It doesnt seem like there would be an audible difference just because there is a SLIGHT cone area advantage.

Well, ~25% per cone could be a differnce once you start to multiply them.

Sure it could all add up, but for the average consumer, having a 10" square driver vs a 10" circular driver, the difference would be less then 25% and likely not audible, tuning the enclosure / raising net volume would be more noticeable

And were not even talking about the actual sd of the driver, this number varies from model to model. And by your standards of gaining more output the driver could just have more xmax and thus more displacement. But theirs a limit to everything and a point to where it's not worth it, everything has it's trade-offs

A 25% increase doesn't sound like much, until you realize there's only about a 35% difference in cone area between a 10" circular driver and a 12" circular driver. So you are almost gaining as much cone area by switching from a circle to a square of the same nominal size, as you would from exchanging a 10" circular driver for a 12" circular driver.

In terms of output, a 25% increase in displacements equates to approximately a 2db increase in output (at equivalent excursion levels). Definitely an advantage, as well as audible.

Why do you need one?

i want to give my amp the most volts. that is a good thing right?

No, in 99.9% of cases it's completely unnecessary. We actually had this conversation in another thread. If you wish to know the reasons why it's unnecessary, please READ THIS THREAD (click me)

As M5 pointed out, in addition to being completely unnecessary in almost all situations anymore, it's also possible to over drive and clip the preamp input stage of the amplifier.....which is bad.

The only time anyone would need or benefit from a line driver is in the very few instances where there is a very specific "problem" that needs fixed.....and pretty much all of that is outlined in the above linked thread. And actually, introducing a line driver could be worse for the system overall if used when not absolutely necessary as it introduces the potential for additional noise and ground loops into the system.

I could be wrong, but if I had to guess I would say that is probably just a typo.

That said; it doesn't really matter whether the subwoofer is wired in-phase or out of phase, as long as you wire it for the best sound. Ideally you would try it wired both in-phase (positive to positive, negative to negative) and out of phase (as the diagram shows) and see which sounds better anyways.

I do want to point out this article, no matter how poorly the whole test was conducted the results still prove my point. .... But the end results are very significant, the differences between MP3s and lossless were detected by all listeners in the test.

Really, you can't make the first statement, then follow it up with the second statement. The quality of the test and methodology has everything to do with the results. If the test and/or methodology are invalid, so are the results.

From what he briefly mentioned of his test methodology, I don't see where any real meaningful conclusions could be drawn.

I do feel that differing class amplifiers can have a different overall sound, and can be distinguished while moving.

A story for another day.....but I would disagree.

Dave didn't give him T/S (of course). Also didn't use LMT coils, just a flat wound aluminum 4".

LOL.....not a snowballs chance in hell that sub is worth the OP (or anyone else) considering then.

Asking LMS prices ($800) for a non-LMS driver, with no T/S parameters, and performance that is not going to be anywhere remotely close to the original driver ?

I'd offer him $200 for the motor itself, then buy the replacement top assembly from PE ~$550. Then you could have an actual LMS Ultra for $750

Personally I'd never recommend a "hybrid" sub unless the seller were able to supply some pretty descriptive details about the driver. What you listed there is pretty meaningless on the whole. Is he able to provide you T/S parameters for the driver? What is the length of the coil and gap height? If he can't answer these basic questions, it would be a no brainer to pass on the "deal" without hesitation.

Also, unless PSI used the LMT coils, which I don't believe he can as the patent is owned by TC Sounds......it would no longer be an "LMS" subwoofer as the coil is what makes the driver "LMS", as "LMS" denotes use of the "LMT" coil. And the "LMT" coil is part of what makes the driver what it is as it improves BL linearity.

Considering his price is only $100 off the price of an LMS Ultra from PE.....I'd just wait for PE to get more stock rather than try to save 10% and get a cobbled together hybrid.

Personally I don't see the appeal of a "hybrid" driver. The "hybrid" driver more than likely doesn't have anywhere near the amount of engineering time invested as the original product did. Chances of a "hybrid" being a superior driver to the original are generally going to be very low, especially when most of the time people can't even supply something as basic as T/S parameters.

It's almost always going to be a better idea to look for something with original parts, which is going to operate as it was designed to operate than purchasing a "hybrid" subwoofer.

Some headunit's "subwoofer" outputs double as a "non-fading" output ,which would be stereo.

I would check and make sure none of the speaker wires are shorting out. Including the wires in the wiring harness.

Is this a new unit, or something that just started happening?

Yes, it's possible for the RCA outputs to work even if the internal power amplifier does not, depending on what's damaged.

