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Thread: center channel

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    center channel

    What is the fundamental difference between a dedicated center and a left/right bookshelf? Why do some centers have two drivers while others have one? And if two drivers are better than one, why is it that some manufactuers higher end centers only feature one driver while their lower end models have two? Furthermore, B&W recommends the LCR 60 to match with my 601s3's. Why not just use another 601, turn it on its side and use it as the center? Just a curious thought. Thanks

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    Quote Originally Posted by cdn guy
    What is the fundamental difference between a dedicated center and a left/right bookshelf? Why do some centers have two drivers while others have one? And if two drivers are better than one, why is it that some manufactuers higher end centers only feature one driver while their lower end models have two? Furthermore, B&W recommends the LCR 60 to match with my 601s3's. Why not just use another 601, turn it on its side and use it as the center? Just a curious thought. Thanks
    the idea is to spread the sound out across the viewing area of the set.
    I use a CC6 for my 602s2's, BUT A LCR WILL DO FINE.
    Will a 601 work? Sure, dont know how it will sound tho.
    Some think this setup is ideal, BTW, three identical speakers across the front, thats the idea behind the LCR, hence its name, LCR (left, center, right)
    If you do use the 601 in the center I'd rather have it standing straight up tho.
    the LCR is specifically designed to be usuable laying on its side as well as standing up
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    Why is it that LCR speakers can be placed either vertically or horrizontally and still be sounically sound but a bookshelf speaker cannot? I'd like to know for accademic reasons.

    Personally I think I'd keep bookshelves upright simply because the manufacturer recommends so. Thanks.

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    Hi cdn guy,

    I'm having a similar problem, as outlined in thread JR149s in parallel - is possible? (JR149s in parallel).


    I wish to have a balanced centre speaker covering a wide projector screen. I feel one upright speaker is not enough and by placing the speaker on its side will give an imbalance to onscreen voices. My bookshelves are 1970s and so there is no dedicated centre speaker available. I believe the tweeter sound is too directionally narrow and if I put one speaker on its side then I might get female voices on one side of the screen and male on the other, so I intend wiring two bookshelves side by side on their sides to spread and balance the sound.

    In answer to your query about using an ordinary speaker in place of a dedicated centre speaker ... in my opinion a lot of it is commercial bollocks. I leave myself open to correction here but my understanding is that in the early days the centre speaker took care mainly of human voices displayed directly on the screen, so the crossovers and bandwidth were geared towards the lower and upper reaches of the human voice. However, nowadays there is much more information being recorded onto the centre channel of movies and so the speaker should be capable of a much wider range of intelligible sound. Hence I believe that a matching L or R speaker should fit the bill, instead of a dedicated centre speaker.

    There are others here who will correct my simple understanding of these matters.

    Slippers at the ready

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    So i replaced my cc6 with a 303 for my centre, turned it on its side (which went horrifically against manufacturers recomendations) and it sounded perfectly fine. In fact, it sounded MUCH better than the cc6 and blended better with my 601 s3 than my dedicated centre efer did. Here's proof that 1) your speaker will not self explode if used sideways and 2) it may make perfect sense in some cases to use identical LCR speakers if you have smaller speakers.

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    Quote Originally Posted by cdn guy
    So i replaced my cc6 with a 303 for my centre, turned it on its side (which went horrifically against manufacturers recomendations) and it sounded perfectly fine. In fact, it sounded MUCH better than the cc6 and blended better with my 601 s3 than my dedicated centre efer did. Here's proof that 1) your speaker will not self explode if used sideways and 2) it may make perfect sense in some cases to use identical LCR speakers if you have smaller speakers.
    that speaker is not designed to be used on its side.
    TWEETERS tend to be on the top because high frequencies are highly directional,
    and are stopped by obstructions, lower frequencies are less directional and more dispersed. Also it takes more energy to produce high frequencies, and when your speaker is laying on its side a lot is being absorbed into the shelf its on.
    Also a lot of speakers are time aligned, this is important for proper soundfield
    imaging, this is the effect of someone standing in one place singing, or a piano in one place , etc. Your imaging will go to crap if that speaker isnt used like it was meant to be.
    YOU WANT TO USE THREE IDENTICAL SPEAKERS IN THE FRONT? fINE, BUT THEY ALL NEED TO BE STANDING like they were meant to be.
    On the other hand if keeping your speakers from "blowing up" is your lowest common denominator go to it, you probably wont even notice what youre missing.
    After all, men came to America looking for freedom, they came to south America looking for gold.
    They got off of the boat to go to the bathroom in Canada and got left.
    Thanks for proving that old canard
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    Pix has it...sort of...

