I tell stories, I love to tell stories. This is the tale of 2-1/2 Hondas. It is a sad story but one that has to be told. First I am a Mathematics major, I also study physics. For me everything can be explained and modeled in a logical and structured fashion. Including sound and SPL. Sound and how it moves is 100% predictable. SPL is just as predictable. I don't personally compete often, I have other things to do, Discrete Mathematics for example. About 5 years ago a customer came to me and said he wanted the loudest car in town. The car he needed to beat was an Explorer with 6 Fosgate 15-inch woofers and 9000-watts. He consistantly posted SPL's of around 155-156 I told him to go away. He was persistant and after about a month I agreed. I had seen the truck we had to beat many times and realized that the box design was not an efficient one. Posting higher numbers with this Honda would be easy. The customer became skeptical when I told him all I needed was 4 12-inch woofers and around 2000 watts. And the work began I turn him down originally because of the amout of work required to build a show car that can SPL really high. High SPL's numbers is easy, in fact, give me a target number and I can reach or exceed it. No Problem. But this car was going to take up shop space for about a 2 months. First we completely tear down the car. This is what it looked like about a month into the build Two months after I started on it, it was done. The terrible orange color was the customers choice not mine. How did it do? How does 159dB sound. This was one loud Honda. But it provided me with the information I needed to start on my Senior Seminar Paper and Presentation (similar to a Masters Thesis). My paper will be on how to break the world SPL record (whatever it is at that time) and its not that difficult. The story does not end here so stay tuned. (back to work on my scholarship application)
Ranger I see that this box here is the same design as in your van (i think it was your van in a previous thread). Could you perhaps tell me about this box design or help me design one like this here one pictured....All my friends think they know their stuff and that more woofers and more power is louder...I wanna show them what a real designed enclosure can do.
Nobody was supposed to see that. I'll explain more later, but what this design does is allow the rear wave (behind the speaker) and the front wave to reach the mic in phase. When the waves couple in this manner there is no cancellation, instead there is an amplification of the intensity of the wave. (This will be hard to understand) The front wave needs to reach the mic at pi/2 and the rear wave needs to reach the mic at 3*pi/2. If this happens the enclosure is 100% efficient. The Honda above is only 38% efficient. The rear wave is reaching the mic to soon. (i'm still working on this part of the explination, I need to simplify it). My van was only 41% efficient. (new motto, calculate twice and check for errors, the van was supposed to be much louder. The Boxes were supposed to be back further, 6 to 8 inches further)
Ah yes, a man man of logical thinking when it comes to SPL systems! I like it.........we need to have a discussion some day on TEF someday in private..... A Little science/math can go a long ways in SPL systems. I did a sytem YEARS ago, 16 XTR 12 DVC's in a single reflex bandapss. 4 enclosures actually. The result was phenomanal. could not exceed 155 dB at the time, no matter what. I told the customer from the begining that time alignement was key to hitting the proposed 163 dB i told him it was capable of doing.... He finally agreed, got ready to order the Rane time alignement equipment to get the speakers output in perfct phase, Then the next week he says his girlfreind got pregnant and has to scrap the system....................I was ****ING ****ED! I worked on that truck for over 8 months....he had over 28 thousand into it!!!!!!!!!! Oh well, never will know hwat the darn thing would do, but I KNOW it was a record SMASHER with the right equipment.... In the system you are describing, with enclosure efficincies, I understand what you are tryin to achieve, but, you cannot change the arrival time of a wave by enclosure alone. My thoughts were always frequency dependant, and the length of the vehicle. The only way to change the arricval times of a wave is through digital manipulation of the input signal. And use the box to tune it to the acoustics of the car. Tuning frequency is key to make the waves coincide at the point of measuremnt. Along with a few other tricks!!! Tell me more....I am truely interested in your thought on the subject!
