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View Full Version : my 2 E8's sealed vs ported...



Alex JB
01-21-2009, 05:40 PM
OK,
So I built the ported box I wanted to with a great result at the tuning frequency of around 34Hz
I think I'll keep it like this for a while but I already notice the peak in audible volume around tuning and I'm not sure if I like it.

I think I want to acheive a better low end and don't mind if I loose dB, I just want low and smoother curve

So here's the question, do the curves below look realistic if I was to turn the ported enclosure into a sealed one?

I know the volume of 1.1 cu ft net was ideal for the ported box, but when that goes up to 1.34 cu ft (ading the slot port vol) if I just seal the end up with a plate, seems large, especially as the recomendation for sealed is 0.28 cu ft per sub.
What will the it do to the subs going to over double the sealed volume?
is it like no air spring, like when a ported box is below it's tune?


http://i79.photobucket.com/albums/j146/alex_jb/truck/2E8ssealedvsportedinsamebox.png

mcsoul
01-21-2009, 05:54 PM
When you say 1.34, do you mean net (minus woofer and port displacement) or gross?

Even if it's net, I think 2 e8's will be fine on that tune in 1.34 vs 1.1 cubes.
If your talking sealed on 1.34, yes it's too much and will lower the power handling.
Unlike a ported box below it's tune, sealed and to big in this case should sound okay,
just easy to bottom out with power. Half rated is a good starting point.

Alex JB
01-21-2009, 06:15 PM
Yes I'm talking about 1.1 cu ft net after port and woofer in the ported set up, that goes up to 1.34 if I was to seal up the end and gain back the slot port volume, so the sealed box would be 1.34.

Basically I'm trying to gauge if it is worth trying the 'block off the port' idea to create the 1.34 cu ft sealed box to tell if I get a flatter curve and more like the sound I want.

Am I effectively going infinite baffle with this idea?

loud-n-low
01-21-2009, 06:19 PM
should hit lows amazing, however power handling will be decreased. I ran 2 crystal cmp 8's in a box that size and had no problems

Alex JB
01-21-2009, 06:31 PM
should hit lows amazing, however power handling will be decreased. I ran 2 crystal cmp 8's in a box that size and had no problems

I think I'm way under power with them anyway, I am running 2 channels of my 4 ch amp bridged into 1 and it does 225rms at 4Ohm.
With the subs wired to give an 8 Ohm load (don't think the amp is 2 ohm bridged stable) I can only be putting 120 in there.

there's another fella on here who is running over 1Kwrms to a pair in a ported box and he hasn't fried them yet...

Alex JB
01-21-2009, 06:33 PM
Think I'll make a gasket and a plate tonight and try it.

I've no equipment to measure though so It's just my ear and compare to the ported set up.

mcsoul
01-21-2009, 06:34 PM
I think I'm way under power with them anyway, I am running 2 channels of my 4 ch amp bridged into 1 and it does 225rms at 4Ohm.
With the subs wired to give an 8 Ohm load (don't think the amp is 2 ohm bridged stable) I can only be putting 120 in there.

there's another fella on here who is running over 1Kwrms to a pair in a ported box and he hasn't fried them yet...

Sounds like that power should work fine to me.

loud_mouth22
01-22-2009, 01:25 AM
let us know how it sounds

gunz4me
01-22-2009, 01:35 AM
You could always seal it up and shrink wrap a Styrofoam block to take up some air space if you are concerned about the box being too big. If you don't have access to a crafts/hobby store, you could also use that Styrofoam insulation from Lowes/Home Depot to take up some air space.

mlstrass
01-22-2009, 02:38 AM
why not seal it inside the box where the port ends?

Alex JB
01-22-2009, 09:55 AM
Thanks for both those suggestions, I think it would bw easiest to take up some volume with the styrafoam.
The folded port is at the RHS like this, so adding a plate inside where the port ends would also work.

http://i79.photobucket.com/albums/j146/alex_jb/truck/IMG_0482.jpg

I just dis this last night to the end with the port.
http://i79.photobucket.com/albums/j146/alex_jb/truck/IMG_0503.jpg

Alex JB
01-22-2009, 02:53 PM
Ok, so I like the low cpability of the sealed version but normal 35-60Hz stuff obviously suffered with the curve being so shallow.