    Quote Originally Posted by pixelthis
    that speaker is not designed to be used on its side.
    TWEETERS tend to be on the top because high frequencies are highly directional,
    and are stopped by obstructions, lower frequencies are less directional and more dispersed.
    Correct.

    Also it takes more energy to produce high frequencies, and when your speaker is laying on its side a lot is being absorbed into the shelf its on.
    Huh? More energy to produce higher frequencies? Tweeters typically have higher sensitivity and impedance, demand less current etc. Woofers are the power hogs.

    Also a lot of speakers are time aligned, this is important for proper soundfield
    imaging, this is the effect of someone standing in one place singing, or a piano in one place , etc. Your imaging will go to crap if that speaker isnt used like it was meant to be.
    YOU WANT TO USE THREE IDENTICAL SPEAKERS IN THE FRONT? fINE, BUT THEY ALL NEED TO BE STANDING like they were meant to be.
    Correct again

    On the other hand if keeping your speakers from "blowing up" is your lowest common denominator go to it, you probably wont even notice what youre missing.
    Afgold.
    They got off of the boat to go to the bathroom in Canada and got left.
    Thanks for proving that old canard:1ter all, men came to America looking for freedom, they came to south America looking for :
    Drugs are bad, mmmkay..you shouldn't do drugs, mmmkay...

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    Quote Originally Posted by pixelthis
    TWEETERS tend to be on the top because high frequencies are highly directional,
    and are stopped by obstructions, lower frequencies are less directional and more dispersed.
    Tweeters can be anywhere on a speaker but are placed on a level where the manufacturer believes your ears will be. It is suggested that the centre speaker be likewise positioned. Normally between 34 and 37 inches off the ground depending on your chair, hence a proliferation of standmount sizes You will see centre speakers on top or below a screen. The first point of reference is to have the tweeter pointing at ones ears. So this is not a problem when the level of the tweeter is in line (off the ground) with the left and right speakers.


    Quote Originally Posted by pixelthis
    and when your speaker is laying on its side a lot is being absorbed into the shelf its on.
    This is true of any speaker, big or small, square or round, upright or laying down. Of course it's important to secure or de-couple, as best you can, from whatever it's resting on.



    Quote Originally Posted by pixelthis
    Also a lot of speakers are time aligned, this is important for proper soundfield
    imaging, this is the effect of someone standing in one place singing, or a piano in one place , etc. Your imaging will go to crap if that speaker isnt used like it was meant to be.
    YOU WANT TO USE THREE IDENTICAL SPEAKERS IN THE FRONT? fINE, BUT THEY ALL NEED TO BE STANDING like they were meant to be.
    :
    Surely 'time alignment' is to do with positioning, within the speaker, of the drive units so that the upper and lower bandwidths set off from the speaker as a single 'parcel' on its way to you in your listening position!
    As long as the front of the centre speaker is roughly in line with the L & R speakers then the issue is solved.

    It is possible that a manufacturer might design a centre speaker so that the drivers are positioned inside the speaker cabinet at an angle so as to point up or down to ones seating position from the screen, but I see no reason where a matching Left or Right speaker cannot be used as a centre if positioned properly.

    So, to conclude, I believe if you wish to use a speaker similar to your L&R speakers as a Centre speaker on its side then you should try to position the centre speaker in the following manner.

