Sepen Posted August 9, 2012 Share Posted August 9, 2012 I am sorry if I am being naive in asking this but I just bought my first Klipsch (Academy) and before I proceed in acquiring more main-etc) what would be the easiest way to compare it against my current center channel? I know that it doesn't match my mains, but for now I would like to at least get a taste of what may come. I have an Onkyo 809 if that helps. I will also need some guidance on how to pull the crossover out of it to send to Bob, Thanks to all, I appreciate any comments. Quote Link to comment Share on other sites More sharing options...
willland Posted August 9, 2012 Share Posted August 9, 2012 To do a true A-B comparison, you really need "A" speakers and "B" speakers, which your Onkyo does not have. What you could do is, in your setup menu, turn all your speakers off except for your center channel and one of your Zone 2 speakers. Connect the Academy to either right or left of zone 2 and switch back and forth from zone one and zone 2. Another option is to get a speaker switcher like the one I have and do it that way. Bill Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 9, 2012 Share Posted August 9, 2012 There are three issues that I see. 1) When two speakers, or systems, are AB tested, the one which is louder almost always sounds better. Therefore for a fair trial you will have to match the levels of the two. So you'll probably have to use two amps. If you have a two channel amp you could use the balance control. Then also pick some freq like 1000 Hz and an audio meter to match their output at that freq. And then switch. 2) Generally, the bigger issue is how close the center matches the flanking units. Now maybe that can be done if you set up the flanking units and then AB the centers while the flankings units are working. 3) Centers are generally smaller than the flanking units and within the choices of centers, you may find that one or the other center doesn't match flanking exactly, in different ways. What a choice to make ! ! ! ! Everyone will love to read your findings. So let us know. WMcD Quote Link to comment Share on other sites More sharing options...
HiFi Heaven Posted August 9, 2012 Share Posted August 9, 2012 A/B comparisons MUST be done at the EXACT same SPL (volume) or they are INVALID! I helped ADVENT engineer their speaker comparator in '73 or so, and named it the LIE DETECTOR! As each speaker pair was selected, the preamp signal was routed through corresponding screwdriver trimpots that adjusted levels to the power amplifier to compensate for the widely different sensitivities of speakers. ONLY when A/B compared at the SAME VOLUME could any subjective decisions be made. My favorite A/B was JBL (Just Be Loud) L-100 vs. the Advent Loudspeaker. Guess who won! Half the price, an octave deeper bass, better top end too! Steve Quote Link to comment Share on other sites More sharing options...
Sepen Posted August 10, 2012 Author Share Posted August 10, 2012 Thanks for the responses. I will dig out my old Onkyo 707 and hook up the Academy to it, then my Rocket Bigfoot Center to the 809. I will level match them and then go to town, as much as I can. I did hook up the Academy to the 809 last night and ran it for a couple of hours with the Rocket RS760's. I level matched them, one thing I noticed is clear vocals and also the bass seemed stronger, much stronger in fact. I do have two ported 15" subs. On a side note the wife saw me surfing and looking at pictures of the Heritage line last night and she said "no, no, no, no more speakers". Haha, she didn't even notice the Academy with its Oak finish in place of the Rosewood Rocket. She is a good woman though, and I know she won't mind. Quote Link to comment Share on other sites More sharing options...
Schu Posted August 10, 2012 Share Posted August 10, 2012 1) When two speakers, or systems, are AB tested, the one which is more efficient almost always sounds better. I see what you did there... Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted August 10, 2012 Share Posted August 10, 2012 I use a Niles selector box, which outputs to up to 6 pairs of speakers and has a volume control for each set. It should also be noted than if you're comparing only one of each cabinet, be certain to use a mono source to avoid differences due to source material. Also the speakers should be tested in identical acoustic spaces (position in room with reference to floor, side walls, corners) and ideally, in a similar acoustic space to where they'll eventually be used. Quote Link to comment Share on other sites More sharing options...
Sepen Posted August 10, 2012 Author Share Posted August 10, 2012 So I did what I said for about an hour today, mono, no processing, no subs, just the centers side by side, with me about 6' away. I did level match them as best as I could. The Academy was more dynamic for sure. The clear voicing of the Academy blew the RCS 200 away. It was as if I was at a concert with the Academy, and the Rocket was like sound coming out of a box. Everything about it sounded better. And with the subs on the difference was even more telling, the Academy just blended so much better with my 15" ported subs, not even close. I know that this wasn't even the best way to approach this, but it is all that I had and could go on. The Academy will be staying for sure. My hearing isn't what it used to be (I had it tested due to concerns- Doc said I am old) and to me it makes everything so much easier to hear and enjoy. My next step is to replace the crossover and possibly more from Crites. I will do this immediately and then sit and wait until I can find a pair of Fortes. They are hard to find at the right price. Thanks to all of you for the thoughful replies. Quote Link to comment Share on other sites More sharing options...
