95Honda

Well good luck! Just make sure you MODEL first and don't arbitrarily choose volumes and tuning... The High Qts (and other attributes) allow for extremely small sealed alignments with a low Fc. It might make designing tough due to a vented section being to small to properly support needed vent area, unless you go external venting... But again, be sure and model before hand so you know what you are getting!

Not sure what size driver that is, but if you are actually going to build a transmission line just choose a taper ratio and base it off a similar size driver with a similar surround. You'll have to tune it for flat impedance anyway, so getting the cross-sectional area dead-nuts-on isn't super critical... Additionally, take any transmission line reviews with a grain of salt on a car audio website. They are very subjective, and a majority aren't even transmission lines... They really aren't a great fit for car audio as they are less efficient than standard 4th order vented or band-pass alignments and they tend to be very large...

4th order vented or band-pass? It will have really bad ripple in a vented alignment...

Don't take this the wrong way, but until you figure out what you did wrong the first time around, no matter what you do (fix leads, FI recone or PSI recone) it is simply going to happen again. So, after you fix your driver(s), you need to make sure that #1 you aren't applying to much power to exceed thermal limits and #2 don't have an enclosure alignment, power level or active filter setting that is allowing over-excursion. I am not questioning your abilities, but I highly suggest you find out how to do both aspects, as it was NOT done before. There are people on here that can walk you through all the needed steps, just ask...

Your 2400 watt amp can be applying as much as 4800 watts of overall power to the subwoofer, at any gain setting. When you fry leads you are applying too much power, period. I would suggest trying to figure out what you were doing wrong in the first place.

Couple of things to point out about this thread- 1) The RMS rating is NOT a power requirement, nor is it any indication of how loud a driver will get with a certain amount of power. I has no relation to output whatsoever, it is simply a thermal rating of the voicecoil, nothing else. Do not base anything output wise off of an RMS rating, period. 2) The nominal impedance is an average rating, your overall alignment determines the final load the amplifier sees. Don't assume that an amplifier will be putting out half the power if you double the driver impedance. 3) There is no such thing as underpowering...

Mine works!

Yup, and I think the 152+db Tempest Durango wall was built well before that! We are getting old!

One is dampening completey different than the other. Almost makes me wonder is something is wonky with one of the suspension components and/or gap alignment...

These drivers look to be very well thought out and designed. I look forward to using one some day... Good job Quentin...

Hey man, first off, nobody is trying to muck up your thread. You don't have to take this to a personal level in your posts. Nobody has disrespected you. We wanted to inform the readers of different avenues of design, and we did that. You question our knowlege and skills without conducting proper research. Please don't take this as disrespect, because it isn't. This is a public forum. We will point these items out as they arise, it isn't a personal attack. I think the readers get the point, there isn't any reason for me to post about it anymore, so I won't. Good luck with your build! -Mike

We aren't saying you design an alignment on a computer and go with it without change, we are simply trying to get people off on an abjective start. When I was working with some of the MECA competitors in the early 2000's (about 200 or so complete builds ago) we would objectively start with a modeled design and then test/tweak from there. We did not arbitrarily start with volumes on a guess, we would still see how the loudspeakers were going to act as a starting point. Case in point, I completed a high efficieny build in 2003 using the first generation RE 8s. I was limited in power to roughly 150 watts. I modeled a multi-tune (pluggable ports, 6 in totall) 4th order vented enclosure and had 3 predicted peaks that went with my 3 tunings. I knew the modeled peak at the highest point was near the vehicle resonance (1978 full size Bronco) of 56Hz. When I modeled for the intended peak to coincide near vehicle resonance I was able to net over 143db, at the headrest, on the Termlab, using 153 watts of total input power to my 8 RE8s (19 watts per driver). This was all possible with little tweaking of the actuall alignment due to carefull planning and simulation. And I was able to hit my peak SPL at 56Hz, as predicted by both alignment peak and vehicle resonance. But again, I was only able to do this as easily as I did because I was fully aware of the alignment response BEFORE any actual testing... Again, we have no doubt that you can build great SPL systems, we are trying to stress to the readers of this thread that there are more objective ways to start. Just think of how many unknown alignment variables you can eliminate by modeling first... I have been doing this for well over 20 years and I still learn new things everyday.

I still don't think you understand what we are talking about, we aren't talking about the cabin gain, we are talking about your target alignment starting point. This where you reliably predict system response and know what the actual output before cabin gain is. It is loudspeaker 101. It doesn't make sense to arbitrarily pick volumes as a starting point, we just want to make sure the novice readers understand this. We aren't trying to clutter your thread, it is open for everyone. We are trying to ensure more than just you learn from this. Nobody is saying you can't design to your goals, we are just trying to let everyone understand that the approach isn't as objective as it could be...

Roger. I may not have been trying to help you as much as other, more novice, builders. You need to remember that many people are reading this thread, many with less knowledge than you. So I would like them to understand that there are objective ways to begin a design, and they may find another route to go that will get them off on a solid footing. The problem is, many will look at the fact that someone chose a band-pass ratio and ran with it without first checking how the drivers will behave. You may be able to get away with this, many others will not. It is important to remember, that while this is your thread, others are learning...

