Sub: Down firing or Front firing (1 Viewer)

[Darrin_R]

Hello everyone. This is my first post.

I am considering a DIY sub. I have read many of the DIY post which are very educational but I have not seen where anyone has covered down firing vs front firing subs. I have owned both configurations and was very happy with each of them. I was wondering if someone could give me the pros and cons of the two.

 

[BrianMu]

Welcome!

I just built a sub and weighed my orientation options so I'll take a stab at this one:

The pros of downfiring are that the driver is not exposed to kicking, etc. and you don't need to add a grill of any kind.

The cons of downfiring are that the sub has to be slightly taller (to accomodate legs beneath the sub) and some drivers don't operate optimally in downfiring positions (Adire drivers are well suited to either position).

I went with front firing because I like the look of a black cloth grill on the front of the sub rather than a huge wood block. I also wanted my sub to be shorter than the arms on the couch it sits next to and the extra 4 inches for the legs on a downfiring design would have made that impossible.

I hope this helps,

Brian

 

[Dave Poehlman]

Also, a downfiring driver, over time, can be subjected to "cone sag" (particularily lower-end/foam surrounds). This can change a driver's efficiency slightly.

 

[Darrin_R]

Thanks for the reply.

In my situation the size of the sub doesnt matter so the extra height of a down-firing sub is OK. (The wife finally decided that it was either an obsession or a sickness that she can not beat) I feel that a down-firing driver will be more protected. I have 3 year old twins which is something to consider. I was just wondering if there were trade-offs that I had not yet considered.

 

[Hank Frankenberg]

Darrin, as aluded to above, you can do downfiring IF the driver design is amenable to it. Just ask the driver manufacturer. Also, Adire has stated that their Shiva 12" and Tempest 15" can be mounted downfiring.

 

[Andrew Low]

There are also benefits to using a downfiring design for some driver designs. The Adire Shiva actually will have more "excursion" if used in a downfiring design.

So, down or front, the design of your enclosure, design goals, and driver selection (even your amp) all have a factor.

Sound complicated? Yes, but in many cases we are talking about a less than 1dB trade-off. So, if you were dealing with a crappy driver and low power amp this might matter -- but when talking about most of the drivers people are using for DIY its almost a non-issue.

Roo

 

[Wes]

Here is an example of what I have found with Front vs Down firing:

My nephew had a big box built for his king cab Nissan PU truck. The store built him a down firing box with two 15"ers. He brought it by to show me, the first thing I noticed was that I could not close my mouth as the bass would chatter my teeth. It was a what I call horizontal shock wave. He also did not care for it so I talked him into letting me re-do the box but now placing the 15"ers pointing at his back (the front seats). I ported the box pointing the front also. Now the shock wave hit you hard in the back and went through your chest with no teeth chattering effects. It was so much better of a feel than the down firing set up. Now live music you have a Bass drum that is always putting out a vertical shock wave and also speakers that are always vertical so the front firing sub is more accurate. Now movies there are some actions that you have a horizontal shock wave such as a Dino's foot steps. I do admit the horizontal would reproduce this better but I find over all a vertical shock wave is more pleasing to me in most cases. So I vote strongly for front or back firing over up or down firing. Now this is just my opinion!

Wes