bracurrie Posted March 2, 2014 Share Posted March 2, 2014 I am trying to adjust an active crossover setup and I keep going back and forth about 2db on the Audio Nirvana full ranger that is crossed at 200 Hz with 2 15's in a LBAT setup in an open baffle speaker. Dave Harris who made them took a month or more to determine that the best crossover point was 200hz with the LF using 3rd order and the HF using a 1st order. I could use the attenuation he used but I thought it would be fun to see what I get by adjusting the levels. So do I I use pink noise and a C weighted db meter to set the levels? Or do I need to use tones at a specific frequency to set the levels? Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 3, 2014 Share Posted March 3, 2014 I use Pink noise and RTA with mic at 3 ft. to understand each driver performance and adjust from there. I use a referecne pair of speakers to help with final adjustments like what you are doing balancing the gains. Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 3, 2014 Author Share Posted March 3, 2014 I use Pink noise and RTA with mic at 3 ft. to understand each driver performance and adjust from there. I use a referecne pair of speakers to help with final adjustments like what you are doing balancing the gains.Thanks for the suggestion. Do you position the mic vertically in front of first the full ranger and then the LF twin 15s? Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 3, 2014 Share Posted March 3, 2014 I mute all channels except one and measure one at a time with the mic at 3' from the driver pointing right at it. In my case I have a 5 way system, so 10 curves. Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 3, 2014 Author Share Posted March 3, 2014 I mute all channels except one and measure one at a time with the mic at 3' from the driver pointing right at it. In my case I have a 5 way system, so 10 curves.My mic is calibrated for use pointed straight up. Do you think that is a problem? Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted March 5, 2014 Share Posted March 5, 2014 My mic is calibrated for use pointed straight up. Do you think that is a problem? Only if you don't point it straight up, apparently. Quote Link to comment Share on other sites More sharing options...
SonicSeeker Posted March 5, 2014 Share Posted March 5, 2014 My mic is calibrated for use pointed straight up. Do you think that is a problem? Only if you don't point it straight up, apparently. Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 5, 2014 Author Share Posted March 5, 2014 My mic is calibrated for use pointed straight up. Do you think that is a problem? Only if you don't point it straight up, apparently. i deserve that. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 5, 2014 Share Posted March 5, 2014 That's funny. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 5, 2014 Share Posted March 5, 2014 Remember, the measurements help but use yours and other's ears, experience, and gut too. The best thing I ever did was keep 1 pair of Klipsch Heritage to use as a reference in the room. It is a pair of cornwalls. These continue to help me immensely. Quote Link to comment Share on other sites More sharing options...
jwc Posted March 5, 2014 Share Posted March 5, 2014 I am trying to adjust an active crossover setup and I keep going back and forth about 2db on the Audio Nirvana full ranger that is crossed at 200 Hz with 2 15's in a LBAT setup in an open baffle speaker. Dave Harris who made them took a month or more to determine that the best crossover point was 200hz with the LF using 3rd order and the HF using a 1st order. I could use the attenuation he used but I thought it would be fun to see what I get by adjusting the levels. So do I I use pink noise and a C weighted db meter to set the levels? Or do I need to use tones at a specific frequency to set the levels? I only use "tones" for giggles. For speaker "balance" among its drivers, I use a combination of pink noise with an RTA and my ears. Don't rely on one alone. The exception would be subs though.....if I'm integrating those with a speaker....been known to leave the RTA out. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted March 5, 2014 Share Posted March 5, 2014 I am trying to adjust an active crossover setup and I keep going back and forth about 2db on the Audio Nirvana full ranger that is crossed at 200 Hz with 2 15's in a LBAT setup in an open baffle speaker. Dave Harris who made them took a month or more to determine that the best crossover point was 200hz with the LF using 3rd order and the HF using a 1st order. I could use the attenuation he used but I thought it would be fun to see what I get by adjusting the levels. So do I I use pink noise and a C weighted db meter to set the levels? Or do I need to use tones at a specific frequency to set the levels? I only use "tones" for giggles. For speaker "balance" among its drivers, I use a combination of pink noise with an RTA and my ears. Don't rely on one alone. The exception would be subs though.....if I'm integrating those with a speaker....been known to leave the RTA out. I'm finding this method to be the most useful for tonal balance as well. It contains all the music ever recorded! LOL. Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 5, 2014 Author Share Posted March 5, 2014 It contains all the music ever recorded! LOL You guys are too funny, but helpful. I just tried doing sweeps with REW and some real-time with Pink Noise and I am still not sure I am right. Just discovered also that my Alesis IO2 card may have an issue that may be affecting my measurements. I am using REW on a win laptop connected to the soundcard via USB. The main outs from the soundcard feed to my Apogee soundcard connected to my MAC running Pure Vinyl with RIAA correction turned off ( so the input is passed unaltered). I have a plug-in for EQ and it shows a graph of the music real-time. So anything coming from the measurement mic should 100% go to the win laptop and sweep tones go to the MAC via usb - Alesis - Apogee - usb - mac. Trouble is I am seeing some sound in the EQ window on the MAC that with hand claps and whistles from me show that the signal from the mic is somehow getting to the main outs of the sound card when they aren't supposed to. I guess its a cheap sound card. I need to isolate this issue before I go any further. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted March 5, 2014 Share Posted March 5, 2014 Yep, I would get soundcard I/O feedback too when I used a soundcard. It always made me question what I was seeing. I ditched the soundcard. I use a USB cable in to the PC from my mic mixer, and a USB cable out of the PC to my Benchmark DAC. Problem solved. 1 Quote Link to comment Share on other sites More sharing options...
Guest David H Posted March 6, 2014 Share Posted March 6, 2014 Make sure the mic inside you laptop is disabled. Dave 1 Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 6, 2014 Author Share Posted March 6, 2014 Yep, I would get soundcard I/O feedback too when I used a soundcard. It always made me question what I was seeing. I ditched the soundcard. I use a USB cable in to the PC from my mic mixer, and a USB cable out of the PC to my Benchmark DAC. Problem solved. Great idea. Do you use REW too? Any other tips from your experience? Thanks. Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 6, 2014 Author Share Posted March 6, 2014 Make sure the mic inside you laptop is disabled. Dave Thanks! I did that at first. Boy was I confused until I go the laptop mic disabled. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 7, 2014 Share Posted March 7, 2014 Which apogee sound card you running? A lot of these recording devices have a feature to monitor the input, which would send your input signal to the output. Likewise, they usually have a feature to control the relative level of playback versus input, which means you can disable the monitoring. Richard Heyser's work on time domain spectrometry shows us why it's better to use a tool with time windowing (like REW) versus steady state analysis (most FFT tools). To make the most of it though, you really gotta dig into the difference between how direct and reflected sound is perceived. Quote Link to comment Share on other sites More sharing options...
bracurrie Posted March 7, 2014 Author Share Posted March 7, 2014 Which apogee sound card you running? Quartet. Its inputs are being used to recieve the REW output from the PC laptop. Last night I setup my DAC to be the output device on the PC laptop instead of the Alesis sound card which is handling the mic input chores per mark1101 suggestion. This works much better as the Alesis card kept sending a wee bit of mic signal to its main outputs no matter the settings. Its a cheap card. The image are the results from sweep test from 30 to 12,800 with no EQ measured with mic 3 feet from speaker at the hieght of the fullranger. I believe it confirms that my crossover bi-amp levels are correct. The red is no EQ and the green is the result at my amateur efforts to improve things with EQ. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted March 7, 2014 Share Posted March 7, 2014 So why all the high end sizzle? The red is no EQ and the green is the result at my amateur efforts to improve things with EQ. Quote Link to comment Share on other sites More sharing options...
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