2 way - hard project

[djiv]

Hello again,

This is the old thread: Audax HM210Z12 project help !

I`m finish my boxes with 22 mm mdf and 44 mm on front. The Net Volume is about 70 litters. The configuration of drivers is 1x Audax HM210Z12 woofer and 1x Peerless DT105H tweeter.
I`dont like the sound in midrange and ask for help, because i want a 2-way system only.
I make few crossovers with my parts, but with no success.
Now listening with 1 order LPF - 1.2 mH and 3 order HPF - 3.3 mf, 10 mf, 0.25 mH and 3.3 Ohm resistor. The result is "No good midrange"

I try with no crossover for the low, but there is a big peak about 1.9 khz maybe is there a phase plug and vocals are nasty.

Help me with other filters and ideas, please
Thanks to all

[inertial]

Hi,
Can you replace the tweeter?
IMHO a seas 27 TFDC with a 4th order at 1500Hz can be decent.
More radical again, a AURA 2" ( a la Linkwitz-pluto) 4th a 1000Hz.

Cheers,
Inertial

[lndm]

You need to ensure your LP is compensating for baffle step diffraction. This step used to give me a hard time until I got used to it.

Even before that though, you may need to flatten your mid/woofer's impedance so your inductor can do its job (using an RC, like a zobel). My guess is that this will do well.

[sreten]

Hi,

~ 2.2mH for a nominal 8 ohm bass unit and ~ 4.3uF for a nominal 8
ohm treble unit first order parallel crossover is a good place to start.
(this is without any Zobel on the bass unit, Re = ~ 6R, Le = ~ 0.5mH)

Seems to me your bass unit inductor is too low a value.

Also wouldn't use 3rd order, attenuation resistor and cap in series,
inductor in parallel with the tweeter 2nd order should work well,
and be easier to experiment with.

/sreten.

[djiv]

Ok, but with 2 mH inductor i don`t have a midrange.
What you think for Notch filter for the peak about 1,9 khz and 1,2 mH 1 order for the audax

[inertial]

djiv,

woofer (2nd damped)
2,2mH series and (18microF+3,3 ohm) shunt

tweeter peerless ( 3th + "L" resistive)

8,2mF ; 0,39mH shunt ; 18mF + 3,3 ohm series; 4,7 ohm shunt

(about 1850Hz acoustic near/4th order - 84 dB - anechoic)

P.S.: moderate volume, the peerless can explode!

regards,
Inertial

[Notax]

Volume of the box must be smaller. About 42 litter. Tuning frequency Fb=41-43 Hz. Compensation at bass 8.2 Ohm and 22 uF. Use that inductor 1,2 mH in series for 6 dB. Try with, and without compensation. Tweeter: 6.8 uF, 22 uF and 0.39 mH for 18 dB, and series 2.2 Ohm (try 2.7) paralel 15 Ohm (-3, -4 dB).
Of course, try tweeter in fase and in contra fase.

[djiv]

Start making filters about volume of the box, i calculate it with BassBox Pro for extended bass.

thanks to all !

[Notax]

Originally posted by djiv
i calculate it with BassBox Pro for extended bass.

Look here.


calculations of bass-reflex enclosures

[djiv]

Thanks for help to all.

i`m not sure that 2-way is good project with 8 inch woofer.
Thanks to Notax. I made the filters, and listen now, but without bass compensation (22mf+8.2ohm). The final configuration is 1.25 mH - 1 order :; 6.6 mF (2x3.3), 0.40 mH and 20 mF (2x10) - 3 order. Again i`m hearing a big peak, betwen 2 - 3 khz, but i`m not sure.

I think ....... 3 way system.
Help me to searching for a good midbass woofer 5, 5,25 inch with good frequency responce. Maybe from 300-400 hz to 4000 - 5000 hz. or other ideas for good crossover