Hell-Razor

Yes pushing on the cone, sorry.Isnt it bad pushing on the cone while its playing? I know not to do it at like full power but couldnt that make the magnet come in contact with the coils? Also, does anybody know what to look for? I am going to pop the woofer out again tomorrow to see if I overlooked anything. Nothing looks bent compared to mine.

Could it be blown even with no resistance while pushing in the magnet manually?

I was helping my friend out today wire 2 12" jls and we got everything setup and things were hunky dory. We took them from his old car, built a new box and tossed them in his new car. We powered it on (using multimeters to measure gains and SSF beforehand) and we started playing some tunes. All is well but I go to turn the volume down low to where the sub is barley playing and I noticed some scratching noise. I went back and pushed on the magnet (power off of course) and no scratching, no huge resistances... about the same as my 15. We took out the subs and they look fine. No bent coils (as far as I can tell), nothing is stuck, no burning...I took a quick peak at the terminals (we used screws in the wood for + and -) and they are pretty loose. Could that be the problem? Or maybe not a good enough ground? I don't think this sub is blown but I think something is definitely wrong.

Alright well I finally have a new box design for my level 5 15". I just need some help with those of you who have built boxes in very tight situations. I have about an inch on the left and right side to spare and a few inches on top. I cannot build it outside and then toss the box in because my trunk space is too small. Rotating it will be difficult as well.. I have read on here people doing very big boxes in small areas inside their car. Pictures will be posted soon in my build log as well!

I was in a bar fight a few weeks ago and I got my VW Passat key cracked pretty bad. The key ring also got taken off when it slammed into the ground. Is there anybody out there that would sell the casing for the key? I know the dealers want something like 400$ for a new key. All the mechanical stuff still works and nothing is really bent, just the plastic outside is cracked. I have taken this key apart several times before and after to know enough that the plastic casing is just a case, nothing in it is permanent. I have googled with no luck though. Any help is appreciated.

Nope. I am positive on this one. I even thought that as well but I am adjusting the subsonic. I just set it at a hair less than halway becuase halfway on a 3500D is 35hz.

Id say a 2010 VW Passat. The Germans are awesome auto makers and I have owned two VW Passat in my time. One (year 94) went at 245k miles and I am sure that the accident it was in is what did the engine in =P (some idiot side swiped it just in front of the A post while it was parked at 3am). Plus the 2010 VW passat looks very classy and fast at the same time. You can get it with any stage turbo you want.... Even if it may be out of yoru price range a hair, I would still go fo it. My 2003 VW Passat right now is still running like that day we got it with 100 miles (now has 85k).

I am so confused right now. I started playing a 33hz test tone, put the SSF at 10hz and I measured the output terminals with a DMM. It came up as 6v. so then 6 x .707 = 4.24200. I then went and put the SSF at about where it looks like it should be on the range and it showed that the voltage went from 6 to 10.25. What the... Its supposed to go down, not up.

Very nice. I did not know this, I thought it was a "brick wall". Anyway, why .707? I have never seen this number in car audio. But then again I am a novice towards this kind of stuff.

Thats what I figured. But you dont know 100% until you ask. I think ill just set things at zero and re do my amp gain.

Currently on my HU there are a lot of options for bass and sub settings. I currently have the bass setting to zero and the sub settings at -20 (lowest it can go) and on my amp I have set my gain using a DMM and reading the "how to set your amp gain" post. Now I was just curious if by having the subwoofer to -20, and having my eq for anything below 50hz set to zero or lower (on my hu) is hurting the performance at all. Currently, the gain on the woofer is about 70% of the way up and its not clipping. Do I set the sub (lets just say) at 0 and same with the built in eq for anything below 50hz? Will this improve anything? And yes I would re set the gain on my amp. EDIT: I forgot to mention my HU is a Pioneer DEH-P7100BT

Well I just started today really trying to tweak everything on my amplifiers to get everything working correctly. I started with my big amp setting the gain with a DMM. all that went well but I noticed that my subsonic may have been off. So I popped in a tone to 33hz to try and make it cutoff at that point and its not. I cranked it up to 60 hz (has a range of 10-60hz) and it is still not cutting that signal out. Is it possible I have a faulty SSF? I have a SAZ-3500D and a SAX-50.4

I was just doing more research on boxes and whatnot and came across Heath and his . Anyway, what is up with his dustcap? Is that what it looks like before / after you blow it off? I know that's a prototype and its not officially released "yet".

/bump

SAZ-3500D!

