My first subwoofer

[Buzzy]

Hi ! I would like to build a sealed subwoofer based on the 12" Peerless 830847 in a 80 litre box. I have trouble finding subwoofer plate amps here. Therefore i would like to power the sub using other means. Can i use gainclone amp or hypex ucd amps to power the sub since these are available where i live ? I am also not sure how much power this subwoofer would require. Any advise would be very helpful.

[richie00boy]

A gainclone will not be suitable IMO.

[Buzzy]

That means i need to use hypex ucd amps ? Should i use 180w or 400w amp ?

[bjorno]

That means i need to use hypex ucd amps ? Should i use 180w or 400w amp ?

Hi,

Your sub needs only an amplifier that is stable with a load of 2 Ohm; maybe 2 paralleled 3886 would be adequate. See Picture.

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[Buzzy]

Is there any unit of measure or something that can tell me how the bass of the designed subwoofer will sound like ( tight or loose )

[bjorno]

Buzzy,

Is there any unit of measure or something that can tell me how the bass of the designed subwoofer will sound like ( tight or loose )

First I think your choice of 80 L is very good for this driver and I would use this volume too if somebody asked me to design a closed box.

I don’t think you can bargain for a better-designed woofer (the volume chosen) with this driver, as it’s in my opinion quite optimal if you are primarily concerned with possible sound quality.

Of course there are always tradeoffs once the Qtc is chosen as you find the Qtc often is chosen within the span of 0.5 and 0.7.

By choosing and with a value of Qtc= 0.6, you’ve landed between an optimal critical damped or transient perfect (0.5 is loose and often considered too over damped) and possible tightest sounding alignment (too warm if over 0.7 and between 1) i.e. very near at a Bessel response (= 1/sqrt (3) or about 0.577) which is the alignment with has the lowest and flattest group delay.

Good reading of this subject:

http://www.geocities.com/kreskovs/Box-Q.html


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[Buzzy]

Thankz bjorno, that article was very informative. I seem to have a problem with exceeding cone excursion if i input more than 10 W of power. Did i make a mistake ? I used winisd alpha 0.50a7 to simulate this.

[bjorno]

Did i make a mistake ?

Hi Buzzy,

No, probably not, but I did.Sorry, I forgot to adjust all values to a 2.5 Ohm load instead of into a 8 Ohm load that all MJK: s programs are referring to.

I recalculated all and you can check if my calculations seem correct, the last two submitted pictures.

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[bjorno]

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[bjorno]

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