95Honda

Until parameters are posted on those subs (won't likely happen) everything like transient response will be heresay. And I mean heresay in a big way. You will find tons of people who will say a BTL has had some of the best sound quality they have heard.... They may say the same of an MT.... They also may say a Tumult sounded horrible.... Seriously, without measurements and objective reviews (very, very rare on a car audio forum) everything about sound quality, is, well...... Subjective.... Chances are, if you spend a bunch of money and do a good job, you are going to think it sounds awesome.

The worst place to mount an amp is on a subwoofer box, especially if it is on a large, unbraced panel.....

I guess what I am trying to say is that clipping will not induce overly high average power levels untill it is very, unquestionably, without a doubt audible. And if you still play your system at this point, you are without help.... It's tough for me. I have been building speakers for almost 20 years now, I have been designing and building amplifiers, crossovers and power supplies from scratch for over 15 years. I use scopes, spec-anys, distortion meters, function generators on a daily basis. I know intrinsically what they do. I ahve installed maybe 100 or more complete car audio systems, and for the life of me, I have never once drug out my bench scope, or my Fluke handheld work scope for that matter, to set the gain of an amplifer. I can't comprehend how some people swear by using this equipment when I know they have 1/100th the experience with it I have (not meant twards you M5 ).... Maybe I am just biased and think people should use common sense 1st, thier ears right after 1st and an oscope somewhere near 73rd on that same list.... I think the problem lies where alot of people think the scope is some sort of golden parachute keping them from ruining all thier brand new equipment they payed and arm and leg for.....

If one fails, it will actually take the acoustic load from the good driver and REDUCE cone excusion above Fc, this is actually a good thing.

Looks like you already have some Partsexpress kits...

The (original) intention of a line driver was to do the following- #1 Be able to drive the required voltage levels into the low impedances that are created by driving the inputs of multiple amps at the same time. Early head units could not source the neccesary current to keep the drive voltage up in these cases. All they (line drivers) really are is a current buffer, they really aren't meant to boost voltage, they are intended to drive the lower impedance loads at adequate voltage levels. #2 (and a distant #2) Improve sound by operating further above (higher drive voltage/less amp sensitivity) the noise floor than the headunit could do on its own. The (missconception) that line drivers are for SPL come from the fact that the only way to drive say 20 amps with one head unit is with a line driver, because they are able to source the neccesary current. If you have one amp, you never need a line driver. If you have 2 amps, more than likely, you never need a line driver. They don't help with clipping, in fact, they make it easier to overdrive your system. Clipping is not DC, does not behave like DC and doesn't heat voice coils up any faster than a sine wave. This is a HUGE missconception. Too much power blows speakers. Period. Amplifiers (attempt) to put out a constant voltage into varing impedances. If you ask an amplifier to produce Y voltage of a sine wave it is equal to X watts. The same amplifer puts out 2X watts with Y voltage with a theoretically perfect square wave. The speaker doesn't care what it gets, as long as it is below it's thermal rating. And if you can sit in a car and listen to music so distorted that the amplifiers are driven into full clipping, you are a tool and shouldn't be able to complain about anything..... Setting your gains with a scope is a waste of time, especially if you have only one sub amp..... If you blow subs, no scope, DMM, "Online tutorial" or shop can help you....

THE RMS OF THE SUBS HAS NOTHING TO DO WITH HOW LOUD THEY GET. The only thing that will tell you which one is louder is whatever one will be in a more efficient alignment. You need to model each driver and look at it the target response in the enclosure you choose. That will tell you which one will be louder. You need to also pay close attention to the impednace curve, because one or the other might not draw anywhere near your 730 watts in the frequency range you want. You simply cannot answer this question with anything but heresay unless you model both drivers.

If they are identical subs, being driven with identical signals, then there is absolutely no reason to have them in seperate enclosures. There is no technical data that will dispute this. Period. Now, if you are adding structural integrity by placing in a divider, than that may help your box. BUT not do to the fact that it divides the chambers, only because it adds rigidity.