And if we could model everything there would be no need to test. everything would be a one shot build. we would have 20 craig butlers. I rough design for volume and tuning on "paper" then built ,test, and mod. Ive had many successful loud daily and spl builds. All from testing. No luck needed. Luck is builds that hit certain numbers and never get louder.If your knowledge of building and testing out weighs mine please feel free to contribute. Otherwise if your certain computer modeling is the way to go you have expressed it thoroughly and you have no further need to post about it in my thread. Look, this forum is about learning. Sometimes people will point things out that may help, don't get defensive. Other people will be reading this thread and may learn something. I asked a simple question because I was curious and looking for insight. I made a comment about objective data. No reason to get defensive. Again, the build looks good and good luck with the outcome, this isn't a smart ass comment, it really means good luck.

Yes, that is a common misconception in car audio. The actual alignment doesn't change in the cabin, and the output can be predicted. Lance Dickson did some pretty extensive testing with this a decade ago, comparing Qtc in and out of a confined environment. Changes were less than 5%. Everything can be modeled as far the actual alignment output... But again, good luck.

Pretty much a stab in the dark then, good luck...

How did it model with both tunings?

That response looks pretty nasty, it may work ok. Honestly though, 6th order alignments are hard to nail down right. Depending on how you design your venting and the way the cabin is, cancellation can become a huge issue... It sounds like your mind is set though, so good luck...

I bought a case (like 16 or 24 or something stupid like that) of the first 4.5" full range Adire CSS drivers (Like FR125s or something, I can't remember the model) back in 03' or 04'. I used them mostly for home audio, but I did play with a few pairs in an automtive environment. A few things of note- Even being 4.5" or so in diameter, they still beam, alot, especially where they are touted for having a good top end. They did not sound very good off axis at all. I added tweeters to most of the installs. They don't play very loud, at all. A 4.5" driver (even with the 1/2" or so of stroke) doesn't have a lot of output, especially if you are driving. I blew one actually, fried the voicecoil. They sound really good on-axis at moderate levels, especially if the aren't being overdriven. They don't have much bottom end unless you put them in a very well designed enclosure. They suck in a car door. I did buy a pair of the Dayton Neo 8" fullranges, they are still in the box, but I think I won't even entertain putting these in a car, they simply will not work off-axis in the slightest up on top...

All of those plots have a lot of ripple and when combined with cabin gain will make it sound like you are missing the top end of the sub stage due to the exaggerated bottom end. You should try and find something that models flatter, or you will be forever stuck with what sound you are describing (without heavy eq'ing...)

I am starting a build for a friend of mine. His goals are a decent amount of bass in a removable package. This will be installed in late model 4-runner. After talking with Brian (BKOLFO4) about some different single driver solutions that would have good output he suggested a single Mayhem 15, and well, kind of going to take his word for it. As for power, I bought a single Cresendo 3500, should be plenty of power. The 4-runner has a decent factory stereo (Nav and all that crap) so we wanted to keep what we could. I picked up one of the new Audio Control LC2i: http://www.audiocont...ol----LC2i.html because I am sick of PAC Trunk LOCs. They are POS's that are nothing but a headache. I only say this because I have installed about 10 of them. The LC2i also has a cool ciruit that defeats the factory compression of bass at higher levels... And remote turn on triggered by signal sense... Way cool. He also bought a 250 amp alt and plenty of 1/0 and a stout battery. So good there... Now, as for the box. This presents a few problems. It has to be small enough to fit behind the rear seat and we want to keep it below the window line. Brian suggested around 4ft3, I am going to go with that. A 30Hz tuning should work pretty good. Woofer and vent will fire back. 1.5" MDF construction, heavily braced. Inside will be heavily coated with Cascade Quiet Coat (I have 5 gallons left over) and outside will be proffesionally Line-X'd. Grill be solid PA style, steel with perforated holes and powder coated black. Will cover the entire back of the enclosure, flush with the cabinet. Now, if there is one thing I hate, it is mounted electronics to the enclosure. But with this install, everything needed to be removable. So the amp and LC2i will be mounted to the front of the enclosure (against the back seat) with these isolation devices: http://www.zorotools...e_Shopping_Feed I am going to countersink them into the cabinet about 3/8" of an inch, so they won't be very visible. I did a little research, these should help alot in the range of vibrations the enclosure will try and transfer to the amp. Since the amp is mounted verticle, I made sure the shear rating was adequate, didn't want them sagging over time. I'll use 6 on the amp and 4 on the LC2i. They will be attached to the cabinet with T-nuts from the inside via studs with LocTite. As for making everything removable quick via electrical connection, I am going with a single 5 pin Neutrik XLR: http://www.parts-exp...tnumber=092-328 for signal and 1/0 breakaways for power: http://www.parts-exp...tnumber=263-112 Nice thing is, for signal, I will use some 18/4 architechual cable with a nice braided jacket placed over it. It will look good and be simple and clean. There will only be the single break-away power connector and the single signal connector going to the box. 2 connections and your done... Anyway, just waiting on the Mayhem right now, I'll probably start the box in a week or so. I'll post pics as the build progresses. -Mike

Optimum port area has NO RELATIONSHIP to the box volume. This is kind of a bad rule of thumb... The only way to know if your vent has enough area is to model for Vent Velocity. "Less ports are more efficent" = Basketballs make good salad dressing Honestly though, both vent options should not introduce much compression with any 15" drivers, I would go with whatever option fits your build better...

The video should be deleted. Horribly misleading. The guy doesn't really have a clue on what he is doing, either...

Your not to blame, it is just understanding what you are measuring. This is why there is a lot of confusion on what is going on when test equipment is involved. Even something as simple as a DMM can get you started down the wrong path if you don't know what you are doing. The terminals could also very well be faulty, but the fluctuations you were reading (especially the ones without the terminals) was being caused by the woofer.