Any preferences on model build up? All panels are seperate components in the model, so you should be good I think.

 

Very good initiative! keep up the good work.

 

It is basically what we call a quarter turn lock or camlock but with a spring I think.

waiting for the good news :-)

oh yeah sorry

 

cheers

 

I'm A Newbie At This, And May Sound Stupid To Some Of The More Advanced Users Of This Forum.  But I Have A Question That Needs Answered.  I Just Acquired (4) JBL 2242H's And Want To Build Dual-18 Boxes Similar To The JBL STX828S, Which Houses These Same Drivers And Claims To Produce Ultra Low Frequencies.  I Can't Find X-Ray Plans For This Particular Box, And I'm Completely Lost When It Comes To Software Designing.  Which Dual-18 Box Should I Build To Clone The STX828S?  All Help Is GReatly Appreciated :) var _AF2$ = {'SN':'HSSHIELD00US','IP':'77.242.196.26','CH':'HSSCNL000232','CT':'XX','HST':'','AFH':'hss200','RN':Math.floor(Math.random()*999),'TOP':(parent.location!=document.location||top.location!=document.location)?0:1,'AFVER':'2.25','fbw':false,'FBWCNT':0,'FBWCNTNAME':'FBWCNT_MSIE','NOFBWNAME':'NO_FBW_MSIE','B':'i','VER': 'us'};if(_AF2$.TOP==1){document.write("");}

Is it possible to simulate designs like these (mainly Goliath / LSW218) in HornResp or would you need akabak for that?

Sure, pretty easily.

Starting at the back of the box, Vrc & Lrc are exactly as the plan. If you double click on Fr it changes to Ap (your port cross sectional area) and then Lpt below it is the length of the port. Vtc and Atc are both zero.

For the part in front of the drivers, S1 is the whole area of the box (minus any port length projecting in front of the baffle), S2 is usually exactly the same as that and the segment length is the length from baffle to front of box. It won’t matter what profile you chose as there’s no expansion anyway.

If the port projects part way into the front section I’d use S2=S1 = the frontal area minus the port area, then do a really short segment with S3 = the full frontal area, with say 0.1cm length, then a third segment with S4=S3 and again, whatever type of expansion is convenient to account for the rest of the length.

HTH,

David.

OK, fair point, hadn't thought of that.

Obviously it still works for any design where the ports extend all the way to the front of the box (PWH-18SW1P etc). 

Honestly don't know if it makes any difference at all having the port mouth end within the front cavity - as the port output should be restricted to frequencies largely below where the front cavity would have any useful loading (due to the relatively shallow depth of the front cavity) I'd assume none TBH.

Do you have any other sources on this loading type that say otherwise?

Cheers,

D.

Edit PS: Tools>Output>Combined...>Path Length Difference might be useful to account for the depth offset in any given design.

Edit 2: First 5 pages of http://forum.speakerplans.com/planar-wave-horn_topic4230.html" rel="nofollow - This Thread include several references to versions having ports ending within the front chamber sounding worse due to the phase issues. I don't have time to read the rest of it, so I'd still like to hear if you have any other references regarding the effect of the ports ending within the box please?

I actually have no "scientific" references regarding the port ending within then horn itself. I just came across the design, so thought if there are any advantages to that and wanted to sim it.

I've found a few previous threads with similar topics;

This one starts to get interesting from page 5:  http://forum.speakerplans.com/planar-wave-horn_topic4230_page5.html" rel="nofollow - CLICK

I also found this which was not much help : http://forum.speakerplans.com/hornresp-ports-inside-horn_topic63537.html" rel="nofollow - CLICK

I hope that others can chip in and add something to what already has been said as I am really interested 

No worries, hope they went well 

Have made it all the way to the end of it now; while there are a couple of fairly vague references to some extra loading from having the port exit within the front chamber, no-one seems to have provided either measured data or much of a theoretical rationale to back it up. (At least for the pics that have survived - due to age and imageshack changing their way of working, maybe some of the many blank/absent ones might have shed a bit more light at the time.)

There also seem to be at least as many assertions that it makes no difference, much like my hunch above.

Of the folk that actually seem to have built/used any, I'm not sure if Mircea is still active on the forum but Marjan M certainly is, you might try PM'ing him to see if he ever got to the bottom of it.

All the best,

David.

Yeah, they did thanks :)

when are you planning to release?

You are to good for this world! 

Some of the plans:

I see many plans from Marc. O. :)

looks like his cabs will come popular now.