How to understand the compatibility between Speakers and Sub-Woofer?

[Hifi_Noob]

Hi everyone,

I know that when we connect some passive speakers to stereo amp we look for impedance and watts to understand the amp-speaker compatibility. Can someone please help me to understand sub-speaker compatibility?

Similarly, how to understand anp-sub-speaker compatibility when connecting them as per below diagram?

Please share some arbitrary example, if possible?

Thanks in advance.

Regards.

 

[arj]

Hi everyone,

I know that when we connect some passive speakers to stereo amp we look for impedance and watts to understand the amp-speaker compatibility. Can someone please help me to understand sub-speaker compatibility?

Similarly, how to understand anp-sub-speaker compatibility when connecting them as per below diagram?

Please share some arbitrary example, if possible?

Thanks in advance.

Regards.

Not sure on what you are trying to do..are you wiring the drivers in series OR is there an actual sub with its own amp and the speaker ? If so there will be some specs.

Since subs have their own amp you will be connecting them either via their high level (speaker level) or low level ( RCA) and for that you need the crossover points to be set.

Need to know the specs of both to figure out what it is.

 

[Hifi_Noob]

Not sure on what you are trying to do..are you wiring the drivers in series OR is there an actual sub with its own amp and the speaker ? If so there will be some specs.

Since subs have their own amp you will be connecting them either via their high level (speaker level) or low level ( RCA) and for that you need the crossover points to be set.

Need to know the specs of both to figure out what it is.

Kind of you to reply.

Friend I am a noob so please bear with me. I am sure my question must be dumb.

Let's take this example:

1. Stereo Amp : Sony strdh190
2. Speakers: Sony sscs5
3. Sub: Polk Psw10

Now let's talk about how we can connect them all, below:

Speaker-Amp Compatibility:
Now, as per Amp's specs max output of amp per channel is 100 watt per channel and supported impedance is 6-16 ohms. So, I know that we can connect Sony sscs5 speakers to it. So, I know how to judge the compatibility between Speakers and Amp.

Amp-Sub Compatibility:
This Amp doesn't have dedicated sub out. So, to connect sub we have to run wires from amp's speaker output to sub and then from sub to speakers. This diagram is what I have attached in my main post. But, how to understand compatibility here. Can, I connect any sub to this amp? Or it depends on the power output of amp and power required by sub? This is what I want to understand.

Sub-Speaker Compatibility:
To connect Amp, Sub & Speakers, we run wire out of amp to sub and then from sub speaker level output to speakers. Now, how we judge the speakers Compatibility here with sub? Can we connect any impedance speaker to our sub? This is what I want to understand.

I hope I able to put my question properly.

Regards

 

[ssf]

To connect Amp, Sub & Speakers, we run wire out of amp to sub and then from sub speaker level output to speakers.

That is correct.

Can we connect any impedance speaker to our sub?

Yes. The sub is an independent unit with it's own amp. So, impedance of the main speakers do not matter.

What needs attention however is the frequency response of the main speakers. Amazon tells me that the sony speakers go down to 53 hz. So the crossover (low pass in the polk) in the sub needs to be set to around 10 or 15 Hz above the speakers low frequency response. In your case, you could start with around 65 to 70 Hz and then see what sounds best to you.

 

[arj]

since you have mentioned your sub as Polk PSw10
am assuming the below is how our sub amp looks like ?

As mentioned by the FM above. connect your amps terminals tothe speaker level input and your speakers to the speaker output on the sub and dont worry about compatibility. just make sure you do npt mix up on L/R and polarity ie Red/Black.

Adjust the crossover to the point you are getting a good sound and should be at a point above 50hz..you will get their via trial and error
There is a phase switch move it to the position where bass is loudest at the current position of the sub.
Adjust the volume so that the bass is not overpowering..ideally you should just hear the sub when on but miss it when off.

 

[Hifi_Noob]

That is correct.

Yes. The sub is an independent unit with it's own amp. So, impedance of the main speakers do not matter.

What needs attention however is the frequency response of the main speakers. Amazon tells me that the sony speakers go down to 53 hz. So the crossover (low pass in the polk) in the sub needs to be set to around 10 or 15 Hz above the speakers low frequency response. In your case, you could start with around 65 to 70 Hz and then see what sounds best to you.

Talking specifically abt this connection over here i.e. running wire out of amp to sub and then to speaker, then is my below statement correct?

