peniku8 Posted April 18, 2020 Author Share Posted April 18, 2020 3 hours ago, SME said: In a HT setting though, this amps doesn't look like it's going to hold up to one that can sustain the output for several hundred milliseconds at least. Did you read my last post and look at the graph? It's not 80ms, it's 260ms. It then gradually drops to 4.5KW over a span of another 500ms. Quote Link to comment Share on other sites More sharing options...
klipsch Posted April 18, 2020 Share Posted April 18, 2020 11 hours ago, peniku8 said: @klipsch I've read about it blowing up. notnyt is actually the guy who sold me the Pmillet Soundcard Interface, which I'm using for my tests 🙂 Nice! I am using an FP20000Q. 2 of the 4 channels are used independently on 2 skrams with Nsw6021s.  Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 18, 2020 Author Share Posted April 18, 2020 I updated the first post with some info. More coming soon. I have hopes on the amp. The mains relais switches on the power supply with a delay. The amp shorts and trips the breaker as soon as you flip the on switch, which means that the PSU doesn‘t cause this. It might still be good. I‘ll get a replacement power input board (30$) and hope for the best. Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 18, 2020 Author Share Posted April 18, 2020 Sanway FP-13000 1x2Ohm Quote Link to comment Share on other sites More sharing options...
SME Posted April 19, 2020 Share Posted April 19, 2020 19 hours ago, peniku8 said: Did you read my last post and look at the graph? It's not 80ms, it's 260ms. It then gradually drops to 4.5KW over a span of another 500ms. My apologies, I was rushed when I posted my last reply and did not read your detailed post. Yeah, the numbers you posted look a lot better. I don't really like the blowing up part though. Good luck with that! Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 19, 2020 Author Share Posted April 19, 2020 2 hours ago, SME said: My apologies, I was rushed when I posted my last reply and did not read your detailed post. Yeah, the numbers you posted look a lot better. I don't really like the blowing up part though. Good luck with that! Yea I didn‘t particularly like that either. Shouldn‘t happen even if the amp is 7 years old. But it did 1 minute of 4KW output before it blew up! Quote Link to comment Share on other sites More sharing options...
kipman725 Posted April 20, 2020 Share Posted April 20, 2020 On 4/18/2020 at 5:43 PM, peniku8 said: I updated the first post with some info. More coming soon. I have hopes on the amp. The mains relais switches on the power supply with a delay. The amp shorts and trips the breaker as soon as you flip the on switch, which means that the PSU doesn‘t cause this. It might still be good. I‘ll get a replacement power input board (30$) and hope for the best. Have you checked the relay is open when the amps switched off? the contacts may be welded shut Also what amps do you have to test?  Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 20, 2020 Author Share Posted April 20, 2020 36 minutes ago, kipman725 said: Have you checked the relay is open when the amps switched off? the contacts may be welded shut Also what amps do you have to test? Â The relay seems to be working just fine. The Thermistor that broke seems to be the issue. It blew its ceramic shell, but the (soldered out) resistance still measures the value stated in the data sheet. My conclusion was that it reaches 0 resistance way too quickly now, which basically bypasses the soft start feature of the amp. The current spike trips the breaker. Amps tested are the FP-13000, a KMT LC1300 (old German 3U amp) and the popular (at least in Europe, particularly Germany) t.amp TSA1400 and the t.amp TSA4-300. Amp I have not yet tested are the Sanway DP10Q. Amps I could probably have easy access to for testing are a tamp E800, iNuke 1000, l.acoustics LA8 and a Crown XTi model I forgot Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 20, 2020 Author Share Posted April 20, 2020 One funny thing I‘ve noticed thou was one of the transistors not being soldered to the board. I‘ve corrected that now  Quote Link to comment Share on other sites More sharing options...