I'm torn now :(

Do I...
A) Stick witht he smooth response of the large sealed enclosure and risk damage if I increase the power to it ?

B) Maybe add some blocks to remove a little volume to get some airspring back?

C)Go back to ported and rip out the folded port to gain box volume and add an external tube port (there's a space for it behind the box, under the seat backs)?

http://i79.photobucket.com/albums/j146/alex_jb/truck/2E8ssealedvsportedinsamebox2-1.png

Alex JB
01-22-2009, 04:57 PM
OK, so I have another related question!

If I was to seal the folded port exit (like I have done) and cut a hole in the box near the middle, so the hole goes into the large airspace, and take 4" tubing out of the box and cut to length for the freq I want... would the volume of the old slotted port just act as normal box volume now?
I know it's a restricted size but because there's not ait flowing through this space anymore it should just now be box volume right?

Alex JB
01-22-2009, 06:52 PM
Last question for today I promise...

box end of a port as shown a bad idea?
the port itself would be external in the direction of the arrow.

only oyher option would be port hole in the box at the arrow tip and the port opening would be where the oval is right by the subs.

http://i79.photobucket.com/albums/j146/alex_jb/truck/boxexternalport.png

c_james_s
01-22-2009, 07:12 PM
Stupid question but who makes the e8? ive heard alot about them but i always get home audio when i google it. thanks.

mcsoul
01-22-2009, 07:53 PM
Sundown

and

Stay ported and add power.

cx-7heaven
01-22-2009, 07:58 PM
Can you build a smaller sealed experimental box to play with? I would prolly run those around .35 sealed a piece, that should bring that higher subbass back up, and increase power handling as well.

c_james_s
01-22-2009, 10:47 PM
whats so special bout this sub? i googled it and it didnt look too fantastic. let me know please. are they super spl or sq or are they just the best 8" sub out there?

Alex JB
01-23-2009, 11:53 AM
spent an hour or so playing with the crossover frequency and taking the sealing plate off and on.
the ported setup is obviously much louder at and up to 20hz above tuning, but the low extension of the oversized sealed setup is way better and I defo choose that over the loudness of the ported.

next step is to reduce the volume so I can switch over to my 500rms amp wire to 2ohm and see if I can get to the same audible volume as the ported does at tuning.

grimreper912003
01-23-2009, 11:59 AM
I think I'm way under power with them anyway, I am running 2 channels of my 4 ch amp bridged into 1 and it does 225rms at 4Ohm.
With the subs wired to give an 8 Ohm load (don't think the amp is 2 ohm bridged stable) I can only be putting 120 in there.

there's another fella on here who is running over 1Kwrms to a pair in a ported box and he hasn't fried them yet...

Hey, I know that guy ;)


whats so special bout this sub? i googled it and it didnt look too fantastic. let me know please. are they super spl or sq or are they just the best 8" sub out there?

They are Very loud, clean and strong for their price.


spent an hour or so playing with the crossover frequency and taking the sealing plate off and on.
the ported setup is obviously much louder at and up to 20hz above tuning, but the low extension of the oversized sealed setup is way better and I defo choose that over the loudness of the ported.

next step is to reduce the volume so I can switch over to my 500rms amp wire to 2ohm and see if I can get to the same audible volume as the ported does at tuning.

SO what do you like better? I sent one of my 8"s in for repair (Coil looked fine, just played it under tunning unexpectidly) so I was going to build a sealed box for my 1 sub. Does the sealed box hit lower to you?

Also did you get your package?

Alex JB
01-23-2009, 01:27 PM
Hey, I know that guy ;)



They are Very loud, clean and strong for their price.



SO what do you like better? I sent one of my 8"s in for repair (Coil looked fine, just played it under tunning unexpectidly) so I was going to build a sealed box for my 1 sub. Does the sealed box hit lower to you?

Also did you get your package?


Hey,
Yes I got the speakers thanks!

As for the E8's sealed... I'm loving the low extension sealed, you should definately try a 0.5 cu ft box and fill it up with MDF or whatever packing to 0.28 Cu ft as recomended. Run it with the 0.28 and get a feel for the sound then take some packing out and see the lower end extension get even better...

with just one sealed and close to the recomended volume, I'm guessing you could do like before and feed it loads more power than the recommended 200rms.