what the best sub for the power

Post by **stipud** » Thu Oct 21, 2010 2:45 pm

Try searching it man. There have been a million threads.

audiophyle_247 · Post by **audiophyle_247** » Thu Oct 21, 2010 6:26 pm

If you do sealed you're gonna have to make it as large as what will fit, so you dont suffer from the lack of power. (bigger volume = more efficient)

Single rsdc in a ported box will be LOUD on 480w rms, and sound ooooh so sexy.
I'd run a 1.75cuft box, with 24sqin port area, tuned to 30hz. (12"x2" slot port 38" long)
That would give you a very crisp & responsive sub, plenty of low end, and all the volume you can handle. A similar setup I built for a customer, those box specs, & a single 12" RSDc on an Alpine 600w rms amp, and it metered 137db peak at the dash on music in a Civic sedan with zero deadening. It was pretty damn loud, and had the clarity to match. I would be very surprised if such a setup was not enough bass for most people.

Post by **kg1961** » Thu Oct 21, 2010 6:30 pm

we are talking about the 10" subs right? i have 500 watt rms 4ohm bridged on the amp im going to use
so 250 rms each this is a amp only rated at 12 volt so im sure its a little more watts
i was told .70cub each your saying 1.75 each?

let me know
thanks again
mike

Post by **Bfowler** » Thu Oct 21, 2010 9:19 pm

^hes giving a ported box dimension.

sealed is great at .7cf

audiophyle_247 · Post by **audiophyle_247** » Thu Oct 21, 2010 9:30 pm

My bad, all this talk about 12's had me thinking thats what you had.
I did 1.75 for a 12", but would recommend 1.25 to 1.5 for the 10" in a ported enclosure.

Post by **stipud** » Thu Oct 21, 2010 10:57 pm

Factory tuning frequency for SQ is 27.38Hz. But it suggests using a 1.5" port, which is ridiculously small. Vent velocity exceeds 100ft/sec below 40Hz, so you will get lots of chuffing on low bass.

I tried making a larger box with a bigger port and the same tuning frequency. 1.5 cubes total, 3" vent, 17.5" long. This gives it more output, and vent velocity stays in check. However, group delay below 30Hz is somewhat higher than the small port box (though this is less noticeable on deep bass). Phase response is identical between the two boxes. Of course phase/delay is way better on the sealed box but that's the tradeoff for about 10db extra output at 30Hz.

With two woofers you could run two 3" ports in 3cuft, of course, or go with a single slot port. Whatever you prefer.

Blue = 1.5cuft 3" box
Orange = factory SQ box
Purple = sealed 0.6

Anyone feel free to chime in with ideas, as I do not run a lot of ported boxes.

Post by **kg1961** » Fri Oct 22, 2010 5:38 am

Thanks Tom
so your saying make one box 3cub with one or 2 3" port how long?
also does it matter what way the port or facing in the box setup?

man that a large box

if i went sealed you say .7 is great but if a made it a little bigger to account the 250-300 watt rms would this help?? or would i be wasting time?

Post by **stipud** » Fri Oct 22, 2010 6:33 am

.5-.6 is all you need for sealed.

With two subs you would need 3cuft ported with two 3" ports 17.5" long. The ports could fire up through your parcel shelf or forward with the speakers. Brenzbmr did a really cool parcel shelf setup with his Elite 12D exactly like you are planning. A smaller box is also possible... 1.5 per sub was about what was necessary to even fit a 3" port in the box.

Post by **kg1961** » Fri Oct 22, 2010 6:55 am

stipud wrote:.5-.6 is all you need for sealed.

With two subs you would need 3cuft ported with two 3" ports 17.5" long. The ports could fire up through your parcel shelf or forward with the speakers. Brenzbmr did a really cool parcel shelf setup with his Elite 12D exactly like you are planning. A smaller box is also possible... 1.5 per sub was about what was necessary to even fit a 3" port in the box.

I can make the box smaller and have the port out side the box right
so is 1.5 including the port in the box? sorry for all the question

Post by **stipud** » Fri Oct 22, 2010 7:25 am

Yes the ports displace 0.084 cuft each. You wouldn't gain too much by removing them.

audiophyle_247 · Post by **audiophyle_247** » Fri Oct 22, 2010 7:40 am

No, you must subtract the air displaced by the port from the overall volume.

pi x radius^2 = area of a circle
area x port length = volume displaced.
A 3" ID round port (assuming 1/4" walls) would be a radius of 1.75",
so 3.14 x 1.75^2 = 9.62sqin
9.62 x 17.5 = 168.37cuin or .09cuft of displacement

So as you can see, moving the port completely to the exterior of the box really wont make much of a difference. Cutting 1" off the length of a box will make a much bigger impact than moving the port outside.

Building larger than .7 sealed per sub will help with output since power is a concern, but its not going to make too big of a difference. I would not go over 1cuft per sub sealed, but def more than .7cuft.

Post by **kg1961** » Fri Oct 22, 2010 7:56 am

audiophyle_247 wrote:No, you must subtract the air displaced by the port from the overall volume.

pi x radius^2 = area of a circle
area x port length = volume displaced.
A 3" ID round port (assuming 1/4" walls) would be a radius of 1.75",
so 3.14 x 1.75^2 = 9.62sqin
9.62 x 17.5 = 168.37cuin or .09cuft of displacement

So as you can see, moving the port completely to the exterior of the box really wont make much of a difference. Cutting 1" off the length of a box will make a much bigger impact than moving the port outside.

