jason str Posted November 12, 2014 Share Posted November 12, 2014 I know what harmonic distortion is. How do they play a roll in the chest thump sensation. If your chest cavity resonated at 60-70 Hz, what difference do the 120-140 Hz distortion frequencies make in that sensation? You answered you own question but in a backwards sorta way, 60-70Hz overtones come from a lower frequency not higher. This is why strings (among other insturments) sound so much cleaner with a horn ( less harmonic distortion). Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted November 12, 2014 Share Posted November 12, 2014 Good horns can get loud enough, in an instant, to cross your eyes...involuntarily. Nuff said. Can't believe this is even debatable. Just don't set your system flat and expect any miracles. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted November 12, 2014 Share Posted November 12, 2014 (edited) Ok, time to address this distortion thing, lol. Most subwoofers are not producing distortion until they are under significant stress. The vast majority of the time in the HT this happens with explosion and similar action parts of the film. In these situations the sound is so loud in the room that you can reliably tell the difference. Distortion in the low bass is much harder for the human ear to detect. Many DR subwoofers have low distortion. Seaton Submersive, Rythmik, JTR and many of the DIY subs to name a few. There are trade off with all the various subwoofer designs. Figure out what you want out of your bass system and go from there. There are nice Horn bass system and nice DR systems that will make you jaw drop. Edited November 12, 2014 by derrickdj1 Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted November 12, 2014 Share Posted November 12, 2014 Explain Most subwoofers are not producing distortion until they are under significant stress. The majority of comparative data indicate otherwise. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted November 12, 2014 Share Posted November 12, 2014 (edited) I know what harmonic distortion is. How do they play a roll in the chest thump sensation. If your chest cavity resonated at 60-70 Hz, what difference do the 120-140 Hz distortion frequencies make in that sensation? Who says it's 60-70 Hz? That's a wavelength of order 5 m... It has to be much higher than that if we are talking resonance... Its a well known thing. As for resonance of our internal organs, its actually much lower, the true resonant frquency of our organs is like 7 hz. Either us or the french even weaponized it. Edited November 12, 2014 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted November 12, 2014 Share Posted November 12, 2014 http://www.audio-issues.com/music-mixing/how-to-use-eq-to-improve-your-kick-drum-sound/ This article breaks down the kick drum frequencies and recommends a high pass filter at 50 hz then boost 80-100 for a good low thump. thats not how most people think subs should work. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted November 12, 2014 Share Posted November 12, 2014 (edited) http://www.audio-issues.com/music-mixing/surefire-frequencies-for-a-better-kick-drum-sound/ "60 hz will make the kick hit you n the stomach." That guy is an audio engineer but I imagine there are plenty of other sources as well. Edited November 12, 2014 by MetropolisLakeOutfitters Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted November 12, 2014 Share Posted November 12, 2014 (edited) "60 hz will make the kick hit you n the stomach." That guy is an audio engineer but I imagine there are plenty of other sources as well. That's with live sound where the low end of the signal crest factor is typically in the 14-18 dB range. With recorded playback, achieving those level of transients is a whole 'nother challenge because, given the source material, the information simply isn't there. This is why us horn guys are always comparing and often times complaining about the DR rating of certain albums. Live sound technique to home sound is not necessarily a direct translation. There are certain caveats to be aware of. Edited November 12, 2014 by Quiet_Hollow 1 Quote Link to comment Share on other sites More sharing options...
Mallette Posted November 12, 2014 Share Posted November 12, 2014 My respect for Carl's knowledge of subs is immense. My "goto" guy on such things. I don't quite understand the mechanics of which he speaks here, though. Logically, it would seem that the much faster response due to the shorter excursion of a horn sub vs anything else aside from IB would create the cleanest "whump" you can get from a driver at a given frequency. In line with PWK...who is my "goto" guy in all things loudspeaker. Dave Quote Link to comment Share on other sites More sharing options...
jason str Posted November 12, 2014 Share Posted November 12, 2014 Ok, time to address this distortion thing, lol. Most subwoofers are not producing distortion until they are under significant stress. False, distortion is present even at low volumes The vast majority of the time in the HT this happens with explosion and similar action parts of the film. In these situations the sound is so loud in the room that you can reliably tell the difference.Distortion in the low bass is much harder for the human ear to detect. Once you become accustomed to a horn the sound of distortion is easily heard when you switch back to a DR type & a woofer is where you benefit most from horn loading not the least. Many DR subwoofers have low distortion. DR subwoofers are much higher in distortion than a fully horn loaded model and not by a small percentage either the factor is many times fold. Seaton Submersive, Rythmik, JTR and many of the DIY subs to name a few. Brand makes little difference, the distortion percentage numbers are not too far apart normally compared to a horn anyways. There are trade off with all the various subwoofer designs. Figure out what you want out of your bass system and go from there. There are nice Horn bass system and nice DR systems that will make you jaw drop. Quote Link to comment Share on other sites More sharing options...
psg Posted November 12, 2014 Share Posted November 12, 2014 I don't disagree that 60-70 Hz hits you in the chest. I didn't know that resonance is the reason; the wavelength is very long so that's not exciting any oscillations, so it has to be frequency (time domain). Do organs internally bounce back from a hit at that frequency? The chart here http://physics.stackexchange.com/questions/37543/does-the-human-body-have-a-resonant-fequency-if-so-how-strong-is-it shows lots of response at very low frequencies (around 10 Hz) and the chest wall does indeed show up at 50 to 100 Hz (a fairly wide margin, but higher than the 10 Hz range). This paper http://www.ncbi.nlm.nih.gov/pubmed/9306739 has the resonance of standing humans at 12 to 13 Hz. Quote Link to comment Share on other sites More sharing options...
