95Honda

Well, I guess since I figured out how to use photo bucket... Here are the XXXs in the living room...

You know it....

OK, here is where serious efficiency meets serious bottom end... 2 cabinets, each 20ft tuned at around 25Hz, 400+ pounds each, 1 1/4" MDF construction 4 Aura NRT 18s... Underhung Neo motors w/4" Voice coils and serious 10" spiders... 95db pro-audio woofers meet real enclosures meant for serious low end wang These things were (are) ridiculous, would hand any IMAX sub system its ass... I built these for an Air Base movie theater while in the middle east last year...

I feel every pain of your install...

The real efficient 8 box... All 375 pounds of it...

Well yes... and no.. All vented alignments gain efficiency with size, but this efficiency comes at the expense of bandwidth (greater ripple in response) or, in simple terms, the box gets real peaky... The correlation between "small box woofers" and low efficiency is, that when a subwoofer is designed, the designer can lower the Vas (all else being somewhat equal) to allow the driver to achieve a lower target F3 in a smaller box, but the efficiency of the subwoofer also drops. This doesn't mean that the subwoofer works best in a small box, it means that the designer sacrificed efficiency to design a driver that will still achieve a low cut-off point in a small box, and they do this by making the driver less compliant (small Vas/stiff suspention) a good majority of the time. But the downside to this is a loss of efficiency. So, to combat this, you design a driver that can handle a ton of power and you overcome the efficiency problem with brute force. If you can see the connection here, now you may know why the big 18" prosound drivers that are fairly efficient have a pretty large Vas most of the time and need a big-ass box to realize thier full potential... This is one area where designers find ways to gain efficiency. And they tend to not worry about box size so much because these are going on stage, not in a small tire well.

Actually, no, this is the mistake being made. At 500 watts the BTL is more efficient than the SSD (and Q and Bl etc) and will play louder. The BTL is more efficient at 1 watt, 10 watts, 500 watts and 1000 watts, etc..... But I think we are beating a dead horse at this point.... Some will get this, some won't... Take it for what it is.

Sorry I don't have any IM. email any time you want though. [email protected] I am in Germany though, so the hours are a little different. -Mike

Exploiting efficiency can be the name of the game.. A few years ago I was trying some different tuning combinations and came up with a 143db Termlab score on the windshield in my 78' Bronco with 154 watts..... It was all about a super efficient box alignment... This was done with 8 RE 8" subs or about 19 watts per woofer........ Black00 made the TL measurements.. I was only thinking what I could have done if I would have actually used some real efficient drivers.....

No apologies BigJohn, that's not why we are here buddy.. And believe me, I am not suggesting everyone buy a BTL and run it off deck-power, I just wanted to point out the fact that the BTL will get louder at the same power as all the other subs due to its efficiency being the highest. Additionally, efficiency isn't the highest only at 1w, it is measured at 1w most of the time because #1, that is where the industry has set the driver sensitivity standard (1w/1m) and #2 this is where the driver is the most linear. If you could see driver efficiency vs power, you would see how much more un-linear and in-efficient drivers get as you increase power. The efficiency curve really takes a nose dive at the thermal limits of the driver. You also have to remember that the RMS or thermal rating of a subwoofer has absolutely nothing to due with the amount of power a sub requires. All this rating is usefull for is telling the user that at XXX amount of wattage, you will begin to have thermal breakdown of the driver (glues fail, VC wire melts, formers come apart). The other driver parameters (Vas, Xmax, Qe, Qt, Spl, Bl) and much more indicitive of how much power you will need, and the most important factor 99% of the time is the chosen enclosure alignment... Sometimes we forget that a driver may need 100 watts to reach it's peak output in one box, and 200 watts for the same driver to have the same output in another box.... Why not pro audio drivers? I have wondered this alot myself. I really think in the past it really hasn't been super popular because of the fact that the real efficiency of the pro audio drivers (even 18" subs) is higher in the frequency range than you would think. Most 95-97db rated pro audio subs are only this efficient 100Hz or higher, not down around 40-60Hz where you would really want for music, in most cases they are only as efficient or even less efficient as some car audio subs down low. But, there are some exceptions, last year I built a set of 20ft subs with dual 18s in each box for a movie theater. I used the Aura NRT18s... These things are about 96db efficient, have 15mm of xmax and an Fs of 25 Hz.... They also have 4" Voice Coils and some serious suspention... Absolutely insane low end.... I remember talking to Marshal (Black00) about these when I was working on this project, and believe me, we were really thinking these could do some seriously mean #s in a car, with very low amounts of power... The problems we saw were that #1, these only had 8 ohm coils, so you would have to start re-thinking your amplifier stratagies unless you could get some custom coil configs, #2 these things are $1000 each.... #3 well, we never got to #3...... Anyway, you get the point.... I hope this is usefull information for you guys. -Mike Edgar

Errr, OK, think we lost you on this one... Have fun with this, I'm gonna crash for the night (it's 11:30 here in Germany) Holler at you guys in the (my) morning. Later. -Mike

Cool thanks, I'll give it a shot. I was surprised when you couldn't download a pic straight on to the site. This way probably saves a lot of server space.

