SB Acoustics SB20FRPC30-8 (8" Fullrange Cheap Monster II)

[perceval]

Make sealed boxes and add EQ to reach 35Hz with your 10 or 12" drivers.

Keep the big woofers for OB. You'll need lots of cone area for OB

 

[wchang]

Haha, I was trying to demystify pass/notch filters sorry. The standard formulae required a calculator; simplified formulae for common 8ohm impedance 1st-order high-pass XO frequency ~ 20khz/uF (off by 0.5%, immaterial since typical LRC part only rated within 5%). Very high frequency above that gets "recovered" going through the capacitor; low frequency below baffle-step goes through the inductor; broad notch zone a combination of all three LRC running parallel.

Example WAW with notch filter to flatten mid-high but passing supertweeter frequency.

W

Post in thread 'Full Range Speaker Photo Gallery'

2023-11-24 5:19 am

Let me try to win Ugliest Prize (though far from my cheapest). The sound of the 6x10 DEW-alnico fullrange is kind of like eating creme brulee -- buttery rich crispy textured. When I picked up a pair early 2022 (one of my first forays into bargain vintage alnico) I was so taken by the sweet-not-sour sound I then "fished" four additional drivers. While I had some success combining OB-U (openback shallow box) with side-firing inductor-BSC, even with a third driver I couldn't reach bass much below ~70hz. Tried bi-amping with a 6x9 auto speaker but the sensitivity gap was ~11dB. Finally, last...

• wchang

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[satx]

Thanks for your explanation gents!
I haven’t ever used additional circuitry… but I guess it would be interesting to tune the sound if you know what you are doing! ( I don’t!)

Unless the driver has built in compensation in the response, like some of the Mark Audio drivers then you will definitely benefit from a circuit.

Just start with a calculator based on your baffle width. That’ll get your inductor value and then buy a handful of different resistor values and tune it by ear. You can just wire it outside of your finished speaker to the positive post. It probably won’t be completely optimized, but it’s an easy, cheap and fun way to substantially change the bass weight and brightness of your sound.

 

[JohnnyDee]

Thanks satz!


Referring to Tigeranand’s post earlier about speakers to go from 35htz to 16khtz…
This SB Acoustics driver is amazing 🤩… however I’m very doubtful that it will get to 16 khtz with any Authority…
If Convincing treble around 13=16 khtz is required, then a smaller “ Full range “ driver might be a better choice. ( As you plan to get the bass from a dedicated Bass driver).
Just my 2 cents worth…