NDMstang65

Awesome! Let us know when you get it hooked up! Thanks! Nick

Email me.. I want to make sure your stuff is taken care of!

Yes I did get a tracking number for each sub. The one that hasn't shipped is still listed as 'Order Processed'. Still wondering what's going on. Your 4th one is the very first one for us to build when the magnets get in. All of the steel parts are sitting..waiting..wishing to get out of here!

aeroport it bass will come

yes

personally i think nick is wrong on the soft parts not being fragile in the cold..... for example i just reconed my BL 18's not even a month ago and was slamming on them and it was in the single digits outside and even below 0 sometimes and i cracked one of my spiders.. Nick tries saying it was cause i was playin below tuning and blah blah blah subsonic filter needs to be set higher yada yada yada when i dont EVEN play low shit on my system especially nothing below 30hz thats for damn sure.... of course thou its never the manufactures fault always the consumers... since ive owned the BL's before i reconed them for over 2 years with NO issues... We have been using that spider since before the days of RE, we know the limitations of that spider..and exactly how it breaks and what causes it. Here's the problem. You do not KNOW if you are playing "low shit on my system below 30Hz" You could have reverberations in the recording or a pop/click of the mic that is at 8-10Hz that you can't hear (granted it should be filtered out, but who knows if you even had the filter on)..it can happen so fast that you do not even know that it happened, yet you keep playing the track. The quality of the recording of a track can make things do stupid stuff. Loading in the enclosure can cause issues..if a sub is not 'behind' a port and one is 'behind' a port then you have 1 woofer that loads completely differently than another one. One will move more then the other one will...resulting in your situation with the popped spiders. The BL only has a 1.8" tall coil, and a .9" tall top plate. (xmax of 18mm 1 way linear travel) The spiders do NOT lock up until 30mm in ONE direction...when they lock up they pop like a potato chip radially across the weave of the spider. So you are definitely playing below port tuning frequency, with too shallow of a subsonic filter...OR your tuning is off (which is more likely because resistors have a set value that is defined by mathematics..a port length has far more human error in the equation) Those spiders only pop when they 'lock up' or move past the mechanical limitations. When you move it past 30mm (or so) you begin to form right angles radially in 4-6 spots in the spider (generally 4), at that point it makes a 'crease' in the phenolic resin and when you keep hitting that same spot on that same song it eventually pops and rips all the way through at that stress point. Sorry you feel that we should be held responsible..those spiders simply do not have issues, they have been the same spider we have been using for 12 years, with the same materials and everything. It does not have issues unless you push it past the mechanical limitations.. It is no different then a tab on a coke can. You can bend it back and forth within its limitations all day long, when you start moving it PAST the limitations it then pops and breaks at that stress point. The temperatures here have absolutely nothing to do with it. You are not going to shred a spider in the states..it does not get cold enough. Alaska now, that could potentially be an issue as they get down to 30 and 40 below zero...but I doubt it very seriously...the spiders are made out of poly cotton, the same stuff your t-shirt is made out of...

Laws of physics state for every action there is an equal, but opposite reaction.. You're going to lose bottom end. It will be more 'snappy' with the smaller enclosure. There's no free lunch

Doesn't appear to be anybody around you. Shoot brian an email. bkolfo4 @ ymail.com

We here at FI CAR AUDIO have used this rule of thumb with great success and so have dozens of clients around the world. So, we say feel free to use the rule of thumb.

I thought you guys had suggested port area specs as well, like how IA did/does? If not, I think that'd be something good to have; a solid figure(or suggested span) for how much port area is necessary to avoid port noise at full xmax(maybe even more). We do.. Basic math.. 3-5 cubic feet (you pick 4 cubic feet) 12-16 square inches of port per cubic foot of volume (you pick 14) 14 x 4 = 56 square inches of vent.. Doesn't get any simpler then that.

Think about it.. There is a LOT of information and processes that we have refined over thousands upon thousands of iterations.. That takes YEARS to figure out on your own. We hire somebody in..they work for a month and disappear. Next thing you know somebody else is doing something to mimic what we do.. We've already given the industry enough as it is over the years..if you look around and don't see that you are simply blind I see so you are just trying to protect your work.. You can always make the employee sign a contract stating, that if they were to use any of your designs they will get sued to the fullest extent. I do realize how much FI has contributed to the speaker world, If it weren't for you guys sub-woofers wouldn't be the same! Think about this.. So a new employee goes and signs a no compete contract and then runs away. They have nothing to sue them over..and our ways of doing things are lost either way. No thanks , I'll pass.

Oh god, I know this must be some "magical" situation wich no software can predict... Go ahead and put a BTL in a box that winisd predicts (it is about the size of a shoe box) will have the "flattest" response curve. It does not deal with a very low vas and low qts woofer very well at all as far as 'predicting' an 'ideal' enclosure. It will be anemic as hell, no bottom end..and peak like a high school prom date. Even though winisd says it should be fairly flat. The guidelines have worked fine for years, thousands of people have used it. It is MUCH better then spending 12 hours on a phone trying to tell somebody how to model and plot something. You seem to forget that many people who buy these things do not know the difference between a dual 1ohm or dual 2ohm coil or how to wire it. You also seem to forget that the 16 year old kid doesn't "normalize" his amplifier power when he clips the piss out of it either..he just clips the piss out of it. Not quite sure what has chapped your hind parts lately..but if you don't like it, don't read it. You are only going to confuse them even more by doing so, which causes us even more of a pain in the ribs having to explain why you are confusing the hell out of them. Please stop. There is absolutely no need to complicate things more then what they are already. Basic rules of thumb and box designs work absolutely fine and there are no issues with them.

