How to effectively wire Yamaha YST-315 Sub to PM5005 Stereo Amplifier

[swamytk]

I have PM5005 Stereo amplifier connected to a pair of Wharfedale Diamond 220 speakers at front. Now I have ordered a Yamaha Sub YST-315.

PM5005 has two sets of Stereo speaker terminal where I use one set only (A). I don't use the other set of terminals (B). Amp can select either one set of speakers or both simultaneously.

Sub YST-315 has Bass, High cut (40Hz - 140Hz), Phase and Volume Control

Query 1: Wiring of Sub with Stereo Amp

The Sub manual has given below two methods.
Method-1: A out ---> Front Speakers and B out ----> Sub
I expect a overlap of low frequency sound from both Speakers and Sub. I am not sure how far it is serious.


Method-2: A out ---> Sub ----> Front Speaker
In this method, Sub can filter out all low frequency signals and pass out only mid/high frequency signals to Speakers. There is a clear cut defined roles for Speakers and Sub.


Please suggest me a right way to do.

Query 2: Placement of Sub in a cramped hall

I am planning to keep the Sub at front corner. But there is no plain wall opposite to Sub to reflect the low freq sound. There is a long wooden furniture and diwans only. Sub sound will enter into bottom of wooden sofa and reflect. Is it some thing serious to worry?

 

[MaSh]

Hi,

That is a very good sub I am told. Regarding hooking it up, I would go with Option 2. Amp to Sub to the speakers. Connect Speaker A on the amp to Speaker IN on the Sub. Then Speaker OUT on the SUB connects to respective Speakers. Set the crossover on the Sub. This is the perfect way to keep everything in sync.

MaSh

 

[swamytk]

Hi,

That is a very good sub I am told. Regarding hooking it up, I would go with Option 2. Amp to Sub to the speakers. Connect Speaker A on the amp to Speaker IN on the Sub. Then Speaker OUT on the SUB connects to respective Speakers. Set the crossover on the Sub. This is the perfect way to keep everything in sync.

MaSh

Thanks, it helps. Any suggestion on placement query?

 

[MaSh]

Thanks, it helps. Any suggestion on placement query?

Oh placement of sub is not so easy. It is unique to every room. There is a popular method called Sub Crawl method which does work well to find the right spot. In short, it involves keeping the Sub at the listening positioning and playing a tube with a continuous beat. You then have to go around the possible placement spots and check where the sound is sounding as close to your liking as possible. Place the Sub at that spot.

MaSh

 

[swamytk]

I received the subwoofer. I tried connecting sub in between amp and speakers in high level output path (This is the only possibility with my amp). When I tested with various movies, songs and test audio - one thing obviously I noted that my left/right speakers voice and music became flat (not clear enough and not sharp). It looks like Subwoofer in between amp and speaker distorts the signal to speakers. Is it something possible or is it my illusion?

Any way this subwoofer was found damaged physically out of box, so I have ordered for refund.

Now I consider other options if a subwoofer supports new configs shown below. In that case I can try a subwoofer preferred config.

Option-1:
Nvidia Shield -> DAC ---RCA---> Sub Line in ---> Sub -----> Sub Line out---> Stereo Amp -> L/R speakers

Option-2: Keeping both the set of Speaker terminals (A & B) on simultaneously
Nvidia Shield -> DAC ---RCA--->|| Stereo Amp (Spk Terminal A) -> L/R speakers || Stereo Amp (Spk Terminal B) -> Sub High level In -> Sub ||

Can you provide your valuable inputs on this configuration?

 

[yugaaa]

The sub will filter out the low pass freq and what ever output comes from the sub will be for sat type speakers . I am guessing there might be a passive crossover to filter out with such an arrangement .
The simpler way is to get a RCA splitter and then input the signal to the sub and the power amp. The speakers can be connected to the amp directly .

 

[MaSh]

I received the subwoofer. I tried connecting sub in between amp and speakers in high level output path (This is the only possibility with my amp). When I tested with various movies, songs and test audio - one thing obviously I noted that my left/right speakers voice and music became flat (not clear enough and not sharp). It looks like Subwoofer in between amp and speaker distorts the signal to speakers. Is it something possible or is it my illusion?

Any way this subwoofer was found damaged physically out of box, so I have ordered for refund.

Now I consider other options if a subwoofer supports new configs shown below. In that case I can try a subwoofer preferred config.

