TWWWW 2.5 Way Question

[zach_t]

Hello everyone- I have a 2.5 way question for you all using a TWWWW format. The woofers would be wired in a parallel/series config.

My question is, what would the pros/cons be of having the top two woofers in a sealed enclosure with a sallow Q (0.5-0.707) and the bottom two in an ESB style ported enclosure? Theory would be since the bottom two are used for baffle step compensation, they would roll off before port resonance became an issue and give you the extra bass then if you had an all sealed enclosure.

Would you run into impedance problem if the woofer (which are wired together) are in two different enclosures? Would group delay be an issue? Overall sonics?

[Pete Schumacher ®]

http://www.theaudiologic.com/gallery/gallery/Pete%20Prototypes/IowaDIYprojectcomplete.jpg


> Hello everyone- I have a 2.5 way question
> for you all using a TWWWW format. The
> woofers would be wired in a parallel/series
> config.

> My question is, what would the pros/cons be
> of having the top two woofers in a sealed
> enclosure with a sallow Q (0.5-0.707) and
> the bottom two in an ESB style ported
> enclosure? Theory would be since the bottom
> two are used for baffle step compensation,
> they would roll off before port resonance
> became an issue and give you the extra bass
> then if you had an all sealed enclosure.

> Would you run into impedance problem if the
> woofer (which are wired together) are in two
> different enclosures? Would group delay be
> an issue? Overall sonics?

Port resonance won't be a problem with the internal volume properly damped.

The other problem is that the two different alignments won't be phase matched in the bass region, causing all kinds of issues.

I used a rear port on my WTWWW 2.5-way towers. It's 2.6 cubic feet tuned to 24Hz with a 10" long port. I've got the interior broken up with some loose fiberglass along one wall and acoustic foam on the rest, with a continous open space between the port and that interior volume. It's a very dead space inside that box for frequencies in the port resonance range. And the rear port reduces what little may be there even further.

Don't worry about port resonances and let all the woofers work together at the lowest levels.

[Chris Roemer]

[Pete Schumacher ®]

He's good too.

His camera has that nice fish-eye style lens, and he literally laid it on the ground in front of the speaker and clicked the shutter without even looking into the finder, first shot.

[gordoncalder]

I thought it was taken by a really really short photographer.

:-)

[jtaylor]

My Brother just finished his last speaker Project in RECORD TIME: 10 YEARS, lol. He's now looking for something new to build for the next 10 years, LOL. I really like this 4 driver with the tweeter tower design. Could someone please provide me with the plans so he can begin another tedious time consuming project that I will have to finish for him. He's great with wood working skills, but I have to do all the XO and wiring work.

BTW, his last project was Dick Olshers Polly Natalias. Which were about the only speaker plans available on the net when he first started. Now all the drivers in that plan are all discontinued, which is a real shame. That is one sweet sounding speaker. Audax made one heck of a nice midrange driver for that speaker. He loves the Bass extension as well.

TIA, to whom ever would so kindly post the plans, for the speaker in the picture. I may have to request a hard copy of the plans as we both have WEBTV and reading the small details in some of the very small printed designs is extremely difficult to read. I would be willing to pay the expense for snail mail of these plans. To whom ever responds with the plans, I will email you my address so you can mail me the plans, I will mail any costs back to you from your return address, and that won't take 10 years, LOL.

J. Taylor

[Pete Schumacher ®]

> My Brother just finished his last speaker
> Project in RECORD TIME: 10 YEARS, lol. He's
> now looking for something new to build for
> the next 10 years, LOL. I really like this 4
> driver with the tweeter tower design. Could
> someone please provide me with the plans so
> he can begin another tedious time consuming
> project that I will have to finish for him.
> He's great with wood working skills, but I
> have to do all the XO and wiring work.

> BTW, his last project was Dick Olshers Polly
> Natalias. Which were about the only speaker
> plans available on the net when he first
> started. Now all the drivers in that plan
> are all discontinued, which is a real shame.
> That is one sweet sounding speaker. Audax
> made one heck of a nice midrange driver for
> that speaker. He loves the Bass extension as
> well.

> TIA, to whom ever would so kindly post the
> plans, for the speaker in the picture. I may
> have to request a hard copy of the plans as
> we both have WEBTV and reading the small
> details in some of the very small printed
> designs is extremely difficult to read. I
> would be willing to pay the expense for
> snail mail of these plans. To whom ever
> responds with the plans, I will email you my
> address so you can mail me the plans, I will
> mail any costs back to you from your return
> address, and that won't take 10 years, LOL.

> J. Taylor

I've got the XO and baffle layout drawn up for the pictured system in my photobucket page, but I can't access that right now.

Shoot me an email and I'll check it when I get home.

[jtaylor]

> I've got the XO and baffle layout drawn up
> for the pictured system in my photobucket
> page, but I can't access that right now.

> Shoot me an email and I'll check it when I
> get home.

Thank you for being so kind, I hope he can build these under 2 years. BTW, I'm going on 2+ years on a project Curt C drew up for me, at least I have a disability that I can use for my slow excuse. I hope to finish Curts project by no later than January 2008, for the first four speakers out of six for my 7.1 HT system.

J. Taylor