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Discussion Starter #321
When i got home from work today, nobody was home, so i got to play with the sub cranked all the way up:)

Put a glass in front of it and watched the water ripple, then after that i put a paper towel in front of it and watched it dance, after that lost its amusement i went to the kitchen, took out the ear plugs and listen to how many things i could find rattling, then did the "driveway test" hahaha, you can definately hear it, even at the mail box :D Yes, i am easily amused hahaha.

One thing i did realize while playing with this sub this afternoon, is one of the reason i can't see moving like bassththertz's video in his thread, is beacause my baffle is completely flush with the surround where on his, you can see the entire face of the speaker. If yall remember its 4 layers thick. 2 layers of 3/4 mdf that the speaker is screwed to. Then the 3rd layer was MDF to give it a sucken in look, but i decided to cover it in birch which was the 4th layer and that was another 3/4 inch. So the speaker is sitting in a hole thats 1 1/2 deep. It was one of those DUHHHH moments
 

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Discussion Starter #322 (Edited)
Those are the same photo's Notnyt posted on the Clone amp thread at the AVS.
i didn't read the whole thread the other day (its long), but when i got these pics today i thought that they looked similar if not the same to the ones i had seen. I looked at pics from the other company gisen and they definately had their differences not sure if these pics will load but i will try

There is another company, Guangzhou Hao Yang Pro Audio Manufactory, that offers it with a one year warranty
 

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The clone looks just like the REAL Lab Gruppen amp on the outside. There are a few minor differences on the inside. I saw a Lab Gruppen opened up on a Pro Audio website a couple years ago.
 

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Brandon you are bottoming out your LMS.

From the 13 seconds I could see, it looks like you have too much infrasonics there and not enough upper bass.
You need to apply a more agressive high pass filter before it is too late.

I have somehow managed to put both acceleration and deacceleration dents in my cone, and dents on the coil too.
It was a 3 second burst of 30hz with 4-6kW's behind it that did it to her. :dumbcrazy:
This is what mine looks like now, and this is 'after' I pushed the dents back in.

 

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Discussion Starter #325
BassThatHz said:
Brandon you are bottoming out your LMS.

From the 13 seconds I could see, it looks like you have too much infrasonics there and not enough upper bass.
You need to apply a more agressive high pass filter before it is too late.

I have somehow managed to put both acceleration and deacceleration dents in my cone, and dents on the coil too.
It was a 3 second burst of 30hz with 4-6kW's behind it that did it to her. :dumbcrazy:
This is what mine looks like now, and this is 'after' I pushed the dents back in.
I'm glad to see you chime in. If you have read and of this, you will know I based by box originally off you and island1000 and then later seen sub_crazy's build and got ideas from his.

My question is, if it is bottoming out, then why isn't it still doing to at a little over half gain on the amp? That's where it was doing it at 120v. Now it's at 3/4 gain on 240v?

I think building the box was tge easy part, this electronics stuff is the stumper.
 

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I don't know what to say . . . . .
The LMS and Ultra are rated for 2500 watts . . . . .
"4-6 KWs" . . . . ?
where do you find that kind of power?
 

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Discussion Starter #328 (Edited)
robertcharles123 said:
Island,

He is running an itech8000 from what I remember.
Yes he is, that's why I originally brought it up in this thread

Maybe I don't need that much power afteralll.... That would definitely ruin ur day
 

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You can run more power into a LMS Ultra but you have to have a HPF in place to keep that power in check. Just an example is the clone amp, with 4400 watts into a 4cuft enclosure make sure and put a 11hz HPF in place to keep your LMS from getting those nice dents. With 2500 watts and no low end boost you can get away with no HPF since you don't run out of excursion till about 5hz. Drop the size of the enclosure to 3.5cuft and you can apply 3000 watts safely.