    1. Tweeter to be at same height as L&R speakers.
    2. Front of speaker to be on the same plane as L&R speakers.


    Slippers On

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    Quote Originally Posted by Slippers On
    Surely 'time alignment' is to do with positioning, within the speaker, of the drive units so that the upper and lower bandwidths set off from the speaker as a single 'parcel' on its way to you in your listening position!
    As long as the front of the centre speaker is roughly in line with the L & R speakers then the issue is solved.

    It is possible that a manufacturer might design a centre speaker so that the drivers are positioned inside the speaker cabinet at an angle so as to point up or down to ones seating position from the screen, but I see no reason where a matching Left or Right speaker cannot be used as a centre if positioned properly.

    So, to conclude, I believe if you wish to use a speaker similar to your L&R speakers as a Centre speaker on its side then you should try to position the centre speaker in the following manner.

    1. Tweeter to be at same height as L&R speakers.
    2. Front of speaker to be on the same plane as L&R speakers.


    Slippers On
    There's more to it than that. Certain speaker alignments exhibit different horizontal and vertical dispersion characterstics. When you tilt a speaker sideways, you take a speaker with a horizontal dispersion strength to a horizontal dispersion deficiency in many cases. What's worse, the further off axis you sit from the sweet spot, the more likely you are to experience lobing, lose accuracy, smear imaging, skew the soundstage, etc. This is somewhate alleviated by distance from the speaker in many rooms, and still in many cases, untrained ears just don't notice or don't care. So for some people who only sit in the sweet spot and never move, just want clean, loud sound, or don't care about other viewers, this isn't an issue, but for others, this approach is just unacceptable.

    For movies, I wouldn't sweat it so much, for multi-channel audio sources such as SACD, I'd work hard to avoid that compromise.

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    Quote Originally Posted by kexodusc
    There's more to it than that. Certain speaker alignments exhibit different horizontal and vertical dispersion characterstics. When you tilt a speaker sideways, you take a speaker with a horizontal dispersion strength to a horizontal dispersion deficiency in many cases.
    I am certainly not dismissing your description as I'm open to help in solving my own problem with a centre channel, however I can't quite get my head around these dispersion characteristics you mention.

    Your argument holds true possibly for reasons NOT to use a Centre speaker as a L or R speaker, but I don't see it the other way around.

    When home Centre speakers first came on the market they were designed as a magnetically shielded means of making voices appear close to the visually moving lips - 'voices' coming from a TV screen. They were cheaply made but attempted to create a 'balance' across the screen - hence a common formation of Tweeter in the middle with Woofers on either side. Since then they have become a little more sophisticated with more information being directed from the processor to the centre channel.

    Then it seems, along came a different breed of centre speaker, some doing away totally with L&R speakers. These contained directional drivers across the horizontal axis and were aimed at more than one seating position/listener. Perhaps in these cases L&R speakers were designed in harmony with these new centre speakers but I don't think this is the case with Cdn Guy's situation.

    The horizontal of music speakers is dictated first and foremost by the position of the tweeter. If all are in line then the next point is the woofer....as pointed out by Pixelthis the lower frequencies are less directional, more dispersed, so the height off the ground is not so important, (within reason).

    Some people experience great SACD with no centre channel.
    Some people find better music with their speakers facing the wall and listening to the rebound.

    In my own case my problem is slightly different than Cdm Guy's in that I will have a wide projector screen to fill with sound so I will be wiring 2 extra L&R speakers as one centre speaker. I am perfectly happy to have these two speakers tilted over in the horizontal position as long as I use my starting point based on tweeter line up and all speakers on the same plane. After that I can play about with positions.

    In Cdm Guy's case, he seems more than happy with his outcome. If it works for him he shouldn't be ridiculed for not adhering to the Manufacturers advice. After all the Manufacturer has a vested interest in selling dedicated centre speakers.



    Slippers On

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    Quote Originally Posted by Slippers On
    I am certainly not dismissing your description as I'm open to help in solving my own problem with a centre channel, however I can't quite get my head around these dispersion characteristics you mention.

