Questions about Vifa Impulse

[Jensk]

Yes, I decided on the Vifa Impulse to build, But have thus the design downloaded of Speakerland.nl, and just to Vifa-speak.com for technical information

Now that falls me 1 thing on, by the Vifa technical information stands that the tweeter 104 MM, on the design stands that he 105 MM is, consequently 1 MM differ.

The same money for the woofer, the woofer according to vifa became 170MM only as I on the building design looks he has been drawn on 171 MM, look I to the job measures that as holes from the tweeter is 83 MM only on the design stands it as 77MM, a difference of 6 MM!, before the woofer counts it same the measure of the woofer is 146 MM, butDesign must the arch 150 MM its. thus 4 MM differ.

If I now view to the building design see I that I for the woofer 4,5 MM , but the woofer thickness am 4,2mm thus than is he 3 mm broadens?

For the tweeter counts 4,0mm meanwhile the tweeterrand thickness 4,5 MM amounts to consequently knocks this building design not, or be these good measures for strakheid etc? For 77 mm on the design and on technical gegevens 83mm is at least 0,6 mm find the odd maarja

Someone can the explain, for I want everything want to have without restrains to lose. Comes the tweeter it now 0,4mm above from woofer stick?

Eager answer, so that I take measured can the good!
Sources: http://www.vifa-speak.com
Tweeter: D25AG-35-06
Woofer: P17WJ-00-08

Building design:
http://www.audiokit.it/ITAENG/KitDif...s/impuls_1.gif

[Jay]

Hi jensk,

1) The drawing you provided (www.vifa-speak.com) is not accurate, it even has errors. Try search the drivers at www.partsexpress.com and you can download a precise tech info in pdf.

2) The hole for the tweeter is fine (77mm) because the tweeter diameter is 73.5mm maximum, not 83mm.

3) If you want to build the enclosure (or have someone else to do it) it is important to make a "maal" or template from paper or something (based on your driver actual size). You cannot just give a number because your ruler may have errorrs.

4) While doing a measurement, pay attention to the position of the driver centers. No need to pay attention to the distance between drivers ends, or other minor measurements.

5) Driver dimensions are not 100% constant from driver to driver. There are tolerances. So it is important to make a SAVE approximation (It is better that the hole is larger than the size of the driver, than smaller, right?). For example, the diameter of P17WJ can be 169.5mm or 170.3mm so it is save to pick 171mm (You cannot measure a 0.33mm with standard ruler anyway)

BTW, I think a P17WJ in a small vented enclosure is a bad idea. The woofer is known to have bad dynamic capability. With that enclosure, you will get the mid (vocal) only, not the bass quality, which is the reason why you have to choose a P17WJ over a P13WH, and you also expose the driver's weakness. IMHO, for P17WJ, the enclosure is very important than for others. I prefer a bit bigger volume, and SEALED. I guess John K design works better. This is just a quick look. Don't trust me 100%