turbobusa65 Posted February 10, 2007 Share Posted February 10, 2007 two speakers on the right channel and two speakers on the left channel this is adcom equipment and has no a/b speaker selector, the pre amp has three knobs balance, bass, and treble, So wouldn't this be called 2 channel? Quote Link to comment Share on other sites More sharing options...
SilverSport Posted February 10, 2007 Share Posted February 10, 2007 if they're two channel stereo and there are three speakers to a side it is 2 channel! Bill Quote Link to comment Share on other sites More sharing options...
Chicago_Pete Posted February 10, 2007 Share Posted February 10, 2007 A stack of solid state soulless black boxes. Yikes, I had that same nightmare yesterday! Just kidding, deuce channel, yes sir. Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 Thank you!! Quote Link to comment Share on other sites More sharing options...
lwhaples Posted February 10, 2007 Share Posted February 10, 2007 Yikes! Man that must put out some sound. Nice pics! Larry Quote Link to comment Share on other sites More sharing options...
mas Posted February 10, 2007 Share Posted February 10, 2007 Nice sound?!?!? Folks, you miss the point! The irony is that each speaker may be flat from 0Hz to gamma rays, have perfect time domain characteristics, act as true point source, AND feed the dog while you are away! It just doesn't matter what brand of speaker these are! Heck, they could all be Jubilees and the situation would remain the same! The reason is that obscure brand name that most overlook called "physics". Unfortunately this configuration renders even the most ideal speakers as comb filter/polar lobing city! And if the reason is not immediately apparent, you really need to find out why! Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 Could you explain this in laymen's terms. I talked to a tech guy "from klipsch"on the phone who said this would be fine and im fairly new to this so please let me know what you think should be done. It sound's very good to me but i'm no sound engineer Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 wow!! guess I shoulda bought a bose wave! Quote Link to comment Share on other sites More sharing options...
mas Posted February 10, 2007 Share Posted February 10, 2007 Sure! Having two spaced sources which reproduce the same signal (eg.: the speakers for the left, and the 2 speakers for the right channels, respectively) will result in the wave forms combining in a process referred to as "superposition" (a fancy way of saying that the waveforms are super-imposed and sum). The waveforms, by virtue of their physical separation and the different distances traveled, will vary in phase at the point of listening, and the frequencies that are precisely in phase will add positively and be 3 dB higher in gain, while those 180 degrees out of phase will cancel and that frequency will literally be 'gone'. And the signal in between q degrees and 180 degrees will correspondingly add and subtract in gain. The result will be a frequency response that while it may have been literally perfect for one speaker, for two playing the identical signal will exhibit what is called comb filtering, so named for the comb like appearance of the summed frequency response. The frequency nulls will appear at multiples of the fundamental null based upon the inter-driver separation. These frequency nulls will also correlate to a polar lobing which refers to the energy distribution on the horizontal and vertical planes. Thus, if you walk from side to side in front of the speakers, you will enter into null areas where a particular frequency is canceled due to the phase combination. Additionally, other areas will result in exaggerated or diminished gain at that frequency as well. And these enhanced areas and interspersed nulls will be in differing places for each frequency. But one can generalize and say that for the lowest frequencies that each polar lobe will be wider ( a lower 'Q') and fewer in number, and as you increase in frequency, the lobes will become an increasing higher 'Q" (narrower and more focused) as well as more numerous. But don't try to hard to understand the verbal description. Take a look at the attached graphic. For differing spacings of drivers reproducing the same material, you will see both the frequency response with the comb filtering and the corresponding horizontal polar patter (imagine you are looking down from above the speakers). Oh, btw, the way to minimize this is to only operate one stereo pair. It is the second speaker for each side that will cause this interference - so your gain in gain (sorry!!!) will also be accompanied by a greater introduction of audible acoustic interference. Oh! And btw, this anomalous comb filtering and polar lobing interference CANNOT be corrected with EQ! I hope this helps a bit.PolarPatterns&CombFilters&Balloon.s.pdf Quote Link to comment Share on other sites More sharing options...
mas Posted February 10, 2007 Share Posted February 10, 2007 wow!! guess I shoulda bought a bose wave! Whoa dude! This problem has nothing to do with the brand! This happens with any multiple sources reproducing the same signal! But if you start with Bose, especially one of their 'direct/reflecting' systems, you are beginning with a system erroneously designed to introduce not only more early reflections into a room where we need to remove them as they impinge upon the intelligibility of the sound within the room , but with the additional specular reflections, the problem I mentioned becomes even more chaotic. And as we mention impinging upon intelligibility, this leads one to understand the origin of the real problem with Bose where the Bose designers refused to let advances in acoustical understanding (which exposed the fundamental problem) dampen their flawed engineering approach! Instead they just simply decided to build on their name/brand recognition as they spent more money on marketing! What that means is that rather than having listening positions where you can tell a rather large change between pretty good and very bad, with Bose's 'direct/reflecting' nonsense, you have a uniformly mediocre distribution everywhere - meaning that instead of a good-bad difference, you have a pretty bad-pretty bad experience no matter where you move - leading many to surmise that it is better due to the lack of a radical change in sonic quality. Well, ignorance is bliss. You've got great speakers! Just be smart and don't make problems! That physics stuff can help or bite you![] ...Just don't be really crazy and jump off the cliff by buying a real mistake! Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 someone elsewere said side by side is hard to get imageing right and sugested stacking them head to head one on top the other does this make sense to you? oh! and thank's Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 wow!! what you said just hit me like a ton of bricks I hear you mas!!! thank you very much for explaining!!! Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 wow!! what you said just hit me like a ton of bricks I hear you mas!!! thank you very much for explaining!!! By having two speakers side by side on each side and in different spot's on the floor all producing the same signal it would be nearly impossible to get the imageing right and hard to justify calling it "two channel"...................I think!! MAS?? Quote Link to comment Share on other sites More sharing options...
