View Full Version : spl q&a
Im gonna open this thread up to answer questions regarding SPL. im also going to try and dispel the myths. so post your questions and ill answer them to the best of my ability. I'm not patient enough to write a long winded essay on the subject so ill just do it this way.
William from NOLA
07-31-07, 08:28 AM
Is it true the more sponsor stickers you have, the more dB's you gain?
CaptainPioneer
07-31-07, 08:33 AM
Is it true that SQ guys can go for hours where as only SPL guys can only last for short quick bursts?
Is it true the more sponsor stickers you have, the more dB's you gain?
Yes each sticker is worth .3 db gain. ( i need more stickers)
Is it true that SQ guys can go for hours where as only SPL guys can only last for short quick bursts?
This is true but only for DBdrag guys who burp :) for guys like myself who like it loud constantly are the best because were intense for long periods ;)
Ryan from Ohio
07-31-07, 11:16 AM
Is it true the guy with the most subs in his vehicle usually has the smallest tool
?
:dancing
I think this is a good topic Bill except for the few that will mess with ya :p
CaptainPioneer
07-31-07, 12:02 PM
Bill i do have a real SPL question for you...
Why are you allowed to run your engine in your vehicle in some classes and not in others?
Bill i do have a real SPL question for you...
Why are you allowed to run your engine in your vehicle in some classes and not in others?
The reason they allow you to run you vehicle in diffrent classes is to manipulate the amount of power you can use from your electrical system. with the alternator running your voltage is usually around 14.4v vs no alt at 12.8v. for instance
say you have a 4000w amp and you can battery can supply 300amps of instantaneous current at 12.8v = 3840 total watts available
same situation but with 14.4v = 4320 total watts available
although thats only a difference of about 500 watts in the spl world 500 watts is a lot of power.
look at the classes classes with unlimited voltage/unlimited battery's dont have an alternator restriction for the most part.
breakjunki
07-31-07, 12:23 PM
sorry for hijacking bill, but theres a point, kinda..
For example, I was talking to a RDAudio guy the other day, their selling a promo on the new comp amp the Med'ellin, sweet amp. Whats cool they rate it at 10.8v comes out to over 2000+rms. But at full throttle the monster will put out WAY over 4000+. So Thats kinda a reason why.
Edit -- There may or may not have been a point to the above statement :happy055:
William from NOLA
07-31-07, 12:36 PM
They have some really nice looking amps. http://rdaudio.net/amps.php
y someone rates there amps at 10.8v is beyond me. your not gonna gain over 2k just buy upping your voltage to 14.4 stupid marketing people...
for instance again.
300 amps x 10.8v = 3240w
300 amps x 14.4v = 4320w
3240w - 4320w = 1080w
CaptainPioneer
07-31-07, 01:10 PM
y someone rates there amps at 10.8v is beyond me. your not gonna gain over 2k just buy upping your voltage to 14.4 stupid marketing people...
for instance again.
300 amps x 10.8v = 3240w
300 amps x 14.4v = 4320w
3240w - 4320w = 1080w
actaully thats a negative 1080w bill lol but i catch your drift lol
breakjunki
07-31-07, 01:32 PM
about the power, if you could feed it a constant 16v+ it'd be a substantial gain..
See below post.. I got the #'s kinda wrong...
i doubt the amp will take 65v. thats retarded
breakjunki
07-31-07, 01:37 PM
edit on the above. I got it wrong... it was 2200 @<hidden> 1 ohm at 10.8v
does over 65v @<hidden> 1 ohm at 14.4
so rating it at 14.4 it'd be over 4000 rms.. sorry I got it right that time.. cleared up what I meant with the rating differeence from say 10v to 14..
either way... I was just trying to give an example of the power difference btween car on car off, type of scenario..
cargodz
07-31-07, 01:54 PM
Is it true the more sponsor stickers you have, the more dB's you gain?
