Crossover layout for portable speaker

[Innovant]

First, let me say i'm new around here, so hello everyone

I'm making a portable speaker and have learned a lot on this forum, so thanks a lot guys! For now i can't seem to find the right answer, so here's my question

I'm using a sure electronics 2 x 15watt TA2024 amp, and like to connect it via passive crossover to 2 tweeters, 2 mid, and 1 or 2 subs (all 4ohm) in stereo of course. The problem is that i can only use one cabinet for the sub, also i only have room for one amp..

So is it possible to connect the L and R from the crossover on to one sub, or is it better to use two sub speakers in one cabinet (because of the stereo mixing up). Or maybe you guys know a better solution?

Any help would be greatly appreciated.

Sven

 

[cT equals piD]

You can use a dual voice coil (DVC) sub-woofer. If you have limited space, the DVC woofer is better than two separate sub-woofers, as the cone area is cut in half, assuming one size of sub-woofer.

-Pete

 

[picowallspeaker]

properly, a sub is not a woofer. It's supposed to deliver what a regular woofer or setup
cannot .

 

[cT equals piD]

I've always understood "sub" as being a short expression for sub-woofer. Also IMHO sub-woofer means a driver intended to reproduce at frequencies below those normally handled by a woofer.

Sub = below

But I'm certainly not going to get upset if anyone dares to disagree with what I understand.

How DARE you disagree with me, Mr. picowallspeaker! Just kidding, of course.

-Pete

 

[picowallspeaker]

Yeah, it's been discussed somewhere

Also on an italian forum, a guy ( named Vulcanbrain BTW )
was in the same situation like the OP, as he wanted to do a 'totem' speaker.
Eventually he made it after two months, doing an exceptionally refinished with
veneer single tall box with two woofers on the low side and mid and tweeter slightly inclined on the top, a cheap kit for car. He put wheels under and finds
it very performing with the Ipod attached !

 

[Innovant]

Guys for the responses,

Now let's get really freaky..
I happen to have this baby lying around! http://www.hi-wave.com/img/HIBM110H10-8_2.jpg

How about ripping out the PCB so i can wire the coil separately (one left, one right). Because a DVC is would also run left and right though one conus, right?.. Would this work? My plan is to run the sub/mid crossover at 800Hz

PS the amp can't be bridged

 

[picowallspeaker]

No please don't...!
I have also similar speakers gutted from a Sony Tv ( the internal subwoofers , I've already used them as normal woofers in little two-way) and they might be good for midrange, if any good might come from them... ( horizontal...or vertical ?? )
The fact is that you cannot simply force the electrical ( coils ) and the mechanical ( cone, surround, voice coil former) part of a DVC to reproduce different signals such those from dual channel ( stereo)path.
It's been done in the past ( not nowadays) in car audio only for space limitation but if you think....What happens if one channel has some signal ( power applied to speaker's coil) and the other none ? The (unused) coil would generate some electromagnetic force itself, so it's not a trasducer but...a producer !

My plan is to run the sub/mid crossover at 800Hz

No way ! Again, just a little study on how sound propagates and what are the frequencies involved . Then apply it to speakers and what common sense and frequently used techniques suggest...

 

[cT equals piD]

No please don't...!
The fact is that you cannot simply force the electrical ( coils ) and the mechanical ( cone, surround, voice coil former) part of a DVC to reproduce different signals such those from dual channel ( stereo)path.
It's been done in the past ( not nowadays) in car audio only for space limitation but if you think....What happens if one channel has some signal ( power applied to speaker's coil) and the other none ? The (unused) coil would generate some electromagnetic force itself, so it's not a trasducer but...a producer !

Sorry, picowallspeaker, but IMO the above two parts of your post are completely wrong. Summing with a DVC woofer is exactly the same as summation with active electronics. It makes no difference that the two signals will sometimes add, and under different conditions subtract. Nor is there any mechanical opposition, as the two voice coils generate a net field that acts against the magnetic field.

Voice coils are continuously producers of an opposing force (back EMF). That isn't a problem as the speaker functions much better as a motor than as a generator.

-Pete

 

[dumptruck]

While pico is wrong, pico is also right when it comes to the driver in question - look at the picture! (it's not DVC, it's a flat panel driven by dual motors)

 

[cT equals piD]

What is the circuitry of the flat panel driver? That's the question that I would ask before throwing it out. As dumptruck says, it could be that it wouldn't work properly applying left/ right channel signals separately to the dual motors.

 

[Innovant]

I just checked out the speaker, and they are two 4ohm 5w coils, put in series to create 8ohm 10w. I think i will just run some tests and see were it goes, they aren't that expensive luckaly.

But if it doesn't work out, does someone know a small 2.1 amp (preferably the same size as the sure electronics TA2024)? I once took apart a 2.1 computer sound system, to see how they get a left and right signal into one bass signal, and it suprised me how small the circuit was. If i'm correct it had a 20w subwoofer, and 5w speakers..

 

[picowallspeaker]

They can make prodigies, if not miracles
(assumed that you don't force them to operate at where the point of
distortion start to rise, which is about at 1 W )