Question about decibel rating

[ArxFatalis]

Hi, I recently purchased a budget " high current" marantz receiver ( marantz SR 4500) . This receiver is hooked up to a pair of MTX tower speakers with 12 subs rated at 200 watts RMS. The marantz is rated at 80 watts maximum power output. Here is my question : In order to really give "juice" to these power hungry speakers do I have to set the decibel rating at the maximum wich would be + 10 decibels ? Would this produce distortion at high volume levels? Can this distortion damage the speakers? If I lower the decibel rating ( example . +3 ) am I really not making the speakers "shine" and sound as they are supposed to ?

Are there major differences between +10 dec and + 5 dec. I read somewhere that it really doesn´t matter cause it goes by the rule of + 3 ?
Anyone there can explain to me this rule ?
Thankyou for your time.

 

[Buckeyefan 1]

MTX home speakers are generally very efficient. Their spl rating is usually 92dB or higher. SPL is sound pressure level, and is rated with a mic at 1 meter at 1 watt. The higher the spl, the louder the speaker at 1 watt. For every 3 dB drop in spl, you need double the amplifier power to obtain the same reading. So a 89 dB rated speaker needs twice the power to play at the same volume a 92 dB rated speaker needs. Klipsch are some of the highest, around 98dB.

Turning your dB up on your receiver will most likely introduce distortion. I would not use the dB as a volume control. To get the most out of your speakers, use a 12ga speaker wire, no longer than it has to be, get the towers in the corners of the room for best bass response, and ventilate your receiver to avoid overheating. Keeping the settings flat (not boosting your treble and bass or dB levels) should allow you to turn up your Marantz quite loud without distortion. You can also use a pure direct mode to avoid distortion.

What happens when you turn up your receiver? Are you not getting the loudness you desired?

 

[jimmit]

Here's a handy link for determining the maximum spl of your speakers at the listening position. It will also give you an idea of "how loud is loud."

 

[ArxFatalis]

The speakers I´m using are rated at 94 decibels which according to what buckeyfan says should be very efficient. So what decibel rating should I give to the speakers , +8 +5 +3 ?

The reason I ask is because I want more power to give the speakers, since I don´t have a power amplifier or "separate system" . That´s why I want to give the most juice the marantz receiver can give in order to make these power hungry tower speakers rock the house.

 

[MDS]

The speakers I´m using are rated at 94 decibels which according to what buckeyfan says should be very efficient. So what decibel rating should I give to the speakers , +8 +5 +3 ?

It sounds like you are asking to what level should you set each of the channel trims on the receiver. There is no set level - it has to be determined by doing a proper calibration. Either use a calibration disc like AVIA or DVE or the internal test tones of the receiver with an SPL meter from Radio Shack and calibrate so that all of the channels are roughly equal in loudness. You can do it by ear and get close if you don't have an SPL meter or don't want to purchase one.

Having each of the channels calibrated properly will go a long way toward getting the most out of your system. Simply bumping each channel to the max or an arbitrary point will do nothing beneficial and has nothing to do with 'giving more power to the speakers'. The power capability of the amp/receiver determines how much power is available and with speakers with 94dB sensitivity, you won't need much to make it really loud unless your room is huge.

 

[Buckeyefan 1]

The reason you don't want to turn up the dB on the receiver is because the speakers will distort sooner. It's sort of like turning up the idle in your car. It will go quicker without hitting the gas, but after you're in 4th gear, it doesn't matter. Think of the old loudness buttons on audio equipment. They will provide a small boost at lower volumes. All the dB's do as stated above is balance out a system based on your sitting distance.

 

[ArxFatalis]

In other words, you are saying that it doesn´t really "increase the volume" if I increase the decibles up to + 10 ? So what decibel rating is the "standard " -3 - 1 0 + 3 + 5 + 8 ? Keep in mind this is just for two tower speakers. Just want to know in your case what range do you set the decibels in your receiver for your front speakers.

 

[MDS]

The reason you don't want to turn up the dB on the receiver is because the speakers will distort sooner.

Are we talking about the same thing? I really don't understand what the original poster means by 'turn up the decibels' unless it is as I guessed above and he means adjusting the channel trims.

Also, Buckeyefan could you explain what you mean by the above quote? The volume control and the channel trims work in concert. Adjusting one affects the other. So if we assume the channels were all balanced properly when set to 0 and the receiver is calibrated to say 85dB at 0dB on the volume scale, then bumping all the channel trims to +10dB would simply mean that the 85dB reference level would now be achieved at -10dB on the volume scale. If that is what you meant by saying the speakers will distort sooner then we are in agreement and are on the same page.

ArxFatalis: There is no 'standard'. As stated the channel trims are solely for the purpose of balancing the output. Even if you and I had the exact same receiver and speakers, it is likely the appropriate setting for the channel trims would be different for my room vs yours.

 

[PENG]

I think you guys are on the same page. I suggest the original poster refer to the manual and read about how to calibrate (or balance) the outputs of his receiver. I hope by now ArxFatalis understands what that level trim adjustments (or what he referred to as "dB") are really for.

As Anonymous explained, it allows you to calibrate (balance) the outputs of each individual channels/speakers to achieve the same sound level (in dB) in a room, using test tones, with the master volume fixed at a pre-selected level, e.g. 0 dB, for the duration of the calibration procedure.

Such adjustments, either up or down, does not get you any more power and will not make you speakers sound louder, at the amps rated output.

 

[ArxFatalis]

Thanks for all of the feedback. I don´t have the spl meter at the moment and I´ve had the speaker settings like thise : LEFT , RIGHT, CENTER, LEFT SURROUND AND RIGHT SURROUND AT + 10 ( thinking erroneously I was giving more power to all speakers) I guess I´ll just put all of´em at 0 . I suppose 0 is neutral position ?

I don´t have an audiophile ear so this is kinda hard for me trying to calibrate these speakers.

 

[Nick250]

Thanks for all of the feedback. I don´t have the spl meter at the moment and I´ve had the speaker settings like thise : LEFT , RIGHT, CENTER, LEFT SURROUND AND RIGHT SURROUND AT + 10 ( thinking erroneously I was giving more power to all speakers) I guess I´ll just put all of´em at 0 . I suppose 0 is neutral position ?

I don´t have an audiophile ear so this is kinda hard for me trying to calibrate these speakers.

Am I missing something here? From your first post I understood that you have only two speakers. Which if true you would set your center, surround left and surround right to "off" or "none".