Flared ports...how you do that

[Pioneer~Saturn 5,000+ posts]

I would say 45's would help the flow of things but itd be hard to say exactly how much they help

 

[DS Autosports 10+ year member]

so would you all say this design is for function or cosmetics? Either way it is something I want to try.

 

[bhsdriller 10+ year member]

hahaha...then once it dries you'll have 2" mdf for the price of 3/4...//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

I'm pretty positive that there was a guy here that tried it. It was a while back though and he posted pictures of the wood in his pool

i think

 

[Pioneer~Saturn 5,000+ posts]

so would you all say this design is for function or cosmetics? Either way it is something I want to try.

In most cases its cosmetic but for some setups I would see the kerfed port(s) being functional in that they would act much like adding pvc in certain areas to gain spl in some testing like jacob has done...if you kerf the port and then kerf the corner the kerf is heading towards rather than another 90 degree bend, you may see a tenth showing through somewhere..

 

[WrenchGuy 10+ year member]

Just put a plexi top on 3 boxes.

! with kerfed everything, one with 45's, and one with plain ol construction.

Add smoke machine or dry ice and check the stream line. Would be neat to see.

 

[spltuscon 10+ year member]

The 45's in the corners not only help with smoothing the airflow but they also add bracing that ties 4 sides together with another glue bond, so it adds strength to the box. A good kerfed port or any other effective flaring technique will almost always help your score on the meter.

I should add though, that putting 45's in a box won't always help your score. I added one on a single 15" test box that cost me .5dbs! Took it back out and got it back...

 

[Pioneer~Saturn 5,000+ posts]

The 45's in the corners not only help with smoothing the airflow but they also add bracing that ties 4 sides together with another glue bond, so it adds strength to the box. A good kerfed port or any other effective flaring technique will almost always help your score on the meter.I should add though, that putting 45's in a box won't always help your score. I added one on a single 15" test box that cost me .5dbs! Took it back out and got it back...

You sure it didnt just change your airspace/effective port length and changed the tuning?

 

[spltuscon 10+ year member]

Well it did slightly...good point.

I think in my case it was the specific corner I put it (near the port) that hurt me though, because I added the same size corner in a different spot on the box (separately) and it had no effect either way.

 

[Pioneer~Saturn 5,000+ posts]

Yea, I wish I had a 2nd vehicle to test out stuff in and make a bunch of enclosures with all the same specs but some with kerfs, some just plain ported enclosures with no 45's or anything etc. and just see the differences (id need a tl too //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif)

 

[spltuscon 10+ year member]

That's what I hope to do in the off-season. Except I hope to try ported vs T-line vs 4th order bp/6th order bp vs ABC and then tweak the top performer. It'll be tough to top a good ported box for spl but I've already found the T-line to be a much better daily driver, so it'll be a good learning experience either way //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[dr_peeb 10+ year member]

That's what I hope to do in the off-season. Except I hope to try ported vs T-line vs 4th order bp/6th order bp vs ABC and then tweak the top performer. It'll be tough to top a good ported box for spl but I've already found the T-line to be a much better daily driver, so it'll be a good learning experience either way //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

What's a T-line?

 

[Pioneer~Saturn 5,000+ posts]

What's a T-line?

Transmission Line

Basically a ported enclosure with no 'main chamber' that is tuned based on the whole thing's length, so the subs are mounted at one end of a port...I wish I knew more about them actually //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[WrenchGuy 10+ year member]

Transmission Line
Basically a ported enclosure with no 'main chamber' that is tuned based on the whole thing's length, so the subs are mounted at one end of a port...I wish I knew more about them actually //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Me too. Like to make the thing and it sounds/performs like it should...lol

I guess its not a guarantee even after all the figures. According to some things I've read.

 

[spltuscon 10+ year member]

Basically what was said above...

Transmission line is typically tapered from an area greater than the sd of the sub down to the sd at the Terminus (the opening). You can vary the ratio of the line to change the acoustic properties of the enclosure. The line length is based on the 1/4, 1/2, or 3/4 length of the "tuning frequency" (ideally tuned to the drivers fs or just above). You can also stuff the line to slow down the sound waves and get a longer effective line length. Stuffing the line also lowers the impedance spike.

Sound wise, they are very clean and tight, similar to a sealed box (good transient response) but the output is very similar to a ported box. The low end roll-off is much shallower than a ported box also, so they do very well on the lows.

Of coarse there is more to it, but that's the basics //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[plugitin 5,000+ posts]

i wanted to build my box with all kerfs in the corners instead of the 45's, but it would of taken longer then i wanted to build it...