[Luigi]

Hi Guys

Im wanting to wire up three sets of B200s to mate with my Alpha 15s. Already have two wired in parallel, so around 3ohms. But if I wire up another set it will result in a 1.5ohm load which my amp wont handle.

Is it possible then to series a pair of Visaton B200s for a 12ohm load, and then parallel the final B200 to make a 9 ohm load?

[opnly bafld]

What kind of amp?

2 ohms all parallel or 18 ohms all series

2 series (12 ohms) + 1 parallel (6 ohms) = 4 ohms

2 parallel (3 ohms) + 1 series (6 ohms) = 9 ohms

[Luigi]

A tube/hybrid chip amp from Aussie, the JLTI (just listen to it) Mk II, around 35wpc. Seems to drive a pair of B200s and the Alphas okay.
But not sure it could handle 1.5ohms.
Like what a pair of B200s can do and have another pair, like, hanging around, so thought I would bring them to the party.
Any thoughts on how I should wire these suckers together?

[opnly bafld]

Pick up a 4th pair so you can series/parallel for a 6 ohm load or leave it as is and use the 3rd pair in another set of speakers. 

[S Clark]

Looking at the impedence graph for these guys, it look like they are closer to 5 ohms for most of the range that you are likely to use them in.  I think that I'd use 4 of them....

2 in series (10 ohm) paralleled to 2 in series (10 ohm) = 5 ohm for the group

[Luigi]

As it happens I have a fourth pair; is there some advantage to doing it the 2 in-series paralleled to two in-series way, over using three pairs per side, two in series and one in parallel for a four ohm load?

I realise there will be problems with lobing, peaks and dips and all, but given I have these on hand and it's not a big deal to OB the remaining pairs, I thought I should at least give it a whirl.

Besides, Im finding two pairs definitely better than one pair overall, so four pairs should be the bomb (using no good reasoning whatsoever).

[opnly bafld]

As it happens I have a fourth pair; is there some advantage to doing it the 2 in-series paralleled to two in-series way, over using three pairs per side, two in series and one in parallel for a four ohm load?

All 4 drivers will receive the same power.

With 3 drivers (2s+1p) the paralleled driver with receive 2 times the current.
2 series (12 ohms) + 1 parallel (6 ohms)

With 3 drivers (2p+1s) the driver wired in series will receive half as much current.
2 parallel (3 ohms) + 1 series (6 ohms)

To any professionals: Please feel free to correct my statements as necessary!

[opnly bafld]

Besides, Im finding two pairs definitely better than one pair overall, so four pairs should be the bomb (using no good reasoning whatsoever).

Use a bigger inductor on 2 of them to roll them out sooner like a 2 1/2 way speaker.

[Luigi]

I seem to recall that Danny from GR Research reckoned that chopping the tops off the full rangers and using a rear firing tweeter was worthwhile too, as it reduced the effects of comb filtering when using hordes of the same drivers.

[opnly bafld]

I seem to recall that Danny from GR Research reckoned that chopping the tops off the full rangers and using a rear firing tweeter was worthwhile too, as it reduced the effects of comb filtering when using hordes of the same drivers.

Perhaps in this thread?
 http://www.audiocircle.com/index.php?topic=79482.0

To avoid comb filtering with multiple 8" drivers you would need a much lower x-o than what you have now.


 

[Luigi]

To avoid comb filtering with multiple 8" drivers you would need a much lower x-o than what you have now.


 

Can you be more specific? How low should the X-O point be approximately?

[Luigi]

Perhaps in this thread?
 http://www.audiocircle.com/index.php?topic=79482.0



 

Er, not not that thread. I believe it was in a thread relating to the use of 4 B200s in a line array. He mentioned nobbling the tops of all but the uppermost B200 to smooth out the response of the overall system, ie, to limit the effects of comb filtering.

[opnly bafld]

This might be worth reading (again?).
http://www.audiocircle.com/index.php?topic=70643.20