help for scanspeak crossover

[sma]

i build 2 way system use scan speak D2904/6000 tweeter and 12m/4631G00 midrange in 3 litre box volume.

untill now i use simple 12 db/oct for tweeter crossover.C =5.6 MF,L=0.22mH,R for tweeter level is 2.7 ohm

woofer is 6 db with zobel.Inductor is 0.50mH with Zobel use C=10mF and R=2.2 ohm

Maybe other diy have advice for crossover design or component value replacement?please advice.

[LaMa]

Because the 12M has a very wide frequency band, you'll have to use a bigger coil. I would think in the order of 1-1,2 mH. In combination with your zobel it acts as a "quasi second order low pass" The resistor just decreases the midband output.

The high pass on the tweeter seems to be all right, maybe increase the coil to 0,29 or 0,33mH.

It is very difficult to say something about your situation, I've worked with scanspeak before (not your driver though). Best is to measure the frequency response of the individual drivers and the impedance response of each individual driver. So you can design the cross-over in the best possible way.

On a side note: A 12M in a two-way seems a bit to lean in the bass. IMHO the 15W is a much better choice.

[sma]

Thanks,i am use focal woofer for add the low frequency...sound is already good.just want to make little modification in midrange section,i hear still not flat,at least from my ear

i will try for increase the inductor and see about response at RTA.i response now already flat,but i will try your design..

[sma]

Hi La Ma,i forgot this 12m is 4 ohm...is not to bigger use 1-1.2mH inductor?

[Jay]

Intuitively, 0.5mH is too small for a 3 litre bookshelf. But if you will use a subwoofer, 1.0-1.2mH should be too big. (And you said it was a midrange, so 1mH is really not common)

What is your expected low frequency response? What is the crossover point? Your component values are not standard values, as if it has been carefully designed/calculated.

Or may be you could lend me your 2-way for a few weeks so I can suggest a crossover change

IMO, you can use software to calculate the component values for you, but at the end it is your ears that know if they work. Only people who have worked with exactly the same driver will know what best suit the driver.

[sma]

Hi Jay,

surprise you are at jakarta too.where is your location?maybe if we have time we can meet for future discuss....i am still at experiment.0.50 is too small i know,the midrange still over.i don't have original design from scanspeak.

but i will try in this several days maybe next week i already found the result.

about calculate maybe you can advice me.

[Jay]

Hi sma,

I'm at Setiabudi. And I would love to see you experimenting with your Scan-Speak So you'll have solved the problem next week. I solved mine in months

I mostly rely on my ears. I use Microsoft Excel just to save time.

[sma]

Yes Jay..need a long time for make perfect crossover.i mean 1 week maybe i found at least "only can hear" .but for perfect sound maybe need several month.i will e-mail you for next conversation .