Works fine.. It's better then trying to show somebody how to model something in an anechoic environment that it will never be in

Go take a 120 volt lightbulb..put it on a sine wave Put a 120 volt light bulb now on a square wave. Tell me if the square wave one is not brighter. Rail voltage on an amplifier does not necessarily scale back...and it is not normalized. There is absolutely no point in normalizing things.

Easy as putting the hole for the sub in the top of the box and leaving the port firing back.

Thinking more.. We are not talking about taking a potential 1000 watt amp and making it run at 100 watts sine wave and then square waving it and getting 400 watts...that is a no brainer why you would have more heat. It is more power. We're talking about a 1000 watt amp, putting out maximum power with a sine wave at 1000 watts...it is then driven with a square wave, more heat is present than with a sine wave with the same 1000 watts. It can only make 1000 watts..that's all it can do. 100 volts and 10 amps for sake of the discussion...square wave..sine wave..pink noise..white noise..what have you. 1000 watts. But we really can't talk about watts at this point (because of the rms value here), what you need to look at is voltage. The rails are capable of doing 100 volts peak to peak..that is what it is capable of doing, that is what the square wave does. We are talking about a peaked out rail here...+/- 50 volts the sine wave just touches it. Your square wave hits it 100% of that energy for that period of time. Why is the coil 130 degrees hotter with the square wave form? If..'clipping' does not blow speakers or burn parts up. It has to be the amount of time that the speaker is 'on' 100% at the extreme north and south end where it literally sits there, does not move, and burns. This is not even looking into the MASSIVE acceleration factors and forces going on here either.. Edit: At the two extreme points the coil is 'stopped' or 'dead' and doing nothing but taking the grunt of the amp for the time value of the operating frequency of the output transistors...it's not doing anything (Back to the rev limiter analogy here) It is just like pushing the clutch in and holding the gas pedal to the floor bouncing the engine off of the rev limiter and jerking the gear shift into reverse. Still holding the accelerator to the floor and slamming it back in first..the time that the speaker is stopped is the period of time in which it takes you to physically switch the gear from reverse to forwards without using the clutch....which shanks gears in transmissions, snaps spiders in subs.. Which is due to acceleration factor and more energy per time division..which needs to be tested by an accelerometer..which i'll do when I have time. There is no clutch, there is no braking or slow down. You are 100% forward, and instantly stopping and 100% rearword...and burning in-between. Hope this helps.

My point: If clipping does not break speakers. An amplifier is making maximum power with a sine wave, it is then driven with a square wave. The Coil is 130 degrees hotter..without more power being present...because the amplifier can not make any more power it was already making maximum power with the sine wave previously. The only thing that is changed is the wave form itself, and the time that the coil is "on".

No..can't. If amplifier is running wide open at 2000 watts...sine wave, it is making 200 volts and 10 amps. That is all it will make...that is all the power supply will support, that is all the gates on the fets will switch. Flip the generator over to square wave, by definition in this thread it should have less power...according to RMS calculations done. It was already making maximum power before with the sine wave. There is FAR more heat present...we stuck the fluke probe right to the coil. It was around 130 degrees hotter if memory serves me correctly right after turning the amp off..that is absolute fact. It was hotter. Period. If 2000 watts is 2000 watts...and there is no difference according to a speaker with a square wave form vs a sine wave form..why was there 130 degrees more heat? The amp didn't suddenly make 4000 watts to get it the 130 degrees hotter. The only thing that changed was the wave form, and the time period that it was on...100%. Instead of .707 RMS of a sine wave..because RMS and Peak is the same within a square wave form..

You..don't need those. The only thing you should be calculating a port for is the length for desired tuning, watch the video below.

i have 2 fi ssd 15s and i was gonna change them to btl 15s and recone them If we could do that we would make money hand over fist.. Go buy some pioneer woofers at walmart and throw "btl" parts in them and make BTLs That'd be great!

Because when people purchase recones sometimes they want to go from an 18 to a 15...or vice versa.

Exactly as that is how you describe power. Again, average is implied. Has to be unless you are referring to instantaneous but then it wouldn't be a stress test showing heat as you can't measure instantaneous heat changes accurately. You should think about your calculation of watts. By definition it is average power. You are taking a shortcut of course and using a simple measurement device that only measures instantaneous which is confusing this as it is the wrong unit of measurement for the task at hand. You need to account for the delta T otherwise the whole discussion of heat and cooling makes no sense. Still.. If there is less power by definition using RMS figures.. Why is there more heat present? clipping.

You took voltage away from the square wave...to make it "equal" using the assumption of .707 is the RMS figure (the 3.535dx from x=0 to pi), the sine wave you assigned 5 volts to, the square wave where rms=peak you took power away from it to make it "equal" by RMS figures. I definitely see what you are saying...which begs the question, does voltage actually drop with sine vs. square with same wattage? But at that point how could the same 100 watts for example be the same? If voltage is down on the square wave, and current is definitely down due to a higher resistance of the coil due to induced heat...you are not getting anywhere near the 100 watts that you were with the sine wave, you are getting far less..and there is way more heat present?

I don't quite understand the infatuation with people and bandpass boxes the past two weeks.. Why do you plan on using one?

Energy over time is the definition of power. Yes But 100 watts, is still 100 watts. Sine, Square, Triangle, Clipped. Still 100 watts. What changes, is the time the 100 watts is applied.