Watts per channel needed??

[jeepers59]

Looking at 2 channel stereo receivers with 75 - 80 wpc. is that enough?

running Polk S4 (book shelf) speakers but may upgrade down the road to something bigger.

room size about 250 sq feet

I don't listen to load music but sometimes do.

 

[Verdinut]

Looking at 2 channel stereo receivers with 75 - 80 wpc. is that enough?

running Polk S4 (book shelf) speakers but may upgrade down the road to something bigger.

room size about 250 sq feet

I don't listen to load music but sometimes do.

Your listening room is rather small. In my opinion, a 75w/ch amplilfier should be sufficient. Also, those S4's would have a power handling of 100 Watts. That means that they would only handle 100w for a fraction of a second only. Actually, they only need a few watts to output an average reasonable listening SPL.

 

[jeepers59]

Your listening room is rather small. In my opinion, a 75w/ch amplilfier should be sufficient. Also, those S4's would have a power handling of 100 Watts. That means that they would only handle 100w for a fraction of a second only. Actually, they only need a few watts to output an average reasonable listening SPL.

thanks, I didn't realize that, but good to know. so they are efficient? If I want to upgrade speakers in the future what do I need to look at in order to drive them with a 75 wpc receiver? I probably would be looking at something closer to 20 - 20khz but not huge in physical size, maybe something a little bit bigger.

 

[John Parks]

thanks, I didn't realize that, but good to know. so they are efficient? If I want to upgrade speakers in the future what do I need to look at in order to drive them with a 75 wpc receiver? I probably would be looking at something closer to 20 - 20khz but not huge in physical size, maybe something a little bit bigger.

As a general rule most mainstream loudspeakers are relatively efficient and 75WPC should be sufficient for your needs (from what I have read).

Now, selecting a speaker that reproduces the 20-20kHz range is another matter entirely...

 

[Pogre]

thanks, I didn't realize that, but good to know. so they are efficient? If I want to upgrade speakers in the future what do I need to look at in order to drive them with a 75 wpc receiver? I probably would be looking at something closer to 20 - 20khz but not huge in physical size, maybe something a little bit bigger.

Those speakers are rated at 91 dB according to Polk, but wouldn't be surprised if they were more along the lines of 88 or 89 dB which is still respectable.

This SPL calculator is a popular toy around here. You enter the info into the fields and it will calculate the power requirements with your speakers at a set distance. Wonderful little tool.

 

[jeepers59]

Those speakers are rated at 91 dB according to Polk, but wouldn't be surprised if they were more along the lines of 88 or 89 dB which is still respectable.

This SPL calculator is a popular toy around here. You enter the info into the fields and it will calculate the power requirements with your speakers at a set distance. Wonderful little tool.

thanks for the calculator, i'll check it out. what does the db rating mean? is it at 100 w?

 

[jeepers59]

As a general rule most mainstream loudspeakers are relatively efficient and 75WPC should be sufficient for your needs (from what I have read).

Now, selecting a speaker that reproduces the 20-20kHz range is another matter entirely...

What room square footage would I be pushing the 75w pc ? thanks

 

[Pogre]

thanks for the calculator, i'll check it out. what does the db rating mean? is it at 100 w?

The dB rating is the output level of your speakers with 1 watt at 1 meter. So with a single watt your speaker will produce 91 dB from a distance of 1 meter. That's why sensitivity ratings can be more meaningful than wattage ratings. It take a doubling of amp power to gain 3 db. If a speaker is 3 dB more sensitive than another (91 dB vs 88 dB, for instance) the 88 dB speaker will need twice the power to reach the same spl.

 

[jeepers59]

thanks for the calculator, i'll check it out. what does the db rating mean? is it at 100 w?

plugging different powers doesn't change DB SPL much. is it logarithmic ?

 

[Pogre]

plugging different powers doesn't change DB SPL much. is it logarithmic ?

I explained above. You need a doubling of power to gain only 3 dB. If 100 watts gives you say, 100 dB at 10 feet, then you will need 200 watts to hit 103 dB.

 

[jeepers59]

I explained above. You need a doubling of power to gain only 3 dB. If 100 watts gives you say, 100 dB at 10 feet, then you will need 200 watts to hit 103 dB.

wow, that's interesting.

I looked on a db chart just to see an estimate of db range of my listening, I would say most of it is done between say 40db to 85db. so on the calculator. if I use 88 db (rating), power = 25w, distance of 20 feet > the answer is DB SPL = 89 db

so with a 75wpc amp I should have plenty of room?

 

[Pogre]

wow, that's interesting.

I looked on a db chart just to see an estimate of db range of my listening, I would say most of it is done between say 40db to 85db. so on the calculator. if I use 88 db (rating), power = 25w, distance of 20 feet > the answer is DB SPL = 89 db

so with a 75wpc amp I should have plenty of room?

