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mendon mafia
12-03-2009, 01:51 PM
my take on a jl box design.

does it seem feasible? poor results expected? box will be built for 2 12's, 4 cubes net @ 35ish hz.

http://i837.photobucket.com/albums/zz297/Mendonmafia/hobox.jpg

or this

http://i837.photobucket.com/albums/zz297/Mendonmafia/hobox2.jpg

mendon mafia
12-03-2009, 01:56 PM
ignor the randomness on the second image. lol ms paint ftl when ur in a hurry.

mendon mafia
12-03-2009, 04:54 PM
no opinions? will i get h/o effects like jl or will it just sound like normal ported or will it sound worse?

PV Audio
12-03-2009, 06:53 PM
A waste with the second one being a bigger waste. Use a single port if possible. Otherwise, you're introducing more potential losses into the enclosure than you have to.

mendon mafia
12-03-2009, 06:58 PM
A waste with the second one being a bigger waste. Use a single port if possible. Otherwise, you're introducing more potential losses into the enclosure than you have to.

so basically its there nothing to gain by doing the ports like that?

obviously there must be more to it than porting in front of the woofer cone right?

how does it work with the jl h/o boxes. just dont make sence the same thing cant be applied to all woofers.

ciaonzo
12-03-2009, 07:01 PM
I'm gonna second what PV said. Go with a single vent.

I've also been modeling for you as I said I would and your optimal situation is going to be using both drivers in a single enclosure no larger than 2.5cu.ft. but leaning more toward 2. The only thing that happens by going larger than that is you get a much more peaky response and loss of control over the cone, which is exacerbated with high power input. I'll get the curves to you soon once I have it optimized so you can see what I mean.

mendon mafia
12-03-2009, 07:37 PM
I'm gonna second what PV said. Go with a single vent.

I've also been modeling for you as I said I would and your optimal situation is going to be using both drivers in a single enclosure no larger than 2.5cu.ft. but leaning more toward 2. The only thing that happens by going larger than that is you get a much more peaky response and loss of control over the cone, which is exacerbated with high power input. I'll get the curves to you soon once I have it optimized so you can see what I mean.

wow so 2.5 cubes for BOTH. thats tiny small. what size port do i need with that only like 30" or area or something?

BTW this was not specifically for my alphas just curious if it would have "high output" like the jl boxes designed this way.

mendon mafia
12-03-2009, 07:38 PM
double post ftl

PV Audio
12-03-2009, 07:51 PM
so basically its there nothing to gain by doing the ports like that?

obviously there must be more to it than porting in front of the woofer cone right?

how does it work with the jl h/o boxes. just dont make sence the same thing cant be applied to all woofers.What the HO box does is it partially horn loads the port. What happens is that the port starts narrow on the "inside" of the enclosure and gradually gets wider until it comes out the front. What happens is that the air gets compressed where it's narrows, and as it opens gradually, the pressure lessens and the air displaces more volume once it gets to the outside. This is used in horn design to increase the efficiency of a speaker, but it isn't doing anything to increase the efficiency of this speaker since it's loading into a chamber and is being ported. It's just using that unloading effect to get more output. Unfortunately, this poses two main problems: the output sounds like absolute ****, and because you can use a bunch of technical knowledge to make it sound like you've got a fancy product, they can charge a premium.

GAM3OVR
12-04-2009, 02:01 AM
What the HO box does is it partially horn loads the port. What happens is that the port starts narrow on the "inside" of the enclosure and gradually gets wider until it comes out the front. What happens is that the air gets compressed where it's narrows, and as it opens gradually, the pressure lessens and the air displaces more volume once it gets to the outside. This is used in horn design to increase the efficiency of a speaker, but it isn't doing anything to increase the efficiency of this speaker since it's loading into a chamber and is being ported. It's just using that unloading effect to get more output. Unfortunately, this poses two main problems: the output sounds like absolute ****, and because you can use a bunch of technical knowledge to make it sound like you've got a fancy product, they can charge a premium.

actually the H.O. enclosures, are pretty efficient. and the boxes dont quite sound like ****

PV Audio
12-04-2009, 02:06 AM
actually the H.O. enclosures, are pretty efficient. and the boxes dont quite sound like ****
You misunderstand, I mean efficient in the sense of a horn loudspeaker. That enclosure doesn't make anything more efficient to that level. A loudspeaker horn causes an incredible increase in efficiency. We're talking loudness levels of fully powered big loudspeakers but only using maybe 5-7 watts at most.

PV Audio
12-04-2009, 02:08 AM
And I have not heard a HO box that sounded pleasing. They are incredibly boomy and end up being tuned higher than most.