garyrc Posted August 10, 2012 Share Posted August 10, 2012 ... Therefore for a fair trial you will have to match the levels of the two ... Of course that's good advice, but there is one aspect of level matching I've always wondered about. Choices a,b,c and g would employ an SPL meter, the others as noted. Should we: a) Match the SPL at 1K Hz Match the SPL using Pink Noise c) Match the SPL using White Noise d) Match the SPL by ear using music e) Match the SPL by ear using a different piece of music, which, due to it's characteristics, may alter our judgement of which speaker is louder f) Match the SPL by sending a mono signal into both speakers at the same time and adjusting so the image is dead center g) Match the SPL by performing d, e, or f, but using an SPL meter instead of our ears h) Emulate some magazine reviewers by listrening extensively to one speaker for a week or so, without even having the other speaker in the house, then ship off the speaker you have been listening to, wait several weeks (or months, or years). then bring in and hook up the other one, and listen to it for a week. Try to make your judgment without even a trace of humility, and be sure to make finely detailed comparisons between the two.. Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 10, 2012 Share Posted August 10, 2012 1) When two speakers, or systems, are AB tested, the one which is more efficient almost always sounds better. I see what you did there... What? Huh? I didn't write what you attribute to me. You had me going . . . thinking this a case where I went back and edited. But I didn't;' not even in my sleep. I checked the edit log and there is nothing there. WMcD Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 10, 2012 Share Posted August 10, 2012 Gary goes into deeper waters than I am qualified to answer. But I've go some ideas. The professionals should be deferred to. I think the best thing to do is to pick some some freq where we can can establish a baseline, like 1 kHz. All speakers work pretty well there. It might be a good line of demarcation between the bass and the treble, and easy to measure. My amateur thought is that using noise is not good. This is because the response of meter responds to the overall respone and that can alter the baseline in finding a common ground for testing. Let us start with known responses of two speaker where we actually have some idea of their relative responses. Speaker B is bass heavy but A is otherwise equal in response at the mid and treble. Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 10, 2012 Share Posted August 10, 2012 If we feed both with noise (I think pink noise is best) and hold an RS meter up to measure acoustic output, we will see that B has a higher output. Let's assume the big bump in bass adds 5 dB to reading on the meter, overall with noise. This is because with noise, the measureing device is not discriminating about what freq is putting in more SPL to the microphone,. But overall, the output of the B is higher. Remember that the goal is to ensure, somehow, that the two speakers which we are going to do an AB test upon have equal perceived acoustic output. But we know that looking at a freq response,they vary. in total response because of B's big bass boost Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 11, 2012 Share Posted August 11, 2012 So, in the testing process, we knock down the the response of B by 5 dB to give overall, total output which is equal to A.. Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 11, 2012 Share Posted August 11, 2012 But now you see the problem. We started with the assumption that the A and B had equal mid and treble. Now because we are trying to match them because of overall response to noise, we've created a situation where mid and treble are not matched. The logical conclusion is that using noise (broadband response) to set a baseline is problematic. WMcD Quote Link to comment Share on other sites More sharing options...
HiFi Heaven Posted August 11, 2012 Share Posted August 11, 2012 In the OLD DAYS ('74) - we would quickly adjust the PREAMP-LEVEL attenuator on the LIE DETECTOR to a SUBJECTIVE EQUAL LOUDNESS on the music and the pair of speakers being compared. Want to change music? OK, reset levels. Change speakers? Reset levels. AGAIN! The human ear will ALWAYS prefer the louder of two sounds - maybe that's why PWK & JBL & ALTEC (RIP) sold so many speakers! Quote Link to comment Share on other sites More sharing options...
garyrc Posted August 11, 2012 Share Posted August 11, 2012 But now you see the problem. We started with the assumption that the A and B had equal mid and treble. Now because we are trying to match them because of overall response to noise, we've created a situation where mid and treble are not matched. The logical conclusion is that using noise (broadband response) to set a baseline is problematic. WMcD Gil, thanks for your discussion. I now recall reading that some professionsls (movie mixers) address the problems you brought up by using midrange only to adjust all their speakers to the same level from the listening position (according to Audyssey). It sounds like they use band limited (500 Hz - 2,000Hz) pink noise to make -- 30 dB produce 75 dB at the mixer's ears. Perhaps using a meter to match the midrange only would produce results that seem subjectively equal when music is played, since, as PWK said, "Midrange is where we live." If one of the speakers happens to be bass heavy, it would (naturally) "have more bass," but the two would be at the same subjective level for a bass free passage ( violins, most woodwinds, the female voice). This might get around what I was worried about, namely that one of the speakers might have a big peak or dip right at 1K Hz. HiFi Heaven ... RE: "Altec (RIP)" ... I can't believe ALTEC is gone! When and how did this happen? Quote Link to comment Share on other sites More sharing options...
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