Impious

I don't know who runs that site, but they like to steal other people's write ups/articles and not give credit to the original author.

IMO the most obvious reason a thread like this won't really work is because, as Ryan mention, it's not very difficult for someone to change their IP or screen name and do the same, and there is already a feedback section to air out dirty laundry. If someone is not concerned enough about a transaction to search for a screen name and locate a bad feedback thread, a blacklist isn't going to help much either. Not to mention 9.9 out of 10 times once someone is "caught" as a scammer or has bad feedback left for them, they won't trade under that same name again. So it's going to be filled with a list of names of people who aren't trading under that name anymore anyways. As Aaron mentioned, the amount of scammers here is extremely low due to the nature of the forum atmosphere and general positive attitude of the user base. There are other forums where it seems there is a large percentage of transactions which have some sort of problem. However, it can happen to anyone on any forum and unfortunately there isn't a lot that can be done to stop it. There is a long list of people who have had dozens of positive transactions, only to end up leaving a bunch of people with empty wallets and no product. It happens. It sucks. There's not much, on a forum basis, that can be done to stop it. The mods aren't police. We're janitors. We don't have the capabilities or the information to stop scammers or help those who were scammed, and a "black list" isn't going to stop scammers. With all of ebay's supposed precautions, they still have scammers. The point is, in online transactions bad things are going to periodically happen. Be thankful it happens as infrequently as it does on this site. For those that have been scammed, it's unfortunate.

From the looks of that interface, it appears that the CD changer has standard RCA outputs which are then input to the interface, and the odd looking jack connects to the back of the headunit, correct? If so, should be pretty easy to test with a DMM. I would start with the CD changer. Make a disc with a test tone and play it in the CD changer (music will work as well, just not as easily). Set the DMM to Vac and test both of the RCA outputs on the CD changer itself (disconnect the interface) by placing the red DMM lead on the inside barrel of the RCA connector and the black DMM lead on the outer shell of the RCA connector. If they both show the same voltage, then the CD changer is fine. If they show significantly different voltages, or one of the outputs shows no voltage, then there is your problem. If they both test out fine, then connect the interface and measure again. I don't recall exactly what the actual connector looks like, but somewhere there will be connection for the the left signal, the right signal, and a ground. You will need to figure which is which and see if you have the same voltage again for the left and the right. If it's the same again, then the interface is fine and there is a problem with the headunit. If they show different voltages, or one of the outputs shows no voltage, then the interface is the problem.

You're not going to find a significantly better built amp than the JL's. They aren't the most efficient things in the world, but build quality and design wise they are top notch amps.

Sub sonic has nothing to do with volume. the gain does that and all songs arent recorded the same. sorry for my poor english let me try and explain it in the best way i can think. i understand what a gain on a amp does and i understand what the ssf does as well. what i'm trying to explain is on some song's i listen to i have to listen to them at a low volume since they beat real hard when i say beat real hard i mean to where my subs's will move like crazy and you can start smelling the coils burn a little or you will hear the sub pop and was not sure if it might have to do with the way my ssf is set to or if this is normal. It could be the SSF if you had it set too low and the song you were playing had a lot of content below your enclosure tuning. But that doesn't sound like the problem as 29hz is perfectly fine for a 34hz tuning, generally a reasonable setting is around 1/2 octave below tuning, which in your case would be ~26hz. It sounds like your problem is either too much power for your enclosure, or improper settings such as gain, bass boost, etc.

It's either the cable, the CD changer, or the input on the headunit. What type of connection is between the CD changer and the headunit? Is it a standard RCA cable or another type?

Don't worry about it. Nobody likes to admit it, but we were all this green at the beginning. The questions are "simple" to us because of our experience, but the only way to learn is to ask. If you're unsure about something it's better to ask and get it right the first time. Just to prove a point on another forum I used to moderate, I spent some time and looked up several of the "respected" members early posts on that forum, which were the typical "newbie" type questions, and posted them in my sig. It was funny.....a couple of them actually got pretty pissed off I had done that.

Moved to OT. Good luck with the situation. Best advice has been given......contact his local PD with all of the info.