    Your argument holds true possibly for reasons NOT to use a Centre speaker as a L or R speaker, but I don't see it the other way around.
    In fact, it is the other way around. The typical mid-woofer, tweeter, mid-woofer alignment is actually a pretty poor choice for center channel duty when on its side. Originally it was very popular because it allowed, as you said, the sale of LCR systems where 3 identical speakers split the front duty. They may have been timbre matched, with great sensitivity, but what the marketing folks didn't tell you is that the D'Appolito array (MTM), while offering great horizontal dispersion, suffers from horrible vertical dispersion as you move off axis- hence, vertical alignment of the tweeter with ear level is critical. Flip the center on it's side and you have speaker that has great vertical dispersion (which is great for having a center channel near the floor, or on top of a TV, not aligned with the L/R speakers) but poor horizontal dispersion. The LCR combo was never meant to have the center lay sideways. The folks 3 feet off axis of the tweeter will notice the lobbing unless they're 12 feet away or more...on axis you're fine, but sit on the outside cushions of the sofa and all bets are off.

    Now you see more 3 way center channels, where a 4th driver has been incorporated. This solves the problems mentioned above, but then of course, there is no option to flip that speaker back vertical and sell the identical LCR's again.

    Anyway, I'm certainly not ridiculing anyone's configuration. Despite the weaknesses I described, when I built my own MTM center channnel, I consciously chose to accept the consequences because of the other benefits. No it's not ideal, but my home theater is made for 2 people who sit within inches of the sweet spot.

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    The higher the frequencies produced, the more energy thats required.
    This is what our electronics teacher had the hardest time conveying to a bunch of
    "bass" addicts who liked it LOUD.
    But its true, Call Ripleys if you want, but it IS true.
    This is why remote phones keep climbing (up to 5.2 gig or higher now) because newer procs can handle the energy requirements, and this is why the higher freaks are more desirable, they pass through obstructions and are more impervious to interferrence.
    For your tweeter to put out that sound requires a lot more energy, look at it this way,
    you hear all of the time about blown tweeters, how much do you hear about "blown" woofers?
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    Quote Originally Posted by pixelthis
    The higher the frequencies produced, the more energy thats required.
    This is what our electronics teacher had the hardest time conveying to a bunch of
    "bass" addicts who liked it LOUD.
    But its true, Call Ripleys if you want, but it IS true.
    This is why remote phones keep climbing (up to 5.2 gig or higher now) because newer procs can handle the energy requirements, and this is why the higher freaks are more desirable, they pass through obstructions and are more impervious to interferrence.
    For your tweeter to put out that sound requires a lot more energy, look at it this way,
    you hear all of the time about blown tweeters, how much do you hear about "blown" woofers?
    Transmitting radio waves, is a whole 'nuther ball game. But I can assure when it comes to reproducing sound via dynamic loudspeakers that woofers definitely require more juice. You're forgetting the mechanics of a speaker, Pix.
    It doesn't take very much energy to make a tweeter play 100 dB 15 kHz. Take a look at the sensitivity of most tweeters vs most woofers if ya don't believe me...go visit parts express or madisound and look at some specs for yourself. Tweeters are much more sensitive, meaning they will play louder at a given level of energy...usually two to 4 times as loud.
    Try reproducing 100 dB of 20 Hz bass. You need two things. Cubic displacement and excursion baby. Compared to a tweeter, the mass of the woofer cone is heavier, the swept volume of air is far greater, the excursion exponentially longer, it absolutely requires more energy. There's just more work to be done. Why do you think we see speakers with multiple woofers instead of multiple tweeters?

    Tweeters "blow" not because they require more energy, but because they can't handle all the energy that's being fed to it when the system gets cranked (to make the woofer play at an acceptable level). They're bad tweeters. Chances are it had a wimpy voice coil, with poor electrical capacity. It had nothing to do with high frequencies requiring more energy. You don't see that in woofers as much because they're built to withstand the gobs of power being fed to them. Take a high end Scan-Speak Revelator tweeter and it'll absorb as much power as you can feed it.

