Best way to DIY a 2.1 system

[454Casull]

I'd like to make Zaph's newest project, but I also want some deeper bass extension. What's the best way to cross over to a mono sub?

Thanks

Howard

[peter_m]

As Zaph states it in most of his projects, the best is with an active x-over to an amplified sub. You can find some stereo amplifiers/receivers that have it built-in and ALL 5.1 HT amplifiers/receivers have it. They usually have a setting to go 2.1 instead of the standard 2.0 and 5.1

Peter

[Timn8ter]

Also, most plate amplfiers now have high level in and out connections. These will typically have a 6db active XO tied to them.
Marchand Electronics has active XO kits and Creative Sound has a bass management device they are offering with the purchase of certain woofers.
The Outlaw RR2150 is a 2.1 receiver if you're in the market for such a thing.

[454Casull]

Are there any free plans for an active stereo->mono crossover?

[454Casull]

Preferably simple, as well. I'm not too concerned about absolute sound quality.

[HiFiNutNut]

Rod Elliot's site has a LR2/LR4 component calculator. You can then use PCBExpress to draw it up.

[sreten]

Hi,

There are various "best" ways of doing it.

Build the ZBM4 less deep - around 4 litres sealed and stuffed.

1) Then use a subwoofer with your amplifier outputs.

2) Or if you can split output from the preamp - reduce the input
capacitor values of the speakers power amplifier to roll-off
low bass - pre-amp to the subwoofers low level inputs -
sub converts stereo to mono.

2+) You could modify the power amplifiers feedback loop
such that it forms a 2nd order high pass filter - L/R.
Drive from split output of the preamp.

For 2 driver rolloff is overdamped 3rd order for 2+ if you set
frequency to around 85Hz = near 4th order L/R at 85Hz.

So for 2+ ideally you need a sub plate amplifier with 4th order
L/R roll-off.

/sreten.

[audiobomber]

Originally posted by 454Casull
Preferably simple, as well. I'm not too concerned about absolute sound quality.

Build the main speakers in a sealed cabinet. Insert a pair of 100 Hz high-pass Fmod filters on the inputs of the amp driving the mains. The second preamp feed goes to a sub with an LR4 low-pass filter. The Fmod filters are very inexpensive, but they sound pretty transparent and they do the job.
http://www.partsexpress.com/webpage....nufacturer=265