Woofer running without crossover

[jmar]

What are the things to look for when trying to pick a woofer (6.5 or 8") to operate without a LF crossover?

I do intend to crossover the tweeter however.

I've read there's more to it than just the freq response of the woofer -- what are the parameters to look for? Are there indicators in the published specs?

I'm sure it's also a matter of just listening to it?

I do have some Goldwood 6 1/2" woofers where I'm just using a series cap for the tweeter and they sound very good to me. The high end is rated at 3k.

[Pano]

Look at the published FR curves. A smooth roll off at the top is an indication that you might not need a low pass.
This woofer is known to work very well running "bareback."
SEAS 10"
Expensive driver, tho.....

[Borat]

Originally Posted by panomaniac

Look at the published FR curves. A smooth roll off at the top is an indication that you might not need a low pass.
This woofer is known to work very well running "bareback."
SEAS 10"
Expensive driver, tho.....

that driver certainly would do it.

but WHY ? you're essentially using voice coil's self-inductance instead of an external inductor to accomplish the same thing PLUS extra distortion via flux modulation.

i would rather use a low inductance driver with some faraday rings and an inductor in series with it.

[jmar]

So you want to crossover the woofer above or below it's rated HF limit?


If it's below then --

the crossover notch can create audible nuances?

If it's slightly above then --

not?

[jmar]

It also seems to me that the graph on most woofers I've seen take a gradual decline toward their high end and then essentially look "inactive" after that.

I don't get it --

what do you mean by "smooth" rolloff?

[skeptic43]

Some woofers have response peaks at the high end caused by edge distortion. That's why you should look at the woofer's published FR graph. Problems with response peaks usually occur above 1000 hz.

Suggest you study a number of different woofer's FR charts and you'll see what we're talking about.

[badman]

This can work well. A lot of times there's a challenge in integrating the midrange crossover with the woofer in terms of phase tracking. I used an acoustic absorbent felt pad on a grille in front of a woofer in a recent project to achieve my target slope- worked better than any other solution I've used.

[jmar]

"Edge distortion" -- I'll make a note and look for that.

These Goldwoods I have are very flat to about 3k and then seemingly "out of commision" after that.

[PeteMcK]

polypropylene cones are particularly good in this regard

[Pano]

Originally Posted by Borat

but WHY ? you're essentially using voice coil's self-inductance instead of an external inductor to accomplish the same thing PLUS extra distortion via flux modulation.

Cause it works well. I've heard it and it's a fine driver. Easy to match to a tweeter without a low pass. It can actually work better that way.

Many/most woofers are peaky up top or just plain don't sound great, so a LP filter is needed. But we remember the "Old Days", right? In vintage speakers the woofer was often run wide open. Not always the best choice, it it "worked." Tho I doubt the Goldwood drivers sound great up top or roll off where you'd want, I have not heard them. Easy enough to give it try!