Impious

I don't know anything about the 9887. How is the TA set in the HU? Distance or time?

It depends on how tightly or loosely the power supply is regulated. Is this for competition or daily driving?

you can clip inputs just the same as you can outputs. Keep that in mind when running and reviewing the results of your test.

There are only 3 situations in which a line driver is needed. 1) When you are using a very low preamp voltage source (such as an MP3 player) and it's output is below the level necessary to drive the amplifier to the necessary power levels. Almost any headunit on the market will have sufficient output voltage to drive almost any amp on the market to full power output. 2) When you have unavoidable noise induced into the system during signal transmission and you need to boost the signal to increase your signal to noise ratio (this will be very rare) 3) When you have a low voltage headunit and the amps makes an unacceptable amount of thermal noise with the high gain setting (though this is more a fault of the amplifier than the signal voltage level) That said, line driver is sometimes a generic term and a product that features a line driver will something also offer other useful features such as equalization. But that's a different situation entirely. My comments above were specifically in regards to the line driver feature.

They weren't tested using a valid test methodology with calibrated equipment and compared to the factory specifications using the same thresholds. Which means the answer to my question is no, and the claim that they produce more than rated power is unproven and unsupported. Normally a company makes a claim when they have the evidence to actually support it. Nothing against your amps. But you have nothing to actually support your claim, and unsupported claims I do have a problem with. It's misleading and breeds ignorance among consumers. Especially when a company is using something as useless as a clamp test to verify their "rated power" and promoting it as the evidence that they exceed "rated power".

In short.....if no one can explain why it's better, it's a gimmick. I did a google search for that Octoport before I posted. The only information I could find about it was essentially; "I don't know why it works better, but it does. That Dave guy is really smart and has tested everything. These must be the best because if there was anything better he'd use that instead". BS flag should immediately raise.

So the answer is that you don't have any valid test measurements demonstrating that the amps exceed the factory power specs as you previously stated, as you are relying on those two [meaningless] clamp tests as the evidence that they exceed rated power ?

How exactly were the amplifiers verified to exceed factory specifications? The clamp tests posted in the other thread aren't a valid test result. I assume you used some other verifiable, reliable measuring system in order to make that statement?

Build the enclosure for desired response, not system power

Most people refer to that as a swappable port, and it is accomplished multiple ways from the simple to the complex. An aero port would be the easiest and probably the most cost effective.

If that were the case, you wouldn't need to run your subs to 150hz. That makes it painfully obvious your midbass aren't doing what you need them to do. No. And why the octoport? Please don't tell me you've bought into the nonsense hype.

Keep in mind that while BL increases, Re also doubles which means less current through the motor. Using the standard BL2/Re to express the motor force factor, the D1 SSD15 would have a force factor of ~123 while the D2 SSD15 would have a force factor of ~125. As you can see, they are virtually identical.

While there is certainly more factors involved, Xmax and SPL are definitely related. To make it seem as though there is zero correlation is simply incorrect. It determines the maximum linear displacement of the driver, which determines the maximum linear SPL of the driver. How important they are relative to each other depends on the circumstances of the specific situation, which we don't know the specifics of this scenario yet. Assuming identical alignments, the higher Xmax sub will be capable of more peak linear output. There is no arguing this. And it includes ported enclosures.

It's called +3db because it makes the response of the tweeter +3db over the mid. But really it just reduces the amount of attenuation on the tweeter by 3db. It's not a boost. With the switch set to zero the circuit is actually attenuating the tweeter by -3db. That said, the amount of power delivered to the tweeter will still double compared to a setting of zero, so they will get louder faster and it will be possible to smoke the tweeters with a comparatively lower volume setting (assuming you are running enough power).

That 34230 in your sig is only 740w (370w x 2 @ 4ohm). Don't run it below 4ohm per channel and do not bridge it. Had one years ago when they were first released. Anyways, it's nearly impossible to properly design an enclosure without T/S parameters. Otherwise it's just a guess. It might even be a bad idea to put them in an enclosure. No way to know without the T/S

What are the T/S of the speakers?

