Leaderboard

You have to consider the environment as well. If we were talking about home audio, then yes a Qts of >.5 (ideally closer to .7) and a super-low Fs (<20hz) are pretty much mandatory. In a car, however, things are different. We get significant boost in the lower frequencies from the transfer function of the vehicle, and most times the trunk doesn't act as a "true" IB alignment. So we don't need the drivers themselves to generate flat response down to 20hz....the car helps us do that Generally there are two routes that work well for IB in a car.....low Q (< .4) and low Fs (~20hz), or mid Q (~ .5) and mid Fs ( high 20's - low 30's). If you go with a low Q/high Fs driver, then the low frequency response is rolled off too much. High Q/Low Fs (like home audio IB subwoofers) can work with appropriate EQ to tame the bottom end....with out it, they'll be too bloated on the low end. However, you have to consider how the airspace is going to affect the driver. Chances are you're going to get some increase in Q as a result of the trunk. According to Unibox, in a 15cuft enclosure with two 18" Xcons the Qtc would be .63 with an F3 of 43hz......models pretty well for mating with the transfer function of an automobile. Maximum output is the same as that of a sealed enclosure because peak output is limited by the same factor; peak linear displacement. So the output potential isn't any lower with drivers mounted IB compared to sealed. The difference is in the response curve. Sealed enclosures will usually have a little more output in the upper-subbass (above 40hz) due to the peak generated by the affect of the enclosure.....however, IB drivers will typically have more output in the lower frequencies (40hz and below) due to the lack of enclosure (a sealed enclosure is essentially a highpass filter, so if you remove that you improve low frequency response). So to say drivers mounted IB have "less output" is typically incorrect as you have to consider what frequency region is being discussed And maximum output potential is equivalent between both alignments. As for power.....don't apply more than is required Mechanical power handling is reduced for a driver mounted IB since it doesn't have the "spring" of the enclosure to aid it mechanically. Unibox says you wouldn't hit Xmax in a 15cuft enclosure with 3500w until 12hz......but I would focus on what personal experience tells you there. Long story short....go for it Just be careful, IB drivers are easier to overdrive.

We do not do pre-orders, never have..never will. I see no point in taking somebody's money and making them wait for months on end to help pay for product that doesn't exist, that just screams "I do not have enough money to order 100 pieces from China so I will discount it to raise capital to pay for it before it even exists, and if it comes in with everything messed up I am screwed." ..granted we actually build our own stuff here so it is definitely different. Still absolutely refuse to do it though.

The shirt brings out my tats

I like to use a battery tender. http://www.batterytender.com/

Just throw them on your charger...nothing will happen to your amp, your charger will charge at 14.4 volts, with even less amperage than your alternator, what could it possibly do?

I cannot imagine a single possible reason why you could not do this. Hell, I've done it many times, as I'm sure many others have. If there's a no no reason for doing so I'd like to have it explained in excruciating detail, lol. It's not going to hurt any equipment, nor should there be any effect on charging the batteries together.

If you charge them seperately you should be fine.

You can't push the sound waves, but you can "concentrate" (for lack of a better word at the moment, M5 I know you have a better term for it) them. Think of yelling through a traffic cone for example, there are horn loaded enclosures than can do the kind of thing your idea was moving toward. However, if you remember Impious's post on the length of the waves, it takes a VERY large and long horn to effect the sound waves in that manner and are not really ideal for car audio use due to the size. People have done them, don't get me wrong. I just have never seen one in person to give you any idea of how it worked out. I would still stick with the idea that a properly built, braced and tuned ported enclosure will out perform any other wild idea, like a transmission line or horn, that was done wrong just to fit in the car. Just my .02

Steve Meade stopped by with Mark and we did this quick video.

I agree.... I use that gasket tape on EVERYTHING I build. Seal subs, ports, removable ports/panels just about anything. Look at the bottom of the rubber gasket, you'll see the foam tape.

