A simple battery test takes the the ears (and room) out of the equation. (1.5v battery please)Originally Posted by Fort Knox
A simple battery test takes the the ears (and room) out of the equation. (1.5v battery please)
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
Hey guys, good point. A speaker out of phases could produce low bass, and sound pretty awful, I agree. I rechecked the wires from the receiver to the speakers, they look right...though, I'm not sure I would mention it if they didn't
Internally, I made all the connections, and they should be right...
I really think that it's the room acoustics, but there is no denying what you guys are saying and now I'll doubt myself until I open everything up and verify that everything is connected properly. I let you know if I find a blunder anywhere.
Just connect a 1.5v battery to the input terminal and make sure the same polarity offers the same reaction on the LE14 on both speakers. You don't need to open anything to do that. They're probably correct but it's an easy test to perform and then you can move on.
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
Just looking at the first pictures, here are a few thoughts.
Big room with high ceilings. Lots of air to energize and that absorbs bass
Looks to be even more space on the other side of that wall. More air to energize
Walls and floors seem to be "hard" and highly reverberative
Meaning bass is absorbed by a huge volume and mids are amplified by the hard surfaces. You got the worst of both worlds.
Perhaps a sub (or two) can help.
Thanks Lee. The room dynamics was not only something I thought was an important part, but also what I hoped to understand better. The big tall wall/room makes sense for bass loss, and the midrange is amped and scattered by the floor.......it seems.Just looking at the first pictures, here are a few thoughts.
Big room with high ceilings. Lots of air to energize and that absorbs bass
Looks to be even more space on the other side of that wall. More air to energize
Walls and floors seem to be "hard" and highly reverberative
Meaning bass is absorbed by a huge volume and mids are amplified by the hard surfaces. You got the worst of both worlds.
Perhaps a sub (or two) can help.
Ok, I did the battery test BMWCCA (BTW I have always wondered what it stood for?) These are the 2214's not the LE14's though. I just used a AA and touched the positive to the positive input of the speakers wire's, both woofers went in. So, at least that much is right. I opened them up and everything looks ok. The crossovers and L-pads came to me all hooked up, all I did was extend the wire to the drivers, that all seemed fine.
I also switched the input wires to one speaker. It was kind of hard to tell at first, but then I could here that the stereo imaging was not in sync. The woofers seemed to hit a litter harder in the lower midrange, but lacked deep bass. It wasn't as obvious an effect as I would have thought, but it was a bit more obnoxious.
Someone else might not hear they're sound as bad, but having heard these speakers in my house, I know how different they can be, how good they can be.
Has anyone else had a room they had to dial the L-pads way down for? What are typical JBL monitor L-pads ranges?
.
Could it be BMW Car Club of America?
BTW I have medium size speakers that sound empty and gutless in one room, yet are deep and full in a smaller room.
DOH! Yeah, that's too rich for my blood, maybe that's why I didn't catch it!Seriously though, thought it would be something speaker related.
My L100T(3)'s at home like to be nestled... They have 240ti's flanking them, and a big heavy cabinet in the middle, take them out of there and they don't have the same character..
The "Fletcher-Munson Curves" Reverberation Tutorials bellow will explain why your under damped huge room has no bass..... I did have my recently purchased Adcom 555 hooked up over here...it still sounded pretty horrible.... I think that some improvement can be made, but I'm wondering how much of a problem the room itself will be, or if it's a lost cause....
First note that a comfortable average loudness level of 80 db-C is typical, but perceived loudness depends on two items.
#(1)The sound pressure level(SPL), and #(2) the duration of the sound as defined by the reverberation time constant(RT60)which adds "very loud" duration to the audio signals.
In your live room the RT60 time constant may be as high as 3 seconds which will increase the perceived mid frequency spectrum loudness by as much as 25 to 30 db due to the reverberation duration which continues to stimulate your hearing, forcing you to reduce the volume at least 20 or 25 db, which according to the "Fletcher-Munson Curves results in approximately 30 to 40 db decrease in perceived loudness of the bass.
The Tutorials on #(1)Reverberation & #(2)The "Fletcher-Munson Curves"
#(1)...In acoustics the reverberation time at a particular frequency is defined as the time taken for sound to decay by 60 dB; often abbreviated "RT60" or from the first 20 dB or 30 dB of decay [T20 or T30]. If the overall RT60 is more than 1.5 seconds, the room acoustics will be "live" and echoy.
Too little reverberation and sound does not travel well throughout the room ,& the acoustics are dead and rather unpleasant. Too much reverberation and clarity is lost in a confusing "mish-mash" of echos.
"The optimum reverberation time is given at 500 Hz. Important for music, the reverberation at low frequencies should be increased so that the time constant at 125 Hz is up to 1.5 times the value at 500 Hz.
Reverberation sound components propagating through air, in the process of bouncing back and forth in random modes off the acoustic environment boundaries, do experience increasing attenuation at a rate of 6 db per octave with increase in frequency.
In other words, the reverberation field density increases inversely to frequency, yielding a magnificent warmth in the lower frequencies all the way down to the sub bass.
Unfortunately this feature is corrupted when you need to reduce the amplifier gain drastically to bring the mid band frequencies under control in a very live room.
I remember in 1960, I made a recording with an Ampex 350 tape recorder in a large church here with the floor totally covered with a huge rug. All the seating was fully covered with plush upholstery. We had nearly 100 percent audience attendance.
Note that each person in attendance provides the acoustic absorbsion equivalent of one open window. In the playback of that tape, the bass was simply stunning.