This is what I meant about misapplying Ohms Law. In this scenario P=V^2/R and it's variants apply to the output of the amplifier. It has nothing to do with the power input, the power drawn by the amplifier from electrical system. Yes, if we assume two amplifiers have the same efficiency and output the same power, they will draw exactly the same power (both voltage and current) from the electrical system. For a given supply voltage, they have no choice but to draw the same current from the electrical system. P=VI. If they are both drawing the same power from the electrical system (which they will if their power output and efficiency is the same) at the same supply voltage (the voltage of your electrical system), then it is required by physics that their current draw be the same also. If amplifier A is 1kw @ 4ohm @ 80% efficiency and amplifier B is 1kw @ 1ohm @ 80% efficiency, their current draw will be identical. The two amplifiers will output different voltage and current based on Ohms Law (P=V^2/R, I^2R), but their draw from the electrical system will be identical. Yes, this is fully consistent with Ohms Law. You are misapplying Ohms Law and relating the load impedance to the current drawn by the amplifier with the formula P=I^2R, when the two are not related in this way. That's not how that formula is applied.

The difference in efficiency is the only thing that impacts current draw (well, that and the supply voltage to the amplifier along with power output). You are misunderstanding the application of Ohms Law. The impedance of the load has nothing at all to do with it other than, for the same amplifier, as impedance of the load decreases so does efficiency (generally speaking). This does not mean that amplifier A operating at 2kw into a 1ohm will be more or less efficient than amplifier B operating at 2kw into a 2ohm or 4ohm load. That completely depends on the respective designs of the amplifier. It has nothing to do with Ohms Law other than Volts * Amps = Power. If amplifier A has a lower efficiency, then for a given supply voltage it will need to draw more current than amp B.....if it has a higher efficiency, then it will draw less current. To make this a little more clear; If amplifier A is outputting 2kw (impedance doesn't matter) and is 60% efficient, then it needs to draw 3333 watts from the electrical system in order to output 2000 watts. If the supply voltage is 12V, then it needs to draw 277.8 amps from the electrical system. If amplifier B is outputting 2kw (impedance doesn't matter) and is 80% efficient, then it needs to draw 2500 watts from the electrical system in order to output 2000 watts. If the supply voltage is 12V, then it needs to draw 208.3 amps from the electrical system. Impedance has nothing to do with it. It's efficiency, power output, and supply voltage.

I would question the intelligence of the dealer, and everyone else you've talked to. There's nothing magical about a subwoofer that makes it "come alive" at a certain level of power. In fact, once you reach a certain level power compression begins to set in and each successive increase in power will increase output by a successively smaller amount.

I don't know of any gain that has a setting of "24". The input sensitivity ("gain") is a range of voltages, not a numerical range like a volume setting, and that range is determined by the design of the amplifier. Where the input sensitivity needs set is based on the input voltage of the preamp signal. For example, the range of input sensitivity would be .2V - 8V. The gain would be set somewhere in that range based on the level of the input signal. Anyways, you can set the gain as low as you want. Being too low doesn't hurt anything, you are just not receiving all of the output power capabilities of the amplifier. Getting "close enough" is good enough because under most circumstances you are not going to hear a 25% difference in power (in reality the percentage can be higher, I'm just trying to keep it simple here for you). So if you set the gain too "low" and undershoot power output by 25% you are not going to know because you are not going to hear a difference. As for setting the gain too "high", you are safe for a while. A little clipping isn't going to hurt anything. Clipping is a little worse on speakers than subs because it will probably end up being more audible, but it probably won't hurt anything unless you are already pushing the drivers thermal or mechanical limitations (which is the only time a loudspeaker is damaged). Clipping in and of itself doesn't hurt anything, other than possibly making things sound worse because of the added distortion. A driver, any driver, is only damaged when it's thermal or mechanical limits are exceed. Clipping may be the reason the driver's thermal or mechanical limits are exceeded, as a clipped signal contains more average power over time than a pure sinewave. But it's the increase in power as a result of clipping, not the shape of the waveform or the "clipping" of the signal itself that does the damage. This is why people recommend just setting the gain by ear. Small differences in either direction aren't going to matter. Set the gain a little too low and you won't hear a difference because realistically you need a substantial difference in power to actually hear the difference. Set the gain a little high and the small amount of clipping isn't going to damage anything....with speakers it might sound worse because of the distortion, but generally with subs the clipping won't really be audible. Now obviously you don't want to completely overshoot the gain setting because it is possible to start damaging equipment if you run into heavy clipping and you are exceeding the driver's thermal/mechanical limits. But you need to be really far off and/or running unnecessary bass boost/etc before you reach this territory. If you are absolutely lost, the DMM method is a good place to start and tune the gain from there.

