PM ---YOU CAN SAFELY AMPLIFY THE BASS WITH THE CROWN XTi 4002 AMPLIFIERS PEAK OUTPUT OF AROUND 1400 WATTS INTO A 3 OHM LOAD, BUT THE SPEAKERS WILL BURN UP IF YOU USE THE FULL RMS POWER.
--- End quote ---
Thanks for the reply!
And what would be the maximum rms power with which I can attack each 250-300 w speaker?
Well, in this case, LD SYSTEMS is also too powerful for the two basses, because you told me that on LD I have around 1000 w, although the people from LD declare those nominal powers at 1khz, but we don't know if they are rms.
I want to use the LAB speakers as much as possible, UNTIL THEY ARE DISCONTINUED AND CANNOT BE REPLACED IN THE FUTURE, I have had these speakers for years, 2 since 2016 and 2 since 2020, and there will be another 4 coming soon , the first 4 speakers were amplified with crown XLS 1502, and I said to have something a little more powerful and I got LD DEEP 2400X.
On the xti4002 I can go with the volumes to the maximum and give it a gain from the mixer to take the signal to -20 SO NO MORE, EVEN THOUGH I CAN SAFELY GO TO LAB URI UP TO -10 won't I do it?
Even those from crown do not specify in the manual if the powers of the xti series are rms, but let's say that it would be so.
Art Welter:
--- Quote from: Ionescu Florin Gabriel on March 28, 2023, 02:39:12 AM ---Thanks for the reply!
And what would be the maximum rms power with which I can attack each 250-300 w speaker?
On the xti4002 I can go with the volumes to the maximum and give it a gain from the mixer to take the signal to -20 SO NO MORE, EVEN THOUGH I CAN SAFELY GO TO LAB URI UP TO -10 won't I do it?
--- End quote ---
Again, your mixers gain setting does not determine average power use.
Long term "RMS" limiting with attack and release time constants of longer than 500 ms (milliseconds) should be less than the LAB 12 AES power rating of 400 watts, as AES ratings are conducted in free air, while driver's voice coils heat more when loaded in the cabinet, as the impedance is lower.
Going with an impedance of 3 ohms for the dual LAB 12, 49 volts would be around 800 watts. Half that power (400 watts) would be 34.64 volts, probably a good level for long term limiting.
This document may be of more help than I can provide:
https://www.powersoft.com/wp-content/uploads/2019/01/powersoft_TN009_LimiterSetup_en_v1.0.pdf
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