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Vifa Dipole 2-ways
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This design uses a 7" premium Vifa paper woofer and a grille
protected aluminum dome tweeter.
I designed these speakers for my car, but decided to throw together a
simple dipole baffle for them. I knew I wouldn't get much bass from
them, but I still wanted to hear the mids and highs before I put them in a
4L sealed box in my car (94' Toyota 4runner). The results were very
surprising... |
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Product |
Unit |
Value |
Price |
Total |
Function |
|
3.7 |
ohm |
2 |
1.25 |
2.5 |
Zobel |
|
30 |
ohm |
2 |
1.25 |
2.5 |
Attentuation |
|
2.4 |
ohm |
2 |
0.98 |
1.96 |
Attenuation |
|
|
|
|
|
|
|
|
0.51 |
ohm |
2 |
1.25 |
2.5 |
Attenuation |
|
|
|
|
|
|
|
|
0.01 |
µf |
8 |
0.63 |
5.04 |
BYPASS CAPS |
|
4.3 |
µf |
2 |
2.25 |
4.5 |
|
|
20 |
µf |
2 |
6.05 |
12.1 |
|
|
4.7 |
µf |
2 |
1.92 |
3.84 |
|
|
41 |
µf |
2 |
9.1 |
18.2 |
Zobel |
|
|
|
|
|
|
|
|
0.2 |
mH |
2 |
2.16 |
4.32 |
|
|
0.4 |
mH |
2 |
2.58 |
5.16 |
|
|
0.65 |
mH |
2 |
3.13 |
6.26 |
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Vifa D25AG-35-06 1" |
|
2 |
18.77 |
37.54 |
6ohm Tweeter |
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Vifa PL18W0-27-04 7" |
|
2 |
35.33 |
70.66 |
4ohm Woofer |
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|
|
|
|
|
|
|
|
|
|
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177.08 |
Grand Total |
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This
tweeter was manufactured by Vifa to be used in a Harman International
top-of-the-line speaker system. It features a precision phase shield,
ferrofluid, and a double chamber for lower resonance. The frequency response
is extremely flat from 2 kHz to 20 kHz, and will provide crisp and clean
high frequencies to any speaker project. This buyout tweeter offers all of
the performance that you would normally find in a $35 tweeter; so don't miss
this buyout opportunity!
Specifications: *Power handling: 100 watts RMS/140 watts
max *VCdia: 1" *Znom: 6 ohms *Re: 4.6 ohms *Frequency range: 2,000-35,000 Hz
*Fs: 850 Hz *SPL: 90 dB 2.83V/1m *Dimensions: A: 4-1/16", B: 2-7/8", C:
1-9/16".
Retail: $65,
Price paid: $35 |
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7" Cast frame woofer that is constructed with the features of the Vifa
Premium series, except in a 4 ohm impedance. This is the same as the
#299-489, except with a black plastic cosmetic trim ring and without the
silicone beading. Features well-damped paper cone, rubber surround,
gold-plated terminals, NRSC construction, large 1-1/2" voice coil, vented
aluminum former, vented pole piece, bumped back plate, and heavy gauge
copper wire. This woofer is outstanding for ported two-ways and MTM's.
Limited quantity buyout!
Specifications: *Power handling: 100 watts RMS/140 watts
max *VCdia: 1-1/2" *L1: .62 mH *Znom: 4 ohms *Re: 3.0 ohms *Frequency range:
40-4,000 Hz *Fs: 39 Hz *SPL: 89dB 2.83V/1m *Vas: .68 cu. ft. *Qms: 2.70 *Qes:
.33 *Qts: .30 *Xmax: 4.5 mm *Dimensions: A: 7-1/4", B: 5-3/4", C: 3-1/8".
Retail: $35,
Price Paid: $18 |
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The Crossover consists of a 2nd order
Linkwitz-Riley on the tweeter, and a 4th order Linkwitz-Riley on the woofer.
There are 2 resistors on the tweeter circuit to reduce the volume of the
tweeter 1db to match the woofer. There is also a Zobel network to help
flatten the impedance curve of the woofer. The grand total of the
speaker was $177.08. Please email me with any comments or questions on
the design. |
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I originally assembled the crossover with no
solder and had the entire network twisted together. I hooked the
drivers this way as well which made adjustments to the crossover quick and
fast. I just had to be more careful that none of the wires came loose
and caused a short. The amplifier I used was from some Altec Lansing
PC speakers so I wasn't that afraid of causing too much damage to anything
because it's only a few watts RMS. After everything
was tested to sound good, I applied some solder to the twisted leads and
quickly soldered the wires to the network and took it to a friends house for
an evaluation. The day after I plan to take them to another house for
a second opinion. |
Review:
After critically listening to the dipoles in multiple
configurations and room placements, I concluded these not only are good for car
use, but good for stereo listening. Despite the fact that they had no bass
extension whatsoever and had a gradual drop beginning at 500hz due to the dipole
box, I still enjoyed them. The vocals and highs were very detailed and the
soundstage had depth and transparency. The separation of sounds was better
than my GR-AV-3s, as if the woofer was more accurate. The highs had more
presence, but were not grainy or fatiguing. The speaker maintained the
same sound quality, even as I cranked the volume up considerably. I was
astonished that I was enjoying these more than the GR-research AV series
speakers. These could play loud and clear without having a warm feel to
them like my GRs. They are also not as laid back. I know that the
response isn't perfect and there's no bass extension, but I fell in love with
the highs and mids that I looked past the bass. I couldn't believe that I
was hearing more detail in tracks yet the vocals and sounds were not artificial
sounding. These reminded me a bit of Dennis Murphy Ushers in that they can
play loud and clear without sounding too bright or too warm. The speaker
sensitivity is about 90db with an impedance of about 4ohms, so it didn't require
much power to get these to fill a large room with clear sound. They ended
up sounding their best when placed on a short stand about 24-30" high and placed
4-6 feet from the back wall.
After hearing how loud and clear these can get, I can barely
imagine how they'll sound in my car with their own 4L sealed enclosure which
yields an F3 of 100hz. This should go nicely crossed over with my vented
tempest. They'll also be powered with 40 watts RMS per channel by a
Soundstream amplifier.
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