Building larger than .7 sealed per sub will help with output since power is a concern, but its not going to make too big of a difference. I would not go over 1cuft per sub sealed, but def more than .7cuft.

thanks guys
I am still wating for my sub to arrive int he mail from Thunderdome. this will give me something to measure and think about

I will update when i get a little closer. man wish i had my old kicker c12a back in the day. to date they were the loudest sub i have owned 141. the car was a honda crx and the box was built in the car off the first year of the alpine v12 mrvt500
Mike

updated the mail man just brought me 2 10" packages....lol

man they look better than i remebered

Post by **stipud** » Fri Oct 22, 2010 8:38 am

I am heistant to suggest a huge sealed box for the RSDC's since they are biased for extremely low Qtc. In a .6 box you've already got a Qtc of 0.633... at 1cuft it's 0.55. I find in bigger boxes the comps sound very boomy. They LOVE small enclosures.

Anyways Mike throw those bastards in your soundstream box and tell us what you think!

Post by **kg1961** » Fri Oct 22, 2010 8:54 am

I will try them this weekend and let you know
Mike

Post by **stipud** » Fri Oct 22, 2010 11:09 am

Man what a laugh... I wanted to see what the smallest SQ-ish box you could make for the RSDC10 is. Qtc 0.707 is achieved at 0.29cuft with heavy sound deadening, or at 0.46cuft without. The .29 box sacrifices 3dB on deep bass compared to the 0.46 box, but just think... you could fit three subs in 1cuft, and it would probably sound killer too

And yes that's including sub displacement!

Post by **kg1961** » Fri Oct 22, 2010 12:16 pm

stipud wrote:Man what a laugh... I wanted to see what the smallest SQ-ish box you could make for the RSDC10 is. Qtc 0.707 is achieved at 0.29cuft with heavy sound deadening, or at 0.46cuft without. The .29 box sacrifices 3dB on deep bass compared to the 0.46 box, but just think... you could fit three subs in 1cuft, and it would probably sound killer too

And yes that's including sub displacement!

If i only had the power to run 3 10" in 1cub.... great idea but the new line of pg subs don't do anything for me. Went to Visions.. that all i will say about that..
I used to own the proto 10" RSDC now that was a scary looking sub

I really hope I will be happy with the 2 10"

Post by **ttocs** » Fri Oct 22, 2010 12:25 pm

man you just made my day. I am fairly certain when I made my box for my 8's I came up with .45xxx somethig per side after the displacement of teh 2 woofers per side. My next job on the pggt is to convert that box to fit the 10s that I am invert mounting so they should have just under .5 each, and the roadster at 2 ohms to drive them. Those on top of the Ti9s in the doors should be a big improvement...

sorry to get sidetracked, just never seen anyone post those numbers before.

Post by **kg1961** » Tue Oct 26, 2010 6:08 pm

looks like im going to install a jl 13.5 tw5 in my car
picked one up cheap and it only need .75 sealed than i can put the amp rack and keep most of my trunk
thanks again guy for all your help and info
i felt i really only had the power for one of the sub so i got a sub that hit low like a 15 but very tight like a 10-12

oldschoolfan · Post by **oldschoolfan** » Tue Oct 26, 2010 7:00 pm

kg1961 wrote:looks like im going to install a jl 13.5 tw5 in my car
picked one up cheap and it only need .75 sealed than i can put the amp rack and keep most of my trunk
thanks again guy for all your help and info
i felt i really only had the power for one of the sub so i got a sub that hit low like a 15 but very tight like a 10-12

.75!? That enclosure will look like a pancake!

Post by **stipud** » Tue Oct 26, 2010 7:17 pm

I give up

Post by **kg1961** » Tue Oct 26, 2010 7:41 pm

i know tom i know if my ppi amp was 700-900 i would not have even thought about it but i feel 500 rms is not what they need. these sub only need 500-600 so its 100%
the box will be a pancake with a sealed wall into the car were the sub going were the ski opening in the car is than a amp rack to hope the 2 amps and a cover plate so it should onlt take up about 9inches total but side to side int he rear. my seats don't fold down so it realy not a bad use of the space
subs in the car no bass in the trunk and i have met all my needs for once im taking tomorrow off ot start the install

denim · Post by **denim** » Wed Oct 27, 2010 6:43 am

stipud wrote:I give up

Post by **stipud** » Wed Oct 27, 2010 12:38 pm

kg1961 wrote:i know tom i know if my ppi amp was 700-900 i would not have even thought about it but i feel 500 rms is not what they need. these sub only need 500-600 so its 100%
the box will be a pancake with a sealed wall into the car were the sub going were the ski opening in the car is than a amp rack to hope the 2 amps and a cover plate so it should onlt take up about 9inches total but side to side int he rear. my seats don't fold down so it realy not a bad use of the space
subs in the car no bass in the trunk and i have met all my needs for once im taking tomorrow off ot start the install

Did you even try them? You have the box!

Post by **kg1961** » Wed Oct 27, 2010 1:57 pm

stipud wrote:
kg1961 wrote:i know tom i know if my ppi amp was 700-900 i would not have even thought about it but i feel 500 rms is not what they need. these sub only need 500-600 so its 100%
the box will be a pancake with a sealed wall into the car were the sub going were the ski opening in the car is than a amp rack to hope the 2 amps and a cover plate so it should onlt take up about 9inches total but side to side int he rear. my seats don't fold down so it realy not a bad use of the space
subs in the car no bass in the trunk and i have met all my needs for once im taking tomorrow off ot start the install
Did you even try them? You have the box!

no the wife retoed it i need to have a stroller in the back. it sucks but it is what it is
i got a ok great price on the jl so im done spending money on my winter car.