TC makes the best subs around but they have there limits. I made a nice dent like BTH on a TC3000 (Now Axis) 15" that I ran too much power into. When it bottoms hard you will jump like I did, not a good sound at all. I learned my lesson before I got a pair of LMS Ultra's which were run with a HPF every time even though I was running less than 2500 watts as my low end boost was aggressive.
 

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Discussion Starter #330 (Edited)
sub_crazy said:
You can run more power into a LMS Ultra but you have to have a HPF in place to keep that power in check. Just an example is the clone amp, with 4400 watts into a 4cuft enclosure make sure and put a 11hz HPF in place to keep your LMS from getting those nice dents. With 2500 watts and no low end boost you can get away with no HPF since you don't run out of excursion till about 5hz. Drop the size of the enclosure to 3.5cuft and you can apply 3000 watts safely.

TC makes the best subs around but they have there limits. I made a nice dent like BTH on a TC3000 (Now Axis) 15" that I ran too much power into. When it bottoms hard you will jump like I did, not a good sound at all. I learned my lesson before I got a pair of LMS Ultra's which were run with a HPF every time even though I was running less than 2500 watts as my low end boost was aggressive.
I guess I'm just going to have to get a different eq for this. Now I know what u where trying to tell me, until today, I didn't quite understand
 

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sub_crazy said:
You can run more power into a LMS Ultra but you have to have a HPF in place to keep that power in check. Just an example is the clone amp, with 4400 watts into a 4cuft enclosure make sure and put a 11hz HPF in place to keep your LMS from getting those nice dents. With 2500 watts and no low end boost you can get away with no HPF since you don't run out of excursion till about 5hz. Drop the size of the enclosure to 3.5cuft and you can apply 3000 watts safely.

TC makes the best subs around but they have there limits. I made a nice dent like BTH on a TC3000 (Now Axis) 15" that I ran too much power into. When it bottoms hard you will jump like I did, not a good sound at all. I learned my lesson before I got a pair of LMS Ultra's which were run with a HPF every time even though I was running less than 2500 watts as my low end boost was aggressive.
With that being said, what advantage is there at all to having more power?
 

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With that being said, what advantage is there at all to having more power?
Advantage is you never clip the amps. You have a clean source of pure power. You have enough headroom to handle all the transients that some of the newer films sound sources have. Example- download the Danley fireworks demo. Let it rip and you will know what I am talking about. Make sure you set you levels correctly and listen to it at a moderate level before giving it the juice.
 

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The amp has to have a reserve of power to retain the excellent distortion characteristics of ANY driver.
A driver can draw huge amounts of power when the system is EQd on the lower end. When the amp is supplying a 1000 watts @ 35Hz and a note of 15Hz hits the system, the power requirement might reach 4000 watts to maintain the same volume being ask for by the EQ.
When the voice coil leaves the area of x-max and heads towards x-mech (mechanical limits) the distortion figures go outta sight. That's ONE of the reasons the LMS series of drivers are so excellent. The LMS has a HUGE voice coil and can travel almost it's full length before leaving the area of low distortion.
 

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Also, you need to use the modeling software to see what the system should do at what signal level and whether a HPF is needed. Remember, it takes twice as much power to get a 3Db increase in SPL. So, going from 2400 watts needs to be 4800 to get a 3 Db increase. That is why I told you to get a SPL meter.

Remember, you can only get a finite level of performance out of your sub regardless of which amp and crossover or filter or whatever you apply to it. That said, If you put a different amp on the system with lower output, you will probably notice a difference in the transients, but not much so in the actual overall volume. I would use a SPL meter to show this to you if we were logistically closer. So, even if you went to a larger amp, you would probably see very little difference in output. The amp you have is a serious amp and should do all that you need for the one driver, upgrading usually requires both more drivers and more amps. Remember, you need to go from 1 to 2 to 4 to 8 to 16 drivers to see noticeable differences in SPL. That is the reason why I went with 4 drivers. I wanted opposed systems and more than one cabinet, but to get better performance from what I have and ony a little at that, I would need to have another complete set of everything and only would see a small increase if any at all. I have used just the one cabinet and noone could tell the difference, but it showed up in the SPL readings and the output was about 3 Db lower.
 