Then drive to the closest one.....

Seriously, before you apply power to anything go to your local shop and have them look over your install. Your having a tough time with the real basics, do yourself a favor and have it checked out.

X2 Also, look into the gear from Outlaw, real good bang for the buck, probably the best deal in HT right now. You can get some of thier processors that have all rca and XLR balanced outputs so running the pro audio amp for the sub is super easy. You can't go wrong with a Partsexpress, Madisound or a Zalytron kit for your speakers. Also look into Zaphaudio for some designs. As for the sub(s), you have so many awesome options out there these days you are in really good shape. Look into some of the Dayton, Soundsplinter or Exodus drivers. I would definetly look into seperates though, don't buy a reciever. If you go used you can do so much more for the same amount of money...

Well, no. Here's why... The gauge is a cross sectional area of the wire, it has nothing to do with strand count. You can have 1 strand 0 gauage wire and 4000 strand 0 gauge wire. Obviously the 4000 strand wire will be much more flexible, but it will also be much larger in diameter due to all the extra surface area of the individual strands and the (un-perfect) layering of them. The (DC) current capacity of both of these wires will be exactly the same. Many companies have a lower strand count because it is cheaper to produce. Many companies also put thick insulation on to make the wire look even bigger. But, the bottom line is Awg is Awg as far as total amount of cross sectional area. I really doubt even the crappiest companies cheat this, it just appears they do because they use less, but thicker, stands because it is cheaper to produce.

My favorite is still the smaller boxes are louder... Here is the much debated BTL 18 (old specs)... The 2 plots show an SPL alignment, tuned at 50Hz. The red line, mostly covered is 5ft3. The light blue line is 10ft3. The gain is almost 3db at the peak just above 50Hz.

Here are some predicted responses of that sub. The orange line is a 1ft sealed box, with a Q a little under .7 The purple line is a 2.5ft low Q sealed box The red line is a vented 2.5ft box You can see the vented and sealed 2.5ft boxes have equal response at 20Hz, with the sealed box having increased output below 20Hz. From about 35-50Hz the ported box has around 3-4db more output. The 1ft sealed box has a little more output 60-80Hz region than the larger sealed box, but this is pretty trivial with a subwoofer. This driver can have a real flat response ported in a small box, this may make the bottom end sound a little bloated to some people when you factor in cabin gain of the vehicle. This may also make it tough to blend if ported with the rest of your system. Additionally, a ported box this small and tuned this low will have vent issues with a driver with this much stroke. To keep vent velocity low you would need a big port, big enough that it may increase the physical size of your box 50%+ The choice is really up to you...

45Hz probably would sound fine. A majority of car audio 10-12" drivers will have an F3 around 40Hz when put in a sealed box with a .7ish Q.

Oh sorry, it said 2300 watts.... That's still not very good... And this was to put things into perspective about how loud you can get with only a little power. Ob, you are the one asking the n00b questions.

If your really after IB, you realize you can get almost 2.5 of the Dayton 15s for every Audiopulse, on sale, right? They probably have just about as low of distortion when kept within thier linear stroke as the Audiopulse, or at least real close. I am currently using a pair of XXX 18s for my HT in vented alignements, I like them alot.... I thought of doing an IB, just haven't gotten around to it yet... Honestly though, I have also been thinking long and hard about about retiring the XXXs for a while and trying 8 of the Dayton HF 15s, Isobarik, 4 in each box. That would be cheaper than the XXXs cost me.... I get the HF 15s for $100 a pop.... Just rambling thoughts I guess...

Here are a few I have noticed: #1 RMS ratings have something to do with how much power a driver needs #2 It needs more power because it is rated to handle more power #3 "Give it XXX clean watts and it will be ok".... lol, love that one #4 This woofer doesn't follow the T/S parameter rules #5 Smaller boxes are louder #6 18s are slow #7 You need to buy $5 a foot 1/0 cause' it looks cool.... Blah Blah Blah....

