Upside down speakers

ashok

Member
2002-06-06 4:43 am
3RS
Most speakers we see have the tweeter at the top of the cabinet. Mission has their tweeters below the bass/mid bass unit.
I have a Mission 701 and a Rogers GS1. The Missions sound great ( AFTER being run in for MANY months!) .
I decided to try out the same scheme by inverting the Rogers as it is a small bookshelf model. The speakers were tested on 24 inch tall sand filled stands.
The upside down Rogers sounds different as compared to its normal tweeter on top position. With the Chesky demonstration disk the Rogers sounds better upside down. Even the imaging seems better.
Has anyone tried this with their small bookshelf speakers? What does Mission know that others have not understood yet ?
 
1. there is no secret. many companies put the tweeter at the bottom.

2. try this. let the tweeter be on top but lower your listening height. you might hear the same changes.

i often find i prefer a listening position where my ear is in line with the woofer not the tweeter esp. with small 2 way systems. the might be for the following reasons.

1. in small 2 way systems a the woofer is often producing sound till 3k or so that covers all of the bass and most of the midrange

2. the tweeter being a bit higher than ear ht. means that the tweeter response is off axis and hence a little less bright.

3. the woofer being on axis and the tweeter being off axis means that the voice coils of the 2 drivers are probably aligned with ref. to the ear. this is akin to time alignment (either by sloping the baffle or by stagering the tweeter) that many manufacturers do.

hope this helps.
 
Ashok,

A couple of things come to mind to explain the differences you have heard:

1)Phasing or lobing- if the drivers are placed too far apart with a first or second order crossover, the out of band response can interfere, leading to vertical peaks and troughs in the mid/high range response at the listening position. By turning the box upside down you may have moved from a peak to a trough, or vice-versa, or any degree in between.

2) Room effects- moving the bass driver up or down can affect response at the listening position, due to reflections from the wall and ceiling arriving at the listening chair at different times, again causing constructive or destructive interference.

I'm sure there are many others...:D