Tuning 10hz higher isn't going to give you response to 150hz. You need an EQ, a ton of displacement potential and subs with relatively low inductance if you want flat response to 150hz.

Did you get any of these pieces in with your production order for the Ethos ?

This is the 2nd "review" I've seen from him. The other was a piece about one of the small HAT subwoofers. They are more of a marketing piece than any type of actual independent "review" considering the limited information provided beyond what can be found on the manufacturer's website/literature. Very underwhelming.

Work in sales for a while, that will change. Sean probably has some sage advice like the best sale for company is always the one that meets the customer's needs first. But downward pressure to hit your numbers (if it's really a "sales" job) takes it's toll, and your ideals go out the window pretty damn quickly. I'm a non-salesman stuck in a sales job. I had always envisioned myself behaving the way you describe....here I am 7 years later behaving exactly the opposite.

This has been posted on DIYMA for a while. The original tweeters that meet manufacturer spec are fantastic, but with these being out of spec it's hard to say. If they are just slightly off spec (outside of normal manufacturing tolerances) then they are probably fine and a great deal. If they are way the fuck out there spec wise then maybe not so much. I think I read in one of the prior auctions that impedance can range anywhere from 6ohm to 12ohm. It might have been 8ohm to 12ohm, either way that's a hell of a variance, and without knowing exactly why the specs are off makes it hard to determine how close to original performance you are going to get. Personally if I needed/wanted that tweeter, or a tweeter of that caliber, I wouldn't chance it on the out of spec ones. If it's a shits 'n giggles purchase than why not. It might be worth the gamble if you have $100 to blow and don't mind if they are way out of spec and don't meet original design performance. Or for not much more money you could get a known good tweeter that might fit your needs better, depending on what those needs are.

No, two completely different subwoofers. Maybe, you would need to send the sub in to a company so they could get the necessary measurements to see what they have that might fit. But it wouldn't use the original parts so the original engineering of the subwoofer is out the window and you'd be stuck with basically a subwoofer built out of whatever parts may fit....in short this isn't a good idea even if someone could configure some parts together to fit. Alpine claims a 2.6" voice coil which is a little odd, so finding a replacement coil might prove difficult. Have you talked to Alpine? Can they recone it? Honestly if Alpine can't recone it for cheap just toss it and buy something else. The money spent on shipping and a recone if you could even find one that fit would far exceed the value of the subwoofer. Also, you need to figure out why it blew in the first place, otherwise whatever you replace it with is destined for the same fate. You'll end up just continually wasting money replacing subwoofers until you figure out what you did wrong. On a Type S? No, it's 500w RMS for the subwoofer, meaning 250w per coil.

Sure I watched the video and read the comments. Pretty obvious by viewing them what the intent was. Very unprofessional in every regard especially when it could potentially become a serious issue next year when they try to get everything in order to host the event again. You can ridicule the homeowners for their choice in location all you want. That doesn't mean they might not have a valid enough complaint in the eyes of the city to not allow a car audio event (a hobby which is not held in high esteem to begin with) to continue at that location. Especially when the car audio communities response to the complaint is to mix the voice mail into a video to be posted all around the internet making fun of the complaint and promoting/laughing at the (supposed) fact windows were rattling miles away. I would also gander a guess that the big name televised racing events generate significantly more money for the city than Slamology, which the city does take into consideration.

Anything from about half of their rated power handling up to rated power handling should do you just fine.

No, but Goodyear also doesn't make videos making fun of those who complain. I agree, those participating at Slamology were well within their right given the venue and permits issued by the city. Without knowing where this resident was and how loud it actually was at their house, I'd also agree that if they live too close to the venue then that's their own damn fault. I however agree with Stefan that the video doesn't look good for XS as a company or our hobby in general for making fun of the person, who was at least courteous enough to be polite in her complaint about the noise. Doesn't seem like the same courtesy is being extended back to her with the video. Also, I don't think you all will find that video or voice mail very funny next year if enough (or important enough) residents complain about the noise and the city doesn't issue the permits to allow the event. Food for thought.