kipman725 Posted April 20, 2020 Share Posted April 20, 2020 thats odd, it looks like the leads are meant to be bent through the holes but have been cut too short. Also where is Q50? Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 20, 2020 Author Share Posted April 20, 2020 14 minutes ago, kipman725 said: thats odd, it looks like the leads are meant to be bent through the holes but have been cut too short. Also where is Q50? Bending the leads through the holes wouldn‘t be practical for machined assembly, I doubt anybody would do that. Q50 is probably installed on the Fp14000. The FP13000 is exactly the same amp with a few components missing. Probably the transistor there and two caps for the PSU. Quote Link to comment Share on other sites More sharing options...
kipman725 Posted April 20, 2020 Share Posted April 20, 2020 The leads can be preformed but this is an additional manufacturing step so would add cost. In this image of a real LG amp I found they are also soldered on top but the pads are more surface mount style. This image is actually quite surprising to me as lots of the components look very 'retro' (blue axial leaded capacitors!). Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 20, 2020 Author Share Posted April 20, 2020 1 hour ago, kipman725 said: The leads can be preformed but this is an additional manufacturing step so would add cost. In this image of a real LG amp I found they are also soldered on top but the pads are more surface mount style. This image is actually quite surprising to me as lots of the components look very 'retro' (blue axial leaded capacitors!). Yea the blue PCB sure looks more modern 😄 I don't know how the FP-13000 (14k)'s internals compare to the 10kQ (which is I guess the amp in this picture since there are 4 amp modules), but to me it seems like at least the Sanway clone (and a few others I've seen) took the 'more is better' approach and squeezed more caps and seemingly slightly larger heatsinks in. What wierded me out was the amp starting to smoke when I had it on for half an hour with the fans disconnected. Seems like the 150W or idle power draw is dissipated around the rectifier area, but I couldn't find where the smoke came from since the case was closed at that time. No visual clue remained.  Quote Link to comment Share on other sites More sharing options...
Ricci Posted April 21, 2020 Share Posted April 21, 2020 Here's my wish-list for amplifier power testing. If it were me I'd not test full power sine waves any longer than 5 seconds or maybe 10sec if you really want something a bit longer. There's no point. Even the most dense EDM music has breaks and is not anywhere near 100% duty cycle averaged over 10 seconds. If somebody really needs sustained multi KW power it's probably not for music or HT and it's time to look at an AETechron. Definitely no need for 2 minute full power tests IMHO. Plus as you say that'll get expensive when things go BANG! I'd like to see a few different frequencies tested. 1kHz has been standard for years so I get that but on these huge tour amps that are used for subs I don't think it represents the use very well. Is anyone dumping 10+kW peaks at 1kHz? That's not a concert or theater I'd want to attend. I'd like to see 50Hz or 63Hz used to sim kick drums and typical music bass and 10 or 16Hz for judgment of the deep bass power. Most amps wilt at those deep frequencies. There's almost always less power in the bass. Some amps hold up better than others but it's hard to tell from the 1kHz testing. Like I mentioned earlier I'd like to see something like this. 1kHz: 1 cycle burst (Short term output)/ 6.5 cycle CEA-2010 signal burst (Typical music content output) / 5 second sine wave power vs time (long term output) 50Hz: Repeat above. 10Hz: Repeat above 16kHz: Repeat above to gauge HF capability. The duration of the short term signals is longer for the bass frequencies as it should be. 1 cycle at 50Hz is 20ms and the CEA-2010 burst is 130ms. At 10Hz one cycle is 100ms and it's 650ms for the CEA-2010 burst, so it will be much tougher at the deeper frequencies. At 1kHz there is likely to be no difference between a 1 cycle or 6.5 cycle test. They are both so short in duration .I don't see anything less than a full wave cycle as useful data for the bass range though. The CEA-2010 signal is included in REW's tone generator, Clio and Don Keele's Igor pro program. It wouldn't be hard to sample it for use in other ways. Thanks for the data and discussion. Keep up the good work. Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 21, 2020 Author Share Posted April 21, 2020 5 hours ago, Ricci said: Here's my wish-list for amplifier power testing. If it were me I'd not test full power sine waves any longer than 5 seconds or maybe 10sec if you really want something a bit longer. There's no point. Even the most dense EDM music has breaks and is not anywhere near 100% duty cycle averaged over 10 seconds. If somebody really needs sustained multi KW power it's probably not for music or HT and it's time to look at an AETechron. Definitely no need for 2 minute full power tests IMHO. Plus as you say that'll get expensive when things go BANG! I'd like to see a few different frequencies tested. 1kHz has been standard for years so I get that but on these huge tour amps that are used for subs I don't think it represents the use very well. Is anyone dumping 10+kW peaks at 1kHz? That's not a concert or theater I'd want to attend. I'd like to see 50Hz or 63Hz used to sim kick drums and typical music bass and 10 or 16Hz for judgment of the deep bass power. Most amps wilt at those deep frequencies. There's almost always less power in the bass. Some amps hold up better than others but it's hard to tell from the 1kHz testing. Like I mentioned earlier I'd like to see something like this. 1kHz: 1 cycle burst (Short term output)/ 6.5 cycle CEA-2010 signal burst (Typical music content output) / 5 second sine wave power vs time (long term output) 50Hz: Repeat above. 10Hz: Repeat above 16kHz: Repeat above to gauge HF capability. The duration of the short term signals is longer for the bass frequencies as it should be. 1 cycle at 50Hz is 20ms and the CEA-2010 burst is 130ms. At 10Hz one cycle is 100ms and it's 650ms for the CEA-2010 burst, so it will be much tougher at the deeper frequencies. At 1kHz there is likely to be no difference between a 1 cycle or 6.5 cycle test. They are both so short in duration .I don't see anything less than a full wave cycle as useful data for the bass range though. The CEA-2010 signal is included in REW's tone generator, Clio and Don Keele's Igor pro program. It wouldn't be hard to sample it for use in other ways. Thanks for the data and discussion. Keep up the good work. I was guessing that if an amp does 20 cycles at 1Khz at a certain power, it would do 1 cycle of 50Hz at the same power. Are amps that bad at keeping up current for longer intervals? I think I'm gonna go with 10s test duration. Even the intense EDM song I looked at had a crest factor of 6-7db. And the dubstep sine waves are usually not full power because some headroom is needed for kicks. And I certainly don't wanna blow up any amps anymore. Especially when I'm testing amps north of 5 grand like that LA8 (although I doubt that that amp would NOT have very good protection circuits). I don't like the CEA-2010 test since it hides the temporal aspect and ties it to the frequency. I will most likely create some custom test files, basically sine waves which ramp up quickly. I can do a visual overlay so you'll see where exactly the amps drops off in output voltage. Also, CEA-2010 does not contain a single full output cycle. Just one peak will be at Vmax and the neighbouring peaks will already be a little quieter. Most amps I've seen have HF protections which mute high output above typically 10k anyways. I don't see why high output at 16k would be useful, as the strongest CDs do like 200W, so even if you have like 2 to 4 of those like in very high power line array elements, you don't need 10KW or anything for that. A scenario like that usually has one amp channel for one speaker. I was thinking about doing octaves in the bass region: 60Hz, 30Hz, 15Hz. Any higher than 60Hz would end up in the typical crossover region, so not super hard on amps typically and any lower than that will probably not be possible for me to get super accurate results for. One can gauge single digit results from the 15Hz performance anyways. Quote Link to comment Share on other sites More sharing options...