Back to my story. The Owner of the Honda above did very well over the next year. He accumulated more trophies and awards for his car in one year than I will in a lifetime. He won awards and trophies in both show car competitions and sound offs. This car was a work of art. This was by far the loudest car our shop had ever turned out. Nothing else came close. And there was this one person who (for one reason or another) was jealous. He had to have a car that was better and louder. So without consulting me (I was on vacation), the owner of the shop promised him a car that was louder and better. The owner is a good person, excellent business man, but he has no clue. The Viking and aznboi364 have both seen my method for really loud systems and I wonder if they see one really major problem with it. The methods works and it will work every time, but you need the right car. Heres the problem. My method relies on distances to control when the sound wave reaches the mic. If the distances are not right the method will not work. I saw the 02 Honda SI when I got back from vacation. I was also informed of my task. And after a few measurements I realized that there was a problem. 1. The speaker to the mic distance was longer in the SI (using my method that means the box has to be deeper) 2. The SI did not have enough depth in the back seat and hatch area. 3. The SI was 2-inches less wide that the 90 Civic Any one problem by itself may not have been a big deal but all three problems together, this was bad. The owner still does not understand, I explained the problem an I also explained that anything over 150 would be shear luck. My method does not rely on power (but we need an adaquate amount) nor does it rely on square inches. To make a long story short, he recommended that I use Square Woofers, that would give me 40% more displacement, He also recommended that we double the power to 5000-watts. The end result was a 152 dB. My method did not fail, it did not stand a chance in this car. Because my method relies on distances and time, power and square inches are not near as important as correct distance. The Viking and aznboi3644; both of you have seen my work. The reason it failed in this car was the fact that the rear wave was arriving to soon. It was having a cancelling affect on the front wave. Does this make my work easier to understand? On other thing, the only reason the car got into the 150's was what I call the "Brute Force Approach to SPL". (add enough power and woofers and you will get there.) Anyway there is a little more to the story. Stay tuned. Any insights please post them.
Ranger you truly are an artist and more....This does help me further understand your technique. Do you of anyone else who has ever tried this technique or are you the godfather?
I saw a similar set up in Vegas in 2001, at a sound off. The car was a Ford Pinto, I think it was a 74 model. It did around a 170dB with a single Quad Coil American Bass 18-inch woofer. If I remember right he had 2 massive amps on each voice coil. Power was over the 10,000-watt range. Now whether he knew why his enclosure worked I don't know. Most professional competitors are assholes and won't give you the time of day.
Very interesting! This method of SPL generation is very frequency dependant It appears. The second install issue wit the arrival times being off ever so slightly, could that not be addressed by going to a different frequency, slightly lower or higher to compensate for the length? or perhaps a slight change in the distance from the front of the car? I have been out the SPL game for years and so I am not sure of rules, musical selections allowed, mics/equipment that are used, etc, etc......... Another fine install btw.
Your absolutely right. But the rules is what determines our first distance. The microphone is always in the right lower corner of the windshield in a sanctioned event. Also no speaker (subwoofer) can be in front of the B-Pillar. The first distance is the distance between the mic and the your speaker. That distance determines our frequency. But now you see and understand whats going on. We can be slightly off. I was in the first Honda. But I cannot be 12 and 14-inches off. Thats too much. The first measurement is no problem, it determines our frequency. The rear measurement must be 3 times longer than our first. Lets look at an example. If our measurement is 56.5 inches our frequency is 50Hz. Our rear measurement needs to be 169.5 inches. What happens if its 159.5 inches. Well, a rear wave distance of 159.5 is equal to a frequency of 63.76Hz. And we are only 10-inches off. In this case we would still get a slight amplification of the front wave and it would work. It would be loud. But, in this case, 4 more inches and we break even. No amplification but no cancellation. But here is something I have not had time to look into. What happens if I can match my determined frequency with the resonent frequency of the car? I think the results would be outstanding, but school work takes up all my time. I am an installer because of convenience, the owner of the shop lets me come and go as I please. One thing, This Design is pure SPL. It is not a SQ system. These 2 boxes have 12 and 14 dB above peak. No flat response here.
And now to end my story. Honda A was not happy because he thought Honda B looked better. Honda B was not happy because Honda A was louder. Some how I was in the middle. I reluctantly agreed to do a remake of Honda A. We added 3 more screens, one more amp. The customer got the car repainted and added air bags. Most of the original system remained intact. In this picture we see a change in the color scheme and in the dash there are two gauges used to moniter the air bag system pressures In this picture we see the control box for the air bag system. Each bag can be controled individually. The original box is recovered in gray tweed I hope this picture reinforces the idea for everyone reading this, the amount of work required to do this. The window is removed so we can locate an amp and a video amp there. We have NO more room in this car. Now all the speakers are powered by amps. And yes, that is two really large speaker boxes!! The rear area was also redone. There are many uses for exhaust pipe. Its not just for mufflers any more. Look closely at the doors, you can see the screens in each door, Thats why we needed a video amp. And that was the last system like that I have ever done. Too much time and work is required to pull something like that off. And I realize that Honda A and Honda B owners had problems (Psychological in nature) and neither would ever be happy. I completely refused to do anything more to either car. Honda A was redone again at another shop, Honda B went to Lubbock to have a louder box put in, and I could care less. Where are they today. Honda A is now at a local wrecking yard, it was in an accident last month. (a car like that should be charished not driven). Honda B don't now and don't care. I am now truely happy
It suck to see people with more money then brains. They should give it to us who know how to spend it properly.
