Ed RazorLite

and watch what my roof does at 150

http://video.google.com/videoplay?do...39609353126099

HillsdaleHHR

Forgot to say it looks good Is the surround around the speakers finished?

tahenke

You SPL guys are sick! Lol, both of your rides look insane. Just to give an idea of how hard it is to get higher and higher SPL's if memory serves me correctly you must "double" your power in order to get only a 3db gain! That's not to say that there aren't other ways to achieve higher SPL's but it is a rule of thumb in the SPL arena :) You guys are crazy though!

Ed RazorLite

the rule of doubling the power or doubling the cone area for a 3 dB gain is a rule in theory and perfect conditions only.
In "real world" situations, you have many variables to contend with.
You have impedance rise of woofers, the impedance will change with more movement of the woofer and also change with the generation of heat. You have power compression in the box and the car's cabin. Power compression is when the woofers are moving to the point of compressing the air so much, its at the point where the woofer does not have the strength to compress it anymore, and more power to it just wont make it move anymore.
Then your electrical system has to keep up. By adding another amp, you also are drawing double the current, and you cant get more power out of the batteries than they can give.

My box has very low impedance rise (1 ohm nominal to 1.2 ohm) so with 1000 watts per sub to 2000 watts per sub, I have achieved a gain of 2.8 dB.
With 3000w per sub I start to experience power compression so I gain only 1.2 dB from 3000w per sub to 6000w per sub. So to keep it efficient, I only run 2000-3000 watts per sub at any given time.
I will retune the box to allow for the higher compression and this should give me a big gain at high power levels, but it will sound bad at lower levels.
My test box has yielded 158.1 dB with 3) 12s and 3000 watts per sub. This is not an official score in competition so I dont count this. My goal is to implement that box's design with my SQ box's design to get good sound, and high dB.

I know I am crazy and I love it, thank you.

You guys are awsome and I love all of your cars

tahenke

Yeah I forgot about the double the cone area part! People don't realize that high DB is easy up to a point and then it becomes a real science. Perhaps you will be filling your HHR with concrete next? lol not that desperate I'll bet. I remember back in the early or mid 80's a guy with a VW bug with 2 15's and 1000 watts set a record somewhere close to 150. It was a big deal back then. I'm from Florida origionally and at the second anual Spring Break Nationals I sat in the Rockford Fosgate super van with 4000 watts and 8 18's (back then that was INSANE)! I don't know how loud it was but I couldn't even understand what I was listening to! I was cool to say the least but just never took with me. I've built some loud cars but never for myself and certainly not to the level of what you and that other dude are doing! Keep pushing the envelope and helping to progress the sport. It all seems to surround around DB comps now.

Ed RazorLite

The RockFord van you have seen could have been 1 of 3. Mark Fakuda had one and Team X-Max had the other. I forget the other one. My buddy Jonathan Demuth helped build them all. They were at the top level with about 158 dB on the AudioControl. their 4000w rating was underrated. The amps were modified and it put out more like 20,000 watts. A couple years later they took out the 18s and put in 40) tens and got over the 160 dB mark.
We dont use much concrete anymore because its not strong enough, we use a fiberglass resin mixed with sand. It is much more dense than concrete. And yes, I do have some sparingly already in my HHR. I will use much more if I decide to build the wall but first I have a goal.
My old car was a walled plymouth Horizon with 2) 15s. my top score was 156.3 on the termlab in 2003. But the car weighed 5500 lbs and I kept breaking axles. So my new goal is to use my HHR with a street style box (no wall) and top that score. Once I do that, then maybe I will wall, just not sure yet. The batteries I have are 75 lbs ea, subs are 55 lbs each, and amps are 40 lbs each. I want to keep weight down to the point where I am not breaking the motor mounts, and transmission. I lowered the front 1.7 inches and left the back stock and it sits even now.

