4350 Vent Dimensions

[Chas]

Hi all,
My next weekend project is to make new baffle boards and replace my ancient Altec 414Z's (two per box) with reconed 2231A's (2235H kits). The enclosures are about 8.7 cu ft in gross volume. I hope to add enough fibreglass fill to create a virtual 9 cu ft volume.

Can someone with 4350's measure their vents for me to use as a starting point? Also, from the data I have, it looks like the 4355 had elbows in the vents, maybe someone knows why?

I am also looking for a recommended Fb tuning frequency, I think JBL used 30 Hz. I am trying to achieve lowest F3 possible. Suggestions anybody? I plan to drive them with 400 Watt/4 Ohm monoblocks.

[Chas]

Whoa, I should have compared T/S parameters before posting the message above! I had stupidly assumed that 2231A's and 2235H's had similar T/S numbers.....

Now I am not sure how to interpret my particular configuration. 2235H cone kit in a 2231A basket/motor assembly, ideas anyone?

:banghead:

[Chas]

Thanks Giskard, that's good news. Would you know the dimensions of the two 4355 vents?

[PSS AUDIO]

Hi,

Make a little search, this was discussed months ago in a thread called 4350 thread (or something like that)!

I've done the job for you: http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=425

[Chas]

Thanks again, I understand completely, but it would at least be nice to know the I.D. of those vents as a starting point....;)

[John]

Ok Here are the port specs for the 4350.

3" I.D. x 12-3/4" long, this includes the thickness of the baffle board.

I would be intrested in knowing the port specs of the 4355 as well???

[Chas]

Thanks John, any members using 4355's out there?

[PSS AUDIO]

Originally posted by Chas
Thanks John, any members using 4355's out there?

Yep, a melting pot of 4350/55!

[boputnam]

Originally posted by PSS AUDIO
Yep, a melting pot of 4350/55! Yuri, could you collect some measuements of the ports / ducts? That might be helpful... :yes:

[PSS AUDIO]

Originally posted by boputnam
Yuri, could you collect some measuements of the ports / ducts? That might be helpful... :yes:

Bo,

If I am not mistaken, I posted them in the 4350 thread opened months ago...

If not let me know the measures you need.

[boputnam]

Originally posted by PSS AUDIO
If I am not mistaken, I posted them in the 4350 thread opened months ago... I have no idea, Yuri. I must have missed that post. Maybe you could post it again, or find that old post for the needful?

You'll notice that questions repeat here, from new, or evolving ;) members - it's helpful to them to either re-answer the question, or steer them to your prior post. I don't have a pair of 4355's to measure... :(

*****

Yuri - I searched unsuccesfully for the Thread you refer to. Maybe you can find? Chas would appreciate the info...

[PSS AUDIO]

Originally posted by boputnam
Yuri, could you collect some measuements of the ports / ducts? That might be helpful... :yes:

From what I can see, diameter is 3 inches while length is 12 inches and they are six of those in a cabinet!

Will it do?

[Chas]

Thanks Bo, for chiming in, Yuri it sounds like you have 4350's, not 4355's. I need the vent I.D. for 4355's because I will essentially be using a pair of 2235's per side.

[Robh3606]

Hello Chas

Do you have any software?? Get a copy of WinISD and run the numbers. You don't have to get the exact vent size. Work around what materials you have. As long as you tune around 30Hz it should work just fine. Set the ports up so you can chnage the length so you can adjust the tunning if you need to.


http://www.linearteam.dk/default.aspx?pageid=winisd



Rob:)

[Mr. Widget]

As far as I can tell the 4355 had 6" diameter ports. Since they are so large they need the bend to avoid air path restrictions. When I did my version I used a pair of 4" ports out of convenience. Functionally they are identical. As long as you keep the tuning at around 30Hz as Rob says you will be fine. I tuned mine to 29Hz.

Widget

[4313B]

Hi Mr. Widget,

The designer believes the 4355 used 5-1/4" ID ports with 10" ducts tuning the volume to ~ 28 Hz. I guess this is as good as it gets until someone with the actual system can post the info. The impedance curve definitely shows Fb at ~ 28 Hz. I agree with the dual 4" ID configuration.

[Chas]

Thanks everyone, this gets me to a starting point!
:D

[GUYGELLA]

Thanks!! From 2004!!! Oldie but a Goodie!
Ok Here are the port specs for the 4350.3" I.D. x 12-3/4" long, this includes the thickness of the baffle board. I would be interested in knowing the port specs of the 4355 as well???