PWK Designs? - Page 2

Well getting ready to build one of Bill's AutoTubas using dual 8" and from reviews they are pretty kick ass.

A horn requires a certain length and mouth area to function. Simply put, if the driver is too big there's not enough room left in the box for the horn. And where horns are concerned the adage 'if you're not going to do it right don't do it at all' holds true.

"If I just went with a 4.0 ft^3 sealed enclosure, would I still get that deep base rumble for movies?"

yeah, you would do ok to put each w15gti in a 4 cubic foot enclosure sealed.

an inuke 3000dsp will work for both amp and equalization. each channel will produce about 750 watts, which pushes the driver to about its limit in those enclosures.

yours would be an easy build and very capable system. be sure to build the cabinets solid with good bracing and make them air tight.

if you want to purchase flat packs, check out diysoundgroup.com. i think erich is having some 15" cutout baffles made for the 4.0 cubic foot enclosures. they cost a little over a hundred buck delivered and are a cinch to assemble.

A good single 12 ported would probably have just as much output take up less room and be easier to build.

Plans are simple and easy to read. Now if you was comparing a ported box vs a horn enclosure you were trying to design yourself, it probably would be much easier to do the 12" ported. I would say a dual 8" AT would probably out perform a decent 12" ported sub and use less power and sound cleaner doing it.

$60-150 for a pair of compatible woofers, $15 for the plans and then just the price of the MDF and other accessories and you got a great performing system. 12" ported on the other hand could cost you more just for the driver than the entire AT.

I've read from many people that horn/tuba enclosures have the sound quality of a good sealed system but has some of the benefits of a ported as well. Low group delay, low distortion (woofers barely move) and efficient.

http://www.billfitzmaurice.com/autotuba.html

I have seen the Alpine Type R sell for as low as $99 new, I just picked up 4 15's $300 plus shipping. That's 75 a piece. Know one has any idea what type of real world SPL a Auto tuba produces. The Alpine will over a 130DB's depending on the car and install.

"How do you think it would sound with music? Help!!!"

it will sound good. two 4" ports would be closer to what most folks would use in order to keep air velocity lower (as you pointed out).

I have used PWK for car audio enclosures for the last 5-6 years. They perform and measure as he predicts as long as the information given to him is correct. I started using him because I wanted to try a ported enclosure and had not ever built one. The blueprints provided were very easy to use for assembly. Now he does provide plans for home audio mains as well as subs but has said at least once that he does not have much experience trying below 20 hertz.

He does claim to give you the best performance for what you are asking for based on woofer used and vehicle cabin gain and that the enclosure is very vehicle woofer specific. I disagree as I have tried several of the designs with different woofers and vehicles and had excellent results. I have tried a couple of other "designers in the car audio world and none so far have given what Pete offers. What I have ended up with is usually a ported enclosure tuned to 30-35 hertz with zero attention to excursion for whatever power level I am using. So I give Pete Kudo's for that!

He does say his software is his own design and is not using an off the shelf freeware or purchased product.

I do recommend him to kids (I have a 20 year old as well as 16 year old nephew), mine and their friends, because it is just easier and the performance is always better than a prefab or what I have seen come out of local shops. Of course the same can be said as I have purchased the THT and had excellent results from that and thereby feel comfortable recommending that as well as this website forum for home theater projects.

Hey J1!! cool subs, I agree with you about the coolness factor for a 15... Now, I went a little too fast through your post but you didn't list any room dimensions right? Other people are right in mentioning the listening space and the various room peaks you may encounter depending on your seating location... If you have that room size let us know, maybe 1 sub will do! I would go ported with a slot port (just more port area to play with..)

Cubdenno is right about PWK, nothing wrong in having someone factor in all your variables in his own software to have a more precise model. Now, I'm more of a DIY guy and have always made my enclosures, started when I was 12 and probably have made way more ported than sealed... Sealed is just not my way of thinking, you are just wasting the back side of the cone!! not efficient... Better sounding? Not all the time. Less space? depends on the sub..

What kind of music do you listen to? a 15Hz response is just asking for room rattles instead of music reproduction (not that that is cool or not)... If you listen to Pipe organ music then maybe go down to 20... I know I love it when the lady at church hit's the low notes on the pipes even on church music ... The wife can't hear it, everybody else seems like, "What? that's just the organ right?" (think that the pipes are there for decoration...)

This is predominantly a HT forum, and if you do a little research, then there is often considerable SFX energy down into single digits. Some people here have systems that can go very, very loud and deep. If I was doing a music only system I wouldn't bother much <30Hz.