Topic: Adding a subwoofer to a stereo set up (without sub-out)

[newbieforever]

hi again!

i "inherited" a powered sub from my brother and was thinking of ways to hook it up to my existing setup. i already tried speaker level connections but it introduced a lot of unwanted noise and seemed to degrade the signal altogether. my two options are:

1.  source --> ACTIVE CROSSOVER* --> integrated amp --> speakers
                                                 --> subwoofer
* would most likely be of the pro audio variety given that crossovers for home use are practically non existent

2.  source --> integrated amp --> (preamp out + FMOD PASSIVE FILTER) subwoofer
                                          --> speakers

which among the two would most likely yield the best results? has anyone tried integrating a crossover into their system?

thanks in advance for your time!

[zram18]

what brand of powered sub do you have?

kung REL sub yan, kahit sa left and right speakers out puwede i connect thru neutric speakon connection.

[rochie]

kung meron speaker level input ang sub mo yun na lang gamitin mo.


amplifier speaker out -> sub speaker level in -> sub speaker level out -> speakers

[newbieforever]

@zram18

JBL SUB 200 (part of an HTIB set). walang input for full range. either LFE or speaker level

@ rochie

na try ko na sir. medyo na degrade yung sound nung speaker level input/output ginamit ko.

[Nelson de Leon]

@ rochie

na try ko na sir. medyo na degrade yung sound nung speaker level input/output ginamit ko.

Sir bale from your amplified line output ng amplifier, you connected it sa speaker level input ng JBL sub in parallel sa current speakers niyo? Could you define kung paano na-degrade?

[newbieforever]

Sir bale from your amplified line output ng amplifier, you connected it sa speaker level input ng JBL sub in parallel sa current speakers niyo? Could you define kung paano na-degrade?

yup! nagkaroon ng konting noise/hiss (parang static). naging more subdued din ang mids and highs versus kung walang sub.

[Nelson de Leon]

yup! nagkaroon ng konting noise/hiss (parang static). naging more subdued din ang mids and highs versus kung walang sub.

Dapat sir wala kasi very weak signal lang naman ang kinukuha ng speaker input ng sub, unless na may sira ang sub niyo that "may" introduce static or hissing sa line. Have you tried other sub sir? Taga saan kayo sir?

[uvax]

I had a JBL htib before with the same model sub. From what I recall the sub has L and R speaker level inputs and L and R outputs. You should connect the L/R output of the amp to the L/R line level input of the sub and then connect your speakers to the L/R line level output of the sub.

[qguy]

I have the same/similar  sub in  my bedroom, no noise or any distortion when adding the  sub via speaker level connection.

Try connecting the main speakers direct to the amp and run a separate speaker wire to the speaker level in of the subwoofer.

[Nelson de Leon]

I have the same/similar  sub in  my bedroom, no noise or any distortion when adding the  sub via speaker level connection.

Try connecting the main speakers direct to the amp and run a separate speaker wire to the speaker level in of the subwoofer.

Yes. Dapat nga ganyan. I see no need to use the speaker output ng sub.

[newbieforever]

Dapat sir wala kasi very weak signal lang naman ang kinukuha ng speaker input ng sub, unless na may sira ang sub niyo that "may" introduce static or hissing sa line. Have you tried other sub sir? Taga saan kayo sir?

baka nga may sira yung sub... will try cleaning the terminals and trying it out again. wala nako iba sub sir.

[newbieforever]

Yes. Dapat nga ganyan. I see no need to use the speaker output ng sub.

hmmm... connect ko ang sub and speakers sa same jack sa amp? hindi ba maapektuhan impedance (ie. parallel wiring)?

[Nelson de Leon]

hmmm... connect ko ang sub and speakers sa same jack sa amp? hindi ba maapektuhan impedance (ie. parallel wiring)?

Dapat hindi sir kasi hindi naman malaki ang kinakain ng speaker level input. Baka malakas pa kumain ang LED light na naka-parallel sa speaker level signal.

[sovrain]

Hmmmm.......mailabas nga yung kasamang sub ng lumang tv....

[Nelson de Leon]

Hmmmm.......mailabas nga yung kasamang sub ng lumang tv....

Hehe! Baka walang amp yun sir.

[sovrain]

Hehe! Baka walang amp yun sir.

oonga ano, he he...pero, ang alam ko may volume control...so, baka may amp....

[Nelson de Leon]

oonga ano, he he...pero, ang alam ko may volume control...so, baka may amp....

Kung sakaling built-in sir sa TV, may mga murang amps na ngayon. Baka yun mga Lepai, kung bridgeable, pwedeng gamitin. Xover na lang.

[sovrain]

Kung sakaling built-in sir sa TV, may mga murang amps na ngayon. Baka yun mga Lepai, kung bridg09983777539 20eable, pwedeng gamitin. Xover na lang.

nakita ko na sir, hindi sya built in, may sarili g box,  meron syang 2 pairs terminals (white and red) na suspetsa ko ay speaker input and output, tas my tatlong pot sa likod din at my volume control sa harap at may power button. Brand is sharp tapos may nakalagay na super woofer xb-30...I hope, hindi binahayan ng daga kasi may dalawang port kapag may time to butingting na, balik ako sa thread na ito para sa how to's....

