How to connect a Sub Woofer, If an amp doesnt have Sub Woofer out?

[hydrovac]

@ teddy07x,

What are you currently using in this situation? Also, what is the listening environment like?
Just a guess, but I would imagine that a near field speaker configuration might provide some options to help address this problem.

All speakers adhere to the same laws of acoustics. One could incorporate a mid range dip in a speaker to make it sound better at low levels, but then it would sound too shy in the mids at higher levels.

IMHO if you are concerned about good low volume performance, pay much more attention to your choice of Amp rather than fixate on Speakers.
Any high quality Speaker will sound good at low volume but that entirely depends on the quality of electronics and signal it is receiving.
A more capable and robust amp will sound more dynamic at lower volumes, without sounding lean. No need for 'loudness compensation', either.

Before you go shelling out big bucks on new speakers for better low level listening, maybe consider a change in electronics. It's well known, our ears don't respond well to bass frequencies and maybe some treble at lower listening levels, and some equipment has switchable loudness boosting circuits. Maybe not something you're wanting to use all the time, but might occasionally fill the bill.

You might need to pass the signal thru a graphic equalizer.

 

[ketansethi1987]

Sorry if I am repeating anything!

IMO if the subwoofer has high level inputs, it should be connected in parallel with the speakers. Driving the speakers from high level out would degrade the quality as it will be the sub's amp that will power the speakers and not the expensive amp you purchased specifically to drive your speakers.

In case the subwoofer does not have high level inputs, it can still be connected in parallel with the speakers by using a "high to low impedance converter". I just got it yesterday to experiment the same thing and it gave amazing results. I now have a 2.2 setup. To prevent the low frequencies from going into the man speakers just turn down the bass a little bit and increase the volume of the subwoofer according to your preference. This takes off the low frequency load from the speakers and the main amp and lets the subwoofer amp handle it.

The device costs Rs. 100 and you will be able to get it from any car accessories shop. For those who believe this is a cheap thing and will degrade quality of sound, there are expensive models available as well which cost around Rs. 2600

Here is a link of what I got:

Car High to Low Impedance Converter Adapter Speaker Output to RCA Line Control | eBay

It also has level control and I have set it at 50%

Please do not say that it might damage the system as this a very common problem in new cars with factory fitted systems which do not have RCA out and this thing is being used the same way from years and I do not think it has damaged any car stereo or amplifier.

 

[greenhorn]

Driving the speakers from high level out would degrade the quality as it will be the sub's amp that will power the speakers and not the expensive amp you purchased specifically to drive your speakers.

No
Usually there is a passive crossover inside the sub which splits the signal, much like the crossover inside a speaker. It is the amplifier signal that drives the loudspeaker. The question of the quality of the crossover components inside the sub might arise, but nobody is going to put in a separate amp for the high level speaker output inside a sub, unless the sub is part of an active 5.1/2.1 system

 

[ketansethi1987]

No
Usually there is a passive crossover inside the sub which splits the signal, much like the crossover inside a speaker. It is the amplifier signal that drives the loudspeaker. The question of the quality of the crossover components inside the sub might arise, but nobody is going to put in a separate amp for the high level speaker output inside a sub, unless the sub is part of an active 5.1/2.1 system

Someone please try and connect your sub directly to the input and check whether attaching main speakers to the sub's line level out powers the speakers

 

[jagdish_p]

No
Usually there is a passive crossover inside the sub which splits the signal, much like the crossover inside a speaker. It is the amplifier signal that drives the loudspeaker. The question of the quality of the crossover components inside the sub might arise, but nobody is going to put in a separate amp for the high level speaker output inside a sub, unless the sub is part of an active 5.1/2.1 system

Good Info. I dint know this. Thanks. So for people like me who have a stereo Amp with out any separate sub out and wanting to add a sub in a stereo set up a Sub which accepts high level inputs and has speaker out outs is the best option.

 

[Santy]

It is bass management. When you connect speaker level inputs to the sub, it will take those frequencies it is set to manage and pass the frequencies above that to the speaker outs (typically satellites). This helps in a better integration of sub with the main speakers but at the cost of a possible quality loss (due to passive crossover, as greenhorn mentioned). It also helps to prevent damage to the small drivers (in satellites usually) due to over-excursion.

However, if you have good bookshelves, the best option is to split the RCA input between the DAC and AMP, connect the sub with stereo input and carefully set the crossover factoring in the bass capabilities of bookshelves. Even better is to have two active subs one for each channel.

 

[greenhorn]

Someone please try and connect your sub directly to the input and check whether attaching main speakers to the sub's line level out powers the speakers

ketan, we were talking about using the high level inputs and outputs together. If it use line in, you will not get any signal out of the speakers level output, and the line out cannot drive speakers, obviously

 

[ketansethi1987]

ketan, we were talking about using the high level inputs and outputs together. If it use line in, you will not get any signal out of the speakers level output, and the line out cannot drive speakers, obviously

I was not aware if that. I do believe you are correct but would still love to experiment once. What if sub powers the speakers (maybe small ones) using its own amplifier making it a 2.1 system when we attach the sub using RCA plugs. Has anyone ever tried that? I would have if I had an active sub but those seem to be too expensive for me... so DIY is the way its gonna be

 

[ketansethi1987]

Good Info. I dint know this. Thanks. So for people like me who have a stereo Amp with out any separate sub out and wanting to add a sub in a stereo set up a Sub which accepts high level inputs and has speaker out outs is the best option.

But why to attach the speakers to the sub? Isnt it better to drive them from the main amp in parallel to inputs being provided to the sub?

 

[jagdish_p]

But why to attach the speakers to the sub? Isnt it better to drive them from the main amp in parallel to inputs being provided to the sub?

FM Santy has already answered above on this. If you attach the speakers to the Sub then the input signal to the Speakers will have only frequencies above the crossover point of the Sub. This will reduce the load on the speakers ( No Bass) and possibly improve the overall SQ.

 

[ketansethi1987]

FM Santy has already answered above on this. If you attach the speakers to the Sub then the input signal to the Speakers will have only frequencies above the crossover point of the Sub. This will reduce the load on the speakers ( No Bass) and possibly improve the overall SQ.

Yes, but what everyone usually does is connect the speakers to the main amp/avr and then adjust the crossover in the sub for this.

We do need some bass from the speakers, right? Otherwise why would one buy expensive bookshelves??? Satellites would work fine I guess and would be much cheaper

 

[ketansethi1987]

I was not aware if that. I do believe you are correct but would still love to experiment once. What if sub powers the speakers (maybe small ones) using its own amplifier making it a 2.1 system when we attach the sub using RCA plugs. Has anyone ever tried that? I would have if I had an active sub but those seem to be too expensive for me... so DIY is the way its gonna be

Got the answer on Yahoo... The sub wont power the speakers if RCA inputs are used

 

[jagdish_p]

Yes, but what everyone usually does is connect the speakers to the main amp/avr and then adjust the crossover in the sub for this.

We do need some bass from the speakers, right? Otherwise why would one buy expensive bookshelves??? Satellites would work fine I guess and would be much cheaper

The ideal would be to have an Amp/AVR with crossover selection and a Sub out.
This will ensure that the Bass below the crossover does not reach the speakers thereby freeing them to do a better job of reproducing the Mids and Highs.