#(2)...The Equal-Loudness Contours often referred to as "Fletcher-Munson curves" were developed by Bell Laboratory researchers in the 1936 Worlds Fair on some 1000 hearing subjects. Loudness levels are arrived at by reference to equal-loudness contours of sine waves of differing frequencies. An equal-loudness contour is a measure of sound pressure (db SPL), over the frequency spectrum, for which a listener perceives a constant loudness.
You can see here that "Perceived Loudness" depends on the SPL of the sound, and as the SPL decrease, the perceived loudness of frequencies below 1,000 Hz, decrease rapidly while the midrange loudness remains proportional to the sound level pressure.
Yes, we have a winner!
Some of us have more than one hobby!DOH! Yeah, that's too rich for my blood, maybe that's why I didn't catch it!
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
That's Cool! So BMW (Yes, we have a winner!
Some of us have more than one hobby!), you didn't seem to want to chime in on the room acoustics. Not convinced it's the issue?
I kid, but your opinion is valued...
The "Fletcher-Munson Curves" Reverberation Tutorials bellow will explain why your under damped huge room has no bass.
First note that a comfortable average loudness level of 80 db-C is typical, but perceived loudness depends on two items.
#(1)The sound pressure level(SPL), and #(2) the duration of the sound as defined by the reverberation time constant(RT60)which adds "very loud" duration to the audio signals.
In your live room the RT60 time constant may be as high as 3 seconds which will increase the perceived mid frequency spectrum loudness by as much as 25 to 30 db due to the reverberation duration which continues to stimulate your hearing, forcing you to reduce the volume at least 20 or 25 db, which according to the "Fletcher-Munson Curves results in approximately 30 to 40 db decrease in perceived loudness of the bass.
The Tutorials on #(1)Reverberation & #(2)The "Fletcher-Munson Curves"
#(1)...In acoustics the reverberation time at a particular frequency is defined as the time taken for sound to decay by 60 dB; often abbreviated "RT60" or from the first 20 dB or 30 dB of decay [T20 or T30]. If the overall RT60 is more than 1.5 seconds, the room acoustics will be "live" and echoy.
Too little reverberation and sound does not travel well throughout the room ,& the acoustics are dead and rather unpleasant. Too much reverberation and clarity is lost in a confusing "mish-mash" of echos.
"The optimum reverberation time is given at 500 Hz. Important for music, the reverberation at low frequencies should be increased so that the time constant at 125 Hz is up to 1.5 times the value at 500 Hz.
#(2)...The Equal-Loudness Contours often referred to as "Fletcher-Munson curves" were developed by Bell Laboratory researchers in the 1936 Worlds Fair on some 1000 hearing subjects. Loudness levels are arrived at by reference to equal-loudness contours of sine waves of differing frequencies. An equal-loudness contour is a measure of sound pressure (db SPL), over the frequency spectrum, for which a listener perceives a constant loudness.
You can see here that "Perceived Loudness" depends on the SPL of the sound, and as the SPL decrease, the perceived loudness of frequencies below 1,000 Hz, decrease rapidly while the midrange loudness remains proportional to the sound level pressure.
Wow! I didn't expect such an effort, Thanks!! It may take me awhile to fully comprehend what you have put out there for me. I hope you don't take offense to my ignorance. When you say "forcing you to reduce the volume" do you mean on the receiver, on on the L-pads? When I turn down the high and mids, the bass is essentially turned up in comparison to mid-range loudness. This helps. Too little reverberation is where I am currently at with the mid and high turned down. The room offers little hope for balance, at least I can get the reverberation and the loudness turned down, and get some bass going. It's not perfect for sure....
Thanks again, you are a scholar, and a gentleman..
Sorry. Still have my mind on Woody's 250ti clone project!
I suppose you could always try your setup in a different room. Probably easier said than done.
Room acoustics seem to be one of the few variables remaining.
". . . as you have no doubt noticed, no one told the 4345 that it can't work correctly so it does anyway."—Greg Timbers
Many thanks for the kind words!
I refer to...."forcing you to reduce the volume on the receiver".... This does cut the bass perceived by the human ear more rapidly__ as described by the "Fletcher Munson curves"__ than the volume control reduction of the mid high frequencies as indicated by "Fletcher Munson curves."
Mother nature is very clever, and very intolerant. Our hearing is most sensitive in the mid high frequencies due a resonance in the ear cavity leading to the ear drum and it rings like a pipe organ pipe.
There is a good reason for our low frequency sensitivity declining more rapidly than the mid frequencies at lower SPL, because low frequency energy severely masks the higher frequency perception. My best, herki[Quote/]
Hey pathfindermwd
My upstair living room looks very much like in your picture. Cathedral ceiling, hardwood. Plus one side opened to a dining room. Even with an 8'x 8' shaggy carpet and fluffy sofas, I couldn't get rid of the reverberation in th mids, which "killed" the bass (proportionally speaking). I removed the TV and sound system from that room. It was too painfull and it made me dizzy. The same system that was awfull in the living room got moved to the bedroom, where it sounded perfect with wall-to-wall carpet and big bed.
In your case, if you want to keep some music in there, you'll have to be creative with room treatment.
Very succinct, Lee in Montreal, your advice to move to a smaller quiet room is right on.herki[Quote/]Hey pathfindermwd
My upstair living room looks very much like in your picture. Cathedral ceiling, hardwood. Plus one side opened to a dining room. Even with an 8'x 8' shaggy carpet and fluffy sofas, I couldn't get rid of the reverberation in th mids, which "killed" the bass (proportionally speaking). I removed the TV and sound system from that room. It was too painfull and it made me dizzy. The same system that was awfull in the living room got moved to the bedroom, where it sounded perfect with wall-to-wall carpet and big bed.
In your case, if you want to keep some music in there, you'll have to be creative with room treatment.
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