In addition to what Helotaxi said.....it also depends on your music selection....not a whole lot of "mainstream" music includes information in the sub-30hz range.

I've heard great things about the Hifonics Zxi60.4 + 1k

It's Maxxxsonics new line for Hifonics... i think even brad said they were stout ICR.

If you were referring to me....I believe at the time I was simply stating that no one (at the time) could actually demonstrate that the new lineup was overrated, as that particular thread was littered with people putting them down with no actual information to support that position. You know.... "Yeah but Hifonics is overrated, I'd rather have a Sundown"

It was just one of my "you guys need to think before you speak" sermons

You're welcome

Just to know is this a lie?

http://www.rockfordf...php?p_faqid=806

Down where it says "you paid for 1000 watts... but what did you get?"

For the most part.....yes. They are assuming that another brands "12awg" wire is actually equivalent to "16awg" wire, and that another brands "4awg" wire is actually equivalent to "8awg" wire, which is more than likely not going to be the case unless you bought flea market brand wire.

That said....yes, there is going to be some voltage drop across the wire. Most wire gauge charts that recommend X gauge wire for Y amplifier power is making that recommendation based on expected voltage drop for a given length of wire. The goal is to have less than .5V of voltage drop across the wire. Having greater than .5V drop is generally considered to be unacceptable.

BCAE1 has a calculator HERE for speaker wire.

Word of caution: It's impossible to "compare" two speaker sets in two different vehicle, with two different installations, etc. The setup of the Focals might have just been really bad. The MS-8 is a good unit, but it's not magic or a miracle worker. The sound of the install is still subject to the quality of the installation and setup, and really there are various ways to "manipulate" the tuning of the MS-8.....so just because they both ran an MS-8 doesn't mean that the tuning quality was equal. It sounds like you already understood this for the most part given your comments, but it still needed said just for clarification.

We can't tell you which you'll like better. But,

What is your budget?

What are you using for amplification?

Do you have the knowledge/ability to go active?

What were you looking for advice on exactly?

I would try hitting up Grizz Archer over on DIYMA. He works @ Epsilon. Might be able to help you out with either a schematic or what needs to be done to bypass the circuit.

Besides, the SAZ2k, for example, puts out over 2400 watts at 12.5V in Jacobs test,

Those results are misleading. Don't pay any attention to them.

Any way you could elaborate on this?

For starters, he didn't do anything to measure distortion. For all we know the signal was clipped to all hell, or he was operating the amplifier at a high distortion level.....both of which would be of no use to someone using the amplifier for musical "daily driving" purposes. A lot of people try to compare the figures in Jacob's test to the amplifiers rated power and quickly exclaim that Sundown is significantly underrated......what they don't account for is the fact that rated power is measured at a specified distortion level, and Jacob's test doesn't address the amount of distortion the amplifier was operating at during his tests. So no, someone can not expect to toss a SAZ2K in their vehicle and have a usable 2400+ of power output as the distortion at that level of power may be substantial, or the signal might be clipped, etc. You can get a hell of a lot more power out of any amplifier if you ignore distortion, as Jacob did.

Second, we don't know the accuracy of his test equipment.

Third, he used a reactive load (the loudspeaker). This is a quote I found on another site that sums it up much better than I could:

You must use a non-reactive load, however, when testing an amplifier for power output, because the power measurement is only accurate into a purely resistive load. If you are using a reactive load, the actual output power is equal to the voltage multiplied by the current, multiplied by the cosine of the phase angle between them. Highly inductive or capacitive loads can fool you into thinking you have a higher output power than you really do, because, even though the voltage is higher, the current is not in phase with it, so the real power output cannot be accurately determined by measuring the voltage, squaring it, and dividing by the specified impedance, you must multiply by the cosine of the phase angle. A purely resistive load will have the voltage and current in phase, so the cosine of the phase angle is equal to 1, and can be ignored.

I have probably $75 worth of the Dayton branded RCA's and y-splitters from PE out in the garage....they are too inflexible, so I couldn't use them in my install. I wouldn't recommend them for installations that have tight angles near the connectors.

That said; they are great quality build wise so if they do fit your install they are a good option. But the inflexibility is one of the downsides to a cable primarily designed for home use instead of car use.

This thread took an unpredictable turn.

Anymore I'm not sure if some of these comments are relating to the sub, or a BJ.

Nice looking sub.

And look luck to you all on the BJ front as well.

No experience with any of those.

