Belle mid & tweeter gain control

[Mike 585]

I would like to play with toning down the mid and tweeter volume in relation to the bass bin. They're towed in on a long wall but are not in corners due to a particularly long length to width ratio (30 x 12). So, without any help from a corner or much from the wall due to the toe-in, the bass bin output just isn't enough relatively. I've experimented crudely via a 31 band EQ and it helps. To better manage what's happening at the crossover point I'm wondering if I can use Y RCAs out of a Mac C26 into MC2505s and bi-amp--use one channel for HF & MF, the other for LF? The 2505s of course have gain controls. The Belles have AB-2s. Will this work? Is there a better way?

If this can be done and yield the better blend that I hope it will, I'll likely be inclined to tackle the move to active crossovers but I'd like to try this if possible to convince myself first and it won't cost anything at this point.

Thanks, Mike

[WMcD]

If you are using an amp with an output transformer:

There is the trick of feeding the woofer crossover from the 8 ohm tap and the mid/tweeter section from the 4 ohm tap.

You have to go into the crossover, unless it is set up for bi-wiring or bi amping already

WMcD

[Daddy Dee]

In some rooms I have padded down the mids a bit by dropping the squawker by one tap on the autoformer. That lowers the mid output by 3db. To my ears the results were pleasing.

[Mike 585]

Thanks to you both for the input.

I was hoping I could use the power amp gain control so it the level could be decreased infinitely. From my experiments with the EQ I think I'm looking for in the neighborhood of 6db. It's a pretty live room and isn't that about what I should expect to lose without corner placement?

Anyway, the two suggestions you've made are easily tried and I'll see what -3db accomplishes. Is there another tap on the autoformer that will give me -6db and where can I find documentation of which tap is which? Crossover tinkering is new to me but I'm good with a soldering iron.

[WMcD]

I'm not sure about available taps on the autotransformer you may have.

Let me point out that if you change the tap used, you alter the load seen by the cap which feeds the autotransformer. That will change the crossover point frequency, which is not good. There will be a greater change if you go down two taps.

IIRC the crossover point is lowered in freq and thus bass freqs get into the mid and could blow it out.

If you want to bi-amp, that will certainly work and, as you point out, give you more control.

Belles do not have the low bass response of the K-Horn and taking them out of the corner certainly will reduce what they do have. I just say that so you have realistic expectations.

WMcD

[WMcD]

Here is a schematic which you may find helpful if you are investigating the crossover.

WMcD

[Guest " "]

your MC-2505's should have autoformers. if you want to adjust the mid and hi level relative to the woofer..........cut the red jumper wires on the crossovers that connect the HF and LF together....this will create two sets of inputs......connect the HF to the 4 ohm tap and connect the LF to the 8 ohm tap. That will give to a -3db cut of HF relative to the LF. if you have 4/8/16 ohm taps, connect the HF to the 4 ohm tap and the LF to the 16 ohm taps and that will give you a -6db change in HF relative to the LF.

[Mike 585]

Thanks to you both for the additional information. The 2505s do have autoformers and 4/8/16 ohm taps so the separate-tap options are the next thing to try. Unfortunately a very busy weekend that included adressing some computer issues has kept me from trying it out yet. I expect to have time to play with it tonight.

Thanks again for the help. What a blessing the forum is. Particularly in this day and age when a very knowledgable local hi-fi dealer is pretty much a thing of the past.

All the best,

Mike