what's custom in crossovers for the full range tribe?

[brucegseidner]

When y'all are adding subwoofer support to your full range speakers are you using a passive or active crossovers?

I have been noticing commercially available active crossovers that slice and dice and have super powers relative to what I experienced back when I was more active building systems. I must confess I have an irrational mistrust of op-amps and a Luddite impulse to insist on discrete transistors. Truth be known, and if money were no object, it would be all metal film resistors, polypropylene capacitors, chokes and custom wound audio transformers pour moi.

I had a recent experience that makes me suspicious of introducing anything between the source and amplifier-speaker driver. I purchased a Behringer headphone amplifier recently that was so dreadful that I spent no more than ten minutes listening to it before returning it to the store.

What is best practice for reinforcing the bottom end of a full range? To keep this question simple, lets consider something modest like the Fonken 167 with a sealed 10" subwoofer like the CSS SDX10. Given the efficiency of these drivers are people bi-amping active or staying passive?

[vinylkid58]

Originally Posted by brucegseidner

To keep this question simple, lets consider something modest like the Fonken 167 with a sealed 10" subwoofer like the CSS SDX10. Given the efficiency of these drivers are people bi-amping active or staying passive?

I have a single commercial 10" powered sub with my 167's. Most of the time it's off, but there are occasions when the last octave needs some help. Most of these have plate amps with built-in filters anyway.

jeff

[901Fixer]

I'm an ignernt noobie but I'll tell you what I know. The simpler the better, 1st order capacitors only for high pass if done after the amplifier. Chokes/Inductors are not spoken of here. The preferred method is done "Passive Line Level XO" or PLLXO which is done on the input side of the amplifier.
Search for "Tysen". This was a very well documented build to include the XO points and components used.
Typically a "Sub" isn't necessary for music rather just a woofer capable of ~30hz at the lowest. If this is an HT set up then a Sub is more typical.

[planet10]

<200 Hz really needs to be active.

XOing higher and passive requires VERY careful consideration of the drivers used, and the boxes (mostly wrt baffle step).

The budget, least effort way is to use a plate amp and its XO for the bottom. If feasible, a simple PLLXO in front of the FR amp or none at all. Smaller drivers tend to benefit most from being relieived of the bottom end. Sometimes you can use a sealed box rolloff as part of the HP.

Next step up is to use your own amp & XO on the woofer. PLLXO, buffered PLLXO, the filter on the top being more critical than the one on the bottom. The tube/gyrator XO SY is working on will be really interesting. Personally i prefer 3rd order or less.

And to expant on Mr Fixer's comment, one should consider that they are adding a woofer not a sunwoofer. The "typical" subwoofer does not have an extended enuff HF performance. I expect the SDX10 satisfies that requirement, i certainly hope so, i have 4 of them downstairs

dave

[brucegseidner]

PLLXO, that makes the most sense.

I have thrown in the towel on my Mikasa plans for my office. Way too iconic for a consultation office. I measured and did a mock-up and they would be too much of a distraction. I am going for a pair of Fonken167's and want to load the bases with a pair of sub-woofers that will relieve the FR of sub 100hz duty or where ever it makes the most sense to cross them.

There is a Fonken167 thread that is currently active I will post to it rather than scatter this information.

over and out.

[norman bates]

anything you add will remove some magic from the full range experience.

I found 200hz 24db LR active crossover was the best compromise for keeping the voice all in the full range driver and gaining dynamics, less distorion, but the mids wern't as magical as no crossover.

I can't speak for passive line level crossover, but you would need a stout preamp to drive it, especially a 24db one from marchand.

Norman

[planet10]

Originally Posted by norman bates

I found 200hz 24db LR active crossover was the best compromise for keeping the voice all in the full range driver and gaining dynamics, less distorion, but the mids wern't as magical as no crossover.

from Wikipedia:

The voiced speech of a typical adult male will have a fundamental frequency from 85 to 180 Hz, and that of a typical adult female from 165 to 255 Hz[1][2]. Thus, the fundamental frequency of most speech falls below the bottom of the "voice frequency" band as defined above. However, enough of the harmonic series will be present for the missing fundamental to create the impression of hearing the fundamental tone.

dave

[norman bates]

makes sense.

Norman

[901Fixer]

So is this to say that the majority of vocals in music on a FAST system, like say the world class Tysen, comes from the SDX7 and not the FF85? Once again I have to recalibrate my world after visiting this site. So with a crossover point of ~333Hz, what areas of music are played by which driver?

[planet10]

Vocal fundementals from the midwoofer, critical telephone band and everything above by the midtweeter.

low bass: 20-40Hz
midbass: 40-80Hz
upper bass: 80-160 Hz
lower mid: 160-320Hz
mids: 320-1280 Hz (2 octaves)
upper mids: 1250-2.5k
lower treble: 2.5k-5k
mid treble: 5000-10k
upper treble:10-20k

dave