LMMFAO Yep.. You're one of those guys. sure am, but not because I use the IB3 in the wrong application, as I smash coils with every other sub as well. Ive never burnt an IB3 coil, I havent burnt a coil in 6 years....ever since I started having 4X RMS headroom and stopped clipping. If I never TermLab'ed the van Id never have bottomed those, and if I would have just gotten four 18's for the towers instead of just two to get me by for the 22's always "coming out in a couple months...just a couple more months" I never would have bottomed those either, as I havent bottomed the four new ones yet. I could put any one of your other eighteens in either of my setups and Id still bottom them, cause I always red line, always ride the line..and if you want to hate on THAT someday then youd be correct... and I could run your other subs in the correct applications with the exception of more power than I am supposed to and bottom those as well.... has nothing to do with the wrong application. But what do you keep bitchin for? I throw more money at you every time I break shit. You should be happy. I help pay your rent. And by "one of those guys" I hope you simply mean "turning them inside out" not calling and bitching, cuz Iv never called you and blamed you. I know full well I crank 10Hz sine waves for 10 minutes full excursion at tuning without breaking a sweat. You've never complained about breaking them, and I have always told you that you should not run IB woofers in a ported box, I do not want you to tell other people that you run IB woofers in ported boxes...because they go and do it! Then we get yelled at (not from you, others) because they a) break, b) sound less than desirable...and are peaky as hell. ...I said you were one of those guys that are infatuated with running infinite baffle woofers in a ported box...for what reason I still do not understand nor will I ever understand because it makes no rational sense at all what so ever. It's the people following in your footsteps that cause issue and the ones that buy a pair of 12s or a pair of 15s and slap them in a ported box...that do not have things quite as under control as you do...and turn them inside out. Because they saw it being done on youtube, so they figured they could do it too. So, if they do not see it on the website, they can not purchase it...leading to less problems on our end of having to explain for hours on end why they should have never ran a woofer that is designed for IB use in a car in a ported enclosure. We decided to not do the 22 for the time being..just have to do the cone and surround. Many other things are far more pressing and will actually sell a great deal more than the 22 would.

LMMFAO Yep.. You're one of those guys.

You might want to check out homeaudioforum.net. Blueprint is one of the manufacturers there.

Good post, thats what happens when people have one side of the story. Keep doing what your doing, stuff happens and thats life, people just gotta understand that.

Your argument is stated incorrectly from the start Higher voltage has nothing to do with rejecting more noise. The same amount of noise would be induced into the signal. The difference is the level that of that noise in relation to the level of the signal. This is signal-to-noise ratio, not noise rejection. But to save you some time......if you are picking up enough noise during the signal transfer that a 2V preamp output headunit isn't sufficient....then you have other problems in the system that need worked on first. If the amplifier is generating enough noise with a higher gain setting that the noise is audible during playback, then you have other issues in the chain that need worked on first.

As for changes I am not sure, but one thing I can say with confidence is if there are they will be something you'll appreciate. Fi has done a great job historically of learning what to apply for what use with generational changes. If not, they were already great drivers when used appropriately.

Then you should ignore those "a lot of people" as they don't know jack. I beg to differ. It's kinda about noise rejection... mostly just for induced noise from the RCAs. Say you're feeding an amp that makes 30v wide open with a 1v signal. The signal has to be 'multiplied' (which is actually what gain is measured in) 30 times. If you have 100mV of induced noise then when you multiply that 30 times you'll get 3v of noise on your output. If you feed the same amp with a 6v signal and adjust the gain accordingly then it only has to multiply the input 5 times to reach full output. So your 100mV of noise only turns into 0.5v at the outputs... If you've got 100mV of noise you have other problems. Here is an enlightening exercise for you: Please re-do your argumentation in dB. Then tell us how often is your 4v head unit outputting more than 2v? Be sure to discuss this under listening and not competition. Nobody cares about noise on burps. You differ just went out the window...

FAIL. Try again. We have guidelines for a reason!!

A lack of parallel walls will have zero affect in the subbass. The purpose of non-parallel enclosure walls is to reduce standing waves within the enclosure. For subbass, this isn't going to be an issue to begin with as the dimensions of the enclosure are much shorter than the wavelengths of the sound waves, so standing waves are not going to develop. For subbass, I doubt there would be an audible difference between a well designed and braced MDF enclosure and some other exotic enclosure material. The resonant frequency of the panels is gong to be too high, and any losses from panel resonance/flexing is going to be too small compared to the driver output to audibly affect the sound. On a meter, I doubt you would see much of a difference either as long as the MDF enclosure was properly braced to begin with. Notice I explicitly stated I discussing affects in the subbass frequency range here. As we move up the frequency spectrum where the wavelengths are shorter and you are closer to the Fs of the enclosure panels, those issues can start to become problems (although there are far less exotic means of dealing with them). External panel shape can also affect frequency response in other ways in the higher frequency region....but that's neither here nor there.

MLV stops the transmission of sound. In the case of the box that is of dubious benefit. Obviously if you have a very poorly built enclosure some treatments could be a positive but that isn't the right way to fix the problem. For high frequencies it does, just not for sub frequencies.

