95Honda
SSA Tech Team
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Everything posted by 95Honda
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It's not my knowledge, it is facts based on objective design since the 1940's dealing with this type of enclosure. Like I said before, pretty much all "car audio" T-lines aren't T-lines at all... And most "designers" aren't building T-lines, they are building something else... You need to pick up a copy of the Loudspeaker Design cookbook by Vance Dickson and get ahold of Martin King's T-line white papers before you listen to any car audio "experts" about T-lines as most of them are full of BS... -
Nobody said you can't have a T-line in a car. I have built several for car audio. Just don't expect to be putting a pair of 15's or an 18 in one without a huge enclosure. Your 10" driver may work in one, you just need to understand what you are going to end up with. Pretty much all "car audio" T-line enclosures aren't really T-lines, or they are severely miss-aligned... When people realize that the output will be marginally better at best than a sealed alignment, the reality sets in to what they are going to end up with. Also, I am not sure about the T/S parameters of your 10" driver, but it if has a fairly low Qts, it won't work well in a T-line due to it's self-dampening low end behavior. But like I said, I have no idea about that 10" driver... It is just important that you understand what goes into them, that is all.
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A T-line doesn't have a port, and is not a port, in fact it is completely non-resonant when executed correctly. A T-line doesn't have tuning. It has a cut-off frequency. Tuning refers to resonance, and again, a properly executed T-line is non resonant. A T-line will not have the efficiency of a 4th order vented box under any circumstances, this is do to the non-resonant nature of a T-line. It's efficiency will be between a 2nd order sealed enclosure and a 4th order vented enclosure, with most of it's efficiency being in the bottom octave. The line is roughly the Sd of the driver. There are certain ratios that will effect overall performance. A T-line that will reach down to at least 30Hz will be bigger than pretty much any 4th order vented box for the same driver(s). A T-line can be any shape. If there is any appreciable cabinet volume before the line, it isn't a T-line, and won't behave as one, no matter what anyone says. So, maybe this will clear a few things up for you...
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It's not larger, that is the problem. 0 awg CCW has the same cross-sectional area as 0 awg copper, therefore it doesn't have nearly the current capacity... It is larger only do to strand count and construction, not actual cross-sectional area increases...
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It is just a by-product of a class D amplifier. I kept asking about voltage level and frequency to verify this. There are frequencies very high (and many harmonics) in that amp and some make it through the output filter, 200 mv is negligible... 20V would have been an issue... The frequency was important as if it would have been in the subwoofer band, it may have pointed to a problem somewhere else... This is why it is important to know what you are looking at!
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CCA is a marketing gimmick. Hopefully you bought it for the color and not the performance...
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Also, your xx/xx volume setting is only valid when you took the measurement. It is null and void once you change the CD, touch any EQ or the voltage in your car changes... Don't put any confidence in this measurement...
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OK, you said that waveform appears with no input, so how do you know it is 40Hz? There are two frequencies in your picture, you need to find out what they are. Do you understand how to look at the voltage of the waveform(s) you are looking at? I have a feeling you need to read your operating manual, I don't think you understand how to use your O-scope. You will have nothing useful to help yourself until you can figure out these ^^ things...
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That is a rookie mistake...
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On your picture, what two frequencies are being displayed? An is it 1V Pk-Pk?
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1 V Pk-Pk? Also what frequencies are they (I can't tell from the picture) and is it visible/audible with the subwoofer connected to the output?
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It's 1V Pk-Pk? Also what two frequencies is it (I can't tell in your picture)? And is it audible/visible when connected to the subwoofer? -
There is no such thing as "box rise". Your alignment will have an impedance curve, this both rises and falls. It is varies with frequency. It will never be lower than total DCR. There is no advantage to a pair of amplifiers vs a single one, when driving the same impedance. It is whatever works out best for you. There can be the disadvantage of a loss in dampening with a strapped pair, this will lower the control of the woofers and may effect sound quality.
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If you can't drill the holes right, other stuff is probably jacked up also, lol...
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1/4-20 black oxide socket head capscrew with Hurricane nuts. If you drill your holes right, you can take the driver in and out unlimited times without anything getting messed up.
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Your amp can produce a 1700 watt sine wave. It can produce up to 2X that if it isn't a sine wave. It all depends on what you send into it and how much you ask out of it. If the power supply can support it, it could easily produce over 3Kw under certain circumstances...
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That amplifier is capable of producing more power than the RMS rating of the subwoofer. You probably exceeded the thermal capacity of the driver.
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I will depend on the kind of deal I can get a new flatscreen for. A projector seems more and more appealing in this situation though...
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Still on the backburner... lol...
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If you wire the coils out of phase, you will still measure the proper DCR, phase relation won't change this. If the subwoofers had motors that were knocked out of alignment during shipping, you would have noticed this initially if you know you are doing, this is part of inspecting mail order items for damage. If the cone can move back and forth when you push on it slightly the motor is more than likely fine. Normally, you can lightly press on each quadrant of the outer cone edge (0°, 90°, 180°, 270°) and see if rub is felt/heard with similar pressure. If one quadrant really scrapes easily before another, the coil and motor are out of alignment. Be careful doing this and don't ruin the soft parts... Good luck...
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You need to see about sending them in for a re-cone if they are cooked. If they are still OK, you may be fine... After that, have someone experienced double check you work before you fire it up again...
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You wired the coils out of phase and overheated the voice coils. Warranty won't cover this, sorry man... This is the only way you can pour enough power into a driver to overheat the voice coils without causing any cone movement. The only other possible thing that could have happened was your amplifier was faulty and was in some kind of uncontrolled high frequency oscillation. Warranty won't cover this, either...
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Thanks bro, I think that will get me started just fine...
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I am going to design a H/T enclosure for my brother's SX 15. It is a dual 4 ohm and was built in 2005. I cannot find the original T/S parameters for this driver, and non of my modeling programs have it either. I also have no idea if the current SX drivers are the same or not... Any help would be appreciated!
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That's just it, you don't know which one took the most abuse because you don't know how much power each driver was getting... If the Orion was in an alignment that had a lot of ripple, it could have been tested at an impedance peak and was in fact getting drastically less power than calculated using driver Re. On the other hand, one of the other drivers could have been tested in an impedance trough and received closer to the calculated power...