    Consider that almost all speakers designed today require resistor padding (ie, the famous L-pad) on the tweeter network to resist the electrical current fed to the tweeter in order to bring the tweeter volume down to match that of the woofer. If it took more energy at the tweeter to produce sound, we'd be padding the woofers. We don't.

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    KEXODUSC:- (yes I am shouting);

    I think we are on the same wavelength! We both agree that the business about the vertical and horizontal are crucial to the equasion.

    The only remaining question is, or was, for Cdn Guy's original question, can a L or R bookshelf speaker be used as a centre speaker in a normal room situation?

    The answer has to be Yes, tilt it, turn it, lay it, but take care as to how you place it. [based on tweeter] (yes or no?)

    It's a Bookshelf design; small and nondescript. Put it on its side and it still a small and nondescript design.

    If Cnd Guy was building a Commercial Theatre then you and I might give specific mathmatical advice.

    I understand your maths but for a room like mine (only 5mts by 8mts) I feel that side placing an L or R speaker in place of a Centre is fine.

    PS ........ now I know that you know your stuff I might have some more questions for you....watch this space

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    Quote Originally Posted by Slippers On
    KEXODUSC:- (yes I am shouting);

    I think we are on the same wavelength! We both agree that the business about the vertical and horizontal are crucial to the equasion.

    The only remaining question is, or was, for Cdn Guy's original question, can a L or R bookshelf speaker be used as a centre speaker in a normal room situation?

    The answer has to be Yes, tilt it, turn it, lay it, but take care as to how you place it. [based on tweeter] (yes or no?)

    It's a Bookshelf design; small and nondescript. Put it on its side and it still a small and nondescript design.

    If Cnd Guy was building a Commercial Theatre then you and I might give specific mathmatical advice.

    I understand your maths but for a room like mine (only 5mts by 8mts) I feel that side placing an L or R speaker in place of a Centre is fine.

    PS ........ now I know that you know your stuff I might have some more questions for you....watch this space
    Yes, if all we're discussing is if an L/R speaker can be used as a center even if tilted sideways, the answer is certainly yes.
    On this forum, we usually deal in what's optimal, rather than what's possible. But I'm usually a voice here that advocates compromise when required, and if tilting the speaker sideways is the best option for reasons other than sound, (my wife continues to remind me of such considerations) I'd rather have that than no center at all.

    The only thing I would caution you on is that in smaller rooms speaker placement, tilt, etc, is even more critical and less forgiving. We work with what we have though.

    Welcome to AR.com by the way.

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    Quote Originally Posted by kexodusc
    On this forum, we usually deal in what's optimal, rather than what's possible.

    Mmmmmmm

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    A good tweeter should act as a "point source" meaning it ratiates equally in all directions, so should act the same no matter the position of the speaker's cabinet. Lets say you have three identical speakers in your HT entertainment center. The tweeters will all be radiating on the same plane. If the center is setting back from the edge of the shelf, of course you'll get some reflection from the shelf and sides of the cabinet. As stated earlier, it's more important the tweeters are at, or pointed at ear level because higher frequencies drop off more rapidly as the off-axis angle increases.

    It's also important to remember bookshelf speakers may not be shielded and could interfer with the TV below the shelf causing picture and color distortion. This would be a good reason to go with an LCR speaker over a bookshelf speaker as most aren't shielded.

    There are some center speakers specifically designed for wider dispersion. Also some tweeters with lenses specifically designed for specific radiatiation patterns some horns would be good examples.

    Pretty much all arguments have some validity, except for the tweeter requiring more power than a woofer. The physics don't make sense. Tweeters have less mass than woofers and require less excursion to produce the desired frequency response. I'm not saying they don't require a good amount of power, just not nearly as much as a woofer. If the xover isn't designed correctly the tweeter might be required to take an unusual amount of power trying to reproduce lower notes, but generally this doesn't happen.

