Full range + Subwoofer setup. Criticism needed

[kyle321]

Originally Posted by perceval

Your mind seems to go all over the place, and not focused.
I suggest you step back a bit, take a breather, and look at the concept again. Play with the parts, draw on paper, or computer, and follow your train of thoughts.

Once it is planned, clear and settled in your mind, it will be a lot easier.

I agree.. I'm just trying to figure out what would be the best speaker arrangement I can do for the size of the unit i'm dealing with. -And 4 speakers are the maximum. ...At first, I made a box with (2) 3-1/2" full range drivers and (2) 1" dome tweeters. I can get a decent sound out of it, but i'd like to re-do the unit to sound a little fuller on the bottom.

[kyle321]

Originally Posted by HumbleDeer

Put your crossover frequency up a bit higher, like 180Hz maybe. Your 'full range' drivers will take less bass, which will improve the quality.

When you say, "Your 'full range' drivers will take less bass", do you mean that they will actually play less bass?

If I have the system wired in a way that splits the audio signal two ways:
1- Amp pushing two FR drivers
2- Mono-amp pushing sub

Then, if the low-pass crossover is placed before the sub, it will still affect the sounds coming out of the FR drivers that were split to another amp?


I thought that for the FR drivers to be affected, they would also need to be connected to a crossover, maybe a 2-type...

[perceval]

He meant that the crossover for BOTH the full range and the sub should be a little higher. That means the sub plays up to 180Hz then starts to fade, and the FR play down to 180Hz, then start to fade.

Not asking a smaller driver to play those lower frequencies usually frees it up and makes it sound cleaner in the higher frequencies.

Look at this graph, just move the XO at 180Hz, and picture that the woofer is the sub, and the tweeter the FR.

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The components for the sub are not the same as the ones for the FR, if you are doing it passive.

An easy way to deal with XOs is to make them active, so no added components, using a miniDSP module. Using that module, you can move around the XO with just a few clicks of the mouse. Quite convenient.

https://www.minidsp.com/products/min...ox/minidsp-2x4

[GM]

Hmm, different strokes........after looking at the responses and the bulbous surround on the 4", I'd try 500-600 Hz/1st order to start with and maybe work down from there.

GM

[twocents]

Originally Posted by kyle321

o Crossover: Low-pass 100Hz 8 ohm

I am trying to learn here. Ignoring the use of active xo's - would a High-pass filter not be better in this case? To relieve the FR from bass duty?

[scottjoplin]

^ Yes, you are right, a crossover is two or more filters, in this case a high pass and a low pass that combine to "crossover" the frequencies to the drivers

[GM]

.....with the understanding that the low pass can be just the driver's HF acoustic rolloff.

GM

[chrisb]

Even though the FR driver will have falling LF acoustic output below its natural corner, or depending on the enclosure, a higher frequency, I doubt it ever hurts to high pass filter it to avoid overtaxing the drive train .

[twocents]

Originally Posted by scottjoplin

^ Yes, you are right, a crossover is two or more filters, in this case a high pass and a low pass that combine to "crossover" the frequencies to the drivers

Makes so much more sense now. I think I understand now why an active xo or miniDSP is so much easier and flexible.

And the resistor summing network in Post 3 was also very informative and useful. I learn more every day. Thank you.

[midrange]

An alternative to using a summing network would be to use one of the twin coil Monacor drivers (eg 135 TC) Each channel connects to it's own coil on the same driver. Not necessarily better, but an option.