Big ports, trunk cars and SQL (thor, peas, treossi)

[mendon mafia 10+ year member]

First of all read my sig to see what im working with.

Ok so obviously like the rest of you i want a loud daily system that sounds clean. Everyone tells me i cant have both then i see thor, peas and treossi and others who have loud trunk systems that seem to sound very musical, at least on youtube.

How can i get similar results? I have a pair of rd alpha v3's but wouldnt mind changing if i cant succeed in achieving my goals with these woofers. For power i have an atomic 3000.1 2 spv70's in the trunk, stock batt under hood and a 200 amp alt.

I was always told the larger the box and larger the port area = more output but at what cost? It seems that the large ports have no negative effects in systems like thors and treossi and the internal volumes are pretty much to spec.

When i first bought the subs steve miller told me to do 4 cubes net and ~48" port area tuned to 34hz for BOTH SUBS for sql.

I thought i was going to school on thor and peas and treo using a spec volume and a larger port but i have terrible unloading and distortion in the 45-60hz range. Im currently running my alphas in 2 seperate boxes EACH is 2 cubes @ 37hz w/ 48" of port area. They get pretty loud but unload TERRIBLY in the 45-60 hz range and i need this range to not **** so badly lol. below 45 hz i can thow all the power i have (probably very clipped too) at the subs and they just soak it all up and dont bottom out or anything (until i go far below tuning ~27hz and below)

After trying to find a remedy my issue i had a few people model some boxes for me on bassbox pro. I was told that the best sq (flattest response) box would be 2 cubes net for BOTH subs tuned to 32hz (no port area recommendation) i was told for sql i should go to 3 cubes net for BOTH subs34 hz (no port area recommendation). I was told that the boxes i have them in now modeled poorly but DID NOT account for the issue im having in the 45-60hz range.

I would really like to be able to get louder if anything since im for sure going to build a new box (definitely common chamber) but realize i might have to lose a db or two to get my sq back. I never completely sealed off the boxes from the trunk (even when i was metering) so i will at least be able to gain a bit by doing that.

Any suggestions are much appreciated, thanks

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[mendon mafia 10+ year member]

any help here?

 

[rollinonD's 10+ year member]

Well assuming they're 12's. I'd try them both in 3.5 cubes at 38hz.

 

[Villeza1 10+ year member]

Of course you wont hit very well in the 45-60 hz if your port is tuned so low for daily listening. You'd need a port tuned to 45ish hz to be able to hit remotely in that range. As for power, to be louder with that setup, you'll need more power. Maybe 2 atomic 3000.1d's but then you'd have to be careful not to blow the voice coils. Not sure if they can handle 3k rms each.

When i first bought the subs steve miller told me to do 4 cubes net and ~48" port area tuned to 34hz for BOTH SUBS for sql.

I think he ment both subs would share the 4ft^3 air space. This to me sounds right for a daily "groud pound" system. But if you're going for a higher tuned box capable of hitting the 45-60 hz range, then the port obviously needs to be tuned higher. You will lose the ability to hit the lows though.

EDIT: I suggest 3.5ft^3 tuned to 40hz with an added Atomic 3000.1d. Maybe that will help you achive your goals.

 

[NhustlaR 10+ year member]

Should not matter. If you have them in 2 seperate boxes something could be off slightly causing cancellation in those freqs? Just a guess, but I would def put them in a single chamber. Brad's box is tuned to 33hz and his HIGH on the TL is @ 48hz. You should have no problems between that range even tuned a little lower. Also I know this is a retarded suggestion, but make sure your lpf is set right. If I had to guess I would say something is different between the boxes causing some nasty cancellation in that freq range (just a guess)

 

[ascitiesburn69 10+ year member]

It has to be something like that ^^ because for them to unload at 45hz but play down to 27 hz is pretty unreal. And I'm kind of confused so you have each box tuned to 37? And btw HUGE ports= Big SPL peak at a given frequency, thus losing the flat response. So if you consider that negative(which for daily is more than likely is) than I would advise not to use a huge port.