Option-1:
Nvidia Shield -> DAC ---RCA---> Sub Line in ---> Sub -----> Sub Line out---> Stereo Amp -> L/R speakers

Option-2: Keeping both the set of Speaker terminals (A & B) on simultaneously
Nvidia Shield -> DAC ---RCA--->|| Stereo Amp (Spk Terminal A) -> L/R speakers || Stereo Amp (Spk Terminal B) -> Sub High level In -> Sub ||

Can you provide your valuable inputs on this configuration?

Hmm, what was the cross over you set on the Sub? if it's too high, then yes that can muddy the vocals.

I would suggest try all the connectivity options and then decide what to do.

MaSh

 

[swamytk]

Hmm, what was the cross over you set on the Sub? if it's too high, then yes that can muddy the vocals.

I would suggest try all the connectivity options and then decide what to do.

MaSh

I mostly tried crossover set between 80 to 140, not below. Does it make difference? I just tried lower crossover around 60 for a few seconds, not really analyzed vocal/music with this level.

 

[MaSh]

I mostly tried crossover set between 80 to 140, not below. Does it make difference? I just tried lower crossover around 60 for a few seconds, not really analyzed vocal/music with this level.

Yes makes a difference. Check how much the speakers can do. Cross the sub slightly over that point. Say the speakers can do 50hz. Cross the sub at 60hz.

Idea is to allow the sub to support the speakers. Once you set the crossover, set the sub gain. Turn it to zero and slowly increase the gain till you just start feeling the bass at the seating position. You might need an extra hand to turn the gain knob.

MaSh

 

[swamytk]

Yes makes a difference. Check how much the speakers can do. Cross the sub slightly over that point. Say the speakers can do 50hz. Cross the sub at 60hz.

Idea is to allow the sub to support the speakers. Once you set the crossover, set the sub gain. Turn it to zero and slowly increase the gain till you just start feeling the bass at the seating position. You might need an extra hand to turn the gain knob.

MaSh

Here is my speaker spec:

Frequency response (+/-3dB)	56Hz - 20kHz
Bass extension (-6dB	45Hz

Now I understood that I should have tested with around 60hz as crossover. Awesome


BTW What is "Bass extension" in the spec above? Do I need to consider it?

In this sub there is no Gain control. I assume it is Volume control knob in Sub. Please confirm.

Once I get my replacement order delivered I can try again. Now I am confident of setting up right, thanks to friendly suggestions from you.

 

[MaSh]

Here is my speaker spec:

Frequency response (+/-3dB)	56Hz - 20kHz
Bass extension (-6dB	45Hz

Now I understood that I should have tested with around 60hz as crossover. Awesome


BTW What is "Bass extension" in the spec above? Do I need to consider it?

In this sub there is no Gain control. I assume it is Volume control knob in Sub. Please confirm.

Once I get my replacement order delivered I can try again. Now I am confident of setting up right, thanks to friendly suggestions from you.

Yes, try with 60Hz. Also place the sub in the right spot. Sub placement is very important.

You can ignore the -6db point. A -3db point would still have been meaningful.

Yes the volume knob on the sub is the one you need to adjust after setting the crossover.

MaSh

 

[swamytk]

@MaSh If you don't mind I have another question on understanding Subwoofer. When I connect speakers to "High Level output" of Sub, does the Sub takes only signal and drives the speaker (OR) still the stereo amplifier drives the speaker?

 

[MaSh]

@MaSh If you don't mind I have another question on understanding Subwoofer. When I connect speakers to "High Level output" of Sub, does the Sub takes only signal and drives the speaker (OR) still the stereo amplifier drives the speaker?

Sub only takes the signal and passes on to its internal amp to drive the subwoofer. After applying crossover the rest of the signal is passed on to the speakers. Your stereo amp is driving the speakers only, not sub

MaSh

 

[swamytk]

@MaSh The speaker I was expecting to reorder is out of stock. Since it is very old model it looks like not in market. Even if a few available in Amazon, they all look like the one returned by customers in bad condition. So I am forced to take alternative one.

The one such within 25k budget having both Hi level In/Out is
Polk Audio PSW-10. It costs 17k only. It is avilable in nearby store which is good for reliable new piece delivery and support.
Freq resp: 40-160Hz,
Crossover: 80-160Hz

1. Speaker freq resp starts at 56Hz whereas Crossover of Sub starts at 80 only. Based on our earlier discussion here I worry about muddling of vocal due to clash of SPK & Sub in low frequency range of 56 to 80Hz. How serious is this?

