Active vrs passive

[SY]

Put the driver in a smaller than recommended box and use a Linkwitz Transform?

Nope. No active circuitry, no extra amp, any alignment you wish. Keep tryin.'

 

[Pano]

In any case, if the overall transfer function of an active and a passive crossovered speaker is the same, they'll sound the same, and one can do either to achieve it. No magic.

Quite agree. And that's what I did with my speakers. Found the filter functions that worked best for my speakers and room via active (DSP), then built a passive implementation of that. They aren't 100% identical, but are so close as not to matter.

There's no magic in speaker engineering, just art and craft. The art is choosing the transfer function (which includes polar patterns and the way the speaker is configured to interact with the room). The craft is implementing the bits and pieces to achieve the target.
.

That really should be the wrap-up of this thread. It sums it all up nicely.

 

[James Lehman]

Nope. No active circuitry, no extra amp, any alignment you wish. Keep tryin.'

You can make a special EQ to shelve out the extra loudness of the woofer.

Again.... I'd say YUK.

 

[SY]

Again.... I'd say YUK.

So would I. One more guess.

Hint: you haven't exhausted the list of passive components.

 

[James Lehman]

Hey that was three guesses just from me!

1. resister in series with the coil
2. added mass to the cone
3. special EQ

Like I said, you can't get more out of the mids or tweets. So you have to lose the high SPL of the woofer somehow.

 

[Cal Weldon]

XO the woofer down where it naturally rolls off and use a beefy mid/bass from there.

Or use a resistor on the coil in a series crossover.

 

[James Lehman]

So would I. One more guess.

Hint: you haven't exhausted the list of passive components.

Resisters are the only passive crossover elements that are not supposed to be reactive, and therefor would effect the entire range of the woofer evenly.

 

[SY]

Passive and reactive are not opposites. For example, a capacitor is reactive and passive. One more, James!

 

[James Lehman]

Passive and reactive are not opposites. For example, a capacitor is reactive and passive. One more, James!

I never said that or implied that! I know that resisters, capacitors and inductors are ALL passive elements. Resisters are not supposed to be reactive. That is what I said!

 

[SY]

OK, so one more try- how do we deal passively with a woofer to match its spl with a less sensitive mid and tweeter without affecting the efficiency of the alignment? Clearly, a series resistance won't fulfil the challenge.

 

[planet10]

MJK's passive baffle and any system that XOs from woofer to mid-tweeter at the bafflestep requires a woofer with higher sensitivity than the mid-tweeter.

A little less wiggle room with the latter.

dave

 

[James Lehman]

OK, so one more try- how do we deal passively with a woofer to match its spl with a less sensitive mid and tweeter without affecting the efficiency of the alignment? Clearly, a series resistance won't fulfil the challenge.

Get used to a tubby sounding speaker.

James.

 

[Pano]

Sure, I've done OBs that way. But I can't say that it doesn't compromise the alignment efficiency. The woofer has cancellation losses.

 

[SY]

Get used to a tubby sounding speaker.

James.

Not if you come up with the right answer. Stop thinking about resistors. Keep whatever box and alignment you like. C'mon, dude, I have confidence in you, which is more than I can say for Carl.

 

[James Lehman]

Fire the woofer out the back of the box into a well damped corner.

 

[SY]

BAWP!!!!! No, sorry, that changes the alignment and the efficiency. But thanks for playing our game and we have a home version of Guess The Crossover for you, along with a year's supply of Swanson Frozen Dinners. Swanson, for when you're too busy to cook.

The right answer is: step-down transformer or autotransformer.

 

[James Lehman]

Oh. That's nice. Screw up the impedance of the whole system.

Not for me.

Not for most anyone who likes solid state amps either. One of the big benefits of solid state is not having to use an impedance matching transformer.

 

[SY]

Actually, a solid state amp is ideal- low source impedance, so it makes hitting the target transfer function easier.

You gotta think outside the box now and then.

 

[Cal Weldon]

which is more than I can say for Carl.

Ok that's it. No Bybees for you mister.

 

[James Lehman]

Using a transformer is a bad idea. If the woofer, mid and tweet all are the same nominal impedance to start with then that will get all screwed up with a transformer on the woofer. The only way to compensate for that is to give the low end current another path around the woofer. Bad idea! There goes your SPL!

The nice thing about multi-way amplification and active crossovers is that every amp gets to work at its peak performance with as little non-sound-producing power consumption as possible.

In general power amps tend to increase in distortion as they increase in power toward their own limits.

I'm surprised no one has commented on an actual example of everything I've stated in this thread.

http://www.diyaudio.com/forums/multi-way/23208-system-pictures-description-221.html#post3207732

All three sections have different SPLs and even different nominal impedances.

James.