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Old 30th March 2008, 20:59   #1
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Running 2.65 Ohms speaker impedence to 4 Ohms Amplifier

The amp is GM X374 which is 4 channel amp and has 35 X 4 at 4 Ohms, 50 X 4 at 2 Ohms and 100 X 2 at 4 Ohms.

Recently I took the infinity Reference 6020cs comopnents and JBL 527 coaxials.

Infinity Components are at 90 WRMS @ 2.65 Ohms and JBL is 45 WRMS @ 4 Ohms.

Now i need suggestions to get better sound and power.

First thing can i bridge the components to make 100 X 2 @ 4 Ohms in Mono mode and run the rear coaxials from HU ?

If I run 2.65 Ohms component speakers on 4 Ohms amp will it damage the amp.

Next can i use connect the rear coaxials also to the same bridged setup. Its like connected two wires - one from Comp and one from coax ?

Also If I bridge it will I get to notice notes which are meant to left and right channels (in short Fader control).

And what Gain should i set on amp? Should i keep it to normal?

Hope its not confusing.

Experts advice pleasee.
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Old 31st March 2008, 10:38   #2
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On the contrary, extremely confusing is what it is: ! Difficult to figure out what you are trying to do, and what you want to achieve.

Quote:
Originally Posted by kiran1103 View Post
Now i need suggestions to get better sound and power.
Do you mean "play louder, yet clean"?
Quote:
Originally Posted by kiran1103 View Post
First thing can i bridge the components to make 100 X 2 @ 4 Ohms in Mono mode and run the rear coaxials from HU ?
You don't want "stereo" sound? Of course you can run the rear coaxials off of the HU any time.
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If I run 2.65 Ohms component speakers on 4 Ohms amp will it damage the amp.
No. Your amp can feed anything between 2 and 4 ohms.
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Originally Posted by kiran1103 View Post
Next can i use connect the rear coaxials also to the same bridged setup. Its like connected two wires - one from Comp and one from coax ?
You have not mentioned the nominal impedance of your speakers. However, from your data it looks like you will get 1.59 ohms if you wire your speakers in parallel (that is what you are trying to do!) - and that is not healthy for your amp.
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Also If I bridge it will I get to notice notes which are meant to left and right channels (in short Fader control).
Hello, Fader control is about "front v/s rear", not "left v/s right". I think what you are trying to ask is whether "stereo effect" will be maintained, in which case the correct term is "Balance control". If you wire the bridging correctly (left to the amp 'front' set, right to the amp 'rear' set), yes you will.
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And what Gain should i set on amp? Should i keep it to normal?
That will be known when you tune it
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Old 31st March 2008, 11:23   #3
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Quote:
Originally Posted by kiran1103 View Post
The amp is GM X374 which is 4 channel amp and has 35 X 4 at 4 Ohms, 50 X 4 at 2 Ohms and 100 X 2 at 4 Ohms.
Recently I took the infinity Reference 6020cs comopnents and JBL 527 coaxials.
Infinity Components are at 90 WRMS @ 2.65 Ohms and JBL is 45 WRMS @ 4 Ohms.

First thing can i bridge the components to make 100 X 2 @ 4 Ohms in Mono mode and run the rear coaxials from HU ?

If I run 2.65 Ohms component speakers on 4 Ohms amp will it damage the amp.
Hope its not confusing..
You seem to be a bit confused.

the amp you have will drive 4 speakers (2 components and 2 coax speakers) without trouble but not in bridged mode.

If your HU has 2 sets of pre outs (front and rear) the above is what I'd suggest you do.

The 2.65ohms rating is a nominal rating and should not trouble your amp too much. However if you do find your amp getting too hot to touch then you might been a better amp.
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Old 31st March 2008, 14:51   #4
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Ok, Some of the things sorted, like my ideas on Balance and Gain controls.

The user manual of the Pioneer amp says this :-

To prevent damage

• Speakers to be connected to the amplifier should
conform with the standards listed below. If they
do not conform, they may catch fire, emit smoke
or become damaged. The speaker impedance
must be 2 to 8 ohms. But in case of two-channel
and other bridge connections, the speaker
impedance must be 4 to 8 ohms.


