Say I have a speaker rated at 50 watts RMS with a 92db sensitivity rating, and a speaker rated at 70 watts RMS with a 86db sensitivity rating (both measured at 1w/1m), and I put the recommended RMS power to each, which will sound louder? and why?

 

There is no way of knowing becouse ALL speaker manufactures lie and twist numbers to thier favor. The consumer electronics market is a lousy place for an honest audio engineer to work. Trust me on this.

 

I think i agree with you on that one. I've heard of manufacturers doing that alot, especially now. I saw a pair of $2000 home speakers the other day. It consisted of 2 floor type speakers. In each box there was a sub, midrange, and tweeter. Well, come to find out, they only used $75 raw speakers, what costs so much was the design to make the "perfect" enclosure for those speakers! I couldn't believe it!

 

Most call that...........Bose.

 

Very true, don't get me started on Blows....i mean Bose....haha

 

Another good question MR Clarke....could it be considered a rhetorical question?

Anyhow.....as far as the speakers are concerned, frequency response will also have a direct impact on the final result....as will the amplifier's power supply pushing the speakers. The materials used on the speaker itself will also have a key role as some cone maerials are sturdier andreproduce the sound much better than the distortion prone paper elements...

As far as tweeters and midranges go.....the titanium dome tweeters offer much crisper highs due to the rigidity of the metal dome.....while the silk dome
or mylar dome midranges smooth out due to the dampening effect of these two materials...

All things created equal (amplifiers having same sig to noise ratio and wattage/power supply) the more efficient speaker (higher db rating) will
more often than not, put out more dbs of sound.

Only an RTA would tell for sure....

 

There aren't any regulations within the car audio industry, which is why I use my ears to do the final testing. Sensitivity and freq. response ratings are the most fudged numbers within the car audio industry.

Jclarke, don't forget enclosure construction, design (they test hundreds of designs during R&D) and the proper design/integration of the crossover. Overhead, shipping, and marketing play a role, too.

BUT, you can go to PartsExpress or Madisound and buy all the raw drivers, x-over parts, cabinet building materials, etc., many manufacturers use and build/design your awesome set of speakers.

 

Mr. jclarke, you have asked an interesting question. I am not an expert, or an engineer-but I have some amature experience with audio. Here goes...
The 50w. and 70w. speaker ratings are power handling capabilities. That is, the speaker can handle that much average power without burning up. I am not sure, but I think this has to do with the ability to disapate heat from the coils driving the speaker cones.
Now, 3db is a half power change. That is, if you run the same power into a 86db sentsitive speaker you get half the power out as if you ran it into an 89 db sensitive speaker.
To make up for a 3db change you either have to accept half the power output (less sound) or double the power-in (to make up for the 3db change) to keep the same sound level.
If you ran a 92db speaker with 50w you would get a loud speaker. If you wanted the same loudness from an 86db speaker you would really have to increase the power to the speaker. The difference between 92 and 86 is 6db, or think of it as 3db plus 3db.
You were using 50w of power on a 92 db sensitivity speaker. To get the same power out of an 86db speaker you would need to double the power (3db), and then double it again (3db).
Back to your question, I think that you would have to drive the 86db speakers with a 200w amplifier to deliver the same sound level as the 92db speakers with 50w. (50wx2=100wx2=200w)
If you have such a choice, I would buy the more sensitive speaker (92db), if I liked the sound, and spend what I saved on a more powerful amp to buy a better quality front end and amp.
Your question should be sent to Car Talk for Tom and Ray to use as their "Puzzler." It was great and I am sorry that I could not answer more clearly. But I tried!
jimmyj
04 F150 XLT SCab 5.4L

 

Gentlemen, I must correct someting I said about ALL speaker makers lieing on thier specs. This comment was followed by a post about Bose speakers. To set the record straight, Bose is the most accurate company when it comes to living up to thier claims. Let me explain before the ropes come out. I deal with high end sound systems. The sound system that my company chose to use on the 1996 and 2002 Olympic torch train were Bose speakers driven by six 1000 watt QSC amps. We mounted 8 line radiator speakers ( $3000 each) on the corners of car and 4 low freq. bass bins ( $4500 each) inside the carbody ported out. This is the setup that we traveled 7,000 miles around the country for the 96 Atlanta Olympics and another 4,000 miles for the 2002 Salt Lake Olympic games. Although these speakers saw the worst conditions possible, they never failed, and in fact in testing them in the railroad yard at the end of the Salt Lake games they sounded strong and clear with full dynamic response a full quarter mile away! Some of the Carmen in a near by shop came out to see what all the Olympic music was all about. Those my friends are speakers you can live by. IMHO

 

The best speakers are the ones that sound best to you. Everybody hears differently. If you follow all the laws of electricity and the speaker specs are true then the 92db would be louder.

 

Bose may be accurate with their claims, but are nowhere near the best! Especially their receivers....ugh! but this thread isn't about that, so lets return to the subject....

jimmyj, I've heard the same thing before about the 3db change. So that has to make someone wonder, what makes the 86db speakers cost more, it sounds to me they just need more power and money, to crank as loud.

 

Something to ponder...

Decreased sensitivity is usually (though not always) attributed to increased moving mass. When you increase moving mass, you decrease sensitivity and efficiency (both are different, contrary to many using the terms interchaneably). The increased mass will allow the speaker to drop lower and easier, at the expense of needing more power to achieve the same spl as your higher rated sens/eff speaker.

 

You have an interesting point there......The material used on the moving
mass of the speaker will have a direct impact on the accuracy of the sound being reproduced....

The moving mass will also represent an electrical load on the circuit
which is why alot of companies are coming out with composite materials
to fabricate the speaker cones.......in order to elevate efficiency.

Another thing to ponder is the materials used in the magnet of the speakers....this also has a direct impact on the flow of electrons moving through the voice coil...

excellent post.

 

The subject of this post; "What makes a speaker better?" is so much more involved than sensitivity ratings and RMS ratings. As an extreme example, you can take a Seas Lotus component set-up and connect it to two different amplifiers of seriously different "build quality", and have true audio heaven or true crapola. System design and a carefully planned installation, and patience and not cutting corners is what separates the men from the boys. You can have a $1000 system that will play rings around a $5000 system under the right circumstances. Same as you can have 86db speakers play rings around 92db speakers. There's no magic involved, just doing things correctly.

 

True, LinearPower...there are a lot of things that affect the final sound of a speaker. Without a specific speaker in question, though, we are stuck making generalizations, though.

Those Lotus' won't sound that good (uh..they'll be more than harsh) unless you throw on a notch filter...