Bi-pole 2-way idea... help!!!

[RichardJones]

Ok,

I have "found" these SEAS H522's. They have a low fs and qts and are very flat with a nice natural roll-off at 0,30, and 60 per the curves.

How feasible is it to run these drivers flat-out and just cross the tweeter with a 6db 1st order crossover? What x-over frequency should I use?

Then I was going to build a cabinet which has a width of the driver.

One driver in front and one on the rear... operating in parallel, same phase.... this cancels the baffle step problem.

Run them in a vented enclosure (0.5 cu feet), H of 1.4.

Just need a good tweeter for them..

How should I align the tweeter? Should it be positive or negative polarity?

I want to preserve phase etc..

Opinions etc...?

Thanks!!!!!

 

[planet10]

How feasible is it to run these drivers flat-out and just cross the tweeter with a 6db 1st order crossover? What x-over frequency should I use?

Looks very feasible. The T should probably be rolled in somewhere between 4 & 7k. The way i figure this is to take a handful of caps and start with one that is too small, and keep adding and listening, until it just starts to be too-much, then back it off.

One driver in front and one on the rear... operating in parallel, same phase.... this cancels the baffle step problem.

Bipolar-- go for it. Make sure your design allows for tight mechanical coupling of the mids to take advantage of push-push.

Just need a good tweeter for them..

How should I align the tweeter? Should it be positive or negative polarity?

Go looking for a low Fs tweeter, chambered-back preferred, with as small a profile on the front as possible -- there are lots of good Ts to pick from. The T should be wired in the same polarity.

dave

 

[planet10]

SEAS H522

And what are you going to do on the bottom -- these should really be considered mid-ranges, and have something below 200-250 Hz.

dave

 

[psarin]

have a look at the TL_B

slighltly off-topic if you are thinking in the box 😉 ..

but please look at the Bilpolar Transmission Line design (TL_B) posted at www.t-linespeakers.org. this should also take care of your bass issues. i recently built a pair using RS 40-1354A (pics at the link below) and am quite pleased with them!

cheers -

pradeep

-now playing 'Dark Star' on my TL_B's-
http://web.mit.edu/~sarin/www/tlb.html

 

[planet10]

Re: have a look at the TL_B

i recently built a pair using RS 40-1354A (pics at the link below) and am quite pleased with them

Those look really nice (i've seen them before but i can't remember if i mentioned it). Did you do any tweaks to the 1354s?

My 1354s should be arriving soon. I'm going to do a bipolar ML-TQWT with them-- probably the middle one.

dave

 

[RichardJones]

hmmm perhaps the PH13 thingy

Well instead of the H522's... how about the Vifa PH13 woofer?

It looks very good and has a nice gentle roll-off up top.

I might get down to 60Hz with these with a larger enclosure tuned a little lower.

Then it is essentially the same as that TLB project.

Does anyone have the inside dimensions for that?

Thanks!!!

Richard

 

[planet10]

Re: hmmm perhaps the PH13 thingy

Well instead of the H522's... how about the Vifa PH13 woofer?

The P13 is excellent in this role.

dave

 

[Electro]

Manufactures that designs bipolar loudspeakers makes one woofer produce the lower end. The other woofer does the high end. Though, they are using the same model woofers. For example, one manufacture crossover the rear woofer with a low-pass filter set ~500 Hz. The front woofer uses a highpass filter from ~500 Hz.

You may want to try this if you have a few inductors and capacitors in the junk box.

The rear speaker drivers needs some diffusing material on the wall to help dispersed the sound into the room better.

Check out http://www.decware.com/speakers.htm if you want more surround sound effect.

 

[planet10]

Manufacturers that designs bipolar loudspeakers makes one woofer produce the lower end. The other woofer does the high end. Though, they are using the same model woofers. For example, one manufacture crossover the rear woofer with a low-pass filter set ~500 Hz. The front woofer uses a highpass filter from ~500 Hz.

Usually the front woofer is run all the way down for a bi-polar 2.5 way.

dave

 

[Electro]

Usually the front woofer is run all the way down for a bi-polar 2.5 way.

Please be more specific.

There is not such thing as 2.5 way. You can not have a half a speaker driver.

 

[AudioFreak]

Actually Electro there is such a thing as 2.5 way it involves using a single tweeter and 2 identical woofers. The tweeter and one of the woofers are run as per a normal 2 way and the 2nd woofer is crossed in at the baffle step.