I've added a diagram of the Bose 2001 crossover to my imageshack. I don't know what the white ceramic component is or whether the green component is a capacitor or a resistor, but the photo of the front of the board is at the link also. Hopefully someone else recognizes what they are?
http://my.imageshack.us/v_images.php
http://my.imageshack.us/v_images.php
I have a few questions.
Are they boomy when playing together or also alone 4001+2001's vs 2001's only?
If you are lucky of having any components around try an inductor in series. (Instead) To use a power resistor look for the power W's you are about to use. What kind of Amp you are using? Can't you just disconnect them? To use the speaker (2001's) and if it's not a good design/alignment you will need to measure for the T/S specs and consider a new box (volume). There's no easy solution in this case I'm affraid. You say about using the crossover from the 201. There are different series and the internal volume might not be the same also. Also make sure of impedance of the drivers you have (2001's in this case). Maybe you can find someone with a better idea. Have a nice DIY tweaking.
edit: to me the crossover looks like a 4uF/50V for the tweeter and a resistor (R value?). Maybe they also have/had Polyswitchs or lamps.
Are they boomy when playing together or also alone 4001+2001's vs 2001's only?
If you are lucky of having any components around try an inductor in series. (Instead) To use a power resistor look for the power W's you are about to use. What kind of Amp you are using? Can't you just disconnect them? To use the speaker (2001's) and if it's not a good design/alignment you will need to measure for the T/S specs and consider a new box (volume). There's no easy solution in this case I'm affraid. You say about using the crossover from the 201. There are different series and the internal volume might not be the same also. Also make sure of impedance of the drivers you have (2001's in this case). Maybe you can find someone with a better idea. Have a nice DIY tweaking.
edit: to me the crossover looks like a 4uF/50V for the tweeter and a resistor (R value?). Maybe they also have/had Polyswitchs or lamps.
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They sound boomy by themselves, but way worse when playing together with the 4001s. I'm driving them with a yamaha receiver. The manual says that when I have one main set of speakers hooked up, it gives each 4 ohms. With two sets of main speakers, it gives each speaker 8 ohms. An inductor in series with the woofer? What spec inductor and on the positive or negative terminal of the woofer?
There would be some guessing going on at this point. Some of the things that may help would be that we could see some measurements. Failing that maybe decipher the crossover (I can't see it on imageshack for some reason but I saw part of it this morning), and you might later be able to carefully describe what it is lacking or overdoing.
The ceramic box is a resistor, but I did not see where it went. I think I recall a polyswitch and three lamps, each of which is a protection device. There were also two capacitors which I assume were to high-pass the mid and tweeter. The 2001 crossover had one resistor and one capacitor if I remember correctly.
The ceramic box is a resistor, but I did not see where it went. I think I recall a polyswitch and three lamps, each of which is a protection device. There were also two capacitors which I assume were to high-pass the mid and tweeter. The 2001 crossover had one resistor and one capacitor if I remember correctly.
Allen, I'm not interested in redesigning the 4001 crossover. I just thought it might be useful for comparison since it uses the same speakers in a different crossover circuit. I'm thinking that rolling off the bass early in the 2001s might be the best option since my 4001s can handle the bass. The question is how many uH it should be and where it should be inserted in the circuit? Does anyone make potentiometers with built in inductors? If I could find one, I could adjust the rolloff once I install it in the circuit and experiment.
I just figured that understanding the 4001 crossover might uncover a clue as to what is happening?
Rolling off the bass to a woofer can be a little tricky. Using an amplifier's tone control would be one easy solution. Making an L-pad out of large resistors might help. Using a capacitor could make things worse as easily as better. You could experiment or preferrably measure and calculate your way through.
Other things you could do are to change its position in the room, keep the port blocked, try damping the port, take the back off, or even stop using it?
Rolling off the bass to a woofer can be a little tricky. Using an amplifier's tone control would be one easy solution. Making an L-pad out of large resistors might help. Using a capacitor could make things worse as easily as better. You could experiment or preferrably measure and calculate your way through.
Other things you could do are to change its position in the room, keep the port blocked, try damping the port, take the back off, or even stop using it?
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