pauln Posted February 10, 2007 Share Posted February 10, 2007 What about all the RF series speakers that use pairs of radiators ( some even more), what about the Jubs? The vertical orientation just rotates the comb distribution 90 degrees- it is still there, right? Quote Link to comment Share on other sites More sharing options...
mas Posted February 10, 2007 Share Posted February 10, 2007 someone elsewere said side by side is hard to get imageing right and sugested stacking them head to head one on top the other does this make sense to you? oh! and thank's Yep, the way to minimize the comb filtering and polar anomalies while adding to the gain, you can take two identical speakers and (assuming a single speaker with HF driver on top - imagine a LaScala), you can invert them and stack one on top the other - with the HF drivers in the center in order for them to be within 1/4 wavelength to couple, while being sure to align their acoustical centers (point of apparent origin of the signal in the time domain - this not the front of the speaker). There will still be some 'cosine error' in that there will be a differing path length and hence time of the direct signals relative to the listening position, but the effects, while not eliminated, will be significantly diminished. But this is useful ONLY if you need GAIN (higher SPLs) at the price of the response. And I doubt you really need this. And I worry if you try to stack two narrow columnar speakers as I suspect someone will get killed, hurt or property damage will result when they topple! So please think this out! Stacking in such a manner is usually only needed in Sound Reinforcement (SR) applications. Oh, and as far as imaging with 2 speakers horizontally arranged on each side. What imaging? [][] You are undoing everything that the pair does well! And if I were a betting man, I would bet that you DON'T need the additional gain! Sorry for typing so much - it must be the coffee! [] Quote Link to comment Share on other sites More sharing options...
ARTIELANGE Posted February 10, 2007 Share Posted February 10, 2007 turbob beautiful setup I love the "souless black box" adcom look! get down! Quote Link to comment Share on other sites More sharing options...
mas Posted February 10, 2007 Share Posted February 10, 2007 What about all the RF series speakers that use pairs of radiators ( some even more), what about the Jubs? The vertical orientation just rotates the comb distribution 90 degrees- it is still there, right? Multiple drivers spaced within 1/4wavelength will typically couple - ideally, but not completely in the real world. That is what the inverting and stacking does. The MTM (nid tweeter mid) or Di'Appolito configuration that so many marvel at attempts to correct for a vertical 15 degree polar lobing tilt due to the odd order (I think 3rd) Linkwitz Riley crossover alignment. (One L/M driver lobe tilts downward to compensate for the upward tilting lower polar lobe). Is it ideal? No! But they are trying to compensate for another anomaly that caused the polar lobing to reach for the ceiling! Here they are trying to use an anomaly to compensate for a greater anomaly. Regarding the Jubes, they are fine. There will be some comb filtering and polar lobing anomalies associated with any crossover region where two drivers share the reproduction of the same signal - especially if they are at or near the same gain levels (This behavior becomes less noticeable if one source is distinctly greater than the other). Right! The vertical orientation simply rotates the horizontal effects 90 degrees (gee, a Hilbert space!) If you look at the polars in the attached graphics, if you rotate them 90 degrees, you will see a vertical alignment tends to result in wide horizontal polar lobing that exhibits cutoffs more in the 'vertical' aspect, such as near the head and feet if you are standing for LF - but which is more uniform from side to side. As you increase the frequency the lobing will be more 'frequent' in number. But the effect is still there - just rotate 90 degrees. (Pardon the poor description - just rotate the graphic onto its side.) Superposition is a matter of magnitude and order (as in exponential order and magnitudes of order). It occurs within the same speaker with multiple drivers and between multiple sources as well as with multiple virtual sources such as diffraction and reflections. The greater the separation, the greater the effects. You will find that superposition is a phenomena that will recur over and over in the strangest manner. And it occurs between every source that reproduces the same signal at similar levels. So there can be many orders of magnitude of he effect in the same system. So you will at least want to address the largest contributors first! And two speakers in this arrangement are one of those cases! Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 10, 2007 Author Share Posted February 10, 2007 Thank you mas!!! I am very excited to have learned something!! do they have a book oh say audio for dummies? how about i build a cage attached to the floor and ceiling to keep everything in place do you think that would be ok?..........................thank you Artielange!! Quote Link to comment Share on other sites More sharing options...
Fish Posted February 10, 2007 Share Posted February 10, 2007 It would be nice but,,,,,,,,mas has explained the downside pretty well.A larger more powerful amp,maybe a better pre or sub would be prefered by me over 4 speakers used as a stereo pair.Bottom line though,it's your set and very nice at that,if you like it thats' all that matters.But...have you tried just a stereo pair,maybe with a sub? Quote Link to comment Share on other sites More sharing options...
turbobusa65 Posted February 11, 2007 Author Share Posted February 11, 2007 Not yet but remember this is all very new to me and I have a lot to learn!! this will be a long but fun road!! Quote Link to comment Share on other sites More sharing options...
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