Elf Audio also has the Arc Mini amplifier boards. They only have the 2-channel on their site but I believe they offer all 3 models. There was a long debate on DIYMA about whether or not they used inferior parts to their Arc counterparts. At one point someone owned them both and posted internal shots of both amps, although I honestly can't remember the results. Moral of the story is that I'd expect the Elf and the Vibe to be similar.....so if the Elf used lesser quality parts than the Arc's, I'd expect the same from Vibe.....and if you can find the Elf's for less than the Vibe's, that could be another option for you as well.

Another option would be the new Zed line, one each of the Leviathan and Kronos. Fits in your budget and you'd have 10-channels of high power amplification in just 2 reasonably sized chassis. Or if you really wanted flexibility go with two Leviathans. That'd give you 12 channels to play with, but it'd basically hit the cap on your budget.

Proper setting will give you more amplifier headroom than if you had the gain setting mismatched. This doesnt make the amplifier make for power.

If there is no more power then there is no additional headroom. Headroom is power available beyond what is needed for normal sound production. If the amp is capable of producing 200W and the normal power used on music is 50W you have 6dB of headroom in the system. Gain setting is not related to headroom. Gain setting is not related to how "hard" the amp works. Setting it correctly allows you to get full power from the amp regardless of source voltage. Having it set incorrectly does one of two things. If it is set too high, you have a very limited range of usable source volume control before the amp is driven into clipping. If it is set too low, you simply will never get full power from the amp. It is really that simple.

Just to reinforce this......amplifier gain setting has nothing to do with headroom.

So your saying that the output voltage a HU puts out has NOTHING to do with the output of the speakers?

Nope.

So then what is the purpose of an line driver?

Mainly to allow the manufacturer to get more money out of your wallet and into theirs.

Some of them also include other "useful" features, such as some equalizer bands and such, which in certain circumstances may be of benefit to the system (note that it's the other features and not the "line driver" feature that would be the primary benefit to the system in this case).

But other than that the only, ONLY, benefit to a higher preamp voltage is if you are experiencing noise in your system that can only be eliminated with either a lower gain setting or higher signal voltage level, and this is rarely the case. As helotaxi said, a higher preamp voltage improves the SNR of the signal transfer and allows for a lower gain setting. Some amplifiers can have audible noise with a high gain setting, so increasing the preamp voltage allows the user to lower the gain and eliminate the noise issue. But with modern amplifier designs, this is pretty much a non-issue in most situations. Or if there is a high noise floor during the signal transfer, increasing the voltage of the signal increases the SNR of the signal. But again, this is rarely the case and in most cases routing signal cables away from noisy areas in the vehicle will solve the issue.

I'm confused, so by the installer wrongly adjusting his gains after installing a higher rated HU, the output is louder until he readjusts his gains?

The gain (or input sensitivity) knob is on the amplifier to allow the amplifier to output full power with a wide range of input voltages. The gain knob basically adjusts the level of the input signal so that it will effectively "see" the same amount of input voltage. Rather you start at 2V or start at 8V, if you properly set the gain the amplifier won't know the difference and it will output the same amount of power in either circumstance. If you properly set the gain, there would be no difference in output levels between a 2V headunit and an 8V headunit.

Now, what happens if you start with a 2V HU and then switch to an 8V HU but don't readjust the gain? The amplifier is set to adjust the input signal based on an expected 2V of input signal. But you are now sending it 8V, so it's not properly adjusting the level of the input signal. It's receiving a lot more than it was expecting to see. As a result, it's going to output more power because it's letting too much of the input signal pass through to the amplification stage. This means the amplifier is going to output more power with the gain set to the 2V setting and an 8V input signal than it would with a 2V setting and 2V of input signal. In order for the amplifier to properly adjust the input signal for the higher 8V input signal, the gain would need to be reset to the 8V setting.

Now you might be thinking "Hey, cool, if I don't readjust the gain that means I can get a lot more power out of my amplifier then, right?" No, this is bad. This is bad because the amplifier is going to amplify the input signal too much and clip the signal it is outputting to your speakers or subwoofers. This clipped signal contains more average power than the amplifier operating below clipping (with a properly set gain), and as a result could potentially damage your speakers or subwoofers depending on the circumstance.

Why can't they be? If you know your setup up and down, you can hear 1-2db difference.

Example. I tested 3 amps. 500 watt 750 watt and 1500watt. Same sub same car same day.

First run with 500 watt amp. 142.

2nd run with 750 watt amp 143. And it was a BIG difference to me.

Third run, with double power was 144.5. And another BIG noticeable difference.

I could go pull up the old post on ca.com with pictures and proof if needed.

at the same frequency all three times?

also.. if any of those tests were clipped.. or clipped more than the other.. a square wave will produce peaks in MANY frequencies which will cause your ear to perceive a sound audibly louder than what it might be because of frequency shift.

