[speedzak]

Originally Posted by panky12345

If you supply 500+ RMS to a 300W sub, you're going to fry it!

No BABA! Unless somebody ignorant about tuning installs it.
It will play very nicely if tuned properly. The amp will also run kewl without breaking a sweat.

[panky12345]

Originally Posted by speedzak

No BABA! Unless somebody ignorant about tuning installs it..

Thats very right zak! the statement was made given the sorry state of our local "dilli" wale installer..

You'd be surprised to know that they can actually make 2 speakers AND a sub run off a 2 ch amp. How? Simple.. attach 2 channels to 2 speakers and simultaneously bridge them to sub!

[speedzak]

Originally Posted by panky12345

Thats very right zak! the statement was made given the sorry state of our local "dilli" wale installer..
....
.... attach 2 channels to 2 speakers and simultaneously bridge them to sub!

Simple! Just avoid them. No matter if they stay next to you/are very good friends/he'll feel bad kinds.. Whatsoever!
God forbid, you get close to them!

[nitinralli]

Originally Posted by panky12345

If you supply 500+ RMS to a 300W sub, you're going to fry it!

BTW: There are better options than Pio 304F.. some better models take 400W!

Actually this is the current sub i have in my car rightnow,so wanted to know if this sub will do its duty with a Mono. I am open to buying a new powerfull sub which can take more than 600W RMS.
Yes there are local installers who will try to get every penny out of you without giving you anything in return. I had this experince myself from a installer in Lagpat Nagar, but now i have shifted to Driven which i think does well.
Hey Panky, any possiblity that i can audition your setup??

[abhinav.gupta88]

Oops i misread the rms ( i took the peak one)


It wont make much of a difference because the companies quote the rms at 14.4v and ideal conditions while effectively you drive on a 13. something volt battery and other factors affect the 100% functioning of the amp.

[Sam Kapasi]

Originally Posted by panky12345

You'd be surprised to know that they can actually make 2 speakers AND a sub run off a 2 ch amp. How? Simple.. attach 2 channels to 2 speakers and simultaneously bridge them to sub!

Panky, you'd be very surprised to know that this is a technically correct form of connection called tri-mode. Ideally it would require a passive crossover in series with the woofer.

You can read more about it here.

And from here I quote:

But what if you're starting out with just a simple two-channel amp and you still want to power a pair of stereo speakers and a sub? No problem. That's where a feature known as "Tri-way mode" (or "Tri-Mode") kicks in. You'll notice that virtually all the amplifiers on our website and in our catalog are described as "Tri-way capable." That means you can attach a Tri-way crossover to a pair of stereo amplifier channels to produce three channels — two stereo channels for front speakers, and one mixed-mono channel for your sub.

And in case you don't have this passive crossover, everything will work, but the subwoofer will play full range.

You should also read this. Tri-Mode Speaker Connection

BTW AFAIK ALL bridgeable 2 channel car amplifiers are tri-mode capable.

[Magma]

Sam
to do this do you require a higher rated 2 channel amp

i mean
consider a 4 channel 60*4 rms amp ( 2 channles bridged to the sub and 2 channels to the front speaker)

will the above produce the same output as a 2 channel 60*2 rms amp in trimode with passive crossover for the sub

Note : i am referring to same output volume wise/clean sound/SPL level, and not referring to anything to do with better control(filter settings etc) over the sub and speakers

logic says yes - you would require a more powerful 2 way amp
whats the real answer
hope you understood

my next question would now be-whats advisabel and why
100rms 2 way amp in trimode
or 60*4 rms 4 channel
(consider 60rms front speakers and 275 rms sub)

[Sam Kapasi]

Originally Posted by Magma

Sam
to do this do you require a higher rated 2 channel amp

i mean
consider a 4 channel 60*4 rms amp ( 2 channles bridged to the sub and 2 channels to the front speaker)

will the above produce the same output as a 2 channel 60*2 rms amp in trimode with passive crossover for the sub

Note : i am referring to same output volume wise/clean sound/SPL level, and not referring to anything to do with better control(filter settings etc) over the sub and speakers

my next question would now be-whats advisabel and why
100rms 2 way amp in trimode
or 60*4 rms 4 channel
(consider 60rms front speakers and 275 rms sub)

I would have immediately answered "The 4 channel" because of independent active crossover settings, but your question states that you do not want to discuss filters.

So let us discuss the 60*2(amplifier A) amplifier versus the 60*4 (Amplifier B) amplifier. In ideal conditions the 60*4 amplifier should be exactly equal to 2*AmpB - in most cases it is not because the 60*4 amplifier shares the power supply.

But that is not important in my discussion

Let me simplify tri-mode power for you.

let us say Amplifier A (60*2) produces 60Watts into each speaker in stereo mode (assuming each speaker is 4ohms)
The same amplifier could theoretically produce 100W in a single 4 ohm subwoofer in bridged mode.

