I need help with new crossover

[EarlK]

I have four 4x8 sheets of Owens Corning 703 2" thick that I can make into a four foot long tunnel to measure my drivers in. Is that overkill?

Also, I'm going to do some studying today as I don't really know what a FRD or ZMA file is or where to find them or how to make them.

Once you provide some .FRD + .ZMA files I'm sure someone will take a crack at creating a different crossover for you.

.FRD file is a frequency response file ( as captured using your UMIK-1 microphone along with REW (and then exported from REW as an .frd file )).

.ZMA file is an exported impedance file ( created by your DATS system when hooked up to your horn/driver combo , +/or your woofer mounted within your enclosure > each,, measured separately without any passive components in line/place ) .

 

[djn]

I thing they can sound better with better components but I don't know if a different type or higher order would sound better yet.

I'm just not well versed in this. I built the current crossovers to get ready for an AKfest in a rush and never changed them.

 

[djn]

How do your current crossovers not meet your sonic expectations ?

They sound good but I just "assume" they might sound better.

Once you provide some .FRD + .ZMA files I'm sure someone will take a crack at creating a different crossover for you.

.FRD file is a frequency response file ( as captured using your UMIK-1 microphone along with REW (and then exported from REW as an .frd file )).

.ZMA file is an impedance file ( created by your DATS system hooked up to your horn/driver combo , + your woofer mounted in enclosure > each measured separately without any passive components in line/place ) .

Great Earl. I'll get to measuring.

 

[EarlK]

Dennis,

A good start here would be to display a frequency response of the system ( with existing crossovers ) as measured ( on-axis to the Edgar horn ) at 1 Meter and then again at 2 Meters.

- You can simply "zip" the .mdat file ( which is an REW file extension ) then up-load + attach it to your post ( if that's any easier for you ) .

 

[djn]

Will do Earl. I have to wait a couple days until my new laptop arrives. My old one gave up the ghost.

 

[the Glyph]

I am very satisfied with these in their current configuration just think it's time to build the crossovers they deserve. I'm not looking to change the components.

I am not going to give up. Third order tweeter xover helps low frequency from harm to the tweeter better than first order. I depends on xover Hz, tweeter design, and SPL output if needed or not.


Your use of resistors to pad down mid/tweeter is a choice, I use/prefer autotransformers for this in my crossovers. But the way you appear to use the resistors bungles up the capacitors value for blocking low frequencies.

 

[djn]

in the schematic the caps show as polarized but I've never seen a polarized cap in a crossover.

1st Order Normal Polarity

5000 Hertz / 625 Hertz

4 Ohm Tweeter / 16 Ohm Mid / 8 Ohm Woofer
0 db Bandpass Gain, Spread = 8 : 3 octaves

Parts List
Capacitors
C1 = 7.95 uF
C2 = 17.93 uF
Inductors
L1 = 0.45 mH
L2 = 2.04 mH

 

[EarlK]

Good Eye Dennis!

That capacitor symbol is for a polarized capacitor.

How To Read a Schematic

Another reason ( I suppose ) to not place to much trust in those sites.

 

[djn]

I maybe I learn a bit more about crossovers so I found some tutorials online about Xsim. A lot simpler than I thought so I down loaded it and will give it a try.

 

[djn]

Hi all. I was working on my GM70 amp for a bit but now my garage is toooo hot (between 105 and 98 in the summer) to work out there so I am back on this crossovers.

One thing I thought as I got back into this project is if I have a 4ohm tweeter, a 16ohm mid-horn, and a 8ohm woofer, do I just average that out to determine what tap I should use on my amp??? I have 4, 8, and 16 ohm taps.

 

[AllenB]

I think I would start at 8 ohms to maximise power transfer re the woofer. The mid and treble should be ok with this.

If your amp is one that is sensitive to the speaker impedance I would then tweak to optimise extension vs output, and tame midrange peaks.

 

[djn]

I'm not sure if it is sensitive to speaker impedance. It is a SET GM70 with a 12GN7 driver tube......if that matters.

 

[AllenB]

Hard to guess, it's the output impedance that does it. Maybe one day when you have nothing better to do, put an 8 ohm resistor in parallel with the speakers, readjust the volume and see if the tone has changed.

 

[djn]

I'll try that Allen. Thanks.

 

[djn]

Hi All. I had to put this aside - No work, No Mon, No Fun. Back to work now and waiting to get my Bedini 150/150 amp back and will start back on this project hopefully next week.

 

[djn]

Hi all. I've been so busy starting a business that I only now have the time to get back to this. I have forgotten what crossover design program I was going to use. Any suggestions?

 

[djn]

Never mind. I found it. Xsim

 

[djn]

Hi all. sorry I had to drop out. A medical condition knocked me out for 8 months, but the docs figured it out and now I'm back.

First, I'm going to use my 3-way active crossover to determine the xover points I like best, then I'll take the measurements and post them here.

I haven't been in my listening room for 8 months. It feels great to get back into it.

 

[grindstone]

Glad you're back, man! Hang-tough.

 

[djn]

Thanks G. It’s good to be back.