Subwoofer without Amplifier works..

navin · 8th July 2008, 12:58

Quote:

Originally Posted by headers

Ok sir, agreed. But if only one channel is connected to drive the sub as advised. I should not theoretically fry the HU!

no you wont but your sub will not be used fully.

Quote:

Originally Posted by greenhorn

Personally, I've never had issues driving speakers with underpowered amps[Driven or Elegant for this installation

actually this is more true forspeaker systems involving tweeters. an amp that clips will produce a lot of HF energy (square wave) and this energy will damage the tweeter.

redfire · 8th July 2008, 13:04

I am not a guru but have experienced this, even with well matched amps/speakers. A good quality amp though underpowered may play OK if you are very carefull with volume control. Gradually increasing the volume level and setting it to a moderate level before clipping may work and the setup may run for short/long according to the quality of components. But things will go kaput when a sudden volume level increase/something like that occurs. Last week I had to change two fuses in my home amp (100W RMS @ 8 ohms connected to matching speakers) because of my son who turned the volume control to 80% and I switched on the amp without noticing this. But I have turned the volume to 80% gradually without any problem (even he used to do it, then will get frightened by the volume/punch, cry and run to his mom

).

navin · 8th July 2008, 13:30

Quote:

Originally Posted by redfire

But things will go kaput when a sudden volume level increase/something like that occurs.

What you are experiencing is a blown fuse (atleast that is what should happen) not a blown amp.

redfire · 8th July 2008, 13:39

Yes Navin Ji, luckily I faced only a blown fuse. But as a whole, the equipment is blown and not playing (in layman's view) and it could be some other components if not fuse next time. Hope it never happens.

anujmishra · 8th July 2008, 14:29

In my Sony HU I can see there are 4 channel normal output plus one sub output. In settings, I can see in the SUB setup that can be set in dB from 0 dB to 10 dB.

What, if I try to connect SUB without amplifier in dedicated SUB output of HU ?

If it is not recomended, then why Sony has provided separate SUB output in HU?

DerAlte · 8th July 2008, 14:32

Must have been a Fast-blow fuse (thin copper wire). Replace it with a Slow-blow fuse of the same rating. This will not blow on a surge current, yet protect the amp in continuous overload conditions, like lower than designed speaker impedance etc. This used to be a common problem with old CRT TVs - surge current while switching on (early Sunday morning auntie-ji comes running: "Beta, jaldi se kuchh kar de, Mahabharat / Ramayan miss ho jayega").

Your "rotating the knob in a flick" will do the same: produce a surge current. This will, as Navin explained, only blow the fuse by not fry the amp.

greenhorn · 8th July 2008, 14:35

[A bit OT ] just a doubt. What if the amp had to reproduce a transient of the same magnitude ? will the fuse blow then also ?

DerAlte · 8th July 2008, 18:15

Depends on magnitude and duration of transient! The fuse blowing characteristic is a time-current relationship, so higher the current for a short duration, the faster it will blow.

raajsree · 9th July 2008, 00:10

Quote:

Originally Posted by greenhorn

yup, that was one way to get surround out of a 2 channel amp in the ye olde days. however , to get the difference signal, you need to connect the + and - of the speakers to either both the +'s of the amp, or both the -'s.

a good idea would be to connect the Right surround speakers + to the left channel +, and the speakers - to the right channel +
the Left surround's + can be connected to the left channel's - , and the speakers - to the right channel's minus ( I'm not entirely sure about the polarities, but i think this should work) And since equal currents will be drawn from all terminals , it should balance everything out .

in a car HU, the amp's ground (0V) terminals are not acessible , only the + and - are ....

Connecting a speakers to both the +'s or both the -'s should not be an issue , since there wont be a lot of current flowing , only the difference.

I only objected to shorting the + and - of the HU. everything else is fine

PS: I didnt get the ridicule bit. Have we ridiculed anyone ?

a bad automotive analogy would be to claim that if you drive around with your handbrake on , the tyres wont be damaged because you are driving slowly or because the engine is underpowered.

no matter how little current you supply, a shorted output is a shorted output ,and will eventually fry your IC's

Thanks for the green signal.
and the ridicule was not for you but for those who try to make the blog more interesting.

godseed1670 · 9th July 2008, 00:51

Hmm, An Indigo One ton transport vehicle then a Sub with no Amp.
Someones really into destructive testing. But if it works - What the heck?!
Way to go Vikram. BTW I no see ,one Nitrous on this thread. How come? I thought you to go hand in hand in all threads. Fighting....

headers · 9th July 2008, 08:27

Quote:

Originally Posted by godseed1670

Hmm, An Indigo One ton transport vehicle then a Sub with no Amp.
Someones really into destructive testing. But if it works - What the heck?!
Way to go Vikram. BTW I no see ,one Nitrous on this thread. How come? I thought you to go hand in hand in all threads. Fighting....

OT: Sir, thank you for actually coming online and browsing through the forum. You have improved!

BTW, what is destructive testing?

