Sold aeroports and 2 channel for sale

[thegreatestpenn 5,000+ posts]

okay, I still have a few items left from my huge sale, here they are. get'm while I'll sell'm. you can contact me quickest at wbrandonp@yahoo.com (I CAN'T CHECK PMS AT WORK!!!!! SO EMAIL ME!!!!)

Phoenix Gold PLD-1 Linedriver

8vrms 2-channel linedriver with power plug

40 shipped

Concept ca-802 2-channel amp

75x2@4ohm, 135x2@2ohm, 270x1@4ohm ground and power screw terminals replaced with allen screws

60 shipped OBO (low ballers welcome)

6" Aeroport

8.5" outside diameter, 18" long. never mounted

40 shipped (pretty firm on this price)

2 4" aeroports

6.5" diameter, both 6" long

22 shipped for both

Click to read more...

 

[FineLinePimpin 10+ year member]

Amp in good working order? No problems or anything? Also got a better pic of the connections where you sub'ed in allen screws?

 

[thegreatestpenn 5,000+ posts]

Amp in good working order? No problems or anything? Also got a better pic of the connections where you sub'ed in allen screws?

amp works great. I can get better pix later tonight (on my way out)

 

[RAM_Designs 5,000+ posts]

I knew something sounded a little weird. I actually plugged in the 4" aeroports into the port length calculator at carstereo.com, and it comes out to be tuned to 41hz if you use both in a 4.5ft^3 box. Just letting you know...

 

[adas Pro Seller]

I knew something sounded a little weird. I actually plugged in the 4" aeroports into the port length calculator at carstereo.com, and it comes out to be tuned to 41hz if you use both in a 4.5ft^3 box. Just letting you know...

Actually a little worse....4.5cu.ft would put it at 43.5hz tuning Just off by 10hz:
(not ment to thread crap, sorry)//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[thegreatestpenn 5,000+ posts]

are you using 10 inches or 5 inches? you have to use 10 inches and multiply the area x2. I still get 33 Hz and in the box I used the ports with, it was consistent with my findings on the meter

 

[thegreatestpenn 5,000+ posts]

pix of allen screws

 

[thegreatestpenn 5,000+ posts]

good morning bump

 

[thegreatestpenn 5,000+ posts]

linedriver added

 

[bjfish11 5,000+ posts]

Actually, each port needs to be 10" long, not a total of 10 inches. The box was actually tuned a lot higher.

Anyways, if the ports were brand new Id buy them up. But bump for you.

 

[thegreatestpenn 5,000+ posts]

amidst claims my calculations for frequency were off, I removed the insert I had.

 

[thegreatestpenn 5,000+ posts]

Actually, each port needs to be 10" long, not a total of 10 inches. The box was actually tuned a lot higher.
Anyways, if the ports were brand new Id buy them up. But bump for you.

Okay, all the claims about my calculations have been bothering me. I went to the carstereo.com port length calculator and it doesn't use port area, just port diameter. That can be deceptive. there's no way to easily account for multiple ports. I'm guessing people put in 8" diameter (which gives 21" of port length to get 33Hz in a 4.5cu.ft. net box). But that's not correct with 2 4" ports. the port diameter would be the square root of 8 multiplied by 2 (5.6" or so). That gives a port length of 10" as I calculated. My box didnt' lie, the 2 4" ports were used in a 3.2 cu.ft. enclosure and tuning was at 40Hz. On the mic, my peak frequency was consistently at 43Hz, if I was tuned that much higher, I wouldnt' have been peaking at 43Hz (especially since my car's optimal frequency is 50Hz and yes I did lots of testing to come up with this number, I didn't pull it out the air). If anyone wants to continue this debate, I'd love to. Only makes us better as hobbyists

by the way, the port length calculator I use is off of http://www.subwoofertools.com/forum/portlength.htm and if I don't feel good about the numbers i get I calculate by hand from the equation included with the Precision Ports I bought

 

[bjfish11 5,000+ posts]

Use this calculator. I always use this when working with precision ports. http://www.psp-inc.com

Go to the port calculator, and type in these numbers:

4.5 for the volume

43.5 for the tuning frequency

4 for the port diameter

2 for number of ports

It will give you a length of 6.03" for a flared port. Each port will be this length, which is what you have, so those are your specs.

Not looking to dump on your thread btw... just showing ya a little info, and a good port calculator to use.

 

[thegreatestpenn 5,000+ posts]

^ it doesn't specify on that calculator if that's for both ports or just one of them (referring to their length). Not saying I don't believe you, but that info is missing and nowhere does it make that distinction on the page. Add to that the fact of where my box would peak speaks even more to my side. In addition, I modified my box that I talked about up there by adding wood inside to make the box's internal volume smaller, to 2.2cu.ft. so it would be tuned to 48Hz. After doing this my peak frequency changed to 53Hz. My calculations can be disputed, but the termlab is pretty accurate when it comes to reading frequency. If the termlab's frequency readings are consistent with the tuning, I'm gonna roll with that every time

 

[bjfish11 5,000+ posts]

Its just understood that its the length of each port. Type in specs of a box, then cut the volume in half, use half as many ports, but keep the tuning and size of port constant, and you will get the same length of port. Cant argue with math...