The BTL, off 1 watt, 10 watts or 500 watts. That was the point of this whole thread...

Don't take me the wrong way. I'm a guy who has a pair of XXX18s and 5KW rms in my living room.. But I also see a lot of misinformation spread all the time, and this is one of those times. We are here to help each other, best way to do that is to get the facts straight when you give people advice. And saying a BTL needs more power to be any louder than any othe FI sub, is, well.... misinformation...

Why? Because I'm kind of new here, but one thing I have noticed, pretty much daily are quotes like this- "BTL will need more power which means more electrical upgrades which means blah blah blah" About 10-20 young guys (and girls) really interested in audio who really want to learn get a little dumber every time something like this is posted...

Ding, nailed it again....

I think you just made my point.....

You guys realize that with 500 watts, the BTL is the loudest sub you will get from FI, right? And yes, it will be louder with 3000 watts..... But, it will still be the loudest with 500 watts.... I think this is where the disconnect is....

Why? Because I'm kind of new here, but one thing I have noticed, pretty much daily are quotes like this- "BTL will need more power which means more electrical upgrades which means blah blah blah" About 10-20 young guys (and girls) really interested in audio who really want to learn get a little dumber every time something like this is posted...

Sweet. I hope everyone on here reads this thread.....

My dad has almost the the exact same truck, I think he has the 00'. I did 4 Tangband Neo 8s ported with a MMATS DHC2200.1. Seat goes all the way back and reclines all the way (he has the bench seat) and there is still 2" in front of the box. His distro block is within inches of where you mounted yours... LOL... Amps almost exactly same position also.. I also gutted all the interior in there and sprayed 5 gallons of VBX-1 in the cab/doors... Those trucks need it!! I tried posting pictures last night, I couldn't figure it out, it seemed they needed to be from a URL to post on here? WTF, I know I'm missing something... -Mike

Mike S is right. This is a standard "parallel" filter network, both sections work independant of each other. Just feed them from the same input point like Mike pointed out. The only time you will see a filter that both sections operate together is what is called a "series" network. These are more rare and you won't see them that often. They rely on all the drivers working together to complete the filter circuit, you remove a section and the whole thing quits working. I use this filter on my mains at home right now because it sounds really good and can be a really simple circuit. With the parallel filters, you could remove any of the sections and the rest would still function because they do not electrically rely on each other and they are better at isolating drivers (they make it easier to work out response abnormalities). -Mike

OK, here is a simple explanation. (I thought you already had the passives and subs???) Passive radiator alignments and 4th order vented alignments have rougly the same output. Passive radiator is more expensive, usually more complex and easier to mess up. When Thilo told you they acted like a 3rd and 4th woofer, he was just trying to explain it in a way you could easily understand... And yes, the passives do augment the output of the box, just like a port does... It is just a different approach that gives you similar results. You can get just as loud with a port as a passive radiator and vise-versa. Judging by your posts, I would reccomend straight forward 4th order ported. Also, slow down and try and be a little more articulate in your posts (questions)... You will get better responses that way. -Mike

Thilo didn't steer you wrong. A passive radiator alignment is almost identicle to a standard 4th order vented alignment (regular ported box) with slight variations in response around the passive radiator Fs. The only real disadvatage to a passive radiator is cost, but since you already bought them, you are good to go. They have many advantages, to include- Lower tuning than possible in a small size box vs. ported, better behavior below tuning (helps woofers keep from unloading), no port resonance and increased mechanical noise suppression. The passive radiators do not need to have 2 times the Sd of the drivers you are using, but they should have roughly 2x the displacement capability of the active driver, and if you look closely at the parameters, they usually have a lot more stroke than the active driver. More than likely Thilo reccomended the correct passives to go with your woofers, they probably have a lot more Xsus than the Axis woofers have Xmax. All you have to figure out is your box size and tuning, again a passive radiator set-up will have roughly the same response curve above tuning as a standard 4th order vented. There are online calculators that will tell you how much mass you will need to add to get the desired tuning. If you need help, I am sure there are plenty of people here who can help. Don't worry, you have the right stuff, you just have to figure out how to use it correctly... I have known Thilo for a long time, he knows what he is doing.

That is the 12-Spoke basket, right? 1/4-20 hardware fits perfect. Allen socket-heads and T-nuts/hurricane nuts.