Mallette Posted November 12, 2014 Share Posted November 12, 2014 Do organs internally bounce back from a hit at that frequency? Pipe organs don't... Dave Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 12, 2014 Share Posted November 12, 2014 Explain DRvsHornBassHD.jpg Most subwoofers are not producing distortion until they are under significant stress. The majority of comparative data indicate otherwise. Do they list the specific drivers/enclosures for both boxes? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 12, 2014 Share Posted November 12, 2014 Logically, it would seem that the much faster response due to the shorter excursion of a horn sub vs anything else aside from IB would create the cleanest "whump" you can get from a driver at a given frequency. I never said anything about a "clean" whump, nor am I arguing distortion figures between different enclosures. It seems that the Blue Man Group has the correct recipe for chest thump. They may use horn loaded bass drivers, I don't know. I tried to figure out what they used last time I went to one of their shows but really couldn't see what they were. You answered you own question but in a backwards sorta way, 60-70Hz overtones come from a lower frequency not higher. I guess I didn't phrase my question correctly. If you play a 60-70 note which is typically where you feel the thump (for whatever reason) why would the harmonic distortion (120 to 140Hz) make it worse? Quote Link to comment Share on other sites More sharing options...
Mallette Posted November 12, 2014 Share Posted November 12, 2014 Thanks, Carl. Got it... Dave Quote Link to comment Share on other sites More sharing options...
jason str Posted November 12, 2014 Share Posted November 12, 2014 You answered you own question but in a backwards sorta way, 60-70Hz overtones come from a lower frequency not higher. I guess I didn't phrase my question correctly. If you play a 60-70 note which is typically where you feel the thump (for whatever reason) why would the harmonic distortion (120 to 140Hz) make it worse? Your 60-70Hz frequency you were telling Beeker could not be distortion related may be overtones from a lower frequency, your claim on post 132 says distortion has nothing to do with it but it can in way of harmonic distortion. Where the 120-140Hz came from was your misunderstanding in post 139 as it was not mentioned until then. Quote Link to comment Share on other sites More sharing options...
Mystery Posted November 12, 2014 Share Posted November 12, 2014 (edited) Or just build one with Billfitzmaurice's plan. Cheap, goes low and loud. www.billfitzmaurice.com/THT.html 20Hz: 114dB at 4.5% THD. Edited November 12, 2014 by Mystery Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 12, 2014 Share Posted November 12, 2014 Clear as mud, never mind. There seems to be a language barrier here. Let's just say it's on my end and move on. Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted November 12, 2014 Share Posted November 12, 2014 (edited) "60 hz will make the kick hit you n the stomach." That guy is an audio engineer but I imagine there are plenty of other sources as well.That's with live sound where the low end of the signal crest factor is typically in the 14-18 dB range. With recorded playback, achieving those level of transients is a whole 'nother challenge because, given the source material, the information simply isn't there. This is why us horn guys are always comparing and often times complaining about the DR rating of certain albums. Live sound technique to home sound is not necessarily a direct translation. There are certain caveats to be aware of. I could care less about accurate orchestra music, I want to sound like I'm inside a hard rock concert. I used to be in a band where we sent the kick drum and sometimes my bass through six pro audio Yamaha 18's and I was 10 feet away. It was nothing short of amazing. I've been chasing that sound ever since. It may not be totally possible but I got quite a bit closer with my last setup, running two RF-7ii's full range with two 15's right behind me. I got a good low thump that I can feel and the RF-7ii's handle the attack well, the sound of the beater on the skin seems to come from the screen and the thump follows so it sounds cool. But, it's just not the same. The initial attack and upper realm of what concert subs would typically handle is nowhere near as powerful. The RF-7ii's actually do sound pretty accurate on good kick drum material but the power you get from live sound just isn't there. There seems to be a gap in the home, this black hole that exists somewhere between subs and mains that you get on live sound. I think you could almost do it if you had pro audio 18's up front that handled a wider range of frequencies, definitely higher than the 80 hz that most people cross over at for home theater subs. But, that's going to screw other things up, voices and bass guitars would sound boomy since there's no dedicated channel that you're boosting like you can at a concert. So yeah I'm probably chasing unicorns that are ridden by leprechauns but yeah live sound in the home is what I'd like to achieve. When you boost the subs in the home to boost the kick drums then things will just sound sloppy. I keep viewing this as a shortcoming of my subs but maybe it goes well beyond that because I get similar results with both the Klipsch R-SW115 and two sealed Ultimax 18's with an iNuke 6000 on them. The fast attack that you get on live sound subs just doesn't exist. You can shake the room and your chair but it just isn't the same. Getting RF-7ii's and running them full range is the biggest thing that helped with this sound but I can't get the kind of volume you need to pound your chest in with them. Edited November 12, 2014 by MetropolisLakeOutfitters 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 12, 2014 Share Posted November 12, 2014 The RF-7ii's actually do sound pretty accurate on good kick drum material but the power you get from live sound just isn't there. What amp do you have on your RF-7's? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.