95Honda

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....

You know, I keep adding all this up in my head, but seriously, do most people also know how much all this will weigh??? LOL...

That is just stupid... Do you realize that even with 50 watts they will be louder than any other of the FI subs?

I'm in Kaiserslautern, thought I would see how far away you are... Seriously, The SPL is mostly in the execution, I don't put all the stock in the particular drivers or the amount of power. The box in my Avatar used 8 RE 8s. These aren't SPL subs. They are actually quite inneficient, but they still put up 143db on the Termlab with 150 watts of total power. This was verified by Black00 (Marshal Joyner) They did this because I literally spend days on the computer modeling different alignments until I came up with one that had the perfect response curve to achieve the target SPL I was looking for at the frequency I wanted. If you think about it, 143 db isn't much lower than what people are doing with 10X that much power.... It really is all in the execution...

This paragraph makes me realize how much time I wasted in this thread..... Nick- I will never get your comments on the box modeling problem of BTLs. Every time I run the parameters of the old BTLs (as posted on Blade Ice) and the new ones, I always model a ported box similar to the ones reccomended on your site. No speaker program I know of will put a driver with a Q as low as the BTL in a sealed box without severe low end roll-off and the possible need for Eq... Every single driver can be described by its electromechanical charactoristics, I don't think the BTL is an exception. This was the last time I will ever comment on running the T/S parameters of a BTL on this site. -Mike

Where are you in Germany?