This isn't a WTB section. This is for discussion of subwoofers, not selling and purchasing them.

It's terrible to see this happen. My first comp set was a pair of Boston Pro6.5's back in the day.

2kw at 4 ohm would be nice on your electrical Though there is a general correlation between efficiency and load impedance for the same amp, there's no reason to assume those amps running at 2ohm each (strapped into a 4ohm load each amplifier would be operating at 2ohm) would be any more or less efficient than another amplifier operating at a lower impedance. It depends on the design and efficiency of the amplifiers, not just the impedance of the load.

I'd save the $1200, keep the JL's and put $$ into the electrical or other items that really matter rather than dumping it into a new amp you don't actually need.

You can properly set gain any way you want. Oscope will do nothing aside from showing you the wave form. Doesn't mean the gain is set correctly or not. Bingo.

An o-scope isn't any more helpful than a DMM for gain setting.

I got rid of the quadruple post. To remove the items on the left, download Adblock+ and block them. As for gain setting, the DMM method is good for giving someone with absolute no experience a general starting point from which to make more fine adjustments. Generally a -6db or so test tone will provide good results. Most people will probably not be happy with the results from a 0db test tone as that's rather conservative.

I want to yield the best possible results. I will try with just beauty panels, if i'm not satisfied with that, I will just foam behind and around the seal. I very seriously doubt you will hear a difference with and without foam as long as the beauty panels create satisfactory separation between the trunk and the cabin. Obviously if you leave significant gaps then the panels were poorly designed and results will suffer. But if you build them properly and create a good "wall" then it will work just fine without foam. Minor gaps are not going to matter in the grand scheme of things. To me it seems like using spray foam creates a whole lot of work for yourself later when you try to clean it off with no real acoustic benefit. Like I said, I was running IB from my trunk without using spray foam or other sealant, and it worked just fine. If there were problems, they would have been much more readily apparent running IB compared to simply trying to fire an enclosure into the cabin since with IB the only separation between the frontwave and backwave is the baffle itself.

If this is just for a daily system I wouldn't bother with the spray foam or caulking, personally. I would build some beauty panels and simply use those to create the "seal" between the cabin and trunk. It doesn't need to be 100% air tight. I ran IB in my trunk and didn't use an ounce of foam or other sealant. Worked just fine.

That sucks

Also, on their active explanation page it says: FALSE. Active crossovers have exactly the same phase shift as passive crossovers.Though the website has a copyright of 2004, and the latest news is from 2005. So not sure what's up with the company.

Looks like a bunch of audiophile nonsense marketing to me. The active crossover in their component set isn't active in the sense we typically think of or use. The crossover points and slopes are still fixed in their comp set, not variable like we are used to seeing in active crossovers. Which means it suffers from the exact same limitations and restrictions as a passive crossover in that the crossover design does not consider the specific installation and acoustics of the vehicle. The only difference is where the crossover is located in the signal chain. They completely overemphasize the importance of damping factor in the amplifier description. Not to mention they completely neglect to mention the most significant factor in the low effective damping factor of any amplifier.....the Re of the speaker itself. In the tweeter section they fail to consider the fact that a zobel network can be added to a passive crossover to effectively flatten the impedance curve. And I fail to see how being active allows the tweeter to play any lower, that statement doesn't even make sense. Though 1.4khz with a small format tweeter is pretty aggressive, I'd be interested in seeing a distortion and FR plot of the tweeter. And the second statement they make about the tweeter being placed higher, while debatable, can be realized with any component set so I fail to see how that makes them unique. For the mids, their statement that passive crossover component sets allow the mid the play into their break up region is nonsensical. Certainly there are comp sets out that allow this to happen, but that's a function of the selected crossover point and slope and has nothing to do with the fact that they use a passive crossover. And frankly, I find the following statement to be insulting: Apparently they underestimate and/or lack any respect for the amount of research, testing, measuring and tuning we perform to maximize performance of our "contraptions". Sure, it's interesting. But I would hardly say I see much of anything to be impressed with. Appears to be nothing but marketing babble aimed at audiophiles with more money than knowledge.

The parameters of an IB subwoofer lend itself to less than desirable performance in either a sealed or ported enclosure. Sure, you could place it into either enclosure.....but results would be much better with a subwoofer designed to work optimally in those enclosures.