Linkwitz LX521.4 - new build and impressions

[Joecarrow]

Looking at this thoughtful breakdown:

How parallel and series wirings affect T/S parameters

I was researching how wiring multiple drivers in series or parallel affect TS parameters. I decided to capture everything in a table and decided to share here in case this is useful to others. Explanations can be found following the table. I will also include tables for the 4-driver...

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Inductance would be one; I’m not sure if there’s any noteworthy phase shift or not in the passband from the extra inductance. Other than that, you’d need to increase gain for the woofer channel. If you can measure and verify you can probably make it work, but the official advice has always been not to do it.

 

[Joecarrow]

Actually, I thought of another reason- this may or may not matter to you. Adding +6db to the woofer is problematic due to the existing EQ boost since you could run into clipping unless you drop everything else by 6db. That probably had something to do with why he didn’t include it as an option back in the ASP days since it would mean worse analog performance for everything else.

 

[al2002]

Yes, that’s something to keep in mind

The Hafler DH 500 has a gain of about 25 dB. So about 2 1/2 V rms input for full output. So I assume the other channels would need to be half that for full output.

 

[Joecarrow]

It certainly doesn’t hurt to try! I used to have one of those, and it’s quite a beast of an amp.

I’d be more worried about digital clipping; if I recall correctly the boost is about +15db at 20hz, and there’s a gain reduction built into the DSP settings that you’d be basically undoing. I was getting some digital clipping at one point on an input once and the sound is pretty alarming. I don’t expect a trials to physically hurt anything though.

 

[al2002]

Alternatively, a dual op amp with a gain of six db inserted between the DSP and the hafler.

 

[Davey2156]

Yes, that’s what I think too, 6 dB gain change, but would like to know if anyone has actually done this.

Yes, just a +6db gain change required. No change to the EQ.
And, as mentioned, your ASP or DSP needs to be able to accommodate this voltage increase without internal clipping. (Your power amp as well.)