Stuck with port size pionnerW307D4 sub

[Amit_112dB]

hi all
i could not find a poper home audio sub so i thought i'll manage with a Car audio sub, i think it should work fine, ny suggestions??
ok
pioneer W307D4 400rms DVC
Qts .60
Vas 11.8L
fs 33.30hz
Qms 13.99
Qes .63
my taste is ported enclosures, ran Winisd 45litres(36cm*57cm*21cm), with min port dia 6.8cm ,tuning freq is 22Hz the port length is 44cm,
port length is too large, should i go for a rectangular port
or should i drop the idea of ported n go for sealed(which i would hate)
so there is issue port is tuned at 22hz and my lower -3dB is 18hz, any idea if it will be a problem
need help please

[richie00boy]

Those parameters look suspect. Qts 0.6 indicates must be used sealed and even then is pretty high Q. Vas 11.8 litres is astonishingly small for what I imagine must be a 12 inch driver?

If your port is too long, changing to rectangular or whatever won't make any difference if you keep the same cross-sectional area (which you must or it will make more wind noise).

[boydon_lepasci]

There is no rule I am aware of that requires all or any part of a port to be inside the box. I have read, however, that rectangular ports should not have one dimension more than seven times the other dimension. Keeping this in mind, it should be easy enough to design a box with an integrated external port.

[Amit_112dB]

yes u are right its a 12" inch driver

Ok can i use this car audio woofer for home auido ?

yes i agree woofer is designed for sealed, but my taste is ported so can i make a ported enclosure out for it.

Should i change the tuning freq. from 22Hz(WinIsd calculated) to 30hz, this will reduce the port length, would this harm my woofer in any way, will it effect the performance
i play mp3 and i dont think mp3 has any freq. below 30Hz, am i right? If i can change port freq. wat port freq would u suggest.

I am reading which type of stuffing? thread, can i use "cotton" for stuffing? is cotton same as polyfill...

[richie00boy]

You have mentioned you used WinISD - why don't you change the tuning as you suggest as see what the graph says.

I don't think you can reduce the tuning, my opinion.

[Amit_112dB]

ok now WinIsd said fort freq 22hz BUT i changed it to 30Hz and this is the graph that i get, i think its fine, the port length also becomes fine 6cm Diameter and 20Cm length.

but will changing port freq. harm my sub in any way...

all measurement for ported 45Litres

One more issue- i heard ported enclosure will not produce any sound below port freq., my port freq is 30Hz and this graph sayz my lower 3db is 24hz, so can my box produce 24hz or not ????

[richie00boy]

That's a 5dB peak! Do you not think you will hear that?

[Amit_112dB]

it thought this extra 5dB will give a good punch at 30Hzits not so0 spikey

i hear u have been into audio since 10 years, Tell me what do i do, can i increase the port freq(u have seen graph),
should i go for sealed(i will never be happy then)

HELP!!! wat to do

[richie00boy]

Punch is around 70-80Hz.

You get rumble around 30Hz. If you increase the port frequency even more it will become even more peaky.

How do you know you will never be happy sealed? You can't really say you like sealed or ported, what you mean is that of the boxes you have heard the ones you preferred were vented. That does not mean all sealed are bad and you won't like

As I said before, this driver is not 'the best' designed for a ported box either. Can you increase box size? This will help a lot in fitting the port in and also in smoothing the response.

What is your amp? The available power will determine the best way to do it.

Also can you check Vas, I'm certain it's not 11.8 litres. Maybe 118 litres?

[Foxx510]

Where did you get the T/S specs for the woofer from? I can't find much info on the woofer, just this little bit from a retailer:

Qts = 0.52
Xmax = 9.4mm
Fs = 34.8 Hz
Vas = 40.9 litres