95Honda

I ran (6) 4" Aero Ports with my 8 RE8s and that was about as perfect and as loud as you could do... It did 143db on the TL with 150 watts. Definetly not to much port. I had to cut those ports down a few inches from full length also, so I could have ran around 8 at full length and been just fine. I think the box was roughly 6 cubes also... Don't put to much thought into box volume vs port area, these don't have anything to do with each other. The only thing that determains how much port area you need is the displacement of the driver. Companies recommend port area vs volume to keep idiots from running a 2" ID PVC port with an 18" driver because "WINISD said it was OK"..... Or putting a 10" ID port in a box for an 8.... Etc....

It will work perfectly fine. The only downside will be that, if you are running one set in the front of the vehicle and one set in the back, you won't have any fader control, you'll be stuck with it the way it is. If you go active, pay close attention to the crossover you choose. Don't accidently cross over the tweeters at 300 Hz instead of 3Khz and smoke them in 5 minutes.... Do your homework and make sure you know what you slopes and frequencies are.

Yes, they told me the Red top was completely different.

I had to pick some deep cycle batteries a few years ago for use in the Middle East. I ended up buying 150 optima yellow tops. I spoke in length with different engineers at Optima before making a choice. The only difference between the yellow and blue top is the extra set of terminals and extra metal that connects them. The internal plate configuration and specs are identical. For my application I choose the yellow top because I didn't have such high current demands (little over 100 amps). But, with super high current demands, the extra metal used for the connections of the blue top gives you a little lower resistance. Just wanted to point out the actuall differences between the 2.

Yes, we are talking about different things. You are talking about an actual impedance rise in respect to frequency due to inductance, that isn't what I have been refering to, and this also isn't really dependant upon the box. I am talking about the term "Impednace Rise" that gets thrown around here 10 times a day, when people are actually talking about thier box impedance, which goes up and DOWN, hense "Impedance Rise" is not correct...

You pretty much got it. As long as you put 12V across the coil, it will cause one set of the contacts to close, and, in some cases one set to open also. Just make sure whatever you are powering is hooked up to the set of contacts that close when you apply power to the coil. Also remember that you will need to supply 12V to one side of the contacts, that will go to whatever you are powering when they close. I usually take the 12V for the coil from the same 12V I am switching with the relay, I just build a little jumper wire.

I agree 100%. But this isn't "Impedance Rise". It is a free-air impedance curve vs a system alignment curve. I guess what I am trying to get people to understand is there is no such technical term as "Impedance Rise".... This is becuase the impednace goes up, it goes down, it goes up again.... Etc Etc Etc... And this is an impedance curve.... Not "Impedance Rise" I guess peole will just have to let the whole DCR = Impedance thing go.... It will be hard... But they can do it!

Ugghh... There is no such thing as IMPEDANCE RISE. If you have a driver, in or out of a box, it will have an impedance that fluctuates with frequency, this isn't impedance rise, it is an impedance curve, and has been that way longer than anyone of us on here has been alive. DCR has less to do with impedance than almost everyone thinks. Measuring DCR tells you that you don't have a shorted or open coil, and ROUGHLY, I mean VERY roughly what the impedance MAY average. If you don't have an impedance bridge, or something like a Dayton Woofer tester, you, nor anyone else will be able to tell you what your impedance is. You can clamp current and check voltage a hundred times if you feel like it, because that is what you would have to do to plot your impedance without the other things mentioned. And you would have to do it a BUNCH of times... Plan on this, if the manufacturer tells you it's a 4 ohm woofer, there is 99% chance that your impedance will hardly ever drop below this. It will be above this the rest of the time due to the box and the Le of the voice coil. It is impossible (unless you short windings) to have an impedance on any frequency above .00001 Hz that will be less than the DCR. The guys that are "Strapped at .35 ohms" are more at 2+ ohms most of the time... This is due to the box, the Le of the driver, the frequency, the heat of the coils, the resistance of the cables and all the connections, etc..... This why amps that are run at low inpedance will shut off or blow with some songs and not others or sine waves instead of songs, it is all due to the varing impedance and phase magnitude the load presents. Your 1 ohm subs could be 20 ohms at certain frequencies in cerertain boxes... Things really get screwy around tuning and/or resonance...

You don't need to do anything to it. Since it is round (the strongest shape in existance to hole pressure) it is more rigid and capable of holding in air pressure and not flexing than an MDF box that is 4" thick.... The way it easily is crushed has nothing to do with it's properties as a speaker box. Just don't dent it. If you are worried, BTW, they make some that is 3/8" - 1/2" thick, you just have to look around a bit. That is what I used to use when I was building a bunch of these back in the late 80s....

You are going to get the same type of answers here you did on CSO. Don't forget that you already have 8 12s, right? Well again, even if they are crappy ones a pair of any 15s will have tough time keeping up... Do your homework and you will know when people are giving you information they pulled out of thier ass. Read the Loudspeaker design Cook Book by Vance Dickason, think about it for a few days and then re-post your question. You can get the book many places on line, like Amazon.com.

Yup, it has everything to do with the sound....

It is good you are buying a new amp. But please, remember, that no matter what people tell you.... The more power you have the more likely you are to blow a sub. That Lanzar can probably make 500 watts, fully clipped, down-hill with a tailwind... I have no idea what the RMS is on those subs, but if it is more than 500, you would have a real, real tough time blowing them with a Vibe 250. Now, with a 1500 watt class D, you can turn them into junk real quick, just be judicious with your volume control. I am not trying to say you will be irresponsible, I think this just needs to be pointed out after reading this thread.