[Nelson de Leon]

nakita ko na sir, hindi sya built in, may sarili g box,  meron syang 2 pairs terminals (white and red) na suspetsa ko ay speaker input and output, tas my tatlong pot sa likod din at my volume control sa harap at may power button. Brand is sharp tapos may nakalagay na super woofer xb-30...I hope, hindi binahayan ng daga kasi may dalawang port kapag may time to butingting na, balik ako sa thread na ito para sa how to's....

the usual giveaway clues sir kung powered siya is may power cord that needs to be plugged sa outlet.

[sovrain]

the usual giveaway clues sir kung powered siya is may power cord that needs to be plugged sa outlet.

yes sir, may power cord nga pala sya...I hope hindi pa sya sira. This is good for small audio set up....

[Gino]

When you said "degrade signal altogether" I was thinking that your main speakers connected to the sub's main speaker pass through terminals. If this is the case, that explains degradation.

You can try keeping the main speakers connected to the stereo amp and then connect the main speakers to the subwoofer's speaker level inputs. That way the main speakers do not pass through the subwoofer's circuit.

[newbieforever]

When you said "degrade signal altogether" I was thinking that your main speakers connected to the sub's main speaker pass through terminals. If this is the case, that explains degradation.

You can try keeping the main speakers connected to the stereo amp and then connect the main speakers to the subwoofer's speaker level inputs. That way the main speakers do not pass through the subwoofer's circuit.

yup, i initially used the sub's pass through terminals. noticeable degradation.

i'll try your suggestion too, but again, won't it affect impedance? should i even be worried about that?

[bogart.2006]

yup, i initially used the sub's pass through terminals. noticeable degradation.

i'll try your suggestion too, but again, won't it affect impedance? should i even be worried about that?

I connected an active sub to my amp in series with my bookshelf speakers (they share the same terminals).  I then adjusted the subwoofer crossover to the lowest frequency that the bookshelfs can handle, I think the idea there is so that the subwoofer will take over those frequencies.

For the impendance, CMIIW, but I think wiring the speakers in series actually increases the impendance and lowers the load on your amplifier.  If you wire full range speakers in series, this will result in lower power to the speakers.  But since you're wiring a sub which will only take over in low frequencies, I think any power loss is negligible.  I didn't notice too much with mine in case you were wondering :-)   

[newbieforever]

I connected an active sub to my amp in series with my bookshelf speakers (they share the same terminals).  I then adjusted the subwoofer crossover to the lowest frequency that the bookshelfs can handle, I think the idea there is so that the subwoofer will take over those frequencies.

For the impendance, CMIIW, but I think wiring the speakers in series actually increases the impendance and lowers the load on your amplifier.  If you wire full range speakers in series, this will result in lower power to the speakers.  But since you're wiring a sub which will only take over in low frequencies, I think any power loss is negligible.  I didn't notice too much with mine in case you were wondering :-)   

from what i gather from this and other posts, i have two options

option 1
speaker terminal (amp) ------> powered sub
                                 ------> (bookshelf) speakers

option 2
speaker terminal (amp) ------> (bookshelf) speakers --------> powered sub

i think both options would mean i would be wiring in PARALLEL (right?), which would mean i would be halving the impedance (ie. if sub is 8 ohm and speakers are 8 ohms, load for both would be 4 ohms), right? don't have the specs of my bookshelves (Anthony Audio Proac D1 clone) but i'll try to measure them later with a multimeter.

[bogart.2006]

from what i gather from this and other posts, i have two options

option 1
speaker terminal (amp) ------> powered sub
                                 ------> (bookshelf) speakers

option 2
speaker terminal (amp) ------> (bookshelf) speakers --------> powered sub

i think both options would mean i would be wiring in PARALLEL (right?), which would mean i would be halving the impedance (ie. if sub is 8 ohm and speakers are 8 ohms, load for both would be 4 ohms), right? don't have the specs of my bookshelves (Anthony Audio Proac D1 clone) but i'll try to measure them later with a multimeter.

Not an expert bro, newbie lang din ako and my knowledge is all from car audio setups

I don't think wiring the sub in parallel to your bookshelves will work, but I could be wrong :-)  In car audio setups, we would normally wire subwoofers in parallel to get a louder "bayo", but it stresses the amp unless it's 2 ohms stable (car subwoofers are normally at 4ohms)

For a home setup, I think wiring it in series would be ok as you don't stand to lose that much power

[Gino]

He has an active sub. We are not dealing with one amp and raw drivers here. The load of the sub's amp speaker level input is hardly seen by the main amp.

Option 1 is fine for single ended amps (parallel). Meaning it shares a common ground. This option will not work with t-amps. For most tube and solid state amps this will work.

[Nelson de Leon]

Sir newbieforever, your active sub is not basically considered a load kasi active siya sir, meaning amplified. From your diagram, you are considering your active sub to be a passive load.

[newbieforever]

Aaaaahhhhhh ok! hahaha! now it makes perfect sense!

my amp is solid state (NAD 304) so i guess im going with Option 1.

Thanks for all the help guys!

[newbieforever]

Sir newbieforever, your active sub is not basically considered a load kasi active siya sir, meaning amplified. From your diagram, you are considering your active sub to be a passive load.

hindi ko na gets yung nauna mong post. ngayon gets ko na! hehe. thanks sir!

[newbieforever]

quick follow up....

went ahead and connected my active sub to the speaker terminals along with my bookshelf speakers. sounded much better than using the sub's speaker level inputs (and outputs). thanks guys!