If I connect a sub to an amp then the quality of audio output coming out of amp doesn't matter rather quality of audio coming out of sub matters. So, in my case Sony amp is not what is creating hifi sound rather Polk sub is creating that hifi sound. So, in my case I will not get best audio as I am sure amp will create better audio if directly connected with speaker. Right?

Also, can I connect any sub to an amp? Any?

 

[ssf]

If I connect a sub to an amp then the quality of audio output coming out of amp doesn't matter rather quality of audio coming out of sub matters. So, in my case Sony amp is not what is creating hifi sound rather Polk sub is creating that hifi sound. So, in my case I will not get best audio as I am sure amp will create better audio if directly connected with speaker. Right?

Wrong. Many people prefer speaker level connections because the speakers and the subwoofer both see the same audio signal. The subwoofer does not change this signal in any way. However, if you are worried that the sub might change the audio signal, you can connect the sub in the way shown in the link below.

https://www.the-home-cinema-guide.com/how-to-connect-a-subwoofer.html

https://www.the-home-cinema-guide.com/wp-content/uploads/stereo-receiver-to-high-level-subwoofer.png

Also, can I connect any sub to an amp? Any?

Yes. You can connect any sub to any amp.

 

[MaSh]

Yes your chain of Amp >> Sub >> Speaker is correct. The sub will still use its own amp to drive the sub's driver. Your stereo amp will only drive the Sony speakers. Sub will only taste the signal and use it's own amp.

The only compatibility required for the Sub is by your ears. If your ears like how the sub sounds great, else try another sub and cycle continues.

Do let us know how the setup sounds

MaSh

 

[arj]

Talking specifically abt this connection over here i.e. running wire out of amp to sub and then to speaker, then is my below statement correct?

If I connect a sub to an amp then the quality of audio output coming out of amp doesn't matter rather quality of audio coming out of sub matters. So, in my case Sony amp is not what is creating hifi sound rather Polk sub is creating that hifi sound. So, in my case I will not get best audio as I am sure amp will create better audio if directly connected with speaker. Right?

Also, can I connect any sub to an amp? Any?

think of it as water flowing in a pipe. the sub is just taking a portion of the water out via a filter ( ie signals less than the crossover frequency) and the rest is flowing as it is to the speaker ..and the portion taken out would not have been able to be reproduced by the speaker anyway

of course theoretically there is some effect of the filter on the main signal but unless the speaker is extremely sensitive and resolving you will never hear it so its still in theoretical domain.

 

[Hifi_Noob]

Wrong. Many people prefer speaker level connections because the speakers and the subwoofer both see the same audio signal. The subwoofer does not change this signal in any way. However, if you are worried that the sub might change the audio signal, you can connect the sub in the way shown in the link below.

https://www.the-home-cinema-guide.com/how-to-connect-a-subwoofer.html

https://www.the-home-cinema-guide.com/wp-content/uploads/stereo-receiver-to-high-level-subwoofer.png


Yes. You can connect any sub to any amp.

My amp has 2 outputs, A & B. Kindly refer attachment.

Can I connect speakers to A output of Amp and Sub to B output of amp? Will this be better over Wire running out of A output to Sub and from Sub to Speakers?

PS: Sorry for too many questions.

 

[DB1989]

My amp has 2 outputs, A & B. Kindly refer attachment.

Can I connect speakers to A output of Amp and Sub to B output of amp? Will this be better over Wire running out of A output to Sub and from Sub to Speakers?

PS: Sorry for too many questions.

You can insofar as my experience with a REL sub is concerned. I dunno the risk thereof, if any, with respect to a Polk sub.

 

[arj]

My amp has 2 outputs, A & B. Kindly refer attachment.

Can I connect speakers to A output of Amp and Sub to B output of amp? Will this be better over Wire running out of A output to Sub and from Sub to Speakers?

PS: Sorry for too many questions.

yes.. you can do this either way..although you just might get better integration using one- may be better since your speakers will only get the signal after the sub has filtered out wrt what will reproduced

Once you get it right you can experiment with B going to the sub and you will have some reference to compare it with.

 

[Hifi_Noob]

yes.. you can do this either way..although you just might get better integration using one -may be better since your speakers will only get the signal after the sub has filtered out wrt what it will reproduced

Once you get it right you can experiment with B going to the sub and you will have some reference to compare it with.

Gr8. Thanks.

One last question,

Amp is getting it's power from stepdown voltage converter as it requires 110 volt rather then 240 volt Indian standard. But sub is build to take 240 volt. Will this create any compatibility issue. I mean amp running at 110 volt power and sub at 240 volt power.