LOL... I did 143db on the TL with less than 150 watts.... Measured by Black00.... 145 with 2500 watts is pathetic.... Hate to burst your bubble...

There is no reason whatsover to put a high pass filter on anything tuned below 20Hz. It will be fine. I have been building H/T subwoofers for 15 years and have never, ever needed a high pass filter on something tuned that low...

Without any problems, ever? 100 watts..... And that isn't being a smartass. Seriously, a question like that tells me you are looking for a number that you can go totally apeshit with and think you'll be fine. You can blow many drivers with far less wattage than you would ever think if you aren't carefull. The correct question should be- I have a XX" BL in a (sealed/ported) box of XX cubic feet tuned at XXHz (if ported). How much power will the sub need to be brought to it's full potential output? I ask this because I completely understand that power requirements are based mostly on enclosure alignment....

I'm lucky, I never had any of those horror stories happen to me, I know they did though. The only drivers I had (ongoing) problems with were some Adire ones... A friend of mine still has one of the original (mid 90's) 12" underhung TC drivers going strong... He uses it daily...

Soldering is great, so is a good crimp. Both together is almost foolproof.... A bad crimp is just a huge problem waiting to happen. I can't tell you how many ends I have re-terminated because someone used a hammer, pliars or vice to smash the connector on all half-assed...

Just to reiterate. Also, if you can see definite frame rails under the car that go all the way from front to back, it isn't unibody. But, alot of cars these days are unibody. I bet a web search would tell you within a few minutes if you have a unibody car or not.

Efficiency ratings apply in every enclosure application. This rating tells you how much output a given driver will have with a certain input. Watt for watt, the BTL is the loudest sub FI makes because it is more efficient, in the right enclosure, of course.. Yes it would be kind of strange to buy a BTL and send it 100 watts, but it would still be loudest driver you have with your 100 watts.. Just because a driver has stiff suspention doesn not mean it needs alot of power. The suspention is just one of the components thta make up the driver charactoristics. For example, if you have 2 drivers and one has lower compliance (this is the definition of "stiffness") but the other has increased motor strength, the other driver may still have increased cone travel at the same power output.... Same case with a BTL, just because it's suspention is stiff, doesn't mean the cone won't move as much. In fact, it will more than often move MORE because of the increased motor strength... This is how it is more efficient, if the cone wasn't moving more, it wouldn't be ass efficient. But again, this is all on the box and frequency being played.... But hopefully this helps some understanding here... Yes, this has been covered before, alot. But it is good to see a few guys remembering/understanding this... Now there is also a flip side to this. With all other parameters being equal (same motor, cone mass, etc) when you decrease compliance (say add spiders) you do a few things. Generally speaking, you increase Fs, increase mechanical power handling and you decrease the Vas of the driver. Now, efficieny and Vas are directly proportional, so buy decreasing compliance, you decrease efficieny at the same time. But there is a lot of factors that play into this. For example, if you had a BTL 18 and only had 1 very compliant spider, it would be much more efficient than one with stiff suspention, but the downside is that since Vas may have gone up so much, you now would need a much larger box to get the same response, additionally the mechanically handling would be very poor. You may gain a few db or so within it'susable power handling range, but anything more than say 100 watts may send the coil into the backplate of the motor or bottom out the triple joint... Adiitionally the drastic change in mechanical Q may render the driver too peaky for music. So basically, the engineers at FI choose the best ratio of compliance to motor stregth (and yes alot of other paramters) until they got a driver that was efficient enough and had enough mechanical handling to be thier loudest sub. If there was a class that was say 100 watts and a single 18" driver ONLY, you may see a driver design like something I have been talking about here, but of course there is not, so there isn't really a driver designed like that. But hopefully this helps with the understanding of compliance, efficiency, etc....