Phoenix Gold Phorum

Hi!
As the topic says i was wondering about the recomended box size for the RSD Competition Sub 10" both sealed and ported. Will it f.ex play ok in 18-20 liter sealed? And have anyone tested it up aginst the Alpine Type R?

Thanx
Bjornar

18-20 liters is about perfect for sealed.

I certainly like it better than the Type-R.

agreed. i used to run two type-r subs sealed and have now come to realize they were crap, at best. the RSDc sealed has been one of my favorites so far. before that it was the infinity perfect, sealed. the RSDc seems to be even more musical with the ability to handle even more.

Thanx guys, i have 4 Type R in my car now but i would like to try something else. Then i will go for the RSDC in 18-20 L sealed.

1 more question; is the 20 Liters sealed a typical SPL box or SQ box or something in the middle? I lm a SPL guy but it`s also ok to have a little left of the trunk.

Bjorn, that's the SQ box size. For SPL you would need to go ported.

From what I remember, your box had separated chambers with smaller airspace for the middle subs, compared to the outer subs? If that is correct, you should cut some big holes in the separating walls, so that all subwoofers can share the total airspace. That way the subs will all sound the same, and you can minimize cancellations.

the only reason the smaller box size is "recommended spl" size is because of the smaller volume of air in the enclosure acts as a stiffer suspension for the sub, allowing you to run more power before the sub reaches xmax.

it wont "automatically be louder" just by going with a smaller box. unless you are running over 800 watts to the sub, i wouldn't even worry about it. go with the more tonally accurate box. IMO

Yeah... on the same power, the "SQ" sealed boxes will be louder, especially on lower bass. I always build the SQ recommended sealed boxes for this reason.

With ported boxes there's a HUGE difference between SPL and SQ tunings.

Thanx for your answers, I think i will stick with the sealed box, i guess it will be loud enough with 4 of the RSDc 10"

@Stipud: You remember right about the box i have, there are different size on the chambers but i think i will build a new box with one 70-80 Liter big chamber and put 4 RSDc in it.

Bjornar

Bjorn, if you cut large holes through the dividers in your current box, that will work just fine. Plus the leftover wood will act as a brace, which makes your box stiffer, which makes it sound better.

Of course if you are making a new box for cosmetic reasons, that is fine too. Just make sure you add lots of bracing, since a 4 sub 80 liter box will be very long, and easier to flex than a small single box.

@Stipud One guy at Alpine Europe said that i would also get an extra 3 dB if i do as you say and cut holes in the dividers so that the subwoofers get a common chamber so i will absolutely do that

I think i will build a new box for the RSDc, then i can take the Alpine`s and have them ready in the box for spare subwoofers or maybe for sale.

Thanx for your answers.

Bjornar

i dont know about 3db...but it certainly wont hurt anything!

phonixx wrote:One guy at Alpine Europe said that i would also get an extra 3 dB if i do as you say and cut holes in the dividers so that the subwoofers get a common chamber

Really??

I have not heard about that before... Cool...

Nahh.... two subs in separate (and equal volume) chambers will be just as loud, if not louder (due to the stiffer box), than two subs in shared airspace of the same overall volume.

The reason you should do it is because the airspace of your chambers is different. This causes the speakers to respond differently, which can theoretically cause cancellation. So in your case, it MIGHT be a bit louder, but probably not near 3dB.

Yes i guess it was the cancellation the guy at Alpine was talking about. Not sure how big the problem really is in my case, 14 liters vs 18 liters. The idea was to have 2 subwoofers with SPL boxsize (14 liters, tuningfreq approx 48Hz i think) and 2 subwoofers to play in recommended boxsize (18 liters, tuningfreq approx 45HZ i think)

My new box for the 4 RSDc will have holes in the dividers or 4 equal chamber of approx 20 liters. What you guys say; I guess dividers is ok to make the box as stiff as possible?

As long as the chambers are all the same size, dividers are fine too. If they aren't, just cut holes in them, and they will work great as bracing.

I guess it will be 4 chambers with same size.
My new subwoofers are on their way from Audiosavings.com, the has left from NEWARK, NJ, i sure hope next stop is Europe, maybe Paris or something