Same frequencies, I was burping, rolling volume. All these numbers was round abouts, not 100% sure on the exacts until I pull up my old thread. Don't know about clipped, didn't scope them or clamp, so have no idea of actual power.

Point is, I sat there and hear differences that wasn't 3dBs apart.

I know the theories. I know power compression. My point is, I know what I heard.

You know what you heard......but do you know why you heard it? Unless you can answer the question why, and exclude every possible explanation that it was a reason other than what you are suggesting....then you didn't test anything, you can't prove anything, your results aren't valid, and you can not state anything definitive as an explanation. The reason you noticed a difference, even a "big" difference could be reasons completely unrelated the decibel difference of the fundamental frequency. Resonances, distortions, knowing the differences while listening, etc etc etc (and a dozen more things I didn't mention) are all are going to affect the results. Hell, the very fact that you rolled the volume makes your "test" useless.

And I'm not arguing the 3db point. I don't agree with the 3db thing either. But, in another thread you said you could hear .5db differences, in the subbass, at a level of 140db+. THAT is clearly beyond the limits of human hearing. The differences that the OP would experience would be well below 1db, THAT would be clearly inaudible and you tried to argue against that point.

FYI, "I know what I heard" isn't a valid argument. It's been used time and time again by various people arguing various points for various reasons. The simple fact is, that's not a valid defense or explanation. The only means of "proving" this is by means of a scientifically valid test in controlled conditions administered by someone with the training to properly conduct such an experiment.

And what you are describing.....doesn't qualify as any of the above.

Does his brother playing him music with random volumes on a cassette player underwater count?

Only if he's using boobies as headphones. Mainly because I wanted an excuse to throw boobies into the conversation. And I think we can all agree, Boobs are awesome.

Why can't they be? If you know your setup up and down, you can hear 1-2db difference.

Example. I tested 3 amps. 500 watt 750 watt and 1500watt. Same sub same car same day.

First run with 500 watt amp. 142.

2nd run with 750 watt amp 143. And it was a BIG difference to me.

Third run, with double power was 144.5. And another BIG noticeable difference.

I could go pull up the old post on ca.com with pictures and proof if needed.

While I can't agree with your subjective analysis of "big difference", let's just look at the numbers.

You went from 500w to 750w and gained 1db. You should have gained 10*log(750/500) = 1.76db, so you had .76db of power compression.

With double the power, you only gained 1.5db, you should have gained 10*log(1500/750) = 3db. So you had 1.5db of power compression.

How much power compression do you think is going to be occurring with 9000 watts on a pair of subwoofers?

Oh, and I don't care about your personal subjective analysis of the "audible differences". If you want to prove anything at all with regards to your ability to discern audible differences, go have a properly conducted, scientifically valid test conducted in a controlled environment by someone with the proper training in administering such a test.

If you say it'll maybe gain on the meter, then I have to say it'll maybe have a audible difference. You can't give a 100% correct answer cause you have no properly tested the setup on hand.

And you would be wrong. 1.1db is the maximum difference. This is a fact of acoustics. It's been tested. It's been verified. It can be reliably predicted. You might not like this. You might think it's bullshit. You would be wrong. Real world, the increase will be significantly less than predicted because of the real world issue of power compression. I don't need to test anything myself to know this. This has been tested and verified by people far more intelligent than myself for decades.

So realistically we are looking at an increase that is much less than 1db. And based on even a cursory understanding of the human auditory system, it can reliably be predicted that this small of an increase will not be perceptible by human ears. Again, you might not like this. You might think it's bullshit. You would be wrong. It's been tested. It's been verified. It can be reliably predicted.

Everybody lately has been saying you don't ever need extra power. 2500 watts is as good as 3500, so why does all the people buy bigger instead of smaller? For no gain? I think not.

That's because there are also a lot of idiots in this hobby. If you chose to follow those idiots, more power to you. Hopefully they won't lead you into jumping off a cliff, because you would apparently follow them right over the edge.

The alternative is that you are a watching a bunch of SPL'ers who are chasing every last tenth of a decibel. I have and always will concede that in SPL formats the more the better as a tenth of a decibel can make the difference in competitions. However, for "daily driving" setups not primarily concerned with numbers on a meter, this is completely unnecessary and a complete waste of resources, time and space. But because many people have a monkey-see monkey-do personality, they see everyone else running the largest amps they can support (and a lot of times, larger than they can support) and think it's the way to do things. They are full of ignorance and don't have the understanding to know why that route is completely unnecessary for someone who doesn't intend on focusing heavily on the competition circuit.