Flex Your PCD Mettle:

[Starkiller4299]

Re: Flex Your PCD Mettle:

Well, my personal opinion of the matter is that if you can't measure a difference between something that sounds 'good' and something that sounds 'bad', you aren't making the right measurements :p. Not that I'm saying I know all the right measurements, but any true sonic difference should be identifiable, repeatable, and thus measurable with the appropriate equipment.

It's possible that the mdf has a slight amount of magnetic/conductive material suspended in it. That may be altering the characteristics of components over it.

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Simple enough to see. measure an inductor above, and on the MDF. If it hasn't changed, it hasn't changed.

Anything else is hypnosis . . . IMO of course.

[Zvuchniak]

Re: EconoWave Deluxe:

In my Xover I've gone back to a Gedlee style.
I looked at a few photos of Nathan and Abbey xovers on various sites of various ages, 2008-2010.
I measured all the inductors and caps physical sizes using Madisound and stuff I have on hand and came up with a educated guess for values. Photoshop was a big help. So were Gedlee posts in DIY and his diy builders. I'm sure they are not exactly what he uses now, especially as he has improved them in late 2010.
Listening tests tell me my versions of Gedlee xovers improve it more than my version of a Zilch filter.
On a simple FR they no real difference from Zilch-type xover. None. Just like using teflon caps and Mills resistors showed no FR difference.
But everything sounded cleaner and clearer. My girlfriend and my son even noticed. But the FR didn't. It's not worth posting the charts.
Now I know why guys who live and die by measurements laugh at my audio hallucinations, er, subjective listening decisions. I couldn't measure any difference, but it sounded so much better. Gedlee is on to something that hasn't been discussed on this thread.

I had some air core inductors from Madisound. The white plastic type everyone uses.
After I thought my xover sounded great from guessing Gedlee parameters I bought some Jensen Air cores from PE.

Care to post electrical scheme of the xover you used with your speakers ???

Regards, Z ...

[Zvuchniak]

Re: Flex Your PCD Mettle:

I've been doing some more simulations recently. I'm curious, what do you think about this ?

I used two series notch filters to flatten the response but in paralel with the tweeter. That way the sound will not be so dependent/compromised by the components because they are not in the direct path of the signal. Or am i mistaken ?







Regards...

[Pete Schumacher]

Re: Flex Your PCD Mettle:

I've been doing some more simulations recently. I'm curious, what do you think about this ?

I used two series notch filters to flatten the response but in paralel with the tweeter. That way the sound will not be so dependent/compromised by the components because they are not in the direct path of the signal. Or am i mistaken ?







Regards...

The components are in the path of the signal. Doesn't matter whether it's shunt or series. I tried both ways too, and found the series version to present a friendlier impedance and easy component values.

That said, looks real good. I'd widen the 2KHz notch to bring down that region just a touch more. That added emphasis may make female vocals a little too "hot."

[bruson]

Re: Flex Your PCD Mettle:

Simple enough to see. measure an inductor above, and on the MDF. If it hasn't changed, it hasn't changed.

Anything else is hypnosis . . . IMO of course.

(BTW, thanks for all your contributions on Flex your PCD)

I think raising the inductors above the MDF did not change their values.
But I can't measure that.

Perhaps it just changed or reduced their magnetic field interaction with the other components?

As Starkiller4299 says maybe the MDF or paint has a slight amount of magnetic/conductive material suspended in it. I don't know.

I'm reporting what I hear because I can't measure a difference. Suspending inductors, using teflon caps and Mills resistors are no replacement for sound engineering principles and measurements. Maybe a little icing.

Next up: I'll be hypnotizing myself to believe I have made perfect, flawless CD speakers!

[Zvuchniak]

Re: Flex Your PCD Mettle:

The components are in the path of the signal. Doesn't matter whether it's shunt or series.

Totally agree. It's just a little hard for me to express myself in English with that kind of ease, so you could know exactly what i meant. Sorry 'bout that What i meant was that there are number of audiophiles that can say the difference between two types of capacitors, or two types of inductors (with or without core, etc.) . When notch filters are shunt, it should be more immune on that influences (resistance of inductors and certain parameters of capacitors that are used).

That said, looks real good. I'd widen the 2KHz notch to bring down that region just a touch more. That added emphasis may make female vocals a little too "hot."

I'll try both versions of it and see for myself what gives the best sounding solution of this e(wave)quation :D Thanks again.

Regards, Z...

[Pete Schumacher]

Re: Flex Your PCD Mettle:

When notch filters are shunt, it should be more immune on that influences (resistance of inductors and certain parameters of capacitors that are used).

Regards, Z...

It really makes no difference, whether those components are shunt or series. They are there to modify the electrical transfer function, so all of the components are contributing. It makes no difference whether they are the parts directly between the amp and the driver, or those across the driver terminals.

And while different caps or inductors may or may not have audible differences at the minuscule power levels they're used at, it won't matter whether you put that iron core inductor in the shunt part of the circuit, or the series part. It's in the signal path, and that's all that matters.

For AC circuit purposes, the source is a dead short. So if you look at the woofer circuit below with the input shorted to ground, you'll see that the 3mH "series" portion is now a shunt, just like the 4.7uF cap.