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    Based on the purpose and design of Center channels, it would be safe for me to assume that they are designed to be on stands the same height as that of the mains/rears correct? It seems that they are never displayed in this manner at shops. I don't currently have an ideal set up for the center, but then again, it doesn't match my fronts .......YET.

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    Quote Originally Posted by johnny p
    Based on the purpose and design of Center channels, it would be safe for me to assume that they are designed to be on stands the same height as that of the mains/rears correct?
    No. At one point in time this was probably true across the board. These days, it varies with the manufacturer. Some speakers are designed to be very tolerant along the vertical axis so vertical position isn't as critical. Some centers are very discriminiating in where they are positioned. If you aren't sure, the same height as your L/R's is a good place to start.
    Quote Originally Posted by johnny p
    It seems that they are never displayed in this manner at shops. I don't currently have an ideal set up for the center, but then again, it doesn't match my fronts .......YET.
    Yeah, this is a big problem with everything audio. Displays don't always conform to best practices or real life situations. A lot of centers are designed to work well above or below the TV screen, where 99% of these will be positioned. Tweeters are very directional, but with a good crossover, a reasoablyl flat off-axis response at 15 and even 30 can be achieved without much compromise.

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    You are absolutely correct about the correct placement of the speakers. By placing it sideways it is more prone to dispersing sound vertically which is rather uncharacteristic and undesirable as to what a centre channel in a typical setup should be like. This is quite noticeable with voice transitions from the left and right speakers. What a shame... it was so esthetically pleasing having a little speaker tucked away on its side underneath the tv.

    Can someone explain how a speaker can radiate sound with a preference to a horizontal axix? One would figure that a round speaker should radiate sound evenly both horizontally and vertically. Thanks for the enlightenment.

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    Quote Originally Posted by kexodusc
    Transmitting radio waves, is a whole 'nuther ball game. But I can assure when it comes to reproducing sound via dynamic loudspeakers that woofers definitely require more juice. You're forgetting the mechanics of a speaker, Pix.
    It doesn't take very much energy to make a tweeter play 100 dB 15 kHz. Take a look at the sensitivity of most tweeters vs most woofers if ya don't believe me...go visit parts express or madisound and look at some specs for yourself. Tweeters are much more sensitive, meaning they will play louder at a given level of energy...usually two to 4 times as loud.
    Try reproducing 100 dB of 20 Hz bass. You need two things. Cubic displacement and excursion baby. Compared to a tweeter, the mass of the woofer cone is heavier, the swept volume of air is far greater, the excursion exponentially longer, it absolutely requires more energy. There's just more work to be done. Why do you think we see speakers with multiple woofers instead of multiple tweeters?

    Tweeters "blow" not because they require more energy, but because they can't handle all the energy that's being fed to it when the system gets cranked (to make the woofer play at an acceptable level). They're bad tweeters. Chances are it had a wimpy voice coil, with poor electrical capacity. It had nothing to do with high frequencies requiring more energy. You don't see that in woofers as much because they're built to withstand the gobs of power being fed to them. Take a high end Scan-Speak Revelator tweeter and it'll absorb as much power as you can feed it.