SME Posted April 22, 2020 Share Posted April 22, 2020 6 hours ago, peniku8 said: I was guessing that if an amp does 20 cycles at 1Khz at a certain power, it would do 1 cycle of 50Hz at the same power. Are amps that bad at keeping up current for longer intervals? This is a complicated question, and another variable concerns the nature of the load. A highly reactive load may behave very different on an amp than a purely resistive one. Most amps provide substantially less power output below a certain frequency. Most should lose little power at 40 Hz, but I think there are some that are already down below like 100 Hz. ("Burst" power for "very short" bursts, heheh.) Max power output is a lot more likely to drop off below 20 Hz. 7 hours ago, peniku8 said: I think I'm gonna go with 10s test duration. Even the intense EDM song I looked at had a crest factor of 6-7db. And the dubstep sine waves are usually not full power because some headroom is needed for kicks. And I certainly don't wanna blow up any amps anymore. Especially when I'm testing amps north of 5 grand like that LA8 (although I doubt that that amp would NOT have very good protection circuits). I think beyond 10s, you're just testing the protection circuits, which is nice info to have but not worth the cost of amps and the fire and health risks. What might be more interesting are some "real-world" tests using some of that EDM. Like, can you actually do -6 dB average with full-scale kicks for a significant duration? Maybe that still risks blowing any amp, but it's more likely to be encountered in real world use. 7 hours ago, peniku8 said: I don't like the CEA-2010 test since it hides the temporal aspect and ties it to the frequency. I will most likely create some custom test files, basically sine waves which ramp up quickly. I can do a visual overlay so you'll see where exactly the amps drops off in output voltage. Also, CEA-2010 does not contain a single full output cycle. Just one peak will be at Vmax and the neighbouring peaks will already be a little quieter. I think the purpose of the CEA is to keep the test narrowly focused on the frequency region of interest while keeping it transient. Without a smooth on/off ramp applied to the sine wave, the test signal takes on a lot more high frequency content at the start/stop points. Almost all real world signals that "hit the limit" are going to decay more like the CEA sample. Think a kick drum tone that is a decaying oscillation. The CEA isn't so realistic in that it has a slow "on" rather than a hard transient like you'd get from a drum. If you don't like CEA, one option would be a signal that is 0 for t < 0 and a cosine wave for t > 0, multiplied by an exponential envelope (to simulate smooth decay). A cosine wave is a sine wave shifted so the peak is at t=0, so this will be like a hard kick drum transient. If the amp has a LPF, you might just turn that on before feeding this signal, or you can apply your own LPF to it. It's not completely realistic because real-world transients have a lot less HF energy, but it should be a lot closer to a real drum hit. 7 hours ago, peniku8 said: Most amps I've seen have HF protections which mute high output above typically 10k anyways. I don't see why high output at 16k would be useful, as the strongest CDs do like 200W, so even if you have like 2 to 4 of those like in very high power line array elements, you don't need 10KW or anything for that. A scenario like that usually has one amp channel for one speaker. I was thinking about doing octaves in the bass region: 60Hz, 30Hz, 15Hz. Any higher than 60Hz would end up in the typical crossover region, so not super hard on amps typically and any lower than that will probably not be possible for me to get super accurate results for. One can gauge single digit results from the 15Hz performance anyways. For a sub-only amp, 16kHz seems pointless. For a general purpose amp, I think it would be more helpful to know how much if any response roll-off there is in the top. THD+N type stuff may also be helpful. You're right that no one is playing 16 kHz+ at 10 kW or even 200W. My home speakers have ridiculous boosts (20 dB+) above 17 kHz, and it's never a problem. As far as which bass frequencies to test, octaves seem to be a reasonable compromise. I don't think 15 Hz is representative of single digits though. A lot of amps will do 15 Hz just fine but seriously struggle with 5 Hz. Even the SpeakerPower amps have quite a bit less to give down there. Of course performance at 5 Hz is only of interest to a small number of people. Maybe do 10, 20, 40, and 80 Hz? 1 Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 22, 2020 Author Share Posted April 22, 2020 @SME The test files will ramp up, but not super hard, but also not as soft as some others do. Probably 6db gain per cycle, REW does 6db gain over 3.5cycles, which is fine for 1khz testing, but might already be an issue with 40hz. I wanted to test 60Hz since that‘s around the center kick drum sound, especially for live music. And I don‘t think 80Hz is too useful/realistic as the crossover point of any live PA will very unlikely be any higher, so 80Hz would already be shared by two amps 50:50 at an example of an 80Hz bw crossover. I think I‘ll do octaves from 60 to 7.5 then. But I don‘t know if I can get useful results that low, we shall see. Quote Link to comment Share on other sites More sharing options...