[Zvuchniak]

Re: Flex Your PCD Mettle:

It really makes no difference, whether those components are shunt or series. They are there to modify the electrical transfer function, so all of the components are contributing. It makes no difference whether they are the parts directly between the amp and the driver, or those across the driver terminals.

And while different caps or inductors may or may not have audible differences at the minuscule power levels they're used at, it won't matter whether you put that iron core inductor in the shunt part of the circuit, or the series part. It's in the signal path, and that's all that matters.

...................................

Have you tried it both way and then came to the conclusion that there is no sonic/audible difference ? I just, always presumed that there is

I would very much like to know your personal experiences with this issue (if it is an issue at all).

Regards...

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Have you tried it both way and then came to the conclusion that there is no sonic/audible difference ? I just, always presumed that there is

I would very much like to know your personal experiences with this issue (if it is an issue at all).

Regards...

The electrons, which are responsible for the entire thing, don't see a difference. Like I said, the source is a dead short, meaning that the series input section, and the load shunt section, are actually in parallel, with current flowing in each section, adding up to the total voltage at the load. Makes no difference where in the circuit you put an item, it's parasitic impedances will still play a part in the total voltage presented to the load.

[jonpike]

Re: Flex Your PCD Mettle:

It's possible that the mdf has a slight amount of magnetic/conductive material suspended in it. That may be altering the characteristics of components over it.

As an empiricist myself... I agree with what Pete is saying.

That said, you want to keep your mind open to surprises and secondary effects... The first time I measured crossover parts, I got a surprise. At my work we had a nice, $3000 LCR meter. I was going to get a good assessment of how accurate those parts were! The caps were very close, even closer than their 5% rating. But the inductors were off. Way off, like 30% high! I couldn't imagine that they could be so far off, with a 5% or better rating.

Then I lifted one up, and it changed dramatically... down to less than 5% of its listed value. I realized what happened. Due to the LCR meter sitting on a shelf, I had set the parts I was measuring on top of the meter's case... which was a steel box! :eek: Of COURSE the inductor was changing, it had a nice bit of "iron core" added to it by being near the case!

Anyway, hope the story gets folks to think a little wider. To the poster who seemed to hear a difference with the hanging parts, do you have a metal bench top? Might be a similar effect. Or iron or steel parts, screws, driver magnets, etc... unusually close to your inductors? Sometimes there's something right in front of you that you didn't think about.

Happy hunting!

[bruson]

Re: Flex Your PCD Mettle:

......Anyway, hope the story gets folks to think a little wider. To the poster who seemed to hear a difference with the hanging parts, do you have a metal bench top? Might be a similar effect. Or iron or steel parts, screws, driver magnets, etc... unusually close to your inductors? Sometimes there's something right in front of you that you didn't think about.

Happy hunting!

No metal top.
All inductors were sitting on the black painted MDF box for the B&C 10PS26.

Now one air core is 3" from the back of the B&C DE250-8. Before it was suspended, it was about 3", too. Could the magnetic field from that driver affect that inductor as well as the others 5" and 6" away? If so why would lifting up make any difference? They were 5"-6" away before.

The 2 teflon caps I use are enclosed in metal and the end caps are steel that a magnet can attach too. I tried. Their cylinder is non magnetic metal.

When I screw the iron core inductor in place, I'll be using brass screws. Just in case the steel screws mess up the magnetic field. Good output transformers use brass screws for this reason. Or so a handmade tranny maker once told me.

I don't have an answer, I just hear the little difference. It's something I'll be doing in the final iteration of this speaker.
........................................

I'm also be selling the 1/4" wood dowels, 1/2" plastic pipe, coated 18GA copper and pink sewing thread I use to construct this audiophile structure.
One inductor rising audio improving quality structure is $350. A stereo pair is $695, a whole $5 savings!

Inductor structure using audiophile quality parts: Ebony wood dowels, teflon pipe and 99.9999% pure OCCC copper wire with foamed teflon coating and organic cotton uncolored thread.
Sound is fabulous!
Cost is astronomical! $1,150 each monostructure

Go to www.audiofoolandmoneysoonparted.con for more info

;)

[stgdz]

Re: Flex Your PCD Mettle:

where can I get the FRD or ZMA files for the dayton 12" pro audio woofer and the selenium 220? I would really like to play around with the SR setup that zilch built at least the crossover that is.

[Zvuchniak]

Re: Flex Your PCD Mettle:

where can I get the FRD or ZMA files for the dayton 12" pro audio woofer and the selenium 220? I would really like to play around with the SR setup that zilch built at least the crossover that is.

Here it is.

http://techtalk.parts-express.com/sh...&postcount=444

But that is d220ti OMF with QSC 152i waveguide. If you want the combination of D220Ti/JBL-PT look one or two pages back.

[stgdz]

Re: Flex Your PCD Mettle:

ok for the sake of exercise I am trying to learn this program and by doing that I am entering the data into PCD using to see if I understand it correctly.

Anways, I using this crossover


but when I go to input stuff, I can input all of the data for the woofer but I get confused on how to input the tweeter. I looked at the filter layouts in the tab but I couldn't figure out where R2 is entered. I have attached all my data entry's. When I run this data though I get a huge drop at around 1600hz.