In Tri-Mode, this amplifier would give 50W to the subwoofer and each speaker would get 25W each. So while everything would run technically fine, each speaker and the subwoofer would get less power.
So yes, you would need a more powerful amplifier to achieve the same power output as the 60*4 (which, under ideal conditions would offer 60W per speaker and 100W into the subwoofer)

I hope I did not confuse you.

My simple point to Panky and Zak was that this is not something to laugh about. Tri-mode is perfectly acceptable. I only doubt that the installer would use a passive low pass filter in series with the subwoofer. If the installer connected 2 speakers in stereo and then bridged a woofer on the same amplifier, the only wrong thing is that the subwoofer is running in a full range channel.
It's not shocking though!

What is shocking is where I have seen an installer connect right speaker to the right channel of the amplifier and the left speaker PLUS subwoofer in parallel to the left channel. Now that is something to be shocked and laugh about.

[Magma]

thanks sam
nope no confusion your explanation was to the point and clear
Logic had pointed me to the same explanation too, but a i guess i had to hear a confirmation from you

what about my second question-Your choice
a 100 rms 2 channel from a very good comapny in trimode with required crossovers
or a 60*4 rms 4 channel from a moderately decent company
(im guessing every speaker would probably be getting the same power in this case)

a small explanation would also be appreciated as to why that choice

i ask this question for the simple reason because 2 such amplifiers would cost approx the same.
Stingy aint i ?

[Sam Kapasi]

Originally Posted by Magma

thanks sam
nope no confusion your explanation was to the point and clear
Logic had pointed me to the same explanation too, but a i guess i had to hear a confirmation from you

what about my second question-Your choice
a 100 rms 2 channel from a very good comapny in trimode with required crossovers
or a 60*4 rms 4 channel from a moderately decent company
(im guessing every speaker would probably be getting the same power in this case)

a small explanation would also be appreciated as to why that choice

I would easily take either a 4 channel amplifier or 2*2channel amplifiers. Why? Simple - the passive crossover does nothing for me. It offers not enough filtration and I have no control over it.

I can neither use the electronic controls of the HU nor the amplifier, simply because every audio setting affects both the speakers and the subwoofer.

I can neither use a fader, nor a subwoofer level control, nor time delay/alignment. With independent channels for the sub and the speakers I am free to use all of the above and change the setting any way I like, any time I like.

Even simple things like the quality of my recording will cause me to raise or lower my subwoofer volume (using either my HU or the sub level external control) - how can I do this if the sub and speakers are running off the same channel?

[Magma]

SAm

thanks. seems i overlooked a lot
just got too excited with a prospects of triphase!!

[Sam Kapasi]

Originally Posted by Magma

just got too excited with a prospects of triphase!!

Magma, triphase is Viper (Nobody dares get close to my dhoklas) - this is tri-mode.

[navin]

Originally Posted by Magma

my next question would now be-whats advisabel and why
100rms 2 way amp in trimode
or 60*4 rms 4 channel

Originally Posted by Sam Kapasi

Tri-mode is perfectly acceptable. I only doubt that the installer would use a passive low pass filter in series with the subwoofer.

Originally Posted by Sam Kapasi

Simple - the passive crossover does nothing for me. It offers not enough filtration and I have no control over it.

Even simple things like the quality of my recording will cause me to raise or lower my subwoofer volume

Maybe I sound dated but for an amp to be used in tri-mode it must be designed for this. Maybe most/all modern amps are trimode but in the 70s and 80s few amps were trimode capable. Even then when you do have a sub+2 speakers connected to just 1 pair of amp channels the amp must be capable of driving low impedances.

So if you trimode 2 4 ohms speakers and a 4 ohm SVC sub, the amp must be capable of being stable at 2 ohms. So really it is not the speakers that decide if the amp can be used in trimode, but the speaker+sub+amp combination being used that does; hence (since in car audio most speakers have a nominal impedance of 4ohms) you can argue that it is the amp's design - rather than the speakers being used -that dictate if the amp can be used in trimode.

Originally Posted by Sam Kapasi

Magma, triphase is Viper (Nobody dares get close to my dhoklas) - this is tri-mode.

I thought Viper was "out of phase". LOL. Just Kidding Jiggy.

[Sam Kapasi]

Originally Posted by navin

Maybe I sound dated but for an amp to be used in tri-mode it must be designed for this. Maybe most/all modern amps are trimode but in the 70s and 80s few amps were trimode capable.

I am willing to be corrected, but in my belief, all amplifiers that are capable of being bridged (i.e. one channel pre designed to be out of phase with the other and all that) are also capable of being tri-mode.

[gunbir]

Originally Posted by Sam Kapasi

I am willing to be corrected, but in my belief, all amplifiers that are capable of being bridged (i.e. one channel pre designed to be out of phase with the other and all that) are also capable of being tri-mode.

I have always assumed that as well.