Passive Crossover For my First WAW

[ujju3doc]

Just wanted to know from experienced guys which one will work better. Cost factor will be considered last.

PLLXO will not cover efficiently for baffle step loss and diffraction and I think passive crossover will do that better.

 

[AllenB]

I have done PLL with complex shaping. I'd have no problem suggesting you could use any of the mentioned methods to achieve a given result. Of course a DIYer tends to be blind to the amount of effort needed sometimes.. the methods needed for each are quite different.

 

[ujju3doc]

How do I take care of the baffle step loss in a PLL XO? If I go in PLL route one suggestion I got in the past just to increase the amp volume pot for woofer. Later I thought that a hump is created due to baffle loss in the woofer response which will be difficult to take care of by merely increasing the volume pot for woofer.

 

[AllenB]

Off the top of my head I'm thinking two capacitors and two resistors, two parallel in series, and two series in parallel.

I would recommend you use a circuit simulator to work out the values - Installing and using LTspice IV (now including LTXVII). From beginner to advanced. - diyAudio

 

[planet10]

PLLXO will not cover efficiently for baffle step loss and diffraction and I think passive crossover will do that better.

Baffle step is the only diffraction problem that can be tweaked in the XO.

Why won’t a PPLLXO do BSC? You just have to carefully place the XO point such that the gain control on thr bass amp becomes a varuabke BSC dial.

I have executed a nmber of designs where this works well.

dave

 

[planet10]

Off the top of my head I'm thinking two capacitors and two resistors, two parallel in series, and two series in parallel.

A simple PLLXO has 1 R and 2 Cs per channel, small ones. As suggested above BSC just has to take care with design. If the bass amp (it is usually the one needs turning down) does not have a gain control one will somehow have to be added (i added a 100kΩ pot to the iput of my bass amp).

dave

 

[planet10]

Low Pass:

High Pass (the R₂ is the R_input):

General guidlines: XO point somewhere between root(2)/2 and 1 times BS(-3), approx 4560/(baffle width in inches). Driver centre-to-centre is less than a quarter wavelength. I have found that XOs in the lower part of the ranege works best in the examples we have built.

dave

 

[chrisb]

Dave, images don’t open for me (iPad running Chrome browser), anyone else find that?

 

[planet10]

Work now? They are just picked of fthis page: TLS.org | Passive Line-Level Crossover

dave

 

[AllenB]

PLL BSC Circuit

How do I take care of the baffle step loss in a PLL XO?

 

[ujju3doc]

Useful information. I have to carefully learn and understand them. Thank you both.