95Honda

I finally got my 05' Yamaha R1 done this winter. After all the upgrades (Exhaust/filter/airbox/Power Commander/ECU remap) it will do a solid (GPS Verified) 187MPH on the Autobahn, doesn't take too long to get there, either....

OK, just a few things- You do realize you have a sub rated at 750 WRMS, right? This means it is NOT intended to dissipate more thermal heat than 750 WRMS will generate. You have an amplifier that will probably generate well over 750 WRMS, this is more than enough power to fry the voicecoil... This has nothing to do with clipping, pre-out levels or anything else, contrary to what people may have told you. The voicecoil is a piece of wire wrapped around a former. It doesn't care what type of signal it gets as long as it's thermal threshold isn't exceeded. When you ask it to dissipate more than 750 Watts of energy, it overheats and breaks down. Period. This is always the end users fault. What is this crap about Xmax? The damn driver has 18mm of linear throw one way, that is more than many of the "SPL" subs out there, this has nothing to due with you thermally destroying the driver. It has an underhung motor. This more than likely means it has a shorter coil, with less surface area and lower heat dissipation. Again, compounding your user error even further. The geometry leads to an extremely flat BL curve within the excursion limitations, this means low distortion, low enough that you may not hear the driver being destroyed by your overpowering. This is a driver specifically targeted for flat, linear response. This comes at the expense of power handling in your case. My suggestion is to sell the drivers after you have them reconed (you should pay for this) and buy a sub that has higher power handling due to the fact that you cannot tell when you exceed your drivers thermal limits. To be safe, you should buy a driver that has 2X the RMS rating as your amp.... This is not a general reccomendation, this is only for you.

Knu is inferior to welding cable, especially thier aluminum crap. People like it because it looks good. Welding cable is the best quality wire per $.

What is the drivers Q? All of the other stuff listed doesn't mean anything... Also, just food for thought, the highest-end loudspeakers (like the ones that cost more than a new BMW) are very often vented.

oldenglish- Context is your friend. If you re-read my posts you will note that the word "tuning" is used in reference to a resonation point, not the adjustment of the overall alignment. Once you make this connection, everything else will fall in place. It also help if you communicate with a little more clarity and brevity than a 12 year old.

Actually, you need to read Martin King's entire primer on T-lines before you ask any more questions. I have been using his guidlines for T-lines for almost 10 years and find them invaluable. Seriously, read this befor eyou ask any more questions.

My god, who is spreading all this crap about T-lines and high efficiency....? It seems like every time I drop in here there is some new subwoofer urban legend BS, lol...

It is simple. It is a T-line if it is a line and only a line. The Sd to cross-sectional ration doesn't come into play with this definition. It isn't a T-line if there is anything but a line involved. If it is a box, with a "T-line" attached to one part of the box, it isn't a T-line anymore, it is a bass reflex alignment with a big ass port. Also, a T-line has a cutoff frequency determained by length, they don't have a tuning frequency. The longer the length and the heavier the stuffing, the lower the cutoff. They aren't resonators, they are tranmission lines that introduce phase shift.

If you didn't build something that wasn't a T-line, but called it one anyway, then no, I wasn't refering to you. Also, this thread has nothing to do with stiffling creativity, it is meant to cut the BS and give people correct information, that is why we are here anyway, right?

Aditionally, all the "order" refers to is the roll-off of the encloure. Standard vented box rolls of at an average rate of 24db/oct below F3. Hence 4th order. Add another 2nd order HP filter to the mix (like a SSF) and you now have a 6th order bass reflex aligment, which is what many people on this site are running for subwoofer alignments as we speak. They just probably never realized it. And band pass that is 4th order has a vented chamber that has a roll-off of roughly 24db/oct above and below the F3 points..... Seriously, alot of this stuff people are posting is pulled out of thier asses. And like M5 said, most of it causes more harm than good....

I know, it is obvious from his (kirill007) 2nd post that he didn't understand that a 4th order vented box is not a bandpass (I never even mentioned bandpass) and that he completely missunderstands how a T-line works (look into the use of the word "tuning"). Pretty much everyone who believes this, and believes they have built a T-line (when in fact they have build a ported box with a huge port) will go on and on about it..... The whole point of a T-line is NON-resonant behavior and flat response with an enhanced low end. A proper T-line will never be more efficient (except the last octave, in which case they accell, but this doesn't help car audio SPL in the least) than a proper 4th order vented alignment... It is also appratent when someone post a picture of a "T-line" only to find that in fact, they have not built one at all. But like I said before, it doesn't matter what I say, lol...

No. But it doesn't matter what I say, lol....

A true T-line will never be as efficient as a 4th order vented alignment. If you have a T-line that is more efficient than a 4th order vented alignment, chances are it isn't a T-line. The whole point of a T-line is to be very flat in amplitude response, it is about as good of a choice for SPL as a 2nd order sealed alignment.

The safety caps have nothing to do with a passive crossover. These are reccomended for active systems, when you aren't sure how well your gear works....

LOL.. I had about 7 of those Altecs about 10 years ago, and a few of the 200 watt ones... Picked them up at a surplus sale...

The only thing an inline fuse is designed to do is keep you car from catching on fire in the event of a short. It has absolutely nothing to do with amp protection, especially if you are running multiple amps, lol.....

You need to read the whole thing. Twice.

Not worth a second more of my time... Have fun, I'm out...

You know, before you raise a BS flag and tell someone they don't what they are talking about, maybe you should know a few things. I have been designing and building solid state and tube amplifiers form scratch since I worked for Audioprism in the early 90s. I have designed and built over 10 amplifiers, from scratch... I have been using test equipment for decades. I am an active duty Air Force E-7 select who has been a radio and RF systems technician for the past 12 years. I have built over 200 loudspeakers. I design and build RF amplifiers as a side hobby. Here is a picture of my last amplifer, built from scratch....

Uhh, I wrote it.....

Unless the driver has a Q of around .01 and it is below a few Hz, they can't reproduce a squarewave without ringing and are never really at rest... I guess it is interpretation of what rest is beyond this point... jw 2 + 2, did you actually read the results of clipping test?

Clipping is when you reach to voltage limits of an amplification stage. Thats it. It isn't DC, it doesn't blow speakers, it doesn't make a woofer hold still..... If you want to understand it more, read this article- http://www.forceaudio.com/showthread.php?t=15

You should never be allowed to post any advice on here again. The whole point of the SSF is to attenuate frequencies below tuning, to keep the driver from running into over-excursion. You set it so it begins cutting frequencies below tuning. In the case of a 4th order vented box, it can attenuate anywhere from 12-24db/octave below Fb and work pretty good.

Diesel too.... About time....