    Consider that almost all speakers designed today require resistor padding (ie, the famous L-pad) on the tweeter network to resist the electrical current fed to the tweeter in order to bring the tweeter volume down to match that of the woofer. If it took more energy at the tweeter to produce sound, we'd be padding the woofers. We don't.
    radio wave , sound wave, light wave, they are ALL part of the electromagnetic spectrum
    and subject to the same laws.
    But your response doesnt bother me, I still have trouble convincing people that power flows from negative to positive, or that lighting flows from the ground as much as from the sky. Bass doesnt just affect our ears, we feel it, actually.
    So it might seem louder than it is.
    Ever grit your teeth when hearing a very high frequency, feels like its punching through your brain?
    Thats because a lot of energy is pressing on your eardrum.
    Bass requires a larger cone to put out a bass frequency, which is a lot longer, longer than some of the rooms its shot into.
    But you hear it EVERYWHERE because it is such a long frequency. Stand in front of a tweeter, move left or right and the sound drops off very fast, this is because the frequencies are very short, and they peter out, too. You can still hear the bass in the back of the room, are the highs as strong?
    It may not seem that way but that tiny tweeter is working a hundred times as hard, and moving thousands of times faster than a woofer.
    A tweeter playing a measley 12,000 hz is moving 11,800 times a second back and forth more than a sub putting out 20 hz. AT 20,000 HZ? WELL!
    As for the l-pad and using extra woofers, this is marketing decisions, ever since the advent of rock we have been a nation of bass addicts, both of these serve to emphasize the bass, the l-pad helps keep the tweeter from burning out mostly.
    Because you play the music so loud to get the bass, this threatens the tweeter
    You have answered your own question as to why one isnt needed on a sub, if they were so "high energy" then why wouldnt you need one?
    Its not a question of "speaker machanics" its a question of physics .
    Its like my teacher told me, a lot of these electronic theories are just that, theories.
    But they work, and whoever(if anybody did) created this universe didnt really care if it made much "common" sense to humans or not


    In other words the tweeter dont blow because they're "bad" tweeters, they blow because
    in order to get the loud bass, you also get the loud highs, which take more power, so you
    "equalize" the power going to the tweeter with a resistor, but sometimes thats not enough, and they blow.
    This is why a seperate sub is a good idea for bass fanatics, and why the gal breaking
    the glass in a memorex commercial is singing a HIGH note and not a low one,
    a low one doesnt carry enough energy to break the glass.
    Yeah, bass can rattle the floors, but thats because you are creating so much more of it
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
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  22. #22
    Loving This kexodusc's Avatar
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    Quote Originally Posted by pixelthis
    radio wave , sound wave, light wave, they are ALL part of the electromagnetic spectrum
    and subject to the same laws.
    But your response doesnt bother me, I still have trouble convincing people that power flows from negative to positive, or that lighting flows from the ground as much as from the sky. Bass doesnt just affect our ears, we feel it, actually.
    So it might seem louder than it is.
    Ever grit your teeth when hearing a very high frequency, feels like its punching through your brain?
    Thats because a lot of energy is pressing on your eardrum.
    Bass requires a larger cone to put out a bass frequency, which is a lot longer, longer than some of the rooms its shot into.
    But you hear it EVERYWHERE because it is such a long frequency. Stand in front of a tweeter, move left or right and the sound drops off very fast, this is because the frequencies are very short, and they peter out, too. You can still hear the bass in the back of the room, are the highs as strong?
    It may not seem that way but that tiny tweeter is working a hundred times as hard, and moving thousands of times faster than a woofer.
    A tweeter playing a measley 12,000 hz is moving 11,800 times a second back and forth more than a sub putting out 20 hz. AT 20,000 HZ? WELL!
    As for the l-pad and using extra woofers, this is marketing decisions, ever since the advent of rock we have been a nation of bass addicts, both of these serve to emphasize the bass, the l-pad helps keep the tweeter from burning out mostly.
    Because you play the music so loud to get the bass, this threatens the tweeter
    You have answered your own question as to why one isnt needed on a sub, if they were so "high energy" then why wouldnt you need one?
    Its not a question of "speaker machanics" its a question of physics .
    Its like my teacher told me, a lot of these electronic theories are just that, theories.
    But they work, and whoever(if anybody did) created this universe didnt really care if it made much "common" sense to humans or not


