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Old 25th June 2014, 16:37   #46
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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Originally Posted by DerAlte View Post
@Maky's requirement is that of a simple sub to be used with a simple amp.
For his requirement / question I had answered as far as I could.

Quote:
Bi-amping is taking things too far, especially since he wouldn't have any channels left in his Pio 4-channel amp to drive the components with. Or did you expect him to sell that and get a 6-channel amp?

It is not a good idea to know the answer and then try to belittle others - for the sake of proving that you are an 'expert'.
This is the answer when people starting to think they themselves are the 'experts' and others doest know anything by sending provocative replies. Moreover the OP was unnecessary being suggested to go for a DVC sub in post #30.

I was expecting that you could answer my doubt on biamping (one of the important use case) about the "untrue" switchable DVC subs.

Last edited by ::CMS:: : 25th June 2014 at 16:40.
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Old 25th June 2014, 17:34   #47
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

A strange turn of events. An hour ago, My friend who knows of my troubles, told me I can pick his old sub from his house to save money. Attached are pictures. Note there are 4 wires.

This would be a DVC then I suppose, Perhaps someone can confirm by visually identifying. I hope it's in working condition as the last time I heard it run was 3 years ago on the monstrous X944: P.
Attached Thumbnails
Amp & 4 speaker upgrade for Rs. 15000?-photo-1.jpg  

Amp & 4 speaker upgrade for Rs. 15000?-photo-2.jpg  

Amp & 4 speaker upgrade for Rs. 15000?-photo-3.jpg  

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Old 25th June 2014, 17:38   #48
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Originally Posted by Maky View Post
... Can I use the Amplifier I have purchased to power one single Subwoofer(Enclosed) Instead? i.e. all 4 channels on that amplifier to power one single Subwoofer such as this or this one here? ...
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Originally Posted by DerAlte View Post
Well, yes and no.

No, because the subs you have pointed to are single voice coil subs, and you can't drive the same voice coil with two bridged amp channels connected in parallel. Yes, if you use a dual voice coil sub with each coil 4 ohms - each coil being driven by one pair of channels bridged. ...
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Originally Posted by ::CMS:: View Post
... Moreover the OP was unnecessary being suggested to go for a DVC sub in post #30. ...
Strange. I am unable to decide whether it a reading problem, or understanding of English, that is preventing you from understanding the sequence of the question and the subsequent answer. The post you quote also explains why he shouldn't do that. Wonder where you got the idea that a DVC was being "suggested".

So, is your problem me, or some idea that you are unable to reconcile with?

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Originally Posted by ::CMS:: View Post
... I was expecting that you could answer my doubt on biamping (one of the important use case) about the "untrue" switchable DVC subs.
You are not incorrect in expecting an answer, but incorrect in expecting where. You are expected to understand the pointer "we would both be deviating from the topic, and we expect you to recognize that yourself".

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Originally Posted by Maky View Post
... Note there are 4 wires.

This would be a DVC then I suppose, Perhaps someone can confirm by visually identifying. ...
@maky, it would be a simple matter of taking the sub out (only a few screws) and reading the label on the magnet of the sub. Though it sounds obvious, "4 wires" can be misleading information - better to be sure.

You have to anyhow open the box - to fit a connector (like one can see behind PA system speakers). Right now the wires are coming out of a simple hole, and this creates a leaky box, not sealed box.

Last edited by DerAlte : 25th June 2014 at 17:46.
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Old 25th June 2014, 20:59   #49
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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Originally Posted by DerAlte View Post
Well, yes and no.

No, because the subs you have pointed to are single voice coil subs, and you can't drive the same voice coil with two bridged amp channels connected in parallel. Yes, if you use a dual voice coil sub with each coil 4 ohms - each coil being driven by one pair of channels bridged. ...
Quote:
Originally Posted by ::CMS:: View Post
... Moreover the OP was unnecessary being suggested to go for a DVC sub in post #30. ...
Strange. I am unable to decide whether it a reading problem, or understanding of English, that is preventing you from understanding the sequence of the question and the subsequent answer. The post you quote also explains why he shouldn't do that. Wonder where you got the idea that a DVC was being "suggested".

So, is your problem me, or some idea that you are unable to reconcile with?
LOL, yes its because I couldnt understand the Shakespeare english. Instead of telling how to connect a single sub to the 4 channel amp (reqd answer to the question), created one more thing into the confusion, a DVC.

Last edited by ::CMS:: : 25th June 2014 at 21:06.
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Old 26th June 2014, 11:34   #50
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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Originally Posted by ::CMS:: View Post
Please educate me how to biamp
Bi-amping a sub (DVC) usually just means connecting each coil to a separate amplifier channel (this channel might be normal or bridged). The only reasons to do this would be limit current delivery of the amplifier (to within it's capability) and/or to distribute the power of the amplifier over both coils.