Actually that statement might hold a lil truth... If you had enough of them then it would be an added layer of sound dampening on the outside of your vehicle :p
just so you guys know i will be cleaning this thread up in a little while i want to keep it informative.
breakjunki
07-31-07, 02:47 PM
sorry Bill...I promise not to taint the SPL purity with crap anymore:happy055:
anyway, its a good idea though..Alot of other forums have SPL q&a areas.
William from NOLA
07-31-07, 03:28 PM
Actually that statement might hold a lil truth... If you had enough of them then it would be an added layer of sound dampening on the outside of your vehicle :p
oooo nice, thinking outside of the box figuratively AND literally :thumbsup
just so you guys know i will be cleaning this thread up in a little while i want to keep it informative.
What you could do is just move all the informative posts to a locked thread or cut and paste Q and A's. That would probably be the neatest way of doing things.
just to clarify mike meant sound deadining or damping, he didnt really mean to say your car would get wet......bill heres one for you. i get asked this a lot and i figured since this is your thread ill let you handle it. so technically speaking why is it that if a speaker can only move a predetermined amount and you can reach that with 1k watts, why would it be louder on 4k watts?
it wouldnt assuming the enclosure stayed the same. u can manipulate the box however to make use of the power.
so what your saying or not, is that through enclosure design the excursion of a woofer can be manipulated in such a way as to make it handle more power? could it also be designed to make use of less power? your smart and sexy too bill!
yes terry it can. but only mechanically.
now when you say mechanically are you referring to the excursion?
so how would you do that exactly? how does enclosure design factor into an spl design?
scotts1000rr
08-01-07, 08:34 PM
Why are slot ports better? Why are spl boxes so much bigger?You would think with all that space they would just be out of control.
swimmerdude
08-01-07, 08:37 PM
The better question would be why aero ports are better than slot ports, and what are spl boxes so much smaller.
slot ports arnt always better and infact the street classes use small boxes and large aero ports. ill go into more detail about this later tonight or tomorrow. tired from workin on the buick.
and terry if i told everyone that we would all be loud! and no one would buy my designs haha! nah honestly ill write it up later tonight or tomorrow
scotts1000rr
08-02-07, 09:45 PM
so smaller box plus huge ports? explain please
lol i would if i understood it. im digging up info on those boxes. but the loudest street boxes are round tubes about .75 cubes with a 6 inch aero out the back sub firing forward.
scotts1000rr
08-04-07, 06:50 AM
well then whats with the 22 foot wall in the buick? Why not go smaller?
walls work diffrently than a street box does. walls are more about the wave effiecency and displacment where street boxes just want a ton of velocity
snoogins
08-04-07, 12:47 PM
External aeros are great because you can swap them out for different tunings. Suddenly your dd is a big fart box. :)
What about volume? I know if your only burping at a single frequency its safe to bump up the volume (and power) since excursion is lowest at tuning, but at what point does this enter the realm of woofer destruction? Is there maybe a ratio between box volume and power handling?
And what about port area? I've heard for a good SPL box, you should start with sd as your port area. Some say smaller, some say go way bigger. Has anyone had particular benefits for any of these guidelines?
scotts1000rr
08-04-07, 12:54 PM
and what guidelines do you use? Are there formulas for spl boxes? do you still use the subs parameters or does that matter for just going loud?
well here is the crazy thing there are no guidelines in spl other than the rules of physics.
ur volume question gets into a grey area are you using a daily box to burp or are you using a burp box? although excursion is lowest at tuning your usually plain the resonant freq of the car. and the boxes u use are usaually tuned 3-5 freq's below that. but to get the volume you should burp you should measure the output of the amp to find your reactive load then figure out what voltage you need to see out of your amp for that specific freq. then change the volume on the hu as well as the gain till you hit that target voltage.
port area can go either way and to be honest the only way to tell is to test small and large. but for the most part more port area is better.
and what guidelines do you use? Are there formulas for spl boxes? do you still use the subs parameters or does that matter for just going loud?
