Author Topic: Need Advice on Subwoofers Active/Passive  (Read 29498 times)

Offline BosMossel86

Need Advice on Subwoofers Active/Passive
« on: June 24, 2019, 03:19:38 PM »
Hi All,

So I am relatively new to this whole home theaters system but I am relatively technical.

I use to have a Samsung HW-E5500 5.2 home theater system. https://www.comx-computers.co.za/HW-E5500-XA-specifications-78864.htm
I recently invested in an Onkyo TX-NR575E 7.2 amp.
I sold the Samsung amp and kept the speakers to upgrade later.

My problem comes with the Subwoofers. They are Passive, but the AMP needs Active subs.
All the Samsung speakers are 4ohm, and the amp is also 4ohm capable. I connected my subs in series with my Front left and Right speakers, so those channels are running 8 ohm.
Is there a way to be able to use these subs correctly in my system on the Pre sub connections or will I need to sell them and buy Active subs.
(Hoping not as I invested a lot in the amp and will be saving up to build the rest of the system)

I was thinking of installing a Filter as I can hear highs trough the subs, but with them being in Series with my Front channels, I don't think that would work.
I am currently running an Atmos setup 5.0.2 (Subs connected on front channels)

Regards,
Robin

 

Offline KenMasters

Re: Need Advice on Subwoofers Active/Passive
« Reply #1 on: June 25, 2019, 08:06:24 AM »
Is there a way to be able to use these subs correctly in my system on the Pre sub connections or will I need to sell them and buy Active subs. (Hoping not as I invested a lot in the amp and will be saving up to build the rest of the system)

Your best option is to buy an active sub, alternatively you could ditch the height channels and use the bi-amp feature to connect the fronts and "subs" to discreet terminals. Those passive units aren't really subs anyway, think of them rather as externally housed woofers (as opposed to a  traditional two way design in a single cabinet).
While it may not be what you were hoping for, it is a better solution. In fact, considering the receiver, you should look to upgrading the speakers at some point as well.

I was thinking of installing a Filter as I can hear highs trough the subs, but with them being in Series with my Front channels, I don't think that would work.

You don't want to do that, let your satellites take care of the frequencies they were intended to take care of and the same goes for the boxes.

Offline Shonver

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Re: Need Advice on Subwoofers Active/Passive
« Reply #2 on: June 25, 2019, 09:09:48 AM »
The alternative is to use a cheap stereo amp to drive your subs.

Having your speakers in series will only degrade the sound. However, if you like experimenting, you could try the series setup with a capacitor in parallel with the woofer (around 100uF), and you can play around with the cap value.
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Offline BosMossel86

Re: Need Advice on Subwoofers Active/Passive
« Reply #3 on: June 25, 2019, 11:44:07 AM »
The alternative is to use a cheap stereo amp to drive your subs.

Having your speakers in series will only degrade the sound. However, if you like experimenting, you could try the series setup with a capacitor in parallel with the woofer (around 100uF), and you can play around with the cap value.

I found a chart on Google for 80Hz on a 4 ohm speaker, the cap value should be between 350uF to 400uF.
Maybe I should give that a try and see what it does to the base.

Thanks man.

Offline KenMasters

Re: Need Advice on Subwoofers Active/Passive
« Reply #4 on: June 25, 2019, 01:06:43 PM »
I am currently running an Atmos setup 5.0.2 (Subs connected on front channels)

Wait, it just occurred to me that your Samsung system was a 5 channel setup. Do you meant 5 channels and 2 subwoofers, or do you mean 5 channels including subs connected to fronts, and two height channels?

I found a chart on Google for 80Hz on a 4 ohm speaker, the cap value should be between 350uF to 400uF.
Maybe I should give that a try and see what it does to the base.

Do the "subs" not have a crossover dial at the back? Also, I don't know how low those speakers go (can't find documentation), the crossover might need to be set significantly higher than 80Hz.

Offline FranZAR

Re: Need Advice on Subwoofers Active/Passive
« Reply #5 on: June 25, 2019, 01:18:32 PM »
Wait, it just occurred to me that your Samsung system was a 5 channel setup. Do you meant 5 channels and 2 subwoofers, or do you mean 5 channels including subs connected to fronts, and two height channels?

Do the "subs" not have a crossover dial at the back? Also, I don't know how low those speakers go (can't find documentation), the crossover might need to be set significantly higher than 80Hz.
From web owners' manual, seems to be 5 channels plus two subs;




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Offline KenMasters

Re: Need Advice on Subwoofers Active/Passive
« Reply #6 on: June 25, 2019, 02:07:37 PM »
From web owners' manual, seems to be 5 channels plus two subs;




Indeed, but in his initial post he said it was an Atmos 5.0.2 setup - but he must be talking about a vanilla 5.2 setup. If the "subs" have their own crossover, he should just set the Onkyo to bi-amp and run the subs and speakers off of the individual terminals.

Offline BosMossel86

Re: Need Advice on Subwoofers Active/Passive
« Reply #7 on: June 25, 2019, 02:28:22 PM »
My original setup on the Samsung was 5.2.
I am currently running a 5.0.2 Armos setup, thats how the Onkyo is calibrated. But I connected the subs in series with my front channels.
So they are working, but playing all freqencies.

Offline BosMossel86

Re: Need Advice on Subwoofers Active/Passive
« Reply #8 on: June 25, 2019, 03:03:33 PM »
Indeed, but in his initial post he said it was an Atmos 5.0.2 setup - but he must be talking about a vanilla 5.2 setup. If the "subs" have their own crossover, he should just set the Onkyo to bi-amp and run the subs and speakers off of the individual terminals.

The Onkyo is setup as a 5.0.2 setup.
I have two in ceiling speakers.
The subs are Passive and have no controls on the back, they are also connected to the front channels.
One sub for left and one for right.

Offline KenMasters

Re: Need Advice on Subwoofers Active/Passive
« Reply #9 on: June 25, 2019, 04:45:46 PM »
The Onkyo is setup as a 5.0.2 setup.
I have two in ceiling speakers.
The subs are Passive and have no controls on the back, they are also connected to the front channels.
One sub for left and one for right.

Ah, okay. What in-ceilings are you using?

Offline BosMossel86

Re: Need Advice on Subwoofers Active/Passive
« Reply #10 on: June 25, 2019, 05:20:44 PM »
I bought them of the forum, will need to check and come back to you.
But they are not a very expensive speaker...

Offline KenMasters

Re: Need Advice on Subwoofers Active/Passive
« Reply #11 on: June 25, 2019, 05:34:48 PM »
I bought them of the forum, will need to check and come back to you.
But they are not a very expensive speaker...

Well, my advice would be to forget about those woofers and buy a decent active sub once you have the money - and look at replacing the rest of the Samsung speakers later down the line