Ben Building
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Posts posted by Ben Building
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You probably should take a look at this one:
http://www3.shopping.com/xPO-Lanzar-SDBT75...-Lanzar-SDBT75N
We haven't had any problems from these decks at all. They are pretty decent with features like Bluetooth, MP3, etc.
But like the man said it's tough finding a new, warrantied touchscreen for that price range.
lol :01nocomment8so:
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I would look twice at that DAT 2500 if I were you. :hairtrick:
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Spend a little bit more money and you can get (2) .5 ohm stable Opti 2000Ds. That should wake those subs up! :hairtrick:
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South Korean amps there, bro... Don't see trade with them being affected by the North's threats. They've been doing this stuff for years.byebye zenon amps
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What is the brand? and there is probably no monthly fees because tehy will rape you when you call and have the car located with a one time fee.
That's a good question I need to ask. I understood there to be free access to the features, but I will find out.
See, that's why you post stuff on the Forum, guys.
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I ran across a guy today selling GPS car alarms with some pretty nifty features.
You can monitor the car's position in real time via telephone with no service charge.
You can control the door locks, remote start, anti-carjacking;
Check the alarm status via telephone;
Turn off individual sensors via remote;
You can monitor the sounds in the car via telephone;
Speak over the alarm's siren via telephone;
The alarm automatically calls 3 programable telephone numbers when triggered;
Programmable silent trigger mode where the siren doesn't make any noise and you can sneak up on the bad guy.
I am really open off this!
For $499 with no monthly fee...
What alarms have you guys heard of with similar features and at what price?
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Sounds like you've already talked yourself into the 4500. The SAZ is like three times better amp than those Kole/PA's BUT you currently have four of them. I think that if you run only one 3500 you'll lose a little bit on the meter, but your subs might sound better on daily.
Either way, you are going to quake; just make sure you grab that SAZ-4500 at the $1200 if you can. :hairtrick:
OR you can grab a RF T4000.1BD right now for about $900 and call it a day.
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You would need a dual 1 ohm sub for the Audiopipe.
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Look at the AudioPipe AP30001D ($350-ish for 3000w RMS) if you're trying to stay within a budget.
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soak the fiberglass in resin and slap it up there?
Heck no. You'll waste a bunch of resin doing that. Just staple the mat up there like the man said and use a pack of $3.00 paint rollers to roll the resin onto the mat.
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...like I always say; there's nothin a little bass can't cure!! Stay up, dude!
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Congratulations on having a CRX!! Those cars are hands down among the loudest I've personally built boxes for.
With those cars, you should definitely keep all your subs and the port as close as possible to the back of the car.
Here is a Crx test box (before carpeting) I tried a last week for (4) JL 12W3s on a 1000/1 tuned to 28hz and is already a legend in that little car (144-ish). All 4 subs are crammed into the back part of the car. The next unlimited bass box I build for a crx will have the port between the top two subs with the braces integrated into the port.
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Sundown is doing BIG things.
That is one nice amp for a hell of a price. Good luck with these, Jacob.
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nice 5 series. and also nice design wit that box
That's a 3-series, isn't it?
That sub box ought to be a felony.
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You would be running a 2200D on the 10s, but a 1200D on the 15? With more power the 10s will definitely slam harder. Plus, if you want deeper bass with those, just tune deeper.
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http://wimp.com/fastcar/
i'd take this over that supra
Hey, what's my car doing on that video??!!
Here's the really mad owner of a Lamborghini 2008 LP640 trying to race another Supra:
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why even make a video like that with such a shitty camera. It just made that impressive car, not really that impressive.
Did you see the tire marks in the road, tho?
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This is one awesome car:
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im lost in all of this.... but let me know if the info i have on my subs your talking about is wrong.
Of course I was talking about your subs, when I started this Topic (I want those badboys :hairtrick: ). The T/s numbers need to be measured on those or you never know how they'll sound in an enclosure.
Badass subs too, guys; check em out:
http://www.stevemeadedesigns.com/board/ind...showtopic=42368
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All the Q parameters are derived from the impedance graph for the speaker.
That's exactly right. I went back and added some formulas to the earlier replies to keep it together, but please spark discussion or questions as you see fit, okay?
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Wife needs some q.t. so I guess this will have to wait until tomorrow. BB
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Ok, cool. This is waaay easier than Calc2 or I wouldn't be doing it!!
Back to Fs then.
The impedance of a typical subwoofer is represented by a curve on a graph and not a straight line like DC impedance would suggest. Maximum impedance comes at the subs Fs.. In a minute we will go over a test routine that will let you figure the impedance curve and Fs of a subwoofer in FREE-AIR (not inside the box). After the sub gets put inside an enclosure, the Fs rises to a higher number called the Fc (total system resonance) for reasons we'll go into shortly.
SUBWOOFER Q
The parameter Q is a measure of the amount of control the sub's mechanical and electrical parts have over the motion of the cone. Two subs can have the same Fs, but because of a different Q, will sound totally different once inside the box. Like the Fs, the Q value of a sub referrs to Free Air. Once inside the box, Q changes to a larger value called the Qtc (total system damping).
QTS
Qts is composed of two factors, Qes (electrical damping) and Qms (mechanical damping). the Qes is just a measure of the Electrical control the voice coil exerts on cone motion. Qms is the measure of the Mechanical control exerted by the spider and surround material. Qes is usually a smaller number than Qms reflecting the fact that the EMF generated in the voice coil plays a much smaller role in damping than do the mechanical aspects near Fs.