Thanks everyone for all the help.

Really kind of you guys.

yes.. you can do this either way..although you just might get better integration using one- may be better since your speakers will only get the signal after the sub has filtered out wrt what will reproduced

Once you get it right you can experiment with B going to the sub and you will have some reference to compare it with.

Amp is asking me to set speaker impedance on it, it is providing two options to select from:

1. Greater then 8 ohm
2. Less then 8 ohm

What should I select when I am connecting sub to A output of amp and then speakers to sub?

 

[arj]

Gr8. Thanks.

One last question,

Amp is getting it's power from stepdown voltage converter as it requires 110 volt rather then 240 volt Indian standard. But sub is build to take 240 volt. Will this create any compatibility issue. I mean amp running at 110 volt power and sub at 240 volt power.

no..these anyway get stepped down and rectified to DC internally as needed, so as long as they are fed the right power you are good to go.

 

[ssf]

the sub is just taking a portion of the water out via a filter ( ie signals less than the crossover frequency) and the rest is flowing as it is to the speaker ..and the portion taken out would not have

Are you sure about this ? As far as I know, the speaker level out sends the full original frequency without setting any filters to it.

This is the reason why it is recommended that the subs crossover is set 10 or 15 hz higher than the lowest frequency of the speaker so that it blends correctly. Any higher then those frequencies will be produced both by the sub and the mains. Any lower, some frequencies my not be produced at all.

Are you sure about this ? As far as I know, the speaker level out sends the full original frequency without setting any filters to it.

This is the reason why it is recommended that the subs crossover is set 10 or 15 hz higher than the lowest frequency of the speaker so that it blends correctly. Any higher then those frequencies will be produced both by the sub and the mains. Any lower, some frequencies my not be produced at all.

I think this depends on the sub. Velodyne sends a crossed-over speaker level signal to the speakers.

REL sends the full original signal.

Polk psw100 sends the full original signal.

https://www.rsmanuals.com/5274/polk-audio-psw100/page-3/

So this feature is sub dependent and one needs to check the manual for this.

 

[arj]

Are you sure about this ? As far as I know, the speaker level out sends the full original frequency without setting any filters to it.

This is the reason why it is recommended that the subs crossover is set 10 or 15 hz higher than the lowest frequency of the speaker so that it blends correctly. Any higher then those frequencies will be produced both by the sub and the mains. Any lower, some frequencies my not be produced at all.

This is used in sub sat setups usually and the sats are not given the full signal based in the crossover since the Sats anyway are limited range. Here the Subs are in series with the Sats

What you may be talking about is for the higher end subs which usually do not have a speaker out. These are usually kept in parallel to the speaker eg like in REL. The impedance is kept so high that only a very low signal is taken out but still in some amplifiers you can hear a minor reduction in volume when the sub goes on !

 

[MaSh]

Amp is asking me to set speaker impedance on it, it is providing two options to select from:

1. Greater then 8 ohm
2. Less then 8 ohm

What should I select when I am connecting sub to A output of amp and then speakers to sub?

Set it to what your speakers' spec is. Do not consider the self-powered sub as a speaker connected to the amp.

Why not connect the Speakers to the sub and use the crossover on the Sub to avoid overlapping of lowend?

MaSh

 

[arj]

Amp is asking me to set speaker impedance on it, it is providing two options to select from:

1. Greater then 8 ohm
2. Less then 8 ohm

What should I select when I am connecting sub to A output of amp and then speakers to sub?

This is a bit strange but try both and see where you get better dynamics. nothing much to lose...

 

[Hifi_Noob]

Set it to what your speakers' spec is. Do not consider the self-powered sub as a speaker connected to the amp.

Why not connect the Speakers to the sub and use the crossover on the Sub to avoid overlapping of lowend?

MaSh

Yes frnd, that's what I am doing. Connecting speaker to sub and then sub to amp.

But when I started amp it's asking me to set speaker Impedance?

What should I set? My speakers impedance is 6 ohm but they are wired to sub and not to amp.

 

[MaSh]

Yes frnd, that's what I am doing. Connecting speaker to sub and then sub to amp.

But when I started amp it's asking me to set speaker Impedance?

What should I set? My speakers impedance is 6 ohm but they are wired to sub and not to amp.

Then set it to Less than 8ohm. Although they are physically connected to the Sub, you should imagine the speakers are connected to the amp.

MaSh