isobaric ported?

[Hydrastas 10+ year member]

Right now in the cougar i've got 2 15"s in separate sealed boxes. I've heard that just putting one of them into a bigger and ported box that it would be louder than both in sealed boxes as they are now. The problem is space, so if i did make a ported box, i'd only be able to fit one ported box into the trunk and not 2. Any suggestions on how i should use both speakers with one ported box? I'm thinking about just making a normal ported box to the speakers specs and mounting the second speaker face to face with the first one. If i did this kind of isobaric design worthwhile or how else could i use the 2 subs in one ported box?

Click to read more...

 

[Hydrastas 10+ year member]

Has anyone here done isobaric?

 

[snoopdan 5,000+ posts]

Its called Isovent, not isobaric when its ported

 

[Hydrastas 10+ year member]

Thanks for that well informed post, so should i even bother with the isovent or just sell one of the subs and just use one?

 

[djman37 5,000+ posts]

isobaric is used to reduce the airspace needed for a sub by 1/2. Sealed and 4th order see most of that action.

If you're going ported, isobaric doesn't help since you need twice the power to achieve the same output. You COULD do it to make a smaller ported box, but you'd be in a VERY small minority. I think JL's site still has the explanations of all the types of boxes. bcae1.com is good too.

 

[Hydrastas 10+ year member]

If it reduces the needed space by 1/2, what would the output be if you didn't reduce the airspace by 1/2?

 

[djman37 5,000+ posts]

If it reduces the needed space by 1/2, what would the output be if you didn't reduce the airspace by 1/2?

if you don't reduce the airspace, and have the room, USE BOTH SUBS for double the output

 

[Hydrastas 10+ year member]

So if i were to take one of the sealed boxes they are in now and make it isobaric would it be double the output compared to that sealed box with just one sub, or would it be double the output of both subs in both sealed boxes or same as both subs in different sealed boxes?

 

[djman37 5,000+ posts]

So if i were to take one of the sealed boxes they are in now and make it isobaric would it be double the output compared to that sealed box with just one sub, or would it be double the output of both subs in both sealed boxes or same as both subs in different sealed boxes?

in an isobaric configuration, you only get the output of one sub. so really for having two subs and twice the power, you only the output of one sub in a regular sealed setup. The advanage is less airspace is needed for the sub and the output tends to be cleaner, since the cone is kept rigid by the air between the subs. This setup doesn't really help subs with a 100% coverage dustcap, only the traditional cone/dustcap type subs.