Help Removing any BSC on Audax Surrounds?

[mpotoka]

Well I just know enough to know I don't know that much. I built 7 speakers of the audax kits from madisound a couple years ago. I'm considering tearing apart my surround cabinets and builing a box for them to fit into the wall. I was wondering if anyone can tell me how to, or if I need to, remove/modify the xover to eliminate any BSC.

Here's a link to the xover design if that helps

http://www.madisound.com/pdf/Kits/audaxrear.pdf

Or is it not worth my trouble? I figure surrounds don't do that much anyway, do they? This is purely 100% for HT use, no multi-channel audio or anything

Thanks

Mike

[ThomasW]

There is no BSC in that schematic.

[TacoD]

This speaker already has not that much BS, I would lower the series inductor from 1.5 mH to 1.2 mH (maybe 1 mH). You can try to alter one, and listen if it's enough. There is some chance you also need to alter the l-pad for the tweeter, by lowering the series resistor. The extra mid output you get with a smaller coil, can suppress the highs a bit.

[Maximiliano]

My first post I'm a long time lurker, but have some speaker building experience. Maybe I can give some advice.

First, place your surround speakers on your wall (using speaker stands?). Then play some of your favorite music. Turn off other speakers including subwoofer. Listen carefully to the midrange (i.e., electric guitar, voice, etc.). If it sounds okay to your ear, you may be able to use them as is. If you have "muddy" midrange or clear lack of energy in the upper midrange compared to the lower midrange, you'll need to reduce the BSC.

If you need to, instead of buying new inductors, you can simply unwind the current inductor on the woofer net---10 turns at a time---and tape it again. You don't need to cut the unwound coil until you find an appropriate value---just make sure the coil is not self-wound. Listen again to the same pieces of music. Don't focus on the treble for now---you'll need to increase its level later---; try to listen to just midrange. Unwind the coil by 10 turns at each trial until you find a suitable value. Once you find it, cut the extra coil and finalize it. Then, you'll need to change L-padding. I think a 20 ohm resistor in place of the current 15 ohm resistor (in parallel of the tweeter) would work roughly. Otherwise, try different values larger than the current 15 ohms to find a suitable one. You can try any values by using two resistors in series.

Edit by moderator to add
Maximiliano is Woe Jay Kim pretending to be someone else

[mpotoka]

Hey, thanks for all the responses.

My old situation was that the speakers sat on stands, with the backs backed up to the wall (I didn't know about BSC and whatnot back when I finished the room) So if I'm back an additional 9" (depth of the old box) and flush to the wall I don't think its going to make much difference, am I correct?

Besides, according to ThomasW, it sounds like there isn't any BSC to remove anyway.

So I took one of them apart this morning, tried to make an in-wall box with similar cubic inches, and I have now cut the holes in the wall.

I'm going to loose about 180 cubic inches total... but I think that mostly will make a difference below 50hz or whatever the Ft of my new box is? Is that correct, that in reducing box volume you (increase?) Q and Ft?

So my baffles are drying... I'm about to go out and glue the front on the boxes.. perhaps I will put a couple pics on here if anyone is interested

Mike

[ThomasW]

Besides, according to ThomasW, it sounds like there isn't any BSC to remove anyway.

There's no BSC "circuit", the stock network has a bit of tailoring but I don't think it's enough to be concerned with. Taco and Max's recommendations are on target if you want to play around