radical change to a set of kit boxes

[busterno1]

I have a speaker kit which i made the boxes for using there sizing

What i would like to do now is change the box completely . I want to make it narrower, taller & deeper but will keep the litres the same . can anyone see any problems . At least one measurement will be changed by 10 percent or more

Also change the ports from front to back of box . if possible put one next to other or one on top of the other .Can anyboby see any problems thanks

[paulspencer]

Assuming it is not a transmission line there should be no problems at all. The thing most likely to have an effect is the baffle width which relates to the baffle step correction in the crossover, but 10% change is certainly not significant.

cheers,
Paul

PS what kit would that be?

[busterno1]

The kit is the jv 60 from jaycar .I am rebuilding because I am sick of looking at the 2 ports in the front . could you please explain baffle correction how it will effect the box or the crossover .Is it a effect I am likely to hear

[sreten]

Originally posted by busterno1
The kit is the jv 60 from jaycar .I am rebuilding because I am sick of looking at the 2 ports in the front . could you please explain baffle correction how it will effect the box or the crossover .Is it a effect I am likely to hear

Assuming it is not a transmission line there should be no problems at all. The thing most likely to have an effect is the baffle width which relates to the baffle step correction in the crossover, but 10% change is certainly not significant.

As long as you don't change the baffle width significantly the
sound will not change. Siting the ports on the back will sound
slightly better usually.

sreten.

[sreten]

Just had a thought : keep the width similar but bevel the
edges at 45 degrees for a visually much narrower baffle.

sreten.

[busterno1]

thanks for the answers .

I was planning on rounding the edges off as well .

Is there a bad spot to mount the ports for ex directly behind a driver or too close to each other . mabey one directly on top the other ?

[paulspencer]

The JV60 box is not tall enough. Ideally, the height should place the tweeter on ear level when in your seating position. 900mm is usually about right for a normal couch, so the box should be taller, say 1150 - 1200mm tall. Tall and slim also looks better. If you place the vents on the rear of the box, you need clearance behind as if the gap is too small, the effective tuning of the vents will be lower. Don't worry about baffle width, the difference should be more theoretical rather than noticeable.

IMO the Jaycar box has very bland looking proportions. It is ridiculous to have to put a floorstanding speaker on a stand to get the right height as well. 210mm front baffle width looks about right for these speakers. But this may not help if you are only making minor modifications to an existing box.

What is the size of the box you have now?

[paulspencer]

With ports the main thing you have to watch is the clearance around it. If it is very near the floor, then this will extend the effective length and you must allow for this. I'm not sure of the effect of placing the vents close to each other. Unless you can get a clear answer on that I'd avoid it.

As far as rounding the edges, I would consider that primarily an aesthetic change, rather than an acoustic one. It is commonly thought to reduce edge diffraction, but I don't think it is really effective. There is a relationship between the wavelenth of concern and the radius of the curve, which means that the radius you are likely to use is only going to work for the very high frequencies which tend to beam and have very little off axis output anyway. If you want to put on a grille, this radius becomes a pest, and personally I don't think the radius looks as good, but that is a matter of opinion.

regards,
Paul

[busterno1]

at the moment the box is 275 w external .jaycar say it should be 223 internal .the 210 mm you suggest is close to what i wanted maybe a bit smaller [ internal i mean ]

[paulspencer]

The main thing is to keep the same volume. The Jaycar box isn't very well braced, especially considering the dimensions used.