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Secrets of Amplifier and Speaker Power Requirements Revealed
As audio/video hobbyists, most of us grew up thinking that if we have an amplifier with 50 watts of rated output power into 8-ohm speakers, and that combination produces reasonably clean and loud music, then by doubling the amplifier power to 100 watts per channel, the system would then play twice as loud. Many readers likely still believe that. Not so.

Although it's not the easiest thing to comprehend, doubling the amplifier power does not double the loudness. In the above example, the sound from the speakers would not be "twice as loud"; it would only be "a little louder," an increase of 3 decibels. How loud is that? Hearing tests with large groups of people have revealed that a one-decibel (1 dB) change in loudness is approximately the smallest audible step that the average listener can detect, so an increase of 3 dB most listeners term "slightly louder."

So why doesn't that 100-watt amplifier always sound twice as loud? Because the acoustic decibel--the decibel (dB) being the unit of measurement used worldwide to quantify the acoustic loudness of sound--has a peculiar relationship to amplifier power output measured in electrical watts. That relationship is called "logarithmic." If that word gives you an instant headache (nightmares of high-school math), then here's a simpler explanation:

If a sound gets louder by 3 decibels or "slightly louder," it takes twice as much electrical power from your receiver or amp to produce that modest increase. Therefore, a 100-watt amplifier will produce sound only slightly louder than a 50-watt amplifier.

Incidentally, if you'd like a kind of immortality, be terribly clever and work out a system of measurement. It may be named after you. The "decibel," one tenth of a bel and named for Alexander Graham Bell, recognizes his contributions to the understanding of sound. Likewise, we have to thank James Watt, Georg Simon Ohm, and Heinrich Hertz for their contributions to the industry. And then there's the Lofft, a measurement of neighbors' tolerance to testing new speaker systems . . .
So far, so good. But what if it's party time, and you're listening to music "very loud," a level defined as about 90 dB Sound Pressure Level (SPL), and your speakers are gobbling up swings of 15 to 20 watts per channel on those musical peaks.

Drink in hand, you advance to the volume control on your receiver thinking, "I'll just crank this up to make the music twice as loud," and you turn up the volume control until there's a 10 dB increase in the sound level. Now your party-time goal of "twice as loud" will make huge electrical demands on your nice little multi-channel receiver or power amp. The receiver must deliver ten times as much power to double the subjective loudness. Between 6 dB and 10 dB is double the volume level, where 6 dB is four times the power and 10 dB is 10 times the power. In the aforementioned example, the amp must produce 150 to 200 watts per channel for those peaks in loudness. Therefore, every 10-dB increase in acoustic loudness--from 80 dB to 90 dB, or 90 dB to 100 dB--requires ten times as much electrical power in watts.

That's all very well if you have a monster amplifier or multi-channel A/V receiver with huge reserves of power output (most of us don't). If not, watch out. Your receiver or amp may "clip" or distort (or both), which will put a clamp on the output of the amp. When you push your amplifier into overload or "clipping," several things may happen. First, the top and bottom of the waveforms (representing the audio signals) are clipped off, generating distortion. Next, the amplifier's protection circuits are activated, removing those portions of the signal that are causing the overload, generating distortion. And finally, the amplifier's power supply may fluctuate according to the demands of the music signals.

Not everyone is affected by this scenario, of course. Some people (increasingly few, it seems) don't listen to loud music. They like background levels, and with average speakers, background levels demand 1 watt or less of amplifier power. Or they may have very efficient speakers (Klipsch, Cerwin-Vega, Tannoy, and the like) that will play extremely loud using modest amplifiers, the trade-off being a very large degradation in tonal accuracy, a definite harshness, and a complete loss of off-axis performance that accompanies horn-loaded designs. But in many situations, speakers will be damaged and distorted sound will offend many ears.

