A few questions regarding a large, 2-way bookshelf design:
1) When offsetting the two drivers from a vertical alignment in a bookshelf speaker, is there any standard or best practice method of determining the amount of offset?
2)What are the advantages of inverting the woofer and tweeter? When should this be done
3) Is there any method for determining the optimal vertical distance between the woofer and tweeter? I have a tall front baffle and am not sure how far apart to place them.
As a note, I'm using the Vifa XT19 and the Peerless 850122.
Thanks for your assistance!
1) When offsetting the two drivers from a vertical alignment in a bookshelf speaker, is there any standard or best practice method of determining the amount of offset?
2)What are the advantages of inverting the woofer and tweeter? When should this be done
3) Is there any method for determining the optimal vertical distance between the woofer and tweeter? I have a tall front baffle and am not sure how far apart to place them.
As a note, I'm using the Vifa XT19 and the Peerless 850122.
Thanks for your assistance!
IIRC, the idea is to have the tweeter at uneven distances from all 3 nearby baffle edges (top, right, left). So for a start, make sure your offset doesnt end up making one of the side distances to be equal to the top distance.
I do recall some mention of the ideal ratio of these 3 distances, but I can't for the life of me remember when I saw it. Maybe the golden ratio?
hehe It's funny how different people can interpret the same questions differently. The only one I had an answer for was 3, which Simon already answered 
1. I thought the question was regarding time alignment, ie +ve or negative displacement of the tweeter in the vertical plane....
2. I thought the question was regarding invertion physically rather than electrically, ie tweeter on the bottom woofer on the top
Tony.
edit: if you want to model the effects of driver displacement left on the baffle (and have excel) then you should have a look at http://www.pvconsultants.com/audio/diffraction/downloadbds.htm
1. I thought the question was regarding time alignment, ie +ve or negative displacement of the tweeter in the vertical plane....
2. I thought the question was regarding invertion physically rather than electrically, ie tweeter on the bottom woofer on the top
Tony.
edit: if you want to model the effects of driver displacement left on the baffle (and have excel) then you should have a look at http://www.pvconsultants.com/audio/diffraction/downloadbds.htm
Have a look at this thread as it might help on confuse you further
http://www.diyaudio.com/forums/showthread.php?s=&threadid=29159&highlight=
1. Use the centre of the voice coil, mid point of the driver's front plate is close enough.
2. Used in odd order crossovers, 1st and 3rd, to compensate for the downward polar tilt. Reverse the tweeter polarity for 3rd order.
3. Keep the driver centres less than the wavelength of the crossover frequency.... wavelength in metres=345/Hz. Have the tweeter at about ear level in your listening position.
BTW, nice choice of woofer as the 850122 is a freak of nature.... really special.
Cheers
http://www.diyaudio.com/forums/showthread.php?s=&threadid=29159&highlight=
1. Use the centre of the voice coil, mid point of the driver's front plate is close enough.
2. Used in odd order crossovers, 1st and 3rd, to compensate for the downward polar tilt. Reverse the tweeter polarity for 3rd order.
3. Keep the driver centres less than the wavelength of the crossover frequency.... wavelength in metres=345/Hz. Have the tweeter at about ear level in your listening position.
BTW, nice choice of woofer as the 850122 is a freak of nature.... really special.
Cheers
As a suggestion, put the drivers close to the top of the cabinet and have a look at the picture in that link I provided. I tend to put the drivers in the centre of the baffle left to right even though it's frowned upon.
Have a look around what others are doing and also commercial speaker websites.
Have a look around what others are doing and also commercial speaker websites.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.