kipman725 Posted April 22, 2020 Share Posted April 22, 2020 I use a 120Hz crossover to my subs in my PA system LR4 slopes, I match the sensitivity of the subs and the tops so this is also the acoustic crossover frequency. My tops do play down to 80Hz but I want to keep the thermal load off them and reduce the chance of clipping their smaller amp.  A lot of PA's (essentially everyone I know personaly who isn't running a large touring sound company) will use an 80Hz electrical crossover but then tune the sub amp sensitivity by just turning it up until it sounds right. This adds an effective bass boost and puts the acoustic crossover typically around 150 Hz. Another reason I like to cross at 120Hz is I actually want a mono source for 93Hz which is the frequency that rattles the chest, subs can be arranged for best coverage but top locations are more fixed for stereo image . The kick drum in Bicep - Glue is at 53Hz If your interested in tests that might be applicable for higher frequency speakers I find knowing the residual noise with no signal interesting as some amps hiss too much to be used on compression drivers in quiet environments.  Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 23, 2020 Author Share Posted April 23, 2020 20 hours ago, kipman725 said: I use a 120Hz crossover to my subs in my PA system LR4 slopes, I match the sensitivity of the subs and the tops so this is also the acoustic crossover frequency. My tops do play down to 80Hz but I want to keep the thermal load off them and reduce the chance of clipping their smaller amp.  A lot of PA's (essentially everyone I know personaly who isn't running a large touring sound company) will use an 80Hz electrical crossover but then tune the sub amp sensitivity by just turning it up until it sounds right. This adds an effective bass boost and puts the acoustic crossover typically around 150 Hz. Another reason I like to cross at 120Hz is I actually want a mono source for 93Hz which is the frequency that rattles the chest, subs can be arranged for best coverage but top locations are more fixed for stereo image . The kick drum in Bicep - Glue is at 53Hz If your interested in tests that might be applicable for higher frequency speakers I find knowing the residual noise with no signal interesting as some amps hiss too much to be used on compression drivers in quiet environments.  I've been to concerts with high volume sustained output between 80-120Hz. These were not the most pleasant concerts I've been to. I generally think that the power requirement below 70Hz will be larger than that of the upper bass range. But I think the octaves of 10Hz would also be interesting as it classifies the bass pretty well imo. 10-20Hz content for the cinema crowd, 20-40Hz as sub-bass and 40-80 as the typical high power bass range for live events. Sub 10Hz requirement seems to become less sought after, now that so many people use low-power TR devices instead of a pile of sealed subs. At least that's my impression on AVS atm. I too used to just turn up the sub channel to get more bass before I knew better. It's an easy way and often the only way with simple analog systems to shape the response. Luckily dsp amps are finding their way into entry level PA systems, which gives newbies a lot more flexibility. I like the noise idea. Most high power amps will generate noticable hissing if you're less than 3m away from the CD (on axis ofc), but it won't be super noticable any further. Quote Link to comment Share on other sites More sharing options...