No discussion of decibels, acoustic loudness, and electrical watts is complete without an explanation of loudspeaker "sensitivity." (Another way to define a speaker's sensitivity is to look at how efficiently the speaker converts electrical power, in watts, to acoustic sound output in decibels.) Let it be said in a general way that speakers are not very efficient or sensitive devices. They need a lot of electrical power input to produce relatively little acoustic output. Nevertheless, speakers do vary quite a bit in sensitivity.

To determine a speaker's sensitivity, we feed the speaker with 1 watt of amplifier power, using a test signal of pink noise, and measure in decibels how loud the sound is at a distance of 1 meter (about 3 feet). A lot of domestic hi-fi speakers measure in at about 89 or 90 dB SPL at 1 meter. Larger speakers, with bigger woofers and more drivers, typically produce greater acoustic output; smaller bookshelf models have to work harder, and their output is typically less, often between 86 and 88 dB SPL at 1 meter.

Placing the speaker in a room helps (the walls, ceiling, and floor reflect and reinforce the speaker's sound), adding about 4 dB to its output. For example, a speaker like Axiom's M80ti has a measured sensitivity in an anechoic chamber of 91 dB SPL at 1 watt at 1 meter. But putting the M80ti in a room raises its sensitivity rating to 95 dB SPL at 1 watt, 1 meter. A 95-dB sound level happens to be "very loud," as most of us would subjectively describe it. And it is--from 3 feet (1 meter) in front of the speaker. But let's move our listening seat back twice as far, to 6 feet. Guess what happens? We instinctively know that sound gets weaker as the distance from the source is increased, but by how much? A formula called the "inverse square law" tells us that when the distance from the source is doubled, the sound pressure weakens by 6 dB. Among sound engineers, there's a common saying: "6 dB per distance double." So at a 6-ft. distance, the M80ti is now producing 89 dB. Now let's double that distance again to 12 feet, a fairly common listening distance. The speaker now produces 83 dB, which isn't all that loud at all. And if you sat 24 feet away, a not uncommon distance in big rooms, the speaker would produce 77 dB SPL.

But what about stereo, I hear you shout. Here's another oddity of loudness and the decibel. When one speaker is producing a level of 90 dB, adding a second speaker playing at the same level only increases the overall loudness by 3 dB! (The loudness does not double!). So the two speakers in stereo produce a loudness level of 93 dB.

So adding a second M80ti will raise the loudness at 12 feet from 83 dB to 86 dB. And don't forget we're still using 1 watt of amplifier power output into Axiom's most sensitive speaker. But how loud are real-life instruments, orchestras and rock bands? Now, while 86 dB SPL is "fairly loud," it's not nearly as loud as what you might hear from a good seat at an actual rock concert or from an orchestra or pianist in a concert hall. A solo grand piano can reach peak levels of 109 dB SPL, a full orchestra and chorus in a concert hall will measure 106 dB, and a rock group, 120 dB SPL. Now let's try and get our peak speaker sound levels to 96 dB, "twice as loud" as our 86-dB listening level. That isn't that difficult because right now we're only using 1 watt per channel to drive the M80ti's to 86 dB. So we'll need ten times as much power, or 10 watts, to reach 96 dB. Big deal. We've got lots more.

But things begin to change, and rather dramatically. Let's push the M80ti's to what we might experience from a solo grand piano, 109 dB. We're at 96 dB with 10 watts per channel. Let's go to 106 dB. So that requires 10 x 10, or 100 watts. Close, but not quite there yet. Just 3 dB more. Remember, we have to double the power for a 3-dB increase in sound level. So 100 watts becomes 200 watts. Yikes! Our receiver has only 110 watts maximum output! We've run out of amplifier power! And what about the rock concert? Let's lower our expectations and aim for 119 dB. Going from 109 dB SPL, which needs 200 watts per channel, to 119 dB SPL (get out your ear plugs) is another 10-dB jump and--you do the math--that requires 10 x 200, or 2,000 watts per channel!

