"Crossover Design for New Project"

[Altec Best]

[quote=GM;1844527]The 8" was the original design, so when we went to side firing, I spec'd the nearest oversize.

FYI, The dual 6" dia. pipes are big enough that flaring isn't required unless you under-size them. Also, flared vents typically must be a lot longer for a given tuning,

so with no way for me to sim them accurately, you're on your own beyond the ROT of adding the length(s) of the flare(s) to a straight pipe's calculated or measured length.

Great !!

Hmm, if the basic pipe is around 6" i.d., then you may need only one/speaker since it's flared.......

Yes it is Exactly 6"

The flares are just like end caps so they could be used but don't have to, after you get your port length they are held in place with pvc glue.It's more or less a black piece of tube with 2 end caps (Flared) that slide on.I would like to use the flare for the part of the port that mounts to the cabinet veneer, inside flare doesn't have to be used.It will give the outside port a finnished look (Done).

I didn't realize the flares would make that much of a difference.The tube is still only 6"

[westend9]

There is just no end to what a guy needs to know to build an enclosure. I'm glad to have found a lot of it here, at Todd's site. Here is a little reading on flared ports. The differential math begins on pg. 31, should you choose to calculate the effect of the flares. I think I would start long and cut, math gives me a headache.

[Altec Best]

There is just no end to what a guy needs to know to build an enclosure.

Tell me about it !! This will be my LAST !! Except for maybe a published design for my 604-8G's like a 620 or Stonehenge. I wouldn't have gotten this far without the help of guys like Brad,Earl,and especially Pano and GM.

But I see the light at the end of the tunnel.This time next week they will be Home.

[GM]

I would like to use the flare for the part of the port that mounts to the cabinet veneer, inside flare doesn't have to be used.It will give the outside port a finnished look (Done).

I didn't realize the flares would make that much of a difference.The tube is still only 6"

Both ends would need to be flared if only one is used, so for just one flared end you'll theoretically need two vents, though each longer than just the simple straight pipe.

Acoustically, this is like saying that adding a front and back horn to a driver wouldn't make much difference, just the scale is different.

GM

[GM]

There is just no end to what a guy needs to know to build an enclosure. I'm glad to have found a lot of it here, at Todd's site. Here is a little reading on flared ports. The differential math begins on pg. 31, should you choose to calculate the effect of the flares. I think I would start long and cut, math gives me a headache.

Well, this is true if you're trying to make the most efficient, highest SQ design, i.e. most performance in the least bulk for a given BW, driver. Between the T/S design routine and the mostly freeware it has spawned, perfectly acceptable performing designs can be made with no real speaker design knowledge, ditto the various TL, horn alignments thanks to Martin King's MathCad software, David McBean's Hornresp and now its tapped variants with soho's (no real name posted AFAIK) recent Excel SS optimized for easy loading of designs into the latter.

Basically, almost all of the knowledge (and then some) that I learned the old fashioned way has been made available for ~free to anyone with a computer and the ability to use these folk's software, with tutorials along with program and alignment type specific threads to iron out any 'misunderstandings' since there's also a lot of either out-of-date and/or outright intentionally misleading info as the price one pays for such an extensive, open knowledge base.

Yeah, being higher math challenged, the work done by Kinsler, et al were kept from me and even though I knew folks at the time who could 'do the math' and dumb it down for me into rules-of-thumb, I didn't want to 'owe' them for one reason or another. Had the net been available to me though, it would have been a different story, but having managed to get by just fine without it, no longer care at this late date.

That said, I just remembered Bill Collison's extensive 'adventures in porting' that me and others critiqued on the forums which among other things includes a flare designer, though haven't used it: Collo's DIY Subwoofer Enclosures

GM

[Altec Best]

Both ends would need to be flared if only one is used, so for just one flared end you'll theoretically need two vents, though each longer than just the simple straight pipe.

Acoustically, this is like saying that adding a front and back horn to a driver wouldn't make much difference, just the scale is different.

GM

OK I will just use the 6" pipe without the flares if this doesn't work with these pipes (He said the flares aren't that big) I haven't seen them yet (To Measure Precisely). I'll send them back,and I'll go back to the rectangular vent of 16.875" x 3" x 4" length. Done Deal !

He said he will try and send me some pictures of the cabs tonight, if not, tomorrow. :thankU: GM so much for all your Kind,Gracious help and support for which this project wouldn't have been possible.We are approaching the end "My Friend".


Also Pano's help WRT the measuring that was quite extensive (His Assistance) that is. Many,many,emails and phone calls to all hours of the day & night ! Thanks Michael ! :2thumbsup:

[westend9]

Well, this is true if you're trying to make the most efficient, highest SQ design, i.e. most performance in the least bulk for a given BW, driver. Between the T/S design routine and the mostly freeware it has spawned, perfectly acceptable performing designs can be made with no real speaker design knowledge, ditto the various TL, horn alignments thanks to Martin King's MathCad software, David McBean's Hornresp and now its tapped variants with soho's (no real name posted AFAIK) recent Excel SS optimized for easy loading of designs into the latter.

Basically, almost all of the knowledge (and then some) that I learned the old fashioned way has been made available for ~free to anyone with a computer and the ability to use these folk's software, with tutorials along with program and alignment type specific threads to iron out any 'misunderstandings' since there's also a lot of either out-of-date and/or outright intentionally misleading info as the price one pays for such an extensive, open knowledge base.

Yeah, being higher math challenged, the work done by Kinsler, et al were kept from me and even though I knew folks at the time who could 'do the math' and dumb it down for me into rules-of-thumb, I didn't want to 'owe' them for one reason or another. Had the net been available to me though, it would have been a different story, but having managed to get by just fine without it, no longer care at this late date.

That said, I just remembered Bill Collison's extensive 'adventures in porting' that me and others critiqued on the forums which among other things includes a flare designer, though haven't used it: Collo's DIY Subwoofer Enclosures

GM

Agreed, the availability and use of design software, makes enclosure design easy but it is the details about how all of the individual parts coalesce into making a good speaker, the types of materials, the design of the cabinet, intricacies with crossovers, and all the other little bits that I hope to learn. I'm grateful that there are very knowledgable folks that pass some of that along to us neophytes.

OK I will just use the 6" pipe without the flares if this doesn't work with these pipes (He said the flares aren't that big) I haven't seen them yet (To Measure Precisely). I'll send them back,and I'll go back to the rectangular vent of 16.875" x 3" x 4" length. Done Deal !

He said he will try and send me some pictures of the cabs tonight, if not, tomorrow. :thankU: GM so much for all your Kind,Gracious help and support for which this project wouldn't have been possible.We are approaching the end "My Friend".


Also Pano's help WRT the measuring that was quite extensive (His Assistance) that is. Many,many,emails and phone calls to all hours of the day & night ! Thanks Michael ! :2thumbsup:

Here is the Flarit calculator that was linked to from GM's post, above. Mr.Collison has a lot of useful info on the site.

[Altec Best]

GM, WRT the ports Roman said they arrived and they look more decorative (The Flares)than anything else with the vents (Tubes) being 6". I dunno he said he will try and send some pictures either way I will decide wether to use them after getting them home.If they aren't good to use I'll send them back to PE as noted.And go with the original rectangular vent.

But they are starting to look like something he sent a few pictures. Thanks Guys for all your help !!! :2thumbsup:












I'm one Happy Camper !!

[Panomaniac]

Magnifico! :2thumbsup:

[Altec Best]

Thanks Michael,The last few months are finally starting to come together! :thankU: