Two channels for different frequencies in one subwoofer

[hjo]

Hello,

I've found good information for my speaker setup on this forum, but I I've a question I can't find an answer to.

I've an 4 channel (car) amplifier which I can bridge to 2. So I would be able to drive 2 subwoofers.

I wonder if it would be possible to let these 2 bridged channels drive different frequencies on 1 subwoofer, so I can put more gain on the lower frequencies. Adjusting the settings for lpf, hpf and gain must be doable.

But is it possible one way or the other to put the channels together without damaging the system? Or compromise the sound?

Regards, Hajo

 

[Seriosha]

I am not sure i am getting this right. You want to use a Single Sub, and then put 2 Channels on that one, while providing Low Frequencies with more Power on one of those Channels, and the rest on the other one!?

So you just want one Sub in total in that configuration? (Just for clarification)

 

[hjo]

Seriosha,


That is correct.



I need a sub which has a reasonable high range. From as low as possible to approximately 200hz. So I think it would be nice to be able to get more power in the lower frequencies.

 

[Brian Steele]

Technically it's possible, particularly if your subwoofers are dual voice coil subwoofers.

 

[SpeakerBob]

The question is more about what crossover options you have on the head unit and amplifier.

Basically think of the bridged channels as single mono amps and work out if you have the options to filter each sub as you wish.

Personally in a car I'd run the 2 subs together and just EQ. (unless the 2 subs you want to run are very different to each other ?)

Rob.

 

[Jazz Man]

Technically it's possible, particularly if your subwoofers are dual voice coil subwoofers.

Please explain how it's possible with one single coiled subwoofer.

 

[conanski]

It's not advised to connect more than one amplifier to a single voice coil, doing so effectively shorts the two amplifiers to one another which is a good way to let out the magic smoke. And... it's not necessary, as long as a single amp or a bridged pair is powerful enough for the application the only thing needed to add more power to a specific range of frequencies is EQ.

 

[SpeakerBob]

The question is more about what crossover options you have on the head unit and amplifier.

Basically think of the bridged channels as single mono amps and work out if you have the options to filter each sub as you wish.

Personally in a car I'd run the 2 subs together and just EQ. (unless the 2 subs you want to run are very different to each other ?)

Rob.

Just realised you only want to use 1 subwoofer. My mistake, sorry!😱

 

[rayma]

I wonder if it would be possible to let these 2 bridged channels drive different frequencies on 1 subwoofer,
so I can put more gain on the lower frequencies. Adjusting the settings for lpf, hpf and gain must be doable.

Just use an active filter, designed to do what you need, at the input of one bridged amplifier.
There's no need for two amplifiers unless you want two subs.

 

[Disco-Pete]

But is that even possible? I've done it by mistake and blew up a Bedini 100/100.

 

[rayma]

You cannot connect two power amplifier outputs in parallel.

Perhaps with high power 4 ohm series summing resistors in each channel,
but why would you want to do that?

 

[hjo]

Thank you all for your advice.
I will leave it with one channel than.

I rather have a little bit less bass than no bass..

Please explain how it's possible with one single coiled subwoofer.

Jazz Man, the remark is not directed to me, but I think you know quite a lot about my system.
I have two small open baffle speakers and a ripole subwoofer. Yes, according to your post. Mainly for classical (organ) music. And no interest in home theater.

The OB speakers drop off below 200hz. The plate amplifier I took from a sealed subwoofer has a LPF of 150hz. So I get a dip around 150hz.

A second point is a peak at around 40hz if the front opening is pointed towards me. Turning it sideways it just goes down steadily. Ripole problem or bass boost in amplifier? I thought I give it a try with another amplifier which has a higher LPF. And no bass boost. A car amplifier pops up than in my budget. The 12v won't be a problem.
Connecting the two channels separately to the two drivers will ruin the ripole effect I gather? Will it hurt the drivers if I try?


Regards, Hajo

 

[Johno]

Hajo,

I too have open baffle and yes they drop off annoyingly. So I built a pair of THAM6 (tapped and folded horn with any cheap 6 inch driver) to fill the gap down low. I run the open baffle and the tapped horn in parallel from one amp but with a substantial inductor (20mH) in series with the horn.
There are threads on DIYA for the box plans. They are very compact and discrete compared to the OB.

Now I can shake the windows on the house next door when playing the Bach Toccata (grin).

 

[hjo]

Johno,



Thank you for your reply. I've looked to the tham6. The results between 100 and 200 Hz don't seem to fit the bill, but still, I can look further into horns in the future. For now I try it with the ripole sub.


Regards, Hajo

 

[Jazz Man]

Connecting the two channels separately to the two drivers will ruin the ripole effect I gather? Will it hurt the drivers if I try?

It's worth a try, you won't do any damage.

 

[hjo]

I'll do in the coming period. If it doesn't work I might try to put a baffle in the centre, between the drivers. Basically creating two single driver ripoles.