SME Posted April 23, 2020 Share Posted April 23, 2020 Every kick drum sound is a bit different. I note plenty in the 50s and 60 but also some that go down to 30 or 40 or up to 80 --- or 100. Furthermore, depending on genre or mix/mastering choices, kick drums may also be "doubled" creating a subharmonic an octave below the fundamental. This is quite common with music in movie tracks and is becoming more common with music masters too. Kick fundamental is also almost always accompanied by a strong 2nd order harmonic an octave higher. 20 hours ago, kipman725 said: Another reason I like to cross at 120Hz is I actually want a mono source for 93Hz which is the frequency that rattles the chest, subs can be arranged for best coverage but top locations are more fixed for stereo image . Just 93 Hz? Let me point out two things. First, different people come with chest and vocal physiology of different sizes which likely have different resonant frequencies. Second, the body exhibits tactile responses for a very wide range of bass frequencies, roughly anything below 500 Hz in my experience. However the subjective quality of the tactile bass response is extremely sensitive to linear frequency response, and some otherwise minor flaws can mask away most of the tactile sensations. Otherwise though, I agree that crossing up at 120 Hz is often beneficial. Music often has a lot of energy by that point. Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 23, 2020 Author Share Posted April 23, 2020 @SME I had live bands in mind with the 60Hz kick drum range. Studio recordings are very different from live acts. They'll still vary ofc, as not every instrument is the same, but typically the kick lands in the 45-70Hz range. Also keep in mind that the signal processing chain (including the mic) will result in the 100-1000Hz decade being attenuated quite a lot in most modern mixes. It doesn't sit in the mix very well. Yes a natural Jazz recording will likely differ, but anything I've ever experienced live (be it cover music or the actual acts from Robbie Williams, Pink Floyd, Queen, Iron Maiden, Judas Priest and dozens of other Metal bands) followed that principle. I also agree that a wide range rattles the chest, but I disagree that quality of tactile bass is tied so linear frequency response. I get the feeling that TR is tied to voltage sensitivity more than the actual FR. So yes, in perfect free field conditions the TR might track the FR while both are linear, but in a room where you start cutting the modes, the frequency range that gets less cuts will feel more pronounced in TR. I cut more between 10-60Hz than I do above and I get the feeling that the range that I do less cuts in feels more pronounced in TR, even if the FR is linear. Could also very well just be the resonance frequncies of my couch or my own body, who knows! I mainly use Waves' RBass to generate sub-harmonics in the studio. That plugin is pure magic and I love it! When I notice the lack of bass in an instrument during soundcheck of a live show, I often just send it into my suboctaver channel, which does exactly what it sounds like: it doubles the signal once octave lower, which goes through a LPF to not interfer with the original sound too much. I basically always use it when the drummer is playing a Cajon instead of a full sized kick drum. The band I'm "touring" with has a Cajon that kicks at 90Hz. The suboctaver adds a nice fat 45Hz to it and oh boy is it nice! Even the band basically immediately started questioning me about it after the first gig about how I made the kick so massive, it's great. Quote Link to comment Share on other sites More sharing options...
kipman725 Posted April 23, 2020 Share Posted April 23, 2020 the 93Hz (actually 91Hz sorry) is a bit of an in joke, hit someone with 120 dB of 500 Hz and you still get TR: https://forum.speakerplans.com/uploads/8883/Void_System_Tips_EQ.pdf my sub section is 4*15" reflex (soon hopefully 6*15") and my tops (in total) are 2*15" reflex (with a way smaller amp) so it makes sense to keep the crossover high. Another type of user who keeps the crossover high is someone using fully horn loaded tops as usually the horns are too small to have good efficiency at a low sub crossover point.  Quote Link to comment Share on other sites More sharing options...
peniku8 Posted April 23, 2020 Author Share Posted April 23, 2020 5 hours ago, kipman725 said: the 93Hz (actually 91Hz sorry) is a bit of an in joke, hit someone with 120 dB of 500 Hz and you still get TR: https://forum.speakerplans.com/uploads/8883/Void_System_Tips_EQ.pdf my sub section is 4*15" reflex (soon hopefully 6*15") and my tops (in total) are 2*15" reflex (with a way smaller amp) so it makes sense to keep the crossover high. Another type of user who keeps the crossover high is someone using fully horn loaded tops as usually the horns are too small to have good efficiency at a low sub crossover point.  I love that PDF, it's comedic and informative at the same time! "Do not confuse any other frequency with kick, it is 91Hz" lol! "The first things you need are some familiar test tracks that you have played on a variety of different systems." I'd like to add: the more spectral content the track has at any given time, the better. Aka "Apocalyptic Feasting" by Brain Drill. Venues and Hosts will love you when you blast that song for soundcheck. I also see RTA mentioned quite often, but never that you'd supposed to send the return of a measurement mic into one. I don't like equal loudness contours, as it's based on sine waves and research using bandpassed noise have yielded different results. He also takes a very different approach to handling equal loudness contours. Instead of always trying to achieve a flatter reproduction depending on the listening level (like what the dynamic EQ function on AVRs does, which I absolutely hate), he makes the listening experience at high levels sound like you'd percieve lower SPL levels, which is kinda the approach I'm also taking (and basically the opposite of the AVR approach, which basically makes high SPL listening even mode midrange/lower treble centered). Quote Link to comment Share on other sites More sharing options...