T/S paramemters dont matter in spl boxes. the only real way to get loud is to build and test and build and test. and then when you find something that works continue working on it by doing aero enhancements modifing the cf and port.
scotts1000rr
08-04-07, 01:07 PM
where would yoou start
for what an spl box? id start with a large box say for a 12 id start with 4 cubes and about 100sq of port. then start taking some of the volume out and when you stop gaining go to the port. modify the port till you stop gaining.
scotts1000rr
08-04-07, 01:14 PM
so start losing volume then gain on the port? port length or dia.?
if you gain score when you drop volume take volume out if you loose go bigger. take some port out see if you gain if you loose go bigger. same with everything.
scotts1000rr
08-04-07, 01:55 PM
so basically just keep building till its right. lol
scotts1000rr
08-04-07, 07:53 PM
so is fiberglass ok to use or should it be all mdf?
swimmerdude
08-04-07, 08:00 PM
just about every competitor uses a ton of fiberglass.... either that or concrete:)
scotts1000rr
08-04-07, 08:03 PM
lol i would if i understood it. im digging up info on those boxes. but the loudest street boxes are round tubes about .75 cubes with a 6 inch aero out the back sub firing forward.
when you say round tubes are you talking about the enclosure?like a bazooka tube or are you talking about the ports?
scotts1000rr
08-04-07, 08:04 PM
just about every competitor uses a ton of fiberglass.... either that or concrete:)
to help stiffen?
swimmerdude
08-04-07, 09:00 PM
The fiberglass to strengthen so the enclosure doesnt flex.
Literally, a tube is the perfect enclosure. A sub is a circle and you make the enclosure a long circle. I dont know the specifics behind this, but if you think about it, it is the perfect enclosure because of the way air from the sub is pushed/flows.
scotts1000rr
08-04-07, 09:10 PM
thats what i thought he meant but wasnt sure
I went to the darkside today........... They, however, did NOT have any cookies Bill!!!!!!!!!!! After I got over that I did enjoy it. I did a 139.6 with 1k on 1 12", and absolutely no testing :( I wanted a 140 but oh well, I can break that barrier with some testing.
cargodz
08-05-07, 07:55 AM
lol i would if i understood it. im digging up info on those boxes. but the loudest street boxes are round tubes about .75 cubes with a 6 inch aero out the back sub firing forward.
Actually kinda funny that you would mention the round street boxes... As I myself have been thinking about designing one for a 12" sub that would be approximately 1.15 cubes (not including sub displacement) with about a 6.5" aeroport with tuning at around 44hz.
I went to the darkside today........... They, however, did NOT have any cookies Bill!!!!!!!!!!! After I got over that I did enjoy it. I did a 139.6 with 1k on 1 12", and absolutely no testing I wanted a 140 but oh well, I can break that barrier with some testing.
By the way Bill... When you get one of the SQ guys to start pulling 139s and shooting for 140s with a single 12" I think you better send him a cookie ;) :p
When building a wall for BR is it better to just do a large slot ported box, a 4th, 6th order bandpass or aero port?
scotts1000rr
08-05-07, 06:34 PM
a single 12= 139.6 for real
neumann
08-05-07, 06:45 PM
i want a box too, my 12 got a 140.7
scotts1000rr
08-05-07, 08:11 PM
holy crap 140.7
street a guy does 157.2 usa legal. i think the euros are doing 158-159 single 12 and a pair of amps.
loudest i ever did with a single 12 was 144
what 12 was that with bill?
When building a wall for BR is it better to just do a large slot ported box, a 4th, 6th order bandpass or aero port?
thats really a matter of opinion. if you need massive amounts of port area go with slot if you want better sound and easier tuning go with aeros. or do both!
well I want it to sound good BR 149.9 and burp in the mid 150's and also break ur neck with air pressure
then you need to be like me! and you probably will have to tear up the car a bit.
well I'm just gonna have to hear the wall i guess and then make my decision
cargodz
08-06-07, 01:11 PM
I can't wait to hear the wall with the WPs in it... It was scaring people out of it with the Executions and I can just imagine what it'll be like now :D
well have the WP's in and we will be running it at .5ohm stereo. so we should get more power 2
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