I have not read the whole thread but what CMS suggested earlier

"- Power the fronts with the Amp's Ch-1 (L and R), bridge Ch-2 for sub and power rears with the HU(if the option is available in the HU) only as a filler.

- Power the fronts with another good 2channel amp, rears with Ch-1 (L and R) and bridge Ch-2 for s
ub"

are the 2 best solutions (for the money spent). However IF Maky has already got the DVC sub and an amplifier that is not capable of driving both coils from a bridged channel (few amps are so capable) then Maky can just leave one coil open (or even short the coil) and use the bridged amp with one coil leave the other 2 channels for front or rear speakers.

Quote:
Originally Posted by DerAlte View Post
[left] @maky, it would be a simple matter of taking the sub out (only a few screws) and reading the label on the magnet of the sub. Though it sounds obvious, "4 wires" can be misleading information - better to be sure.
Good idea.

Maky, if you can let us know the model number we can determine if the woofer is single or DVC.

Last edited by navin : 26th June 2014 at 11:37.
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Old 26th June 2014, 11:55   #51
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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... However IF Maky has already got the DVC sub ...
@Maky was planning to buy a sub (JBL ported boxes with SVC subs), till by providence he found an old sub with his friend. This sub might be a DVC. He was also trying to get the maximum out of a defined budget. He has a 4 channel Pio amp, Pio components and Pio 6x9 on parcel shelf, and was mighty dissatisfied with that setup, probably because it doesn't have bass punch.
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Old 26th June 2014, 12:10   #52
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

Quote:
Originally Posted by DerAlte View Post
@Maky was planning to buy a sub (JBL ported boxes with SVC subs), till by providence he found an old sub with his friend. This sub might be a DVC. He was also trying to get the maximum out of a defined budget. He has a 4 channel Pio amp, Pio components and Pio 6x9 on parcel shelf, and was mighty dissatisfied with that setup, probably because it doesn't have bass punch.
Thanks DA for bringing me up to speed. I assume the subwoofer has 2 coils of 4 ohms each. Putting them in parallel would be 2 ohms which would be too low a load for most bridged channels.

Hence, my suggestion would be to short 2 terminals (any pair + and -) of the sub (it drops Vb by a bit) and connect a bridged channel of the Pio amp to the OTHER two terminals of sub. If the HU can drive the rear channels he should use the other 2 channels of the amp for the front components (as suggested earlier).

http://www.the12volt.com/installbay/....asp?TID=74640

Maky, You want to balance the sound. The 6x9s in the rear are working in a larger volume (aka the trunk of your hatch) than the front components (which are working in just the volume of the door).

Since the 6x9 are going to be far more sensitive they can get loud with little power (from HU's internal amp) and then by giving more power the to front speakers (from the 4 channel amp) you can get the front speaker's volume up to where it can be heard over the rear speakers and subwoofer (both of which are in the rear).

Maky, think of it this way. When you go to a concert, where are you in relation to the musicians? Are the musicians in front of you or behind you? If the musicians are usually in front of you then why have the music coming from behind you in a car?

Hope this helps.

Last edited by navin : 26th June 2014 at 12:42.
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Old 26th June 2014, 14:10   #53
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

Quote:
Originally Posted by DerAlte View Post
@maky, it would be a simple matter of taking the sub out (only a few screws) and reading the label on the magnet of the sub. Though it sounds obvious, "4 wires" can be misleading information - better to be sure.

Quote:
Originally Posted by navin View Post
Good idea.

Maky, if you can let us know the model number we can determine if the woofer is single or DVC.
I tried but I was only able to get a a few screws out. All rusted underneath & the other few I wasn't able to, It was as if it was welded on!

I am looking at archives & this is the closest one I could find visually matching mine. Please have a look at the archives yourself comparing at attached pictures above and maybe you can find a better match than mine : S. I think that would be it though.

EDIT: After googling about I came across this guy who has a subwoofer that looks exactly like mine! but his quoted W and RMS are different.

Last edited by Maky : 26th June 2014 at 14:19.
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Old 26th June 2014, 14:43   #54
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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I tried but I was only able to get a a few screws out. All rusted underneath & the other few I wasn't able to, It was as if it was welded on!. ...
Carefully spray a little WD40 or equivalent on, around and behind the screw. Wait for some time and try again - it will come out. And use a proper screwdriver whose tip has parallel sides, not tapering.

And no, appearances are misleading - 2 models from the same manufacturer may look alike / identical, but be completely different. Better to know the exact model number.
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Old 26th June 2014, 14:52   #55
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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I tried but I was only able to get a a few screws out. EDIT: After googling about I came across this guy who has a subwoofer that looks exactly like mine! but his quoted W and RMS are different.
Ok we are not worrying about wattage only number of coils and impedance of the coils.

