Egglestone Andra 1 tweeter "crossover"

Dear Andra owner:

Inserting a small-value resistor in series with the tweeter, after the x-over, will certainly lower the tweeter output without varying the factory's x-over point.

The inmediate result would be a "smoothening" of sound in the treble region plus and improvement in music balance. Hi frequency extension would be unaffected.

Only by trial and error you can reach the "best" resistor value, since your musical preferences plus your auditioning enviroment are unique. A resistor in the 0.5 to 2 ohms range would yield the best match. Better to use non-inductive (inductance "eats" hi-frequiencies) 5% or even 1% tolerance resistors with 10 watts or higher capacity.

If temporary cables are run from tweeter terminals trought speaker port to the outside, resistors can easily be interchanged outbound until sound is satisfactory. After the "right" (for your ears) resistor value is found, then permanent connections can be made inside, close to the driver.

Speaker's manufacturers currently include resistors or potentiometers or both in their x-over design to attenuate tweeter output in order to match level with it's mating woofer's. "Monkey business" starts at factory.

The exquisite sound of Stax headphones (and many other first rate transducers) features, among other things a combination of both superb hi-range extension plus a domesticated treble. This taming of treble rarely occurs naturally, tweeters should be almost always attenuated.

Audio is fun. Discovering things that make music more enjoyable is wonderful. An inexpensive mod making my music sound better, that's divine.

Enjoy!

Jeffreybehr, I must commend you on your posts. You have been able to offer very good advice, and to the point.

That being said, I have been around this speaker enough to know that the treble is not bright. In my opinion, while I do agree with padding down a hot tweeter, the Dynaudio Esotar is definitely not hot, nor is the crossover of the Andra I. Rather, I think there must be something else in the system - room, amplification, source, or cabling which is causing the issue. If I were in this situation, I would leave the crossover alone, and look into what is actually the source of your more than valid complaint.

You're welcome. That may have been the only useful thing I did all day!

I bought my multiturn 1K pots at Radio Shack. I imagine most electronic-supplies stores would have something like them. Power rating is not important in my experience; tweeters use VERY little power (unless they're ribbons). Only if you're driving them continuously, as with sinewaves or whitenoise, will you need more than a 1-watt pot. Where are you? (I'm in Phoenix, Arizona, USA.) My 'take-outs' will be available in a few days if you can't find them anywhere else.

Your tweeters are driven full range? HUH?????????? The system is designed integral with an amp that is filtered on its frontend? Or the crossover is outboard?
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Thank to Jeffreybehr, Gs5556 and Audio999 for their comments and suggestions. The Andras haven't crossover (the drivers are directly connected to their imputs terminals). I think it is a good idea to use potentioneters intead of fixed resistors. NMT 1000 ohms pots (how many watts?)? Where can acquire them Jeffreybehr? I will take in consideration the room surface and the wall reflexions as well as speakers placements. Thanks again.

Have you considered the possibility that the "bright" might be from the room surfaces and/or speaker positioning?

Vector, if that's your goal, I'd dig up 2 pots (potentiometers) of relatively low value (say, NMT 1000 Ohms) and wire one in series with the tweeter BEFORE the high-pass section of the crossover. Adjust it to be wide open (= no resistance), play some white noise (FM-tuner noise works very well) and adjust the pot so that the treble output is down just audibly. Live with that setting for a while to see if it's too much or not enough. Adjust the resistor higher or lower as desired for the sound you want. When you're satisfied, lift one wire from the pots, measure them and average those numbers, and order the resistor values you really need, then solder them in permanently. (I use the Mills noninductive wirewounds from Michael Persy.)

Remember, if you install these resistors AFTER the crossover caps, etc., you'll change the filter point of the crossover.

BTW, if your speaker is ported, you can run the pot's wires outside the box so you can adjust them without opening the boxes.

I've done this very thing to my car's system and also to my main home speakers; it works very well. In fact, I'm about to remove a couple pots from my car system so e-mail me if you want them for the cost of postage.
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Thank you for your prompt answer. It is correct, I am trying to lower a little the high frecuency response of the tweeters (I always hear classical and jazz music and sometimes I find them too bright for my taste). I am using VTL MB-250 amplifiers with Transparent Reference XL-V speaker cables to the Andras 1(I also have a Sony SCD-1, AU24 RCA interconects to the Blue Circle BC3 Galatea pre-amp and Transparent Reference XL RCA to the Amps too). I had used another pair of Au24 interconnects between the pre and the amp but the sound was too analytical and crystalline sharp...

Oh oh,sorry,didn't read your post carefully.

"It will also lower the X-over freq. of tweeters."

Uuhh...didn't I just say that?
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It will also lower the X-over freq. of tweeters.

Adding 1 Ohm of resistance in series with the tweeter will at least lower the level of the treble and, depending on where you put it, will alter the filter point of the tweeter crossover.

Is that what you want to do? This sounds like monkey business to me.
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