Impious

Completely depends on the subwoofer being used.

Kind of but I really want do see how good of a sound stage i can get from it. Good luck with that. Chances are good it will make the stage worse unless you go to a lot of effort to eliminate the transfer of tactile sensations and rattles, which will draw your attention to the location of the subwoofer. There's nothing about subbass that makes putting subs up front "better".

People have put subs in their doors before. By the time you add the weight of a subwoofer, amplifier, fiberglass/etc.....you may be in need of new door hinges. You also have to consider the subwoofer you plan to use and if you can work an adequate enclosure into the door. Are you wanting to do this just for the "wow" factor?

if u had that saz-4500d with those 15's, would consider running a spar battery and maybe an compacitor? Is English your second language? You have no business running that high powered of a system as you obviously haven't much experience or knowledge and will end up either wasting money or blowing stuff up (or quite possibly both). Slow your roll would be my advice.

http://www.wooferset...nent-System.htm http://www.wooferset...nent-System.htm The 6x9's are supposed to kick ass, not much talk about the 5x7's however.

Apparently I didn't make my first post clear enough. Let's try it again; YOU DO NOT NEED A LINE DRIVER. Your uncle is wrong, plain and simple, that the sound difference is related to his 4v outputs (UNLESS YOU DID NOT PROPERLY RESET THE GAIN. IN WHICH CASE, CORRECTLY RESET YOUR GAIN). With a properly set gain, there will be NO DIFFERENCE AT ALL in the power output of the amplifier. Get this line driver thing out of your head. You don't need one. It won't help. Waste of money. Go back to my previous post. It explains everything. Things you don't think make a big difference do, in fact, make a huge difference.

Having a speaker connected isn't going to change the voltage an amplifier can supply before clipping occurs. The impedance rise will affect how much power the speaker sees, but not how much voltage the amplifier can cleanly supply.

There could be many factors at play here, none of which are related to the headunit's output voltage. For starters, as was mentioned, the gain control is included on amplifiers for the express purpose of allowing the amplifier to reach full power output with a wide range of input voltages. You first need to properly set the gain control. With a properly set gain control, there will be no difference in output from the amplifier between your uncle's headunit and your headunit. This is exactly what the gain control is there for. You do not need a line driver. Second, you could be experiencing a difference in vehicle acoustics. The exact same system in two different vehicles will sound and behave completely differently. While I don't know the details of the entire system (i.e. this would have been helpful information to have included in your original post) or what the two vehicles are a discussing here, trying something such as different placement and/or positioning of the subwoofer in your vehicle may change the sound of the system for better or worse. But without fairly advanced attempts at creating "equal" results, there will be some unavoidable differences in sound simply due to the two different vehicles. A third issue could be due to the strength of the respective electrical systems of the two vehicles and the amplifier. If the amplifier is not tightly regulated, and your electrical system is much weaker than the electrical system in your uncle's vehicle, then the amplifier will not be performing as strongly. A fourth issue could also be due to difference in various system settings between the two installations (EQ, crossover settings, "loudness" settings, etc) as well as differences of the other speakers and their respective performance involved in the two systems, integration of the speakers and subwoofers in the system, etc. And that's the short list based on limited information. Long story short; Hard to blame a single factor when there is a multitude at play that need to be fully considered. And to eliminate it from your list, the headunit's preout voltage is not one of the factors with a properly set gain.

There are several assumptions involved when setting the gain with a DMM and the voltage formula. These assumptions may or may not be accurate. As a result, your gain setting with the DMM may or may not be accurate. There is no guaranty clipping will not occur with the DMM method because, as stated, the DMM doesn't measure the shape of the wave....only the voltage. The DMM method helps get the gain setting within the general ballpark so people aren't going crazy with the gain control. But in reality it's not an exact or accurate method.

Just an FYI; To find a half octave you can just multiply the frequency by .75 32 * .75 = 24

You would be correct that 22.5hz is half an octave below 30hz. Half an octave is one of many general recommendations. One thing you could do would be to load your sub and enclosure into an enclosure simulator and run an excursion plot. Look at the graph and see when the plotted excursion exceeds the capabilities of your subwoofer.

Wording could use a little refinement, but I think you have the jist of things. Correct, it doesn't matter which filter is set to the higher frequency and which to the lower frequency. As you approach 2nd crossover frequency, the rate of attenuation (or slope) will increase (or steepen). And I just want to clarify that you understand the slope of the crossovers themselves doesn't change. It is the effect of the multiple crossovers summing that increases the final rate of attenuation of the signal. Also want to point out that the word highlighted in red above should be "rate of attenuation", or "slope". Octave describes the interval between frequencies. The term "decibels per octave" is used to describe the crossovers rate of attention, or slope, (in decibels) per the interval between frequencies (octave).

They can be used for that, and that is the reason most manufacturers include them in an amplifier. However they are simply a highpass crossover with a different "label", so if you choose to use them in another manor that is perfectly acceptable also Correct. When you run a driver in a ported enclosure below tuning you run the risk of damaging the driver due to unloading. The SSF can and should be used to help protect the driver.

Correct. You can do a basic active setup with the crossovers in some amplifiers, such as the Sundown amps. IIRC this is the reason Jacob chose the frequency ranges he did for the crossovers in his amplifiers. It will not be the epitome of flexibility, but it will technically work.