Thank you for the kind words and I am in no way trying to down Collyn, I am just trying to breed healthy competition and let people know what these cars are capable of. So far Collyn's install looks sweet and I cant wait to see it finished. I am also dying to see an actual official score posted from his install, I will be quite impressed if it does over a 150, but if it does, I will humbly step down as the worlds loudest HHR.

tahenke

Lol! I hit 142 db with an Orion 225 HCCA and 4 8's once. It was on the Audio Control meter. Back then I did things like turn on my blinker and stuff (anything to make noise) when they checked for spl. I used to compete heavily in the low power classes like the 0-50 and 51-100watt class (those days are long gone). I want to get back into it again. For the last 12years it's just been a hobby to satisfy my listening tastes, nothing fancy just nice sound. With the HHR I am going for nice sound and fancy I have a question: Why don't you guys use high efficiency professional drivers like they use in PA systems? I actually use them for SQ (mids and highs only not subs). Also have you ever considered a bass horn? It's a big box but the efficiency is unreal! The van I sat in had the 2 front seats and 2 captains chairs in the middle and a wall of 18's behind that (4 across the top and 4 across the bottom). It was a Ford Econoline I think? It had 4 of those old school Power 1000's that had the fan cases. They would open the doors and load 4 people in and close it up and blast it (I even remember the song, it was by Yellow "Si Senor The Hairy Grill") and it was flippin' loud! That was well before the whole "practice safe sound" thing! lol

Ed RazorLite

Most of the subs we use in SPL competition are much more suited to get loud than a PA driver. The key is motor force and linearity under extreme excursion. When hitting 170 dB, the pressure will build to the point of exerting 300 lbs on the cone of a 15" woofer. PA speakers will blow apart with that much force and the motors do not have enough horsepower to push the cone into that kind of pressure. Also, alot of us put over 20,000 watts into each sub and most PA speakers cant handle that.
Many of us have built horns but they must be very large to work correctly at low bass frequencies (which is what we play, rules limit it to below 80 hz) So a 20 hz wave is 56 ft long and the diameter of the horn opening must be equal to this. Also, the horn is designed for to project and the point of focus of the highest SPL from a horn is usually 1/4 of the wavelength away from the opening. Even at 60 hz, this will not fit into any car. so when people shrink or compromise the horn's design, it just doesnt work well. So we use ported boxes and/or band basses to use the rear and front wave of the drivers.

Here is a vid of the world loudest street driven vehicle. He can hit 170 on the termlab but keeps blowing windshields as he reaches mid 168s.

http://www.youtube.com/watch?v=EG7AUqsy3o4

tahenke

HaHa i didnt know you guys were limited to 80hz and below. Whats that rule all about? Is it the cool factor or something? Probably some safety thing for human ears just in case I'll bet. On my old IASCA CD's the first one has a Jazz tune we used to play for SPL and then they changed to where there were 4 different songs, one Autosound2000 song and some technobeat bass stuff for the other 3. I've been out of it for a while though so I'm kind of like the dude at skatepark with the wide board and all the kids are riding the newer skinnier ones :) Thanks for taking the time to edumacate me back into the loop! Even though a lot has changed the basic principals are still the same so at least I'm not completely lost. I may have to print out the new IASCA rule book before I start tearing into my car to make sure I'm within the rules. I think I saw on thier site where I could download it but I'm not sure if they will want a membership? Thier site sux btw. Looks like a little kid designed it. lol Thanks again.

collyn

It was a rule that started with a friend of mine named Chris in the 93 IASCA World finals. He used a wave guide tweeter driver to concentrate a frequency "beam" at the "legal" measuring point on the windsheild for the db portion of the scoresheet. He hit a db reading well above what Fukuda and his S10 with 8 15's was able to hit. When he was told he needed to back it up a second time for a new world record, his winsheild was mysteriously broken by a ballpeen hammer between runs. The rule book said you couldn't have a cracked windsheild. The following year...all spl measurments had to be below 200hz. This ruled out the tweeter drivers. Then Alma Gates was competing with the Bronco (then full of PPI) and was running test tones through multiple 10's and using highish tones around 190-200hz...so, then when the uncreative people started loosing...again...they changed the rules...again....and so on and so on....

As far as my readings....they are real and accurate. It really doesn't matter to me though as I am not an "SPL" guy....I am one of the creative people that have rules changed away from us to suit the uncreative people. I am a past world champion....several times over. I do not really compete that much anymore. It isn't really fun to build a $30k-$40k system to the rules....only to have them changed when others get tired of loosing.

As far as trying to beat someone elses HHR? I will not really try. I will however park next to them and we will have the loudest HHR blockparty at a car show!