whether bridging and parallel wiring causes any degradation in sound quality?

[makanaka]

hello friends
in my quest for a good 2 channel sq amplifier, that too on a limited budget, i came across an option to buy a low rms 4 channel amplifier (jbl gto 504) and to bridge the 4 channels (2 into 1 + 2 into 1), to power my 75 rms front components, now i have a slightly technical query, when i bridge 2 channels of an amplifier, then what kind of an output do i get, i mean is it a mono signal or a stereo and which is better quality wise, a single powerful channel powering a single 4 ohm component or 2 channeld bridged into 1 powering a single 4 ohm component, my only compulsoy requisite is total sq setup and the second part of my query is that does using the all 4 channels of an amplifier into bridged mode (2 into 1 + 2 into 1) to power the front 2 component 4 ohms each cause any degradation in sound quality? some sites recommend to never use all the channels of an amplifier in bridged mode, so where does that leave me, either to do the above or to wire my components in parallel so it presents a 2 ohm load to the amplifier, then that brings me to the third part of my query that if i use my components in parallel(2ohms)mode, will that cause any degradation in sound quality? gurus pleasethrow some light on the subject matter.

[DjNik]

The suggested way of wiring is not correct & hence not recommended.

[Bass&Trouble]

Originally Posted by makanaka

when i bridge 2 channels of an amplifier, then what kind of an output do i get, i mean is it a mono signal or a stereo and which is better quality wise,

Very Navinesque intentions.

There are many amplifiers that allow both summed mono and stereo bridging. It is a matter of which terminals are being used, and the input selector switch. I am not sure the JBL will provide this feature.

However, there is a workaround. Use a Y Splitter to split the left channel and feed it to both the inputs in Channel A, or 1/2, as the case may be. Likewise, right goes completely into Channel B or 3/4. And then connect the left speaker to Channel A and right speaker to channel B. You will have bridged stereo this way.

Originally Posted by makanaka

some sites recommend to never use all the channels of an amplifier in bridged mode,

There are very few amps I have come across that have been unsuitable for operation as stated. One used to be a 4-ch from Sony. You will not face this issue with JBL. Especially when you are running the channels full range.

Originally Posted by makanaka

either to do the above or to wire my components in parallel so it presents a 2 ohm load to the amplifier, then that brings me to the third part of my query that if i use my components in parallel(2ohms)mode, will that cause any degradation in sound quality?

I am not able to understand how you will benefit by doing this.

If you have just one set of comps, you will connect them to the same channel and lose stereo, AND have another channel idle in case of a 2-ch amplifier (3 for a 4-ch amplifier). Plus the output on 2 ohms in one channel will not be more than the output of both channels combined at 4 ohms.

If you have two sets of comps, you can do this and retain stereo but lose on fader. Yet with a 4-ch amp, you have 3 channels idle! And I do not suggest bridged 2 ohm with the concerned amp.

None of the above will however have a significant degrading or improving effect on "sound quality". At best, your comps will run healthier on account of the greater power running to them.

[DerAlte]

Why go to such lengths for the sake of matching the numeric figures from the specs? Why do you consider 50W rms / channel low without actually experiencing how loud it would go with the 75W components? You keep saying SQ, but ultimately want to reach SPL levels on a budget somehow? Think again, sir! Please audition first - any good dealer should be able to demonstrate the effect of independent Front and Rear, as well as summed Front and Rear.

IMHO summing FL+RL (and FR+RR) and then bridging the amp to 2 ch will give you a stereo image which will sound like headphones - SQ without decent imaging!!!

[makanaka]

thanks friends for your replies, deralte, i dont have an idea how loud will a 50w rms input on a 75w driver sound, thats why just to be on the safe side i wanted to get an amplifier that can use the components to its full potential, i will try to listen to a 50w rms regular 2 channel amplifier before buying it, for sure, bass and trouble , i was thinking of bridging the 2 channels of a 2 channel amplifier and then wiring my only 1 pair of components to them in parallel, theoretically that way i will have the bridged mono output which is almost double to that of a single channel and again because now the components are presenting the load of 2 ohms, again the power deficiency would be addressed, this is just a query and i am trying to explore various options so pardon my ignorence friends ,