Advice for 4-way passive loudspeaker

[milix]

Hello.
I am starting a new project for a 4-way loudspeaker. In the past I had build 5-6 speakers but crossovers was premade. This time I want to build the crossovers my self.
The speaker is intended for home use, in my living room.
Bellow I list the crossover points I choosen besides the driver characteristics (except for the midrange driver which has been ripped of an existing bookself speaker):

80 Hz Lowpass Subwoofer 8” 4 ohm, 350 Watt max, Fs 58.8 Hz, SPL 86.6, FR 20-5900 Hz
80-600 Hz Narrow Bandpass Woofer 6.5” 8 ohm, 60 W RMS, SPL 88, Fs 52 Hz, FR 52-~3500 Hz (from diagram)
600-4100 Hz Narrow Bandpass Midrange 4” 8 ohm, no other info
4100- Hz Highpass Tweeter 6 ohm, 15 W RMS, Fs 2005 Hz, SPL 90, FR 3500-25000 Hz, ¾” voice coil Ferrofluid

I wish for the following arrangement of the drivers (top to bottom)
Woofer -> Tweeter -> Midrange -> Subwoofer.
everyone in its own baffle but baffles will be connected.

My initial design of the crossover is the following 4 way with a 1st order lowpass for the subwoofer, two 1st order narrow bandpass for woofer and midrange and a third order highpass with LPad of 3.3 dB for the tweeter.



Will this design work?
Any advice in anything from above will be very helpfull for me.
Thank you

[Salas]

No, this will not properly work for quality unfortunately. It may cross but it will be all over the place. Proper work takes response measurements and Impedance measurements on actual boxes, and further processing of the data against some suitable set of target functions. And then proof testing, and then subjective evaluation, maybe changes of target parameters etc. There are numerous threads, read around a lot.

[PeteMcK]

it will work, but from the info you've given we can't answer the q. 'will it work well?' -
I suspect not - the Fs of the sub at 59Hz is too high, and you have no info on the most critical driver - the mid. Do you have a brand and model no. for the mid units?
What drivers have you chosen for the other units and why?

[planet10]

With the XO pint sub to woofer, you would be way ahead going active there... A PLLXO is simple and won't be affected by the roller coaster impedance in that frequency range.

dave

[milix]

Thank you for your quick answers

Tweeter - DAYTON ND20FA-6
Woofer - Peerless 830657
Subwoofer - BUMPER 848IP

I choose them because I want to make cost-effective loudspeakers that sound 'nice' for my living room in moderate levels at most. And they had some good reviews.

Should I do something for the high Fs of the subwoofer? This practically means that around 59 Hz the woofer will play very low?
In my ears I don't like when low frequency human voice comes from the woofer of a 3-way system, this is why I imagined this project this way, with the small woofer placed at the top.

[PeteMcK]

'Should I do something for the high Fs of the subwoofer?' - choose a subwoofer with an Fs in the low 30s

[milix]

Originally Posted by PeteMcK

'Should I do something for the high Fs of the subwoofer?' - choose a subwoofer with an Fs in the low 30s

Unfortunatelly for me, I already bought the drivers one month ago.

@ Planet10
Where exactly should I put the PLLXO? It will replace the inductor L0? I googled for PLLXO and read aboutit but I didn't understand where is its placement in a passive crossover.

[Salas]

PLLXO = passive line level crossover.

[planet10]

Originally Posted by milix

Where exactly should I put the PLLXO? It will replace the inductor L0? I googled for PLLXO and read aboutit but I didn't understand where is its placement in a passive crossover.

Your intended XO is low enuff that you should be bi-amping. the active XO (oe PLLXO) goes between the pre-amp & the power-amps... or if you get a plate amp it more or less deals with it.

dave

[PeteMcK]

'I already bought the drivers' -
if you have the full specs for the sub, perhaps you could model an EBS alignments and see if that would work