bass caps for protection

[unknownuser]

I have a two way speaker with a first order crossover (low pass and high). If I add a 150 hz bass cap, then will my speaker--both the woofer AND tweeter--be able to handle more i.e. allow me to turn the volume knob up louder, potentially, with less distortion (I'm guessing that the woofer benefits but the tweeter does not)? If no benefit, I'll probably discontinue my plan for stereo subwoofers. But if so, I'm also curious, how much more protection would I get with a 300hz bass cap.

Thanks


(Originally posted by: jw)

[Paul O]

150hz bass cap???? Adding more crossover will not increase the power handling capacity. I suspect if you put a capacitor in-line with the speaker system you will get NO bass at all. If you get distortion from the system now, your amp and/or speakers are at the limit already.

[unknownuser]

> 150hz bass cap???? Adding more crossover
> will not increase the power handling
> capacity. I suspect if you put a capacitor
> in-line with the speaker system you will get
> NO bass at all. If you get distortion from
> the system now, your amp and/or speakers are
> at the limit already.

True, it won't make the speakers better handlers of power. So the idea is then to use a bass cap to reduce bass which mechanically reduces power i.e. in relation to the volume knob. That will let me turn the knob up more and get louder upper frequencies (just at the expense of less bass). Then all I would need is a sub to fill in the bass. So I'd have deeper bass AND a louder system over all--the goal.

What really puzzles me is this: If a tweeter is crossed at say 4,000hz, then is reducing bass frequencies under 300hz actually offering anymore protection to the tweeter?
thanks for help


(Originally posted by: jw)

[Paul O]

AHH.. The light goes on. Now I see where you're going. Yes.. putting a high pass on your 2-ways should allow them to get louder.. but. Your amp is still pushing the fullrange signal so it will run out of gas at the same place on the volume knob. And... It will sound much better if you use something higher than a 1st order on the sub, 3rd to 4th order is where it really begins to shine. Once you see the cost of building 2 passive 3rd or 4th order sub crossovers, you'll see why people use active crossovers. They can be had cheap(ebay) and don't create the phase shift and impedance problems passive's do. AND, since the crossover is ahead of the amps, they(the amps) don't waste power producing frequencies you don't want in your speakers. The result, your system can be WAY louder with the same amplifiers.

> What really puzzles me is this: If a tweeter is crossed at say 4,000hz, then is reducing bass frequencies under 300hz actually offering anymore protection to the tweeter?

No.

[oldmongrel]

> I have a two way speaker with a first order
> crossover (low pass and high). If I add a
> 150 hz bass cap, then will my speaker--both
> the woofer AND tweeter--be able to handle
> more i.e. allow me to turn the volume knob
> up louder, potentially, with less distortion
> (I'm guessing that the woofer benefits but
> the tweeter does not)? If no benefit, I'll
> probably discontinue my plan for stereo
> subwoofers. But if so, I'm also curious, how
> much more protection would I get with a
> 300hz bass cap.

> Thanks

I ran a cheapy mod setup for a long time using 200 ufd caps on a pair of Polk Monitor 4s (satellites w/ 6.5 woofers; 12db internal xovers) and some 3 mh (I think?) coils on stereo subs each 4 ohm net with 2 8 ohm 12" woofers. This was all in parallel to a Sony 50/50w receiver.

Maybe it was just a harmonic convergence of random factors (including driver sensitivities, the room, etc) but it sounded great. A friend said that on "Two Tribes" by Frankie Goes to Hollywood, the bass drum felt like someone was kicking him in the chest. (Not that this is necessarily "accurate" sound reproduction.)

Yes, caps will roll off the bass somewhat to the satellites, including the tweeter, although the improvement in power handling, especially to the tweeter, will be negligible. I needed to do this to keep the nominal net impedance above 4 ohms. Just don't count on improved power handling. If your speakers play loudly enough for you now (excluding the bass you will presumably be adding with subs) you might get decent results.

John ("Mongrel")