From all this you can see the huge power requirements inherent in reproducing real-life acoustic sound levels in average or big rooms. The M80ti's are tested to levels of 1,200 watts of input power so they come very close. But the truth is that if we are seeking real-life acoustic sound levels in our listening rooms, there's a very persuasive argument for very large, powerful amplifiers. And if your speakers are less sensitive (and many are), then the power demands rise even more dramatically. Sizeable rooms and greater listening distances will also increase power demands tremendously.

And what many of us don't realize until we hear it, is that clean undistorted loud sound often does not sound that "loud." The key here is that in most or our home listening, there are small amounts of distortion caused by a lack of dynamic headroom (but more on that next month). It's the distortion that makes it sound "loud" in a domestic setting. To remove those distortions and increase dynamic headroom relates to even more power. We've become accustomed to accepting some distortion with our reproduced music, because all amplifier's distortion ratings gradually increase as they approach their output limits or slightly clip the audio signals. When that happens, we turn down the volume, because distortion starts to intrude on our listening pleasure, and it sounds "too loud."

The lesson in all this is that you can never have too much power, and that big amplifiers rarely damage speakers. Little amplifiers driven into clipping burn out speakers. In the scheme of high fidelity, that last barrier to realism is having enough power and being able to approximate real-life loudness levels.

Brandon, give this a read and maybe this will clear things up a bit.

Good luck,

Robert
 

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With that being said, what advantage is there at all to having more power?
Bragging rights?:bigsmile:

Really were you need to power is when your boosting the signal down low to extend response but it's a balancing act. A lot of people talk about having headroom and that's fine as long as you control it. I have run WAY more than I should into the LMS but have always adjusted my HPF to compensate, low bass is what kills most subs.

2500 clean watts of power is more than enough for the LMS Ultra in a 4cuft sealed enclosure. You don't need to use a HPF in that situation but you will be missing out on lower bass. The reason you will be missing out is that a sealed enclosure needs boost down low to extend the response. This means you are turning up the volume at a certain frequency and every 3db's of boost is a doubling of power that's needed. This means if you need 1000 watts to hit 98db's at 20hz and you want 101db's then you will need to add a 3db boost at 20hz and 2000 watts to achieve this. If you want to hit 104db's at 20hz then you need 4000 watts and so on. The problem is the physical limitations of the driver, if there was no limitations we would just run as much power as we could afford and be done with it.

That is why programs like WinISD are so important as they show us the simulations based on what we want to do.

Here is the LMS Ultra, both in 4cuft sealed, red is 2500 watts and blue is 4400 watts and no HPF is used:



You can see that with 2500 watts you don't run out of excursion until about 5hz, with 4400 watts you run out at 21hz so no War of the Worlds for you:nono:

Here is the same sim but this time I added a 11hz HPF to the 4400 watts:



Now here is what the SPL would look like with both 2500 watts and 4400 watts with a 11hz hpf in place:



There are significant gains, at 30hz and above which is almost twice as loud, you just lose output at 11hz and below. You have to give up one to get the other unless you just bombard your room with enough subs and amps to not have to compromise.

These sims don't take into account the added boost I talked about before which is needed for sealed designs. With a boost added to the 2500 watt sim a HPF would need to be employed to control excursion. I believe that is what the Anti-mode does when you use it's "lift 25" function which employs a boost at 25hz along with a HPF if I remember correctly. I would have added more sims showing the affect of the boost but I have run out of time.
 

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sub_crazy said:
These sims don't take into account the added boost I talked about before which is needed for sealed designs. With a boost added to the 2500 watt sim a HPF would need to be employed to control excursion. I believe that is what the Anti-mode does when you use it's "lift 25" function which employs a boost at 25hz along with a HPF if I remember correctly. I would have added more sims showing the affect of the boost but I have run out of time.
I was reading up on the linkwitz transformer earlier today and I'm a bit confused as to it's role in comparison to an Anti-mode type product.

The article I read made it seem like it was all the subEQ one would need, except for a HPF in the case you have more amp than sub.

I guess my question is, when I get my dual LMS setup is incorporating linkwitz in picture a good idea? Why?

If I have a Anti-mode, SMS-1, XT32 or some other way to EQ my subs, would linkwitz be redundant or unnecessary?
 

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An LT circuit is something different and a lot more complicated than what the Anit-mode or SMS-1 add to the low end, XT32 will generally not boost below the subs F3 point. I generally know what it is and used to own a Bassis which is a variable LT circuit.

The Linkwitz Transform is basically a set of EQ's that are calculated to Transform the Q and FS of a given alignment.
Lets say you design a sealed enclosure with a particular driver but you want to keep the size small. You decide on an enclosure that is 2cuft but that gives you a box Q of 0.95 which naturally will mean a peaky upper bass and a quicker roll off down low. With an LT circuit you can re-shape the box Q and FS so your box with a Q of 0.95 and FS of 45hz can be transformed into a more optimal box Q of 0.7 and FS of 20hz. It is a lot more complicated than that but I think that's the basics of it.

You can make a LT circuit from what I have heard with the MiniDSP. I don't have any experience with it though.

With all the advanced room EQ's now like XT32, I don't think an LT has the same usefulness as it once had. You still need to add a boosting EQ like the SMS-1, Behringer FBD, DCX-2496, MiniDSP or any others but XT32 has the ability to re-shape the peaky response that a less than optimal box Q will produce.
 

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Discussion Starter #339 (Edited)
So i was reading the responses today in this thread and was looking up the different EQ's mention. I kept thinking the Anti-mode has had way to many good things written about it and reviews, there has got to something i am missing. Thats when i had one of those sudden "well DUHHHHH :duh: :duh:" moments. This anti-mode has different filter settings! I have been running it flat. I feel like this could be one of those total "NOOB" mistakes. If it is, feel free to do one of these numbers ---> :rofl:

So which one of these modes, would best suit my needs. (my guess was lifting 15-25hz)

(edit) Listened to the 15-25 hz and the 25-35 Hz modes. Neither stopped the Pop noise completely. I watched the amp "clip" and "fault" lights, neither flashed during that scene when the noise occured. I will say however that the 25-35 hz mode sounded much better overall during that passage.



4.2. Lifting EQ
The Lifting EQ button rotates between three equalization modes of AntiMode
8033 and stores the setting if held longer. A brief sound is heard from subwoofer when the
setting is stored.

4.2.1. “Flat”
The first lifting EQ setting is no lifting, “flat.” Neither of the LEDs 'LIFT 25' nor 'LIFT
35' is lit. In this setting, the target response is flat from 5 to 148 Hz.

4.2.2. Lifting 15-25Hz
In lifting 15-25 mode, when the LED “LIFT 25” is lit, the AntiMode will boost
frequencies between 15 and 25 Hz (max. 7dB at 20Hz). This will also activate digital
infasonic filter, which will filter out frequencies below 10Hz, that can be dangerous to
ported subs without proper protection.

4.2.3. Lifting 25-35Hz
Third mode, lifting 25-35
similarly boosts range 25-35
Hz (max. 7dB at 30Hz) on
subwoofer. This mode is active when the LED LIFT 35 is on. This will also activate
digital infasonic filter, which will filter out frequencies below 10Hz.
It is easiest to find out which of the lifting settings gives best result by simply
listening. Lifting below 35Hz could be useful for reflex subwoofers, which have port
tuning above 30Hz, but the lowest frequencies are attenuated to the listening
position. With music, 'flat' is probably the best option, as it gives the most accurate
transient response. Lifting below 25Hz could be applicable for a large subwoofer,
which has 6dB
point too high because of suboptimal positioning.
 

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If the amp is not reaching full power and clip lights are not coming on, I would run it in stereo to see if both channels do it. Is the amp bought used? I would definitely use one channel and then the other to see if it happens.
 
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