I am just exploring the limits! Thanks to you know who!

kalpik · 23rd July 2008, 16:36

Quote:

Originally Posted by anujmishra

In my Sony HU I can see there are 4 channel normal output plus one sub output. In settings, I can see in the SUB setup that can be set in dB from 0 dB to 10 dB.

What, if I try to connect SUB without amplifier in dedicated SUB output of HU ?

If it is not recomended, then why Sony has provided separate SUB output in HU?

+1 i also have a similar output on my 7950.. What that output for?

esteem_lover · 23rd July 2008, 17:39

Quote:

Originally Posted by godseed1670

Hmm, An Indigo One ton transport vehicle then a Sub with no Amp.
Someones really into destructive testing. But if it works - What the heck?!
Way to go Vikram. BTW I no see ,one Nitrous on this thread. How come? I thought you to go hand in hand in all threads. Fighting....

haa! godseed, how is the seeding season this year ? Need any help to lug around your seeds, you know who to call.

Quote:

Originally Posted by headers

OT: Sir, thank you for actually coming online and browsing through the forum. You have improved!

BTW, what is destructive testing?

I am just exploring the limits! Thanks to you know who!

Is there any limits left to explore ?

Sorry for going offtopic.

greenhorn · 23rd July 2008, 17:45

Quote:

Originally Posted by kalpik

+1 i also have a similar output on my 7950.. What that output for?

to drive subs , maybe smaller ones. and definitely not in bridged mode

23rd July 2008, 19:06

Quote:

Originally Posted by greenhorn

to drive subs , maybe smaller ones. and definitely not in bridged mode

Smaller subs ?

Any examples ? Can I hook in my creative PC sub ?

8th July 2008, 13:04	#32
redfire BHPian Join Date: Jan 2008 Location: Chicago, USA Posts: 449 Thanked: 27 Times View My Garage	I am not a guru but have experienced this, even with well matched amps/speakers. A good quality amp though underpowered may play OK if you are very carefull with volume control. Gradually increasing the volume level and setting it to a moderate level before clipping may work and the setup may run for short/long according to the quality of components. But things will go kaput when a sudden volume level increase/something like that occurs. Last week I had to change two fuses in my home amp (100W RMS @ 8 ohms connected to matching speakers) because of my son who turned the volume control to 80% and I switched on the amp without noticing this. But I have turned the volume to 80% gradually without any problem (even he used to do it, then will get frightened by the volume/punch, cry and run to his mom ).
	() Thanks

8th July 2008, 13:39	#34
redfire BHPian Join Date: Jan 2008 Location: Chicago, USA Posts: 449 Thanked: 27 Times View My Garage	Yes Navin Ji, luckily I faced only a blown fuse. But as a whole, the equipment is blown and not playing (in layman's view) and it could be some other components if not fuse next time. Hope it never happens.
	() Thanks

8th July 2008, 14:29	#35
anujmishra Senior - BHPian Join Date: Jun 2008 Location: Bangalore Posts: 1,290 Thanked: 492 Times View My Garage	Separate SUB output In my Sony HU I can see there are 4 channel normal output plus one sub output. In settings, I can see in the SUB setup that can be set in dB from 0 dB to 10 dB. What, if I try to connect SUB without amplifier in dedicated SUB output of HU ? If it is not recomended, then why Sony has provided separate SUB output in HU?
	() Thanks

8th July 2008, 14:32	#36
DerAlte Senior - BHPian Join Date: Mar 2007 Location: Bangalore Posts: 8,069 Thanked: 2,919 Times	Must have been a Fast-blow fuse (thin copper wire). Replace it with a Slow-blow fuse of the same rating. This will not blow on a surge current, yet protect the amp in continuous overload conditions, like lower than designed speaker impedance etc. This used to be a common problem with old CRT TVs - surge current while switching on (early Sunday morning auntie-ji comes running: "Beta, jaldi se kuchh kar de, Mahabharat / Ramayan miss ho jayega"). Your "rotating the knob in a flick" will do the same: produce a surge current. This will, as Navin explained, only blow the fuse by not fry the amp.
	() Thanks

8th July 2008, 14:35	#37
greenhorn Senior - BHPian Join Date: Apr 2007 Location: KL-01 Posts: 7,745 Thanked: 4,401 Times View My Garage	[A bit OT ] just a doubt. What if the amp had to reproduce a transient of the same magnitude ? will the fuse blow then also ?
	() Thanks

8th July 2008, 18:15	#38
DerAlte Senior - BHPian Join Date: Mar 2007 Location: Bangalore Posts: 8,069 Thanked: 2,919 Times	Depends on magnitude and duration of transient! The fuse blowing characteristic is a time-current relationship, so higher the current for a short duration, the faster it will blow.
	() Thanks

9th July 2008, 00:51	#40
godseed1670 Newbie Join Date: Apr 2006 Location: chennai Posts: 15 Thanked: 0 Times	Hmm, An Indigo One ton transport vehicle then a Sub with no Amp. Someones really into destructive testing. But if it works - What the heck?! Way to go Vikram. BTW I no see ,one Nitrous on this thread. How come? I thought you to go hand in hand in all threads. Fighting....
	() Thanks