Completely false. Don't know who told you that, but it's completely untrue. Thanks for confirming it. I didn't do a direct quote becuase it's on a different forum. . So in a nutshell for basic situations, the xover slope is summed together. In a basic nutshell, correct. This is the essence of a Linkwitz-Riley crossover

Hrmph. I guess maybe I presumed you knew something you didn't when I was writing out my previous responses. Suppose maybe I should have began by asking if you understood the crossovers, slopes, etc Maybe this post I made a few years ago will help some also? http://www.caraudio....548&postcount=2 Let us know where you're still a little confused, we'll try to help

fixed for reality I dont understand where you are coming from with this. We changed everything around and then tested the power handling. I dont know if you knew this or not. If you did could you please enlighten us on how to fix the speaker installation so they will be able to handle more power. I believe his point was that once the doors are properly deadened and sealed the speakers may not need as much power to reach an acceptable volume level.

You mean, for example, if we set them to 500hz how would 1000hz be affected? Go back to the BCAE1 link I posted earlier in the thread and look at the graph. I think it would help if we stopped calling the subsonic filter a subsonic filter, honestly. It helps for identification of which filter we are talking about, but I think it might be causing you to think of the subsonic filter as something it's not. Subsonic filter is just a fancy (an in many ways, wrong) term that we use to describe a highpass crossover that can be set to very low frequencies. It is no different than the highpass crossover on the amplifier, or in your headunit. They are the exact same thing, we just use different terms to identify them. We'll call the headunit's highpass crossover Filter 1 and the "subsonic" crossover Filter 2. If we stick with our highly idealized situation and continue to assume they are both the same slope; Setting Filter 1 to 500hz and Filter 2 to 750hz is exactly the same as setting Filter 1 to 750hz and Filter 2 to 500hz. The results would be identical. A better question is; Why would the result be different? They are both doing the exact same thing to the signal. It doesn't matter which comes first if they are both doing the same thing.

Completely false. Don't know who told you that, but it's completely untrue.

So fucking tired of hearing about Tiger Woods. Need to start a show that investigates the pasts of all of these news reporters and Hollywood watcher-types and continually broadcast all of their indiscretions, nationally rub their mistakes in their faces for a while.

Two of the same type of filters (highpass and highpass, for example) won't "cancel out". They will be cumulative, they will combine. How they combine will be affected by a multitude of factors, including but not limited to the slope of the filters and the crossover frequencies. In your example, the signal would be affected by the subsonic filter until the signal begins approaching 300hz, at which point the net slope will be a combination of both the subsonic filter and the headunit's highpass filter. It will increase the attenuation of the signal, or in other words, it will cause the slope to steepen and increase the -Xdb/oct rolloff rate of the signal.

Crossovers unfortunately can be an extremely complicated subject. The above wouldn't even qualify as a snowflake on the tip of the crossover iceberg. But for the basics, if you haven't read it yet, you can start here; http://bcae1.com/xovrslop.htm

I guess I'm a little confused on what it is you are actually asking. Jacob's description is spot on. But I'll give it a shot and we'll go from there. A subsonic filter is nothing more than a highpass filter (crossover). Filters (crossovers) are cumulative; If you are using more than one filter, then the slope of each filter used will combine. For example, lets say you have the highpass filter on your headunit set to 500hz, and it's slope is 24db/oct. You then also use your amp's 24db/oct subsonic filter and likewise set it to 500hz. We will assume both are butterworth filters, which means the crossover frequency is the point at which the signal has decreased by a level of -3db. Now, in this particular scenario since we are using two crossovers of the same slope and alignment, both set to 500hz, the net result is that the signal will be down -6db at 500hz and the net slope will be -48db/oct. This is because, as noted earlier, the two crossovers combine. They both affect the signal. Or we could cascade the filters. We could set the crossover on the headunit to 500hz and set the subsonic filter at 250hz. In this scenario, the signal would only be down -3db at 500hz and the slope at that point will continue at the original 24db/oct rolloff. Now, normally at 250hz (one octave lower than 500hz) the signal would be down -24db due to the 24db/oct slope of the headunit's crossover. However, as we approach 250hz the signal will begin to decrease in level quicker than 24db/oct because the 2nd, cascaded, filter (in this case, the subsonic filter) will also begin affecting the signal. The signal at 250hz will instead be down -27db (original 24db/oct slope + -3db from subsonic filter) and from there continue to decrease at 48db/oct due to the combined effects of both the headunit's 24db/oct filter and the 24db/oct subsonic filter. So the frequencies below 250hz will be attentuated much more quickly than above 250hz. This can be done with any two filters (crossovers). You could use the lowpass crossover on your headunit and the lowpass crossover on your amplifier to obtain the same affect on the top end of your midrange, for example. Or the highpass in your headunit and highpass on your amplifier to steepen the highpass filter on your tweeters. Etc. This is a simple, idealized example for explanation purposes. In reality there may be some other factors to take into consideration such as the Q of the filters and such.....but it should provide you an idea of what Jacob was talking about. Clear as mud ?? Help, not help?

Have you done anything M5 or myself have previously suggested in this thread? If not, then there's no point in continuing to try to assist you. If yes, please report back with what you have done and the results.

The specs appear to be 75w x 4 or 180w x 2 @ 4ohm.