Yup. It's surprising, huh? I'd say most of the time, most of us are only using a watt or 2 for normal listening. Every once in a while I like to really turn it up but I'll bet I have yet to come close to pushing my amp's limits.

 

[SPLaddict90]

how skewed are the sensitivity ratings from the companies in home audio?
I know in the car audio industry they just throw the numbers around and when you calculate it a woofer boasting a 91db rating realistically have 87db. obviously these numbers mean pretty much nothing to us as we tend to over power our woofers with 1.5-3x the rated power to combat impedance rise but were just trying to get loud lol.

 

[SPLaddict90]

Yup. It's surprising, huh? I'd say most of the time, most of us are only using a watt or 2 for normal listening. Every once in a while I like to really turn it up but I'll bet I have yet to come close to pushing my amp's limits.

I have one of these for car audio but it will work with home as well, https://www.ebay.com/itm/223688956563
once my setup is done ill take a little video you'll see the real world power as well as the changes in impedance. nifty little device, I also have a really nice oscope so ill be able to see where everything clips at.

 

[Pogre]

how skewed are the sensitivity ratings from the companies in home audio?
I know in the car audio industry they just throw the numbers around and when you calculate it a woofer boasting a 91db rating realistically have 87db. obviously these numbers mean pretty much nothing to us as we tend to over power our woofers with 1.5-3x the rated power to combat impedance rise but were just trying to get loud lol.

It depends on the company. I'd say for the most part the better manufacturers are pretty accurate to even conservative in some cases. There are a few known to fudge, tho I'd say a difference of 4 dB would be enough to ruffle some feathers.

 

[jeepers59]

Yup. It's surprising, huh? I'd say most of the time, most of us are only using a watt or 2 for normal listening. Every once in a while I like to really turn it up but I'll bet I have yet to come close to pushing my amp's limits.

Yes, very surprising. I thought the SPL would fall off at a faster rate when distance is increased.

How do you narrow down a speaker selection search? say you want something that favors more bass or treble or mids is there a spec. you look at? When I bought my polks, i listen to a dozen or so different speakers and like these the best.

 

[Verdinut]

Yes, very surprising. I thought the SPL would fall off at a faster rate when distance is increased.

How do you narrow down a speaker selection search? say you want something that favors more bass or treble or mids is there a spec. you look at? When I bought my polks, i listen to a dozen or so different speakers and like these the best.

To answer your question, the only sure way to see a speaker response is to look at and be able to properly interpret its frequency response curve provided from a reliable testing source such as Audioholics ans a few other serious audio magazines. In addition to having access to frequency response curves, it's always good to be able to hear the product before purchasing it.

 

[Pogre]

Yes, very surprising. I thought the SPL would fall off at a faster rate when distance is increased.

How do you narrow down a speaker selection search? say you want something that favors more bass or treble or mids is there a spec. you look at? When I bought my polks, i listen to a dozen or so different speakers and like these the best.

That is such a tough one to answer because the only real way to know is to get out and listen. Most retail environments are set up to catch your eyes and not your ears so it's hard to get a good feel for speakers like that. I think what helped me was hearing a true audiophile system, properly set up to maximize the listening experience. It gave me a point of reference.

The more quality systems you can listen to the better. Search for any hi fi audio places or Best Buys with Magnolia stores in them in your area. The Martin Logan electrostatic speakers they sell at the latter are very nice sounding speakers when you're in the sweet spot and they usually have a pair of those set up in a good spot. Bring music you're familiar with, shmooze the salesperson a little and you can usually get them to set you up for some demo'ing.

I will say that if you listen to different receivers and hear big differences it's most likely going to be due to differences in gain structure, or volume (1 or 2 dB louder can be perceived as sounding "clearer") and/or whatever DSP is engaged in one vs another. For instance, if one has DSP turned on and the other doesn't there's definitely going to be a noticeable difference.

 

[lovinthehd]

The dB rating is the output level of your speakers with 1 watt at 1 meter. So with a single watt your speaker will produce 91 dB from a distance of 1 meter. That's why sensitivity ratings can be more meaningful than wattage ratings. It take a doubling of amp power to gain 3 db. If a speaker is 3 dB more sensitive than another (91 dB vs 88 dB, for instance) the 88 dB speaker will need twice the power to reach the same spl.

One qualification, the standard is actually 2.83V at one meter distance.....(8 ohms is 1 watt, but 4 ohms would be 2 watts).

 

[lovinthehd]

Yes, very surprising. I thought the SPL would fall off at a faster rate when distance is increased.

How do you narrow down a speaker selection search? say you want something that favors more bass or treble or mids is there a spec. you look at? When I bought my polks, i listen to a dozen or so different speakers and like these the best.

Try this http://www.sengpielaudio.com/calculator-distance.htm