GooseChaser Posted September 13, 2003 Share Posted September 13, 2003 isn't this just horrible? looking at the chart, I am not sure I measured it right using a radioshack analog SPL meter. I found a chart on this website, http://www.audio-ideas.com/reviews/loudspeakers/klipsch-rb5.html if you compare the two charts carefully, the responses are acutally similar, the problem is that the 2dB drop between 200hz and 700hz on the website's chart is a 10dB drop in my room, and it never recovers. even worse, it drops 20dB between 100Hz and 200Hz. does anyone have a link or advice on how to measure accurately? Quote Link to comment Share on other sites More sharing options...
Deang Posted September 13, 2003 Share Posted September 13, 2003 Did you make the proper adjustments using the calibration chart for the meter? The RS meter is horribly inaccurate. You can find the chart at the Asylum in the FAQ section. Quote Link to comment Share on other sites More sharing options...
GooseChaser Posted September 13, 2003 Author Share Posted September 13, 2003 cali-what? ok, I will look those up, thanks. Quote Link to comment Share on other sites More sharing options...
ben. Posted September 13, 2003 Share Posted September 13, 2003 How do they sound? Are measuring to confirm some problem that you hear, or are you being curious? I try not to get scientific about anything audio-related until I notice something disagreeable. I can be incredibly anal, so poor measurements would bother me even if everything sounded fine before I measured!! Just me? Quote Link to comment Share on other sites More sharing options...
InnovaZero Posted September 13, 2003 Share Posted September 13, 2003 ---------------- On 9/13/2003 1:39:16 PM GooseChaser wrote: isn't this just horrible? looking at the chart, I am not sure I measured it right using a radioshack analog SPL meter. I found a chart on this website, http://www.audio-ideas.com/reviews/loudspeakers/klipsch-rb5.html if you compare the two charts carefully, the responses are acutally similar, the problem is that the 2dB drop between 200hz and 700hz on the website's chart is a 10dB drop in my room, and it never recovers. even worse, it drops 20dB between 100Hz and 200Hz. does anyone have a link or advice on how to measure accurately? ---------------- Holy!...that can't be right! Quote Link to comment Share on other sites More sharing options...
kenratboy Posted September 13, 2003 Share Posted September 13, 2003 They sound good and thats all that matters Quote Link to comment Share on other sites More sharing options...
Audio Flynn Posted September 13, 2003 Share Posted September 13, 2003 Quality Engineer stuff... All measurung devices have error. And the need to be calibrated by a tech once a year. Cheap gages have more error. The Radio Shack stuff as a "guide " is OK. As a serious gage; no. Do not take it too serious. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted September 13, 2003 Share Posted September 13, 2003 Could also be the fact that the acoustics in the room are contributing to the drop in response at the measured frequencies. Quote Link to comment Share on other sites More sharing options...
GooseChaser Posted September 14, 2003 Author Share Posted September 14, 2003 ---------------- On 9/13/2003 11:39:24 PM michael hurd wrote: Could also be the fact that the acoustics in the room are contributing to the drop in response at the measured frequencies. ---------------- that's my thought especially with the bass, I have paper walls, hard floor, and a bunch of furniture in a really small bed room. and the RB-5's are sitting a bit more than 2 feet from the wall in the middle of the room. I did notice a drop in the bass when I was moving all of the furnitures around thinking no compromise to the imaging. they do sound wonderful but I assume I don't know what I am missing since they are as high end as I've heard. Quote Link to comment Share on other sites More sharing options...
leok Posted September 14, 2003 Share Posted September 14, 2003 If that speaker has a rear firing port it needs a corner placement to bring out the bass. Are you using white noise or sine tones for the measurement. If white noise, many many sum & difference frequencies due to IM distortion will be part of the measured result. Are the speakers toed in to avoid room reflections and the microphone directly in line with the hf driver? some thoughts .. leok Quote Link to comment Share on other sites More sharing options...
GooseChaser Posted September 14, 2003 Author Share Posted September 14, 2003 ---------------- On 9/14/2003 8:40:13 AM leok wrote: If that speaker has a rear firing port it needs a corner placement to bring out the bass. yes, but imaging seem to suffer when corner loaded. Are you using white noise or sine tones for the measurement. If white noise, many many sum & difference frequencies due to IM distortion will be part of the measured result. sine tone. Are the speakers toed in to avoid room reflections and the microphone directly in line with the hf driver? yes they are toed in by 2.5 inches, and I actually had the meter facing forward in the center with both speakers playing. some thoughts .. leok ---------------- Quote Link to comment Share on other sites More sharing options...
leok Posted September 14, 2003 Share Posted September 14, 2003 I'm not sure why the imaging suffered, unless you were getting wall reflections. You can take care of wall reflections with acoustic foam and agressive toe-in. Remember, those horns project a 90 degree horizontal pattern (45 deg. right and left of center). Anyway, your placement has an impact on the bass. You really should have the microphone, in the listening position, pointed directly at 1 speaker, with the speaker pointed directly at it. The microphone should be level with the vertical center of the speaker. Use a single channel for the test (leave the other speaker connected, just don't connect the sound source). Lots of reasons for all of that. leok Quote Link to comment Share on other sites More sharing options...
Manuel Delaflor Posted September 14, 2003 Share Posted September 14, 2003 Point directly to the tweeter at about 10 to 20cm exactly on axis. Then do the same with the bass driver and the port driver. Then you will have an idea of the real response of your speaker. Well, what you want to know is the response on your room, of course, but that is difficult. In fact, taking measurements of a speaker is a really complex task, even when you use a calibrated mic and an RTA. As a side note, I do not believe in the "correction charts" for the RS SPL meter, I have found four or five with different values, don't take them by the letter. You can also try with specific frequencies, say 1/3, at your listening possition but pointing the meter directly to both your left or right speaker, then do an average. Quote Link to comment Share on other sites More sharing options...
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