Crossover Question

[OffGridKindaGuy]

Will a crossover network (2-Way) work the same at line level as it does at speaker level?

I plan to do a Bi-Amp project with 2 low power amps but I want the amps to work in different audio frequency "Sections", per se. (Low/High) Full fidelity line level through a crossover, from the crossover to 2 separate amps. Use trimmers to level things out.

Would I need to put a load on the crossover(s) to duplicate the speakers normal load?

 

[richie00boy]

No you can't do that, it would need an 8 ohm load on each output - which would then kill your source.

The simplest (but fairly poor) option is to use a passive line level crossover. But you can make an active crossover pretty easily and cheaply.

 

[OffGridKindaGuy]

What I'm trying to achieve..

I have 2 small stereo amps. (~3 watts/channel) I have 2 small speaker enclosures (2 way) that are full range. (80-20k) 3 watts each will drive them good enough for what I'm doing. The speakers..

Philips 314113000201 R TMM 2-Way LCD TV Speaker Module

I want to add some bottom end to them. I figure one amp for the full range and another amp for some bass. I'm limited for space so I figure an OB sub. The sub driver..

MCM Audio Select 8'' Dual Voice Coil Woofer | 55-1455 (551455) | MCM Audio Select

Should I just run both amps full range on the input and build a passive crossover for the sub instead of trying to filter the input to the amp that drives the sub?

Thanks in Advance!

 

[richie00boy]

An OB sub won't work without adding boost, due to the cancellation.

I'm not a fan of passive sub crossovers.

 

[chris661]

That driver will not work on OB. I've got one. The coil meets the backplate before you get anything useful.

Go sealed, or even ported.

Chris

 

[picowallspeaker]

And, moreover, OB/dipole solution suggests large spaces for the reason that...
1st you don't want first reflections from the walls/furniture being merged soon to direct sound
2nd the backwave is 100% error considering that front emission has PHASE and the rear is 180° rotated

 

[OffGridKindaGuy]

I need to post a pic of the structure that I'm working with. It's a wife thing.. "Hay Hunny, can ya make a speaker outta this?" Appeasement is Powerful.. 😉

It's a multi level corner shelf. (Largest shelf on the bottom and the shelves get progressively smaller towards the top) It's made to sit tight into a corner. The bottom shelf is what I wanted to use for the sub area..

I don't believe 6 watts max is going to make it hit the back plate.. LOL.. Maybe a sealed triangle shape box with a bunch of stuffing? ~.15-.2 sq. ft.?

 

[Cal Weldon]

It's a multi level corner shelf. (Largest shelf on the bottom and the shelves get progressively smaller towards the top) It's made to sit tight into a corner. The bottom shelf is what I wanted to use for the sub area.

V-e-r-y clever. 🙂

Just make sure her trinkets don't vibrate off or move around.

 

[OffGridKindaGuy]

So.. How about 2-3 mH. between the one amp and the woofer with the woofer in an enclosure? I could possibly use a stereo pot before the other amp that feeds the upper speakers to level things out somewhat. Sound like a plan?

 

[chris661]

I need to post a pic of the structure that I'm working with. It's a wife thing.. "Hay Hunny, can ya make a speaker outta this?" Appeasement is Powerful.. 😉

It's a multi level corner shelf. (Largest shelf on the bottom and the shelves get progressively smaller towards the top) It's made to sit tight into a corner. The bottom shelf is what I wanted to use for the sub area..

I don't believe 6 watts max is going to make it hit the back plate.. LOL.. Maybe a sealed triangle shape box with a bunch of stuffing? ~.15-.2 sq. ft.?

You won't get much from that driver OB, so yep, sealed with a lot of stuffing is an option.
I'd recommend you try OB, but be prepared to change it - its good to hear these things yourself.

Chris

PS - try OB, but with a pile of stuffing behind the driver.