Hence, I am now bit reluctant to connect the Infinity Components which is 2.65 impedence to the amp which is will supply 4 Ohms in bridged mode.

However from another source of information about Infinity Reference product description, this is what is said :-

Infinity Reference speakers have two-ohm voice coils. This unique approach extracts more power from your amp or head unit. Many factory OE systems include two-ohm speakers. Infinity Reference speakers are perfect for those applications.If your head unit or amplifier is rated to drive a four-ohm load, Infinity Reference speakers are still the best option.

Again its bit of confusing.
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Old 31st March 2008, 16:29   #5
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Go ahead and connect it dude,nothing will happen as Deralte said amp can feed anything between 2 and 4 ohms.only thing to take care is don't connect the Compos in Bridge mode.
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Old 31st March 2008, 16:38   #6
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Quote:
Originally Posted by kiran1103 View Post
...The user manual of the Pioneer amp says this :-
To prevent damage... The speaker impedance
must be 2 to 8 ohms. ...


Hence, I am now bit reluctant to ...
Yes, that is the correct data, unfortunately written in a way that is confusing for you.
If each section of the amp (FL, FR, RL, RR) is able to feed a 2 ohms speaker, in the bridged mode (2 sections together - FL+FR, RL+RR) also it will be able to feed it - as long as it is not asked to feed a load of less than 2 ohms per section
* The fronts (infinity) will present a 2.65 ohm load: perfectly acceptable for the amp
* If you connect BOTH the fronts and the coaxes, you get a 1.59 ohm load: not acceptable (it WILL play, albeit for a short while before going into protection)
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Originally Posted by kiran1103 View Post
However from another source of information ...
Infinity Reference speakers have two-ohm voice coils. ... Again its bit of confusing.
They are colloquially "3 ohm" speakers, not 2 ohm. That is a bit of creative writing, not completely untrue. The impedance is 2.65 ohms
* round it up by the conventional rule, you will get 3 ohms
* ignore the decimal part and you get 2 ohms!!!

Since most amps are 2-ohms stable, it works perfectly OK. People who don't use an amp will normally play at a moderate volume (ignore the "I want the loudest at the lowest price" cases for a moment), not enough for the HU amp from over-heating and tripping. For the other cases, one has to be totally "tripped out" not to notice the distortion that the amp will produce before tripping.
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Old 31st March 2008, 20:47   #7
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Thats a neat explanation by DerAlte. I am now convinced that I can bridge in Mono Mode from 4 channels. Its like bridging 4 channels to 2 channels. Like Derlite said "left to the amp 'front' set, right to the amp 'rear' set"

Ramie : You said "be sure not to Connect Comps in Bridge mode." Is it true that Components cannot be connected in bridged mode?

Phew now I am getting confused.
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Old 1st April 2008, 09:31   #8
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Relax, @Kiran, no reason why comps cannot be connected, other than the impedance being too low for the amp. @Ramie must have meant comps and coaxes in parallel. Right, @ramie?

You would need some wiring jugglery to achieve the bridge. You have to use RCA Y cables to feed the L signal from HU to both L & R of amp Front, and R signal to L & R of amp Rear.
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Old 1st April 2008, 10:46   #9
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Quote:
Originally Posted by DerAlte View Post
@Ramie must have meant comps and coaxes in parallel. Right, @ramie?
Absolutely true @ DerAlte advised him to connect the speakers in parallel with proper Phase.Dunno why he is getting soo confused,in connecting the speakers???
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Old 1st April 2008, 17:13   #10
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Ok got the idea now, I know its basics but somehow went over my head.
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Old 1st April 2008, 19:35   #11
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Quote:
Originally Posted by DerAlte View Post
Relax, @Kiran, no reason why comps cannot be connected, other than the impedance being too low for the amp.
Impedence is too low here... 2.65 instead of 4 in bridged mode?
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Old 1st April 2008, 19:55   #12
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2.65 is a higher impedance.So,if an amp can work with 2 ohms, it should have no problem with 2.65.
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Old 1st April 2008, 23:05   #13
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But again bridged mode is 4 Ohms
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Old 2nd April 2008, 11:30   #14
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Impedances are nominal. I would not worry with an impedance of 2.65 ohms.
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