    In other words the tweeter dont blow because they're "bad" tweeters, they blow because
    in order to get the loud bass, you also get the loud highs, which take more power, so you
    "equalize" the power going to the tweeter with a resistor, but sometimes thats not enough, and they blow.
    This is why a seperate sub is a good idea for bass fanatics, and why the gal breaking
    the glass in a memorex commercial is singing a HIGH note and not a low one,
    a low one doesnt carry enough energy to break the glass.
    Yeah, bass can rattle the floors, but thats because you are creating so much more of it
    Pixdude, not sure what else I can say - you are of course correct about the flow of electricity and lightning. Unfortunately you remain incorrect about tweeters requiring more energy.
    This is undeniably proven by sensitivity in controlled environments. 1 watt fed into a tweeter vs a woofer...which one is louder? Let me be clear, that's 1 watt....equal energy into both, yet the tweeter is louder. This isn't a case of human hearing being more sensitive, this is unbiased, sound pressure level.
    If you could perhaps explain that phenomenon, I would concede to your point, and congratulate you on the nobel prize.
    Maybe you are a bit confused here. High frequency waves "contain" more energy than lower frequency waves. But they do not require more energy to be produced.

    BTW, you're missing the party. We've exposed PeruvianSkies as the phony liar and nutbar he is in the "Reputation Points" thread. Poor old Lexie probably won't be around here much for awhile..until he creates his 5th, or 6th alternate ego.

  23. #23
    Loving This kexodusc's Avatar
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    Quote Originally Posted by cdn guy

    Can someone explain how a speaker can radiate sound with a preference to a horizontal axix? One would figure that a round speaker should radiate sound evenly both horizontally and vertically. Thanks for the enlightenment.
    I'm not the best person to explain the variety of concepts involved as to why this is the case, but the short version:
    You're correct about the radiating pattern of the single driver unit. The tweeter and woofer both radiate in an omni-directional pattern. A few reasons why the speaker (combination of both woofer and tweeter) won't radiate equally though. First is just directional nature of the higher frequencies. The further off axis you go, the more volume you lose from the tweeter. So let's move 15 degrees below the woofer - the tweeter is now probably somewhere around 30 degrees off axis and far lower in output than the woofer which is only 15 degrees off axis. Already the response is favoring the woofer frequencies.
    By contrast, if you move horizontally off axis by 15 degrees, both the woofer and tweeter are off axis by approximately the same amount, much closer than the above example so the result is a bit "even" for lack of a better term. It's not perfect, but in most cases you'll get further off axis horizontally than you will vertically.

    Also, it's quite common that as you move along the vertical axis, the cancellation effects of phase differences will alter the combined response of the unit as well the further off axis you go. Most crossovers are designed to make the combined response flat on axis vertically, with some room to move in all directions, but you're limited in how far you can move vertically.
    To the average person, being on axis might not seem like much of a big deal, but in fact differences can be seen in the smallest movements.

  24. #24
    Forum Regular pixelthis's Avatar
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    Cool

    I had my doubts about that guy, he got on me like white on rice and wouldnt let go, and
    'not just me, but a few others too.
    Check out the high frequency thing. The person who first mentioned this was an electrical engineer who flew bombers in WWII, and everything I HAVE SEEN SINCE PRETTY MUCH CONFIRMS IT.
    And look at one of your statements, "high frequency waves contain more energy
    but dont require more to be produced".
    that means you're getting more out of the tweeter than you put in, basically perpetual
    motion, a free energy souce, bet that makes the Arabs nervous
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
    sharp Aquos BLU player
    pronto remote, technics antique direct drive TT
    Samsung SACD/DVDA player
    emotiva upa-2 two channel amp

  25. #25
    Village Idiot johnny p's Avatar
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    BACK on track.

    Quote Originally Posted by cdn guy
    Furthermore, B&W recommends the LCR 60 to match with my 601s3's. Why not just use another 601, turn it on its side and use it as the center? Just a curious thought. Thanks
    To the original post, I realize you said you were just curious, but I was thinking about this, and I just gotta know...... Would purchasing a third 601 even be an option? Unless you found one on ebay where the matching speaker is missing for unknown reasons (makes you question what that one went through) how would you obtain a single 601 without purchasing a pair?? Or would you purchase 2 and use the extra for an additional surround ? Left/Right/Center surrounds? No idea what that would do to your soundstage.

    I'm just curious, I don't know if you were just wondering, or if you were actually considering this......

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