Alright, I think I got a new design coming along decently. I think a DC Level 5 15 is about .21 displacement so thats what I about based this design off of. I will be building this box out of 3/4 MDF, 39" W, 19" H, 15" D. This will give the box 4.5cuFt of airspace without displacement. The woofer and port will be firing forward COMPETITION: The port will be 5" W (17.5 inches tall) and 16.5" D tuned to 46hz with a total volume of 4.23 cuFt. Will give me a square port area of 87.5 DAILY POUNDING: The port will be 1.5 "W (17.5 inches tall) and 16.5" D tuned to 26hz with a total volume of 4.8 cuFt. Will give me a square port area of 26.25. i THINK this has to be between 60 and 120 though =/ What do you guys think? The only thing I am not sure about is the competition box. It seems that with a port that big it will reduce the cuFt of the box to about 4 not including the displacement from the woofer... EDIT: I just realized the daily pounding port may do two things 1) I dont have enough port room 2) I may get port noise

Right now with my 3.5cuFt box its holding very very very well (its 3/4 MDF). I put a mirror on it about 5 minutes ago and a laser to see if the box is flexing. Its not but it sure is vibrating....I will fiberglass the box, I plan on doing that and something on the inside to make it nice and smooth. I will tackle that road though when I get to it.But I am up to bracing or moving to 1.5 MDF like you recommended. Its just I am pressed for space is all...

Sweet. Thanks

Clamping the DC side of the amp would tell you how much power the amplifier is drawing from the electrical system, not outputting to the speaker. When someone "clamps" an amp they are measuring the output side of the amp, which is AC. They normally keep a DMM on the power input side to monitor what the input voltage is dropping to, but that's not how they are deriving their power output figures. Anyways.....many people fall under this delusion that they are performing some meaningful act by "clamping" their amplifiers. As Crazy said, they connect their amplifier to a load (normally just a subwoofer in most cases) and play a test tone. They then use a DMM to measure the voltage output from the amplifier and a clamp meter to measure the current on the output side of the amplifier while playing the test tone. They then use basic ohms law to calculate power (Voltage * Amps = Power) and the impedance of the load (Voltage/Amps = Resistance). As I previously mentioned, most people will also use a DMM on the power input side of the amplifier to monitor the voltage drop the electrical supply is experiencing. The problem is, 99% of the time people are simply wasting their time. It's a mostly meaningless endeavor that has been perpetually (and incorrectly) promoted on the internet as having actual relevance. There are several problems with this method. Along with being able to question the accuracy of the measurements themselves for various reasons (accuracy of the devices, the type of measurement being conducted, the varying impedance of the load, the varying stability of the supply, etc), many people try to compare these "clamp test" results to the manufacturer rated power. The problem is, the manufacturer's rated power is specified at a certain distortion level. Nobody performing these clamp tests are measuring distortion. One could make any amplifier appear highly underrated very easily in one of these "clamp" tests as there is a total disregard of distortion. Wow, that actually makes a lot of sense.

How did you not see that pig behind you? Was he in one of those unmarked public cars? Not the police cars with no markings but one of the every-day cars on the road you see now and again.

Hrmm. It looks like I would need some tweaking on the design.... I would need some crazy port. Well I guess its obvious I need a helping hand.

Alright guys here it goes... Trial 2! for my woofer box.... My current design is 31.5w, 22d and 16.5t. I don't remember the wood thickness but I found a scratch paper and I only made my box 3.5cuFt... Which is the smallest they recommend for a level 5 15". Why I did that? I have no bloody idea.... Anyway I re measured and I can add a little more to the box -- roughly 2.25 inches on top, and 7.5 inches on width. I would like to try and reduce the dept the most I can because as of right now I cannot fit more than one battery back there. I would like to be able to lay my amp down nice and neat and have the bat next to it. I will be trying to design my own again but I would love to see people chiming in with recommendations. Pretty sure I want to tune it lower than what I have now (31.5hz) to about 28hz. I would like to add a slide to change the tuning to the mid to upper 40s for competitions. I like having massive output on the lows and seeing my car vibrate to death, probably the reason why I want to tune lower than what I have currently. A rough sketch I came up with (for the complete box) is: 39W, 18.75H, 12.25D with .75inch thickness MDF. This would bring me to just over 4 cuFt (4.02425). Any yays or nays to trying to design a slider with this? Anything jump out screaming "noooo"? My issue right now is that I don't know of any good ways of figuring out a slider to change the tuning.

Shizz -- For setting a SSF through "mechanical means using test tones". What is the best way to do this? What do you listen / watch for?

I have been reading around on some build logs and people are saying that they have an amplifier that is "clamped". What does this mean? I have been googling around with no luck (so far).

What do you mean by "you hope my subs/amps are under warranty". You're the first person that I have ever heard talking about "cabin frequency". And how the sound plays in my cabin, how would that effect the wear and tear on my woofer? If I put something in my back seat, that would change the tuning (adding something). If I have a friend in the car, that would change the tuning. If I had my windows half / quarter up or down. that would change the frequency. As far as what I know cabin frequency only matters for when you do competitions to get that extra tenth of a db. I don't remember the exact number but I think below 20hz your ear cannot hear, so why bother tuning THAT low? Its way way way too low. Most guys on here are from 30-38hz.