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DIY speaker question

Tube Radio

Tube Radio

Super Member
I am upgrading the crossovers in my DIY speakers from 6db/octave passive to 12db/octave passive. I have a Zobel network on the midbass driver. What I was wondering is now that there will be a capacitor paralleled with the midbass driver as part of the crossover network would I still connect the Zobel network in parallel with the midbass driver?
 
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The Zobel may still be useful. Instead of stabilizing the crossover frequency (in a first-order speaker), they'll stabilize the damping of the second-order crossover (which determines the "shape" of the "knee" where the speaker starts rolling off). This will help avoid pesky peaks in the response, sometimes, right at the crossover response... if the impedance rises, you lose damping, and the response of the crossover starts to peak. The Zobel will cancel that all out, if it's happening.

Regards,
Gordon.
 
I've updated the schematic and wiring diagram.

Schematic
12dboctavespeakercrossoverwithZobel.jpg


Wiring diagram
12dboctavecrossoverwiringdiagram.jpg
 
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Tweeter
Aurum Cantus G2Si Ribbon

Midrange
Eminence PSD:2002S-8 1" Titanium Driver 8 Ohm
Dayton H08RW 8" Round Waveguide

Just finished one speaker and the results are what I expected. The speakers are more tame at the crossover frequencies and everything sounds more balanced.

I just realized that I need to get a tweeter with a higher output as my current tweeters have an SPL of 93.5 db while the midbass and midrange are both at 99.2 db SPL.
The Aurum Cantus G3 Ribbon Tweeter at 100 db SPL will work with a 82.92 ohm resistor in parallel and .7 ohm resistor in series with the tweeter. at $190.00 each I will have to wait awhile since the Bill Me Later payment option at Parts Express refuses me.
 
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I've been looking at those Dayton Waveguides for some time now. How are they performing? Can you determine its gain?
 
They are performing nicely. I'm not sure how much gain they have.

Here's the specs for the 12" midbass driver I'm using. What resistor and cap will I need for the Zobel network? I tried one calculator when I got the speaker and got the values I am using now then other calculators provide other values of capacitance and resistance. I'm not sure which to use. The speaker sounds almost better without the Zobel in place which I'm wondering if I may have the wrong values of resistance and capacitance.

Recommended for professional audio in both sealed and vented enclosures. Ideal for full-range, mid/hi, and monitor wedges. Specifications: *Power handling: 400 watts RMS *VCdia: 2.5" *Le: 0.84 mH *Impedance: 8 ohms *Re: 5.71 ohms *Frequency range: 52-4,500 Hz *Magnet weight: 80 oz. *Fs: 51 Hz *SPL: 99.2 dB 1W/1m *Vas: 2.9 cu. ft. *Qms: 7.56 *Qes: 0.37 *Qts: 0.35 *Xmax: 4.6 mm * Dimensions: Overall Diameter: 12.38", Cutout Diameter: 11.07", Mounting Depth: 6.22".
 
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I ordered the resistors and caps today.

I finished the other speaker and the speakers sound much better now then they ever have.

Now I gotta update the schematic and wiring diagram with the correct values of resistance and capacitance for the Zobel network.

EDIT: Schematic and wiring diagram have been updated. Soon as the resistors and caps come in I'll install them and see what I get.
 
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I got a question. In another thread about another speaker build it was suggested I use an econowave crossover. I would like to try an econowave crossover on my DIY home stereo speakers in an attempt to make them sound better. I do have a pair of subs for the frequencies below 150 Hz.

I am currently using a pair of Pioneer 12" subs in a 1 cubic foot box. They work ok, but i want to upgrade them to something better if possible and not too expensive.



Eminence PSD:2002S-8 1" Titanium Driver Impedance: 8 ohms Usable frequency range: 1,200-20,000 Hz Sensitivity: 105 dB (1W @ 1m on axis horn)

Dayton H08RW 8" Round Waveguide

Aurum Cantus G3 Ribbon Tweeter Impedance: 8 ohms Frequency range: 1,300-40,000 Hz SPL: 100.0 dB 2.83V/1m

Eminence Delta Pro-12A SPL: 99.2 dB 1W/1m in 1 cubic foot sealed box
 
I never was a believer in capacitors needing a break in period until now. It's been a few weeks and the speakers are sounding very good. I still need to get that tweeter though so I can match its level to that of the rest of the speakers as I do notice a slight lack of the upper treble.

I think most of my "problem" had to do with the fact that I was so used to how the speakers sounded when I had the 6 db/octave crossover and variable L-pads (set at the wrong level) and when I heard the horns at the level they should be at I figured there was a problem when I was actually hearing what is supposed to be there.

In listening to different types of music I notice that some music styles sound better through these speakers than others. I noticed that when I did a frequency sweep the sound would change some in the midrange being loud in one ear at one frequency yet loud in the other ear at another frequency and also if I move my head I can tell a difference. I am wondering if my room acoustics (wood paneling wall & ceiling with carpeted floor) is affecting how the speakers sound. Also I sit relatively close to the speakers which I know is not too good given their size. Of course my 12' X 12' building is a mess with stuff scattered everywhere and I suspect that isn't helping the acoustics any. What I need is an EQ so I can adjust the speakers to better match my room. I happened to think and I got a couple ceramic disc caps with two resistors to make a high pass crossover around 150 Hz. I am wondering if those ceramic disc caps are having any affect on the sound?

I thought about using these two devices

Crossover http://www.zzounds.com/item--DBX223
eq http://www.zzounds.com/item--DBX231
 
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