Um, you'd waste money? All I've ever heard about doing it is that it would do no good what so ever. However, I used to know some old school enthusiasts who would line a few walls in a ported enclosure with quilt batting claiming it helped in some way. Never did a before and after comparison to see if there really was any difference though. It would probably be tough to keep something like that in the enclosure too with the large ports, high power, and sheer volume of air most of us are moving with our subs and enclosures. Most of these guys were building simpler, smaller, and lower power home speakers. Not a dumb question though.

Stupid question: If his alts are done and have been forever, and you're just waiting to complete the brackets......why not ship the guy his alts (more than likely the most costly part of this transaction), and DC Power contract and pay for someone like tejcurrent, another manufacturer right here on this forum, to build the brackets? It seems like this would go a long way towards completing the transaction on a pretty timely basis. At the very least, this would put the biggest chunk of change back into the OP's hands by having a tangible product in his possession. Then the only thing left is the bracket, which if another manufacturer such as tejcurrent can't produce on a timely basis, it's less of a refund that would need to be made by DC. And the OP can be on his merry way finding someone who can build a bracket for him. With all of the machine shops in the US, and another manufacturer right here on this forum whose explicit business is building alt brackets, I can't believe this isn't something that could have been completed at least since the start of this thread.....much less nearly 2 years.

I assume you mean port volume, and no, you don't. Net box volume is gross volume minus port and sub displacements.

Trust me, we haven't stopped working on it... And I will say that I am personally very happy with how this turned out from a mechanical standpoint. From an aesthetic standpoint, I think he will be very happy with the custom aspect as the alts should be just stunning if they turn out how our last ones this color did.. I know he's not happy, I dont blame him.. Neither am I, believe me, what none of you know or see, is you've never heard me rip someones ASS up one side and down the other over them not getting their shit done so we can actually finish it. Those of you who know me personally know that I'm hot headed, and trust me, Im not afraid to rip someones (suppliers) head off when they aren't doing their f*cking job. The little things NONE of you see, is me sitting on my phone all day calling vendors making sure they are getting their shit done, so you all can get your orders. Case in point, our soon to be former machine shop got a $10k PO the ~20th of Dec, I was told point blank "we will order material in the AM, you'll have parts next week" (last week of Dec) I got back on the 4th, had no parts finished and they wouldn't answer the phone.. So, I drive an hour and a half away to find, drumroll, no F'ing parts.. So I ask (yell at) them, just exactly WTF is going on here?? Oh, I forgot to order material... Excuse me?? WTF do you mean you forgot?? I have a $10k PO on your desk, and your holding up a $40k order, plus making about 20 other customers wait, who were PROMISED, BY ME, because YOU promised ME, they would be done.. WTF??? 4 hours wasted, and I still got no F'ing parts.. And you wonder WHY we just bucked up and dropped a quarter million on CNC machines....... Yeah, because we dont care about how long it takes to get things done... If you only knew...

Just so everyone knows what's going on in the "Days of DC Power" this has become... Look, I know this has been blowed WAY the F*ck out of proportion, but honestly people, why do you all insist on throwing gas on a bonfire instead of just letting it play out and let us finish this before hanging us on the cross?? All I will say, is this is going to be one very, very nice setup, and something I am 1000% sure couldn't be bought from ANYWHERE else, get 5 320 amp alts with the finish they have, with the bracket he's getting, let alone getting it for what he paid for it. So then what, I refund his money so he can dump another grand into having someone else do it (something which NOBODY else has even developed)to get something nowhere near the quality?? That just doesn't compute, at least not to me.... Settle down people.. Anyways... Update, if anyone cares... I made the revisions to the bracket that I needed to in CAD, we had to do this because we're running our new alternators and because they are smaller, as well as the housings being "clocked" different I had to re-arrange everything on the bracket.. So, with me being gone 2 weeks over Christmas, and our waterjet/laser cutter being closed as well to set up their new shop, this now just got finished and I wen't up their today to take them the changes so they could cut it.. The alts are at the powdercoater now that I know I dont have to machine anything on the cases, all of which I told Randy the last time I spoke to him.. And as I recall I told him it would all be done no later than mid- January, which it will. He didn't seem to have a problem with that the last time I called him, which in case if anyone was wondering, I haven't heard from or had any calls from the OP since I called him last.. I will be picking up an engine probably tomorrow so I can make exactly sure the spacing is correct on the bracket, and it's all done.. The only thing I dont recall is what finish to do on the bracket.. Powdercoated or Chrome?? If you read this Randy, either reply here or call me, you have my cell number.. Rob

its not the shop your thinkin, hes a stereotypical arab.....its a cell phone shop, he also works part time at a party store, as well as a gas station! GO ALKITA!