By making the box smaller and raising the power handling (mechanical) of the woofer, all you have accomplished is making the entire system less efficient. Also, due to thermal compression, it will never play as loud as the larger enclosure.... It's pretty much Hoffmans iron law... Look at it this way, if you took say this same woofer and put it in a sealed box of .25ft the mechanical power handling would be through the roof, you could probably easily feed several thousands watts into the driver and never bottom it out at any frequency... The probelm is you would have to pour all that power into the driver to do what 1/2 or 1/4 the power would do in a LARGER box... And still, because of thermal issues (compression, failure, impedance fluxuation) it will still never get as loud. One of the biggest backwards thing people say is "I want a woofer that will handle X amount of power". Not only is this completely backwards, but it is really, really stupid. The way it should go is "I have X woofer in X alignment, how much power do I need to bring the driver to it's full mechanical potential"? This is what you need to be thinking about. Making the box smaller to handle more power is a step backwards in everything right. If you are making the box smaller to achieve a different target response, than that is different. At least understand this, if anything- If you make the box smaller, you alter the response. Especially for sealed alignments.

Black00 (Marshal Joyner) used it on his S10 wall that gained him a MECCA world record. I have never personally used it, but he really said he liked it alot and was happy with the weight savings.

There is a good answer for you. I think alot of guys download WINISD on here, it is shareware and free. You can also use BOXPLOT, it is free also, it is not as detailed as WINISD, put it will still give you vent velocity. Shizzzon also made a good point about power relationship to vent velocity. Since power is going to determain you driver displacement, it also determains your vent requirements. Even if you had a driver like say a XXX 18, you could get away with a single 4" port as long as you never used more than a few hundred watts, do you see the relationship? (THIS IS AN EXAMPLE) You may just be running into port compression noise at full power, which should already be pretty loud and hard to pick up at that point, I would just be 100% sure the noise is from the port size, not something like sharp edges, wierd stuff in the box, leaky joints, etc...

Minimum port area has nothing to do with box size, at all. It all depends on the displacement of the driver. If you heard vent noise (chuffing) the vent was too small. A 3" Areo should be able to handle a lot of flow though.... Just model your sub and port and see what the vent velocity is. The higher this is, the more likely you are to hear port noise and run into compression problems. You'll notice that if you change box volume, the vent velocity stays almost the same as long as the response stays flat.

That is a pretty high system Q, it will probably really exagerate the 50-70Hz range in car. If you want to go sealed, go with a driver designed for it, like everyone else said. BTW, the school of though that sealed = tigher bass, better transients, more accurate is all BS. This just comes from people who haven't been around a properly built ported box, because there are a crapload around. Sealed alignements are easier to get right, that makes them easier for the novice, but never, ever discount the sonic potential of vented alignments.... The MOST expensive loudpeakers in the world generaly are vented if they aren't servo driven, if that tells you anything... I'm talking like the $100K stuff.....

They are $75 now. http://www.partsexpress.com/pe/showdetl.cf...tnumber=264-833

Yep

Get this, My local vendor (Oxyarc in Spokane, Wa) was blowing out 4/0 (yes 0000) Supraflex (like 4000 strands) cable in Red color because they didn't sell much.... For 50 cents a foot.... I bought all they had... about 50'..... Now I have like 80lbs of power cable I have no idea what to do with You never know what you may run imto at your local welding supply shops, check it out....

ANL I have no idea what you can get them for but Partsexpress has the Stinger one for 1/0 that is sealed with O-rings for about $25, and an even cheaper one from PA I think for about $20... Been a while since I looked though.. If you aren't worried about moisture, they have a house brand one that is NOT sealed for under $10. I think the fuses are $1 or so each..... No idea if this helps you or not.. Fuse size for this application has nothing to do with amp or sub, it is only there to keep your car from catching fire if you short out your power cable. Anything up to 300 amps in an ANL fuse will be fine for 1/0 cable... This has NOTHING to due with protecting your amplifier, BTW... Also, why is this in Home Audio?

Anything allowed to resonate can act as antenna. I spent 6 years evaluating/writting test procedures for HEMP hardened 100db EMI/RFI shield rooms, they are now published as Air force technical orders. I have built and used a LISN and a marks bank E2 pulse generator. I have had a car idle next to me and have heard his ignition noise through a (my) stock audio system, presumable from low ohm non-supression "race style" plug wires and probably some huge CD ignition system (MSD stickers all over the windows)... But, what do I know...

I really like a gang of 4 8" subs for regular cab trucks. You basically have the cone area of a pair of 12s, with less box requirements, easy low tuning, small narrow baffle, low mounting depth and good thermal power handling when you divide between the 4 motors. I have done 2 S10s with 4x8 boxes, RE8s sealed and RE8s ported.... They sound awesome if you do it right. Or one of my personal favorites is the Tangband NEO 8. A little over $60 each, handle a lot of power, get low and loud and are built very well. They have tiny neo motors on the back so box design is easy. they also have 12mm of one way linear throw... Toght to beat for the price, really... Here is a picture of them in a box I built for my dad last fall.

Good. Try and be as objective as possible when comparing these different setups and hopefully you'll find out where the problem lies.

I think that M5 is actually nicer than he has to be, he is more tolerant than I. As soon as I see "cuz" "wit" "i" "k" "how many dbs" or anything else written that way, I pretty much realize that all forward progress has now ended... If you speak/talk/post like crap, you should just pay someone to do whatever it is you are trying accomplish with the least amount of effort. That would be better for everyone. If you are really trying to learn (and not have someone else do all the leg work for you) you would be honest, factual and intelligent. I know that I seriously think about my help before I post it. I try and ensure I cover all my bases and give people real answers that come from measuring, training, experience and personal knowledge. This takes time. If people expect to get articulate help, they need to post articulate questions. -Just my 2 cents, of course...