Box recommendations?

[spokey9]

Actuallu using a subsonic filter allows you to usae a smaller box tuned the same as a bigger box or the same box tuned lower "(BASS box pro)".

The ssf prevents the sub from playing below the tuning frequency of the box...it doesn't help you run a smaller box

 

[SlugButter]

Actuallu using a subsonic filter allows you to usae a smaller box tuned the same as a bigger box or the same box tuned lower "(BASS box pro)".

The ssf prevents the sub from playing below the tuning frequency of the box...it doesn't help you run a smaller box

The prefabs don’t actually account for sub displacement also. It doesn’t matter as much on the larger enclosures, but on the smaller single 10 boxes for example, the sub can take a 1.5 cube box tuned to 35 HZ to 1.3 cubes tuned to 37 hz just by putting the sub in the box. This might actually meter higher than a lower tuned box if it doesn’t fall apart, but i wouldn’t like music with a 37 hz port tuning personally.

 

[Doxquzme Premium Member]

The ssf prevents the sub from playing below the tuning frequency of the box...it doesn't help you run a smaller box

That's not what BASS box pro software shows me. With an active subsonic filter, prior to amplifaction, the SSF (or technicaclly the infrasonic filter) does what you say, true, but also allows the woofer to work in smaller boxes as it no longer is having to work on those frequencies blocked by the filter, kind of like it sees the box as if it were a smaller driver. In some instances, substantially smaller boxes. There are limitations too, but all the same, SSF is always a good idea when you are tuning an octave or two above. Rarely is that not the case with car audio subs. Different story in home theater where a lot of infrasonic material is added to the soundtracks. Hit me up if you ever want an expample, I'll run the numbers and show you the graphs, it's kinda cool.

 

[spokey9]

That's not what BASS box pro software shows me. With an active subsonic filter, prior to amplifaction, the SSF (or technicaclly the infrasonic filter) does what you say, true, but also allows the woofer to work in smaller boxes as it no longer is having to work on those frequencies blocked by the filter, kind of like it sees the box as if it were a smaller driver. In some instances, substantially smaller boxes. There are limitations too, but all the same, SSF is always a good idea when you are tuning an octave or two above. Rarely is that not the case with car audio subs. Different story in home theater where a lot of infrasonic material is added to the soundtracks. Hit me up if you ever want an expample, I'll run the numbers and show you the graphs, it's kinda cool.

The smaller box would have a higher tuning frequency...and the ssf would still just be set to protect your sub playing too far below that tuning frequency...it's not a magic filter that allows a sub to play the same in a bigger or smaller enclosure...

 

[Doxquzme Premium Member]

No sense in arguing, the software has helped me do just that, many, many times. When you apply a SSF prior to amplification, (an active filter as we are discussing here) BASS box pro still allows one to keep the tuning frequency the same or lower and allows you to use a smaller or same size box with varying results well within tolerances. I’m an EE not a sound engineer so can’t speak to why that is, mechanically, I just know that it is done with regularity. If I had to guess, I would speculate that because an enclosure is part of the mechanics and the box is acting as component of the actual woofer, when you change what the driver has to respond to by eliminating those lower frequencies from ever entering into the equaiton, you can change the box component too. I have pretty extensive experience in designing home theater subs (in the hobby for 42+ years, subs for at least the last 35) where size is a major consideration for aesthetic reasons; the application to car audio is the same when it comes to the design of any sub for that matter. Granted, you may want a bump at certain frequency in a car sub that you don’t want in a home sub, either way BASS box pro will allow you to manipulate this when an active SSF is used in the overall design circuit and I'm pretty confident that the design engineers that wrote BASS Box Pro know a smidgen more about this than the two of us put together.

 

[Doxquzme Premium Member]

No sense in arguing, the software has helped me do just that, many, many times. A smaller box can be tuned to the same lower frequency in this scenario, there are limits to this, sure, physically, but not within the differences we are talking about here. Optimal is the key, not bigger or smaller. If you can tune to the same frequency in a smaller box or lower Fb in the same size box, the entire band will look different, usually a benefit in a car environment when you employ either calculations using a SSF. When you apply a SSF prior to amplification, (an active filter as we are discussing here) BASS box pro still allows one to keep the tuning frequency the same or lower and allows you to use a smaller or same size box with varying results well within tolerances. Adding an external 12db/octave filter with a q=2 to a vented box whose resonance (fb) has been lowered can extend tend the bass response and produce a 36 db/octave cutoff, in some instances by as much as 12Hz - this applies to the same size box. If you use this in a smaller box and aim for the original cutoff, you can achieve this in the smaller box with the same frequency goal as the original non SSF filtered box, you can accomplish this in the smaller box. I have pretty extensive experience in designing home theater subs (in the hobby for 42+ years, subs for at least the last 35) where size is a major consideration for aesthetic reasons; the application to car audio is the same when it comes to the design of any sub for that matter. Granted, you may want a bump at certain frequency in a car sub that you don’t want in a home sub, either way BASS box pro will allow you to manipulate this when an active SSF is used in the overall design circuit and I'm pretty confident that the design engineers that wrote BASS Box Pro know a smidgen more about this than the two of us put together.