SME Posted April 23, 2020 Share Posted April 23, 2020 7 hours ago, peniku8 said: @SME I had live bands in mind with the 60Hz kick drum range. Studio recordings are very different from live acts. They'll still vary ofc, as not every instrument is the same, but typically the kick lands in the 45-70Hz range. Also keep in mind that the signal processing chain (including the mic) will result in the 100-1000Hz decade being attenuated quite a lot in most modern mixes. It doesn't sit in the mix very well. Yes a natural Jazz recording will likely differ, but anything I've ever experienced live (be it cover music or the actual acts from Robbie Williams, Pink Floyd, Queen, Iron Maiden, Judas Priest and dozens of other Metal bands) followed that principle. Good points about live kick drums used in rock and metal. When you talk about the 100-1000 Hz decade being attenuated are you talking about live music shows too? Or just content mixed for release? FWIW, cinema content tends to be quite a bit hotter below 250-500 Hz. I'm curious in general as to how much 100-500 Hz "mud" is a problem in a large room live setting. My experience is that the fundamental cause of "mud" is resonances in that range, and that the effect of broad boosts and cuts over that range is primarily to accentuate or suppress the effect of those resonances. These resonances can be caused by the speaker, by its interactions with its surroundings, or by EQ problems. OTOH, if response in that region is clean, there is no "mud" even without applying broad cuts. 5 hours ago, kipman725 said: the 93Hz (actually 91Hz sorry) is a bit of an in joke, hit someone with 120 dB of 500 Hz and you still get TR: https://forum.speakerplans.com/uploads/8883/Void_System_Tips_EQ.pdf my sub section is 4*15" reflex (soon hopefully 6*15") and my tops (in total) are 2*15" reflex (with a way smaller amp) so it makes sense to keep the crossover high. Another type of user who keeps the crossover high is someone using fully horn loaded tops as usually the horns are too small to have good efficiency at a low sub crossover point. FWIW, my home system crosses around 100-150 Hz (it's a custom "sloppy" XO) as that seemed to work best with my setup. I also like subs that can play higher. That PDF is where the joke came from? The recommendations in there are curious. Why reduce upper-midrange with a Q=4 filter? That's really narrow isn't it? I don't put much stock in generic EQ recommendations. Every situation is different, and it's good to be able to identify and fix the major problems at whatever frequency region they occur in. That takes a lot of skill and experience though. I don't think you need 120 dB for TR at 500 Hz, which is great because 500 Hz @ 120 dB is bad for the ears. IMO the best TR is *balanced* TR (or balanced FR, if you don't have a dedicated TR device), and I find balance is even more important for TR than for sound. When bass is extremely accurate, it can actually be surprisingly *intense* at relatively modest levels. This is very good for reducing SPL requirements, reducing equipment requirements and protecting health. Quote Link to comment Share on other sites More sharing options...
kipman725 Posted April 24, 2020 Share Posted April 24, 2020 So I wouldn't go as extreme in some ways as that pdf suggests, the bass boosts are way too much and will make a system sound like mud if you actually follow an equal loudness contour. However the tip "110 - 120dB 2.6kHz -5dB BW= 0.34 Q= 4.233" is totally spot on if your playing dance music and system sounds a bit harsh. My procedure for dance music is: 1) system has existing PEQs that make it flat on axis 2pi 2) play pink noise and adjust aiming of speakers to maximize stereo image area (you could get a distinctive whooshing noise in this area) 3) perform spacial averaged measurements in room 4) fit system response to overall room trend (usually about -10dB at 20 kHz) using PEQs 5) start playing tracks and tweaking, normally all that's required is the above and a some bass boost depending on the room perhaps a PEQ at around 50Hz to apply a small amount of boost 6) configure input compressor with 10:1 ratio and slow attack and release times with pink noise at the point the limiters are starting to be occasionally triggered. Quote Link to comment Share on other sites More sharing options...
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