2. Freq resp of this sub starts at 40 only, is it good enough to work with speaker which starts at close 56Hz?

 

[swamytk]

I am moving ahead and dropping both Polk Audio PSW-10 (not enough powered for a big room) and Yamaha YST-315 (since it is very old, not enough stock, I got a damaged returned piece - I returned it again). I am considering other Sub and posting new query on that in a new thread. Thanks to all, especially @MaSh .

 

[Arajsriv93]

I am moving ahead and dropping both Polk Audio PSW-10 (not enough powered for a big room) and Yamaha YST-315 (since it is very old, not enough stock, I got a damaged returned piece - I returned it again). I am considering other Sub and posting new query on that in a new thread. Thanks to all, especially @MaSh .

You can go for the newer polk hts subs / bic / svs (pre owned obviously)

 

[swamytk]

After all chaos in purchasing/returning Subwoofer, I have settled with Yamaha YST-315 (available at htstore.in) along with Marantz PM5005 and Wharfedale Diamond 220 for a 2.1 setup. Since it is my first Subwoofer, I do play with it randomly. I have followed various instructions and guides
mentioned by FMs here along with Yamaha's user guide. Amp out A is connected to Speakers and B is connected to Sub (tried Speaker connection through Sub High level output too). After playing for some time I have noticed following. Your review on this outcome will be highly helpful for me to understand.

1. Phase switch does not make any difference in audio between Normal and Reverse position. Is it expected or am I missing something?

2. Sub High cut set at 65Hz (speakers freq response starts at 56Hz). Amplifier Volume is at 2 o' clock position. While playing 20/30/40/50Hz frequencies I slowly increase Sub volume. When the Sub volume reaches 35 (out of 100), I can feel Sub dominates comfortably over Speakers. Does it look good?

3. I tried two ways of connecting speakers as shown below:
(a) Amp A high ---> Sub High In ---> Sub ---> Sub High Out ---> Spk
(b) Amp A high ---> Spk / Amp B hig ---> Sub High In
I did not feel any difference in audio in either of the connection. I expected Sub to filter out any frequency below 65Hz, but it does not look so. I understood that there is no toggle switch kind of control here, but it is about db level control. But it looks like Sub just passes High In to High Out for speaker. I tested with Sub volume zero in both the cases. The low frequency played below 70Hz is output by Speaker at same db level in both the cases. I tested db level through an Android App (though not accurate it gives rough picture) and also tested with ear. Absolutely no difference between two connection. Same volume level observed from Speaker. Your comment on this will be interesting one.

4. Another interesting observation is Sub volume forms a valley between 20Hz and 40Hz. The volume level goes down between 20Hz to 40Hz. Afterwards it goes up. I again remind that db level noted down with Android App. I tried this test in multiple iterations. It is consistent. The same test I conducted with Speakers, there is no such behavior. Our senior FMs may throw some light on this.

Frequency Played (Hz)	db level with only Sub (no speaker)
20	60
30	56
40	63
50	67
60	67
70	69

Note: Keeping all these aside I enjoyed watching the movie Matrix as first one. It is awesome. But please don't ignore my above questions since I ultimately enjoyed Sub

 

[liverpool_for_life]

4. Another interesting observation is Sub volume forms a valley between 20Hz and 40Hz. The volume level goes down between 20Hz to 40Hz. Afterwards it goes up. I again remind that db level noted down with Android App. I tried this test in multiple iterations. It is consistent. The same test I conducted with Speakers, there is no such behavior. Our senior FMs may through some light on this.

Welcome to the world of subwoofers! What you're seeing is the effect of (primarily) your room dimensions, where you've placed your sub and where you're measuring from.

If this answer piques your curiosity and you end up with dual subs (or more) in your future, feel free to blame me

 

[swamytk]

Welcome to the world of subwoofers! What you're seeing is the effect of (primarily) your room dimensions, where you've placed your sub and where you're measuring from.

If this answer piques your curiosity and you end up with dual subs (or more) in your future, feel free to blame me

Is it something expected with our room which is not acoustic controlled (or) I can play with position and other techniques to get it fixed? If it can be done please let me know a few techniques.

 

[MaSh]

Check out this video on the basic 2.1 setup. It should answer most of your questions.

MaSh