BTW who the hell told you 2cubes shared for two 12"s??? because unless you wanted a sealed box that would be a super ineffiecient box that you would get no output from. Unless steve used his "awesome" customer service dust on them, allowing them to play in small boxes yet still perform optimally.

And btw for daily driver use, rd subs do take an abnormally small amount of port area given the volume of the box. Just ask around

 

[mendon mafia 10+ year member]

thanks guys. i just bought another atomic so im all set for power as long as my battery bank holds up.

to clarify i still have the same problem using only one sub and enclosure so it cant be cancellation between the woofers. If i was able to view my posts and threads i could tell you who told me to use 2 cubes for both subs but for some reason i cant view mine or any ones else posts or threads.

Yes my boxes are tuned to 37 hz. so why would tuning to 40 make much of a difference tuning form 32 to 35 is almost unnoticeable.

Im going to build a box 4 cubes net tuned to 35 hz to test the alphas in and most likely they wont like 3k rms each so im prob going to switch to running 2 konak/ 9512 hybrids.

 

[mlstrass 5,000+ posts]

those subs don't like a lot of port area and you have double what's recommended. Build new box or reduce port area on the ones you have. And you're not going to beat up on Thor with alphas....

 

[mendon mafia 10+ year member]

those subs don't like a lot of port area and you have double what's recommended. Build new box or reduce port area on the ones you have. And you're not going to beat up on Thor with alphas....

not lookin to beat up on him just lookin for a few tips. Im going to build a new box definitely using common chamber but im most likely going to sell my alphas and run konaki motors

 

[PioneerSPL1990 10+ year member]

sounds to me like your looking for a sealed box with monster output. good luck. i would listen to the 32hz and 2 cubes. make a 2 cubic foot box that fits in your trunk, remember to account for wood and subwoofer displacment, and punch it in on a website and say you want 32hz, and try to find the most square port you can meaning shoot for a port width that is at least the same distance off the rear wall of the box or more. thats what i have always done with my boxes, and they picked up lows and peaked ~30hz-55hz when tuned to 36hz, and the car peaked at 43hz.

 

[mendon mafia 10+ year member]

sounds to me like your looking for a sealed box with monster output. good luck. i would listen to the 32hz and 2 cubes. make a 2 cubic foot box that fits in your trunk, remember to account for wood and subwoofer displacment, and punch it in on a website and say you want 32hz, and try to find the most square port you can meaning shoot for a port width that is at least the same distance off the rear wall of the box or more. thats what i have always done with my boxes, and they picked up lows and peaked ~30hz-55hz when tuned to 36hz, and the car peaked at 43hz.

I mean yea i want it to sounds really good but be really loud, but sealed box, definitely no.

Do you honestly think that 2 cubes net is enough for both subs? mechanically im sure they will take 3k each in that size enclosure but the coils will probably cook.

I see what your saying about the port your basically avoiding making it a bent port but to get the tuning i want and a reasonable port area its going to need to bent especially if its 2 cubes net for BOTH (not each) subs.

And just so everyone know ive built at least 10 enclosures just for my own personal use and had many different setups in my car, i am by no means a beginner, this is the first time i have ever had this kind of problem.

 

[PioneerSPL1990 10+ year member]

2 cubes each**.

 

[PioneerSPL1990 10+ year member]

send me your max height width and depth of your trunk. how u want the subs layed out, and specs of each sub. and ill draw you a design to try.

 

[galacticmonkey 5,000+ posts]

If you cant control the subs with a ported box, try a 4th order. Lets you mold the sound and control the speaker much easier than a ported box, where one of the waves is firing into the cabin where you cant control it. When you do a 4th order you can control the front wave and the rear wave to load the sub like you want. A 4th order is much less of a guessing game than a ported box.

I think if you went around 2 cubes sealed, 3 cubes ported with around 60-75in^ of port @ 48hz you would be good. That should give you a good nice wide passband, some good loudness, and alot more control over the subs to stop the bottoming out.

 

[PioneerSPL1990 10+ year member]

calculating a bandpass would get you exactly where u want with some trial and error. hes got a good point^^^^^^