Do you have a multi-meter? If so can you tell us the impedance across the 2 sets of wires in your photo?
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Old 26th June 2014, 15:27   #56
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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Putting them in parallel would be 2 ohms which would be too low a load for most bridged channels.
Maky's new sub seems to be a DVC since it has 4 wires and this amp in no way able to handle 2ohms w/o clipping.

@Navin, shorting the +and - of one set to reduce the load by using only one voice coil may or may not load the amp due to the change in the Qes (almost half) because of the induction current in the unused voice coil. Wont it be a risk for the amp at heavy load (I am not sure about the amp spec)? Instead I would suggest to short the + and - of the Coil2 and Coil1 and connect the bridged amp + to coil1 and - to coil2 which makes the impedance to ~8ohms (if it is a 4+4) which is a safe bet wrt the amp.

@Macky, I would suggest you close the hole for the wires with a proper small speaker terminal if the box is built to the spec.

Last edited by ::CMS:: : 26th June 2014 at 15:29.
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Old 26th June 2014, 16:15   #57
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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Originally Posted by ::CMS:: View Post
Maky's new sub seems to be a DVC since it has 4 wires and this amp in no way able to handle 2ohms w/o clipping.

@Navin, shorting the +and - of one set to reduce the load by using only one voice coil may or may not load the amp due to the change in the Qes (almost half) because of the induction current in the unused voice coil. Wont it be a risk for the amp at heavy load (I am not sure about the amp spec)? Instead I would suggest to short the + and - of the Coil2 and Coil1 and connect the bridged amp + to coil1 and - to coil2 which makes the impedance to ~8ohms (if it is a 4+4) which is a safe bet wrt the amp.

@Macky, I would suggest you close the hole for the wires with a proper small speaker terminal if the box is built to the spec.
Those large golden pins? yes I Intend to.

Quote:
Originally Posted by navin View Post
Hence, my suggestion would be to short 2 terminals (any pair + and -) of the sub (it drops Vb by a bit) and connect a bridged channel of the Pio amp to the OTHER two terminals of sub. If the HU can drive the rear channels he should use the other 2 channels of the amp for the front components (as suggested earlier).

http://www.the12volt.com/installbay/....asp?TID=74640
I read some posts there. It's basically said it's safe but to keep in mind as the RMS/Max limits would be cut in half. What I don't understand is what is 'shorting' the terminals? Just not connecting to amp or is it process of short more complicated?

Thanks everyone so far for your invaluable input : ).
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Old 26th June 2014, 16:42   #58
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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Those large golden pins? yes I Intend to.
Marked in RED, plz check the attachment
Attached Thumbnails
Amp & 4 speaker upgrade for Rs. 15000?-photo-3.jpg  


Last edited by ::CMS:: : 26th June 2014 at 17:05.
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Old 27th June 2014, 10:32   #59
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

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@Navin, shorting the +and - of one set to reduce the load by using only one voice coil may or may not load the amp due to the change in the Qes (almost half) because of the induction current in the unused voice coil.

Instead I would suggest to short the + and - of the Coil2 and Coil1 and connect the bridged amp + to coil1 and - to coil2 which makes the impedance to ~8ohms (if it is a 4+4) which is a safe bet wrt the amp.
Most car audio amplifiers are most efficient at 4 ohms. At 8 ohms their wattage will drop to half. The choice hence would be to use one coil and either leave the second coil open or closed (aka short).

As you stated OC vs SC changes Qes and hence Qts and hence Vb or Qtc (in this case since his Vb is constant). SC will reduce Qtc which might sound tighter given the size of box (looks a bit small for a 12" sub).

Maky, connect the bridge channels to one coil of the subwoofer. Then listen to the subwoofer with the second coil not connected to anything (tape the 2 wires of the second coil apart aka separately so that they do not connect to each other). After that remove the tape and connect the 2 wires of the second coil together (the first coil is still the only coil connected to the amp) and listen again. See which sound you prefer. If you like a bit of bass bosst you might prefer the first option. If you like a less obtrusive bass you might prefer the second option. if you want something in between stick a 10ohm/1W resistor between the two wires...the permutations are endless.

CMS since you seems to understand that I am talking about can you post a picture of this for Maky. I am useless at this internet stuff. Thanks.
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Old 27th June 2014, 20:39   #60
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Default Re: Amp & 4 speaker upgrade for Rs. 15000?

Yes.

I found it cumbersome to open the sub up to find the Ohms of the Voice coils. Decided to go ahead and take a risk. Bridged 4 channels to the two coils of the sub and it's sounding absolutely fantastic. The subwoofer is now 8 years old I'm uncertain on how long it will last but so far so good.

I do hope its compatible in terms of load on the amp. If it's not and blows up or starts cutting I really can't be bothered to work on this anymore. I'm just too tired : ).

I've learned many new things the past week and managed fixed my issue thanks to all of you .
I hope someday I'll come here with a budget worthy of morels and focals!I would like to thanks everyone for your help.
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