Need help with 3-way series x-over

[andrew01]

Gents ( and Ladies ),

I need some help to confirm if a spreadsheet I made up is giving the correct values or not.....just textbook ones at the moment.

If the x-over points are 300 and 3000 for example , I get

HP = 0.42mH
LP = 66uF
BP = 4mH and 7uF

Is this correct ?

also

If I want to pad down the Tw by 3dB using a series resister should the value be 4.5 or 9 ohms ???

Thanks
Andrew

[Andy G]

Some reading and another little spreadsheet to play with.

http://users.tpg.com.au/users/gradds...ss-overs8b.htm

for all 8 ohm load, your values are the same as my spreadsheet gives.

Have fun. but remember, your drivers MUST suit if you expect it to work well.

AG

[sreten]

Originally posted by Andy Graddon
Some reading and another little spreadsheet to play with.

http://users.tpg.com.au/users/gradds...ss-overs8b.htm

for all 8 ohm load, your values are the same as my spreadsheet gives.

Have fun. but remember, your drivers MUST suit if you expect it to work well.

AG

One thing that has come to light is that the mid and the woofer need to be about the same sensitivity.

Need I say more ....... /sreten.

[Andy G]

If you can get away with only padding the tweeter, things seem to work really well!

That 4-way series I did was very interesting to play with, I ended up with padding on both the tweeter and ribbon, and a larger cap on the low end than I expected to use. Because the drivers, particularly the mid, had nice smooth response with no significant corrections needed, I was able to get a very nice sounding speaker just by tweaking the levels of each driver using L-pads.

[andrew01]

Thanks Andy,

By the way , how did you come up with the value of 4.7uF on the Vifa pyramid 3-way ? Shouldn't it be twice that value ?
(or am I barking up the wrong tree ? )

Andrew

[Andy G]

No idea at the moment.
Ask me in a couple of weeks, totally snowed under with Uni til then !!