The Qts (total Q in free air) is figured by a simple product over sum formula:
Qts= Qes x Qms/ Qes + Qms.
QTC (Sealed Box)
When you put a sub into an enclosure, its Q factor changes to a higher value called the Qtc (total damping). Enclosures with large Q numbers are overdamped since they don't have as much control over the subs' response as a low-Q enclosure (attention SQ guys). A high Q sealed enclosure will be louder (+6db where Q=2) than a low Q underdamped (<1) enclusure because of the high-Q example's lack of control around resonance. This same lack of control, however, also translates into muddy, ringing bass when Qtc approaches 2. Most of the time, you will want to compromise with a Qtc of around 1.
HOW TO MEASURE IMPEDANCE (Ohms)
As we already discussed, subwoofer impedance changes as its frequency changes due to the inductive nature of its voice coil. We are going to measure those changes in resistance as closely as possible.
All you will need is a DMM, the sub to be measured, and a test tone CD. If your sub has dual voice coils, the better, because you will only need one subwoofer. If you are measuring a SVC sub, then you will need another mule subwoofer to make the tones.
To start, get a peice of paper and number it from top to bottom starting from 10. Then, hook one voice coil of the sub up to the amp (you don't need a lot of power to do this) and the other voice coil up to your DMM. Set your DMM to read DC resistance and write down the DC (0 hertz) resistance, Re, of your sub. If you are measuring a 2 ohm voice coil, for example, it should read anywhere from 1.8 to 2.2 ohms.
First, play about 15-30 minutes of music through your (free-air) sub to loosen its suspension. Next, start your test tone Cd. Measure and write down the resistance of the open coil at each frequency up to 110hz. You will have noticed that the impedance numbers rise to a high point, and then descend as the frequencies go up. That high point, the Rmax, comes at the sub's resonant frequency, Fs. Go back to those freqs and check your numbers again for the Fs.
Now that you have a Fs (resonant frequency), an Re (DC resistance), an Rmax (maximum impedance), and an impedance plot for the speaker, you can go ahead and figure out the Ro, Rx, Qms, Qes, and Qts. The formulas for those are:
Ro= Rmax/Re
for Reference Impedance (Rx)
Rx2= Ro x Re
for Mechanical Damping (Qms)
Qms= (Fs x the square root of Ro)/F2 - F1
for Electrical Damping (Qes)
Qes = Qms/ Ro-1
and for Total Subwoofer Damping (Qts)
Qts = Qms/Ro
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Well, okay then.
The first parameter we have to discuss is the resonant frequency. A subwoofer's cone is acutually suspended in midair by the mechanical suspension of the speaker (the spider and surround). The mass of the cone in conjunction with the relative stiffness of the sub's suspension interacts in a direct and measurable way. Every subwoofer ever made has a frequency that tends to vibrate at. That frequency, its Fs, is called the sub's resonance. Knowing that number is vital for a number of different reasons we'll get into in a minute.
DETERMINING FS
Fs, the resonant frequency, is a number that almost all subs come with. If, however, for some reason you do not have that number, or you want your box to be EXACT, then you have to use another method. You have to look at the impedance curve of the subwoofer.
Let's talk a moment about voice coils. The voice coil of a sub is typically referred to as having a certain impedance (say 2 Ohms). What we have to understand that a voice coil is acutally suspended inside a very strong magnetic field. As we learned in science class, moving magnets past coils of wire affects the flow of electricity through the wires. a process called Faraday induction.
This means that while the wire in the voice coil has a direct-current (DC) resistance (ohms), that voice coil is also an inductor. Since inductors have inductive reactance, which, along with resistance makes a complicated impedance curve in the range of frequencies the sub is to be used for. Since a sub tends to vibrate at a certain frequency, it will also move FARTHER at that freq with the same energetic input. The coil moving farther through the magnetic field inside the motor causes more of an effect on the current trying to pass through the voice coil. As you might have figured, the coil will read its maximum impedance at the subwoofer's Fs.
That is where the Bass Mechanik CD comes in. You need some way of knowing exact frequencies going through your subs during the test. At the end of the Quad Maximus Cd there is are test tones from 20-80hz. These are very useful for measuring parameters.
Is anyone listening?
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Ok, some unknown 15s I was looking at got me thinking about dusting off the old Bass Mekanik CD to measure some Thiele/Small parameters the old-fashioned way; by hand.
You see, subwoofers are like snowflakes; every one is different. Even subs from the same manufacterer differ in small ways that can affect overall performance. The numbers that tell us what a subwoofer is doing (or is capable of doing) are called parameters. because of the work of the two engineers who pioneered the terms, Neville Thiele and Richard Small. Parameter is just a fancy way of saying "characteristic."
This Topic is devoted to measuring those parameters for yourself. That way, you will know that the next box you build will be a PERFECT match for the subwoofers you're running.
Is anyone interested?
BULL$HI@
in Off Topic - Random, Misc posts - the forum "Junk Drawer"
Posted
You might want to order some alarm remotes if you can't afford to replace the whole thing right now. That way, your alarm will still be good even though the key is still floating around somewhere. After all, if you do nothing, then your truck is completely unprotected.
I hope you can find those keys. Is your key black or grey, by the way? If you have grey keys, then it will cost more to replace than the black-headed keys. Even after reprogramming, understand that the original key will still manipulate the ignition lock even though it won't start it.
Or, you can set a trap for the bastard(s) with your keys and then...
Good luck with all this...