Eminence Alpha 15A (Double Fifteen) playing Reggae
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Forum Name: Ported Enclosures
Forum Description: Post all your reflex and bandpass and 'other' boxes with holes in stuff here...
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Topic: Eminence Alpha 15A (Double Fifteen) playing Reggae
Posted By: Elliot Thompson
Subject: Eminence Alpha 15A (Double Fifteen) playing Reggae
Date Posted: 17 March 2014 at 5:22pm
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Here is a video of a pair of Eminence Alpha 15A speakers I tossed in one of my Double Fifteen Reflex boxes designed for RCF L15 P540. I am definitely planning to build some reflex subs for these drivers by the end of the year. Best Regards, ------------- Elliot Thompson |
Replies:
Posted By: lycantheleopard
Date Posted: 17 March 2014 at 6:31pm
| i would have thought the limited xmax of the alfa series would be a bit of an issue doing sub duty? i know i like them full range but i'm curious as to why you think they would or are doing so well? they would sure make a cheap entry level option for a lot of new builders just looking to try something out |
Posted By: TMH Music
Date Posted: 17 March 2014 at 7:22pm
@Elliot, more details please!!!! What are you driving them with? How big is the cab? What's it tuned to? Just looked at the T/S for Alpha 15a, Qts 1.26?!, BL 7.7???!!!!!!!! VAS 260L!! Is it just me, or does this driver have absolutely no right whatsoever, to sound this good, unless the cab is tuned to a sub-sonic frequency and is 1000 litres+ internal volume? And there was me thinking I knew a bit about speaker design, I'm obviously Manuel (I know nothing!!)  .Going to throw my rule book away now! Edit for incorrect VAS. Also just crunched the numbers, 12300 litre cabinet, tuned to 12.4Hz!!! ------------- Nothing is foolproof because fools are so ingenious |
Posted By: Elliot Thompson
Date Posted: 17 March 2014 at 7:43pm
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They are performing well because the measured frequency
response is relatively flat from 200 Hz to 45 Hz in free air (Shown in the
video). So the driver does not need to rely heavily on xmax in order to
propagate bass within the 200 – 45 Hz region.
Compare the free air response of the Alpha 15A to any of the
popular (The drivers you hear many going on about), 18-inch drivers and the
free air response is –3 dB, -6 dB, and/or –10 dB from 100 Hz to 50 Hz. Under
the given conditions the driver relies heavily on xmax to make up the gain due
to the reduction of the frequency response in free air.
There is a reason Eminence calls the Alpha Series “American
Standard.” It follows the same principals found in American Drivers, which were
common with the majority of home audio systems stemming from 1980’s downwards.
In the current box (not designed for the Alpha 15A) you can
see, the frequency response is registering to 25 Hz in the Spectrum Analyser.
Building a proper box based on the TS Parameters you can achieve a response
below 20 Hz. There are lots of parameters to focus on other than xmax. However,
when the majority only focus on xmax, they overlook all the other parameters
and wonder why they are constantly destroying speakers.
------------- Elliot Thompson |
lycantheleopard wrote:Posted By: Elliot Thompson
Date Posted: 17 March 2014 at 8:15pm
Bear in mind, those speakers are in the wrong box (Designed
for the RCF L15 P540 not the Eminence Alpha 15A). I believe the amplifier used
was the 1986, 4 ru Peavey CS 800 playing the bass or the 1976 version on the
left channel. I already took the drivers out of the cabinet and tossed them in
back their cardboard boxes. As I mentioned, in another thread, I don’t use high pass filtering,
which plays a factor on the sound.
Best Regards,
------------- Elliot Thompson |
.Posted By: Elliot Thompson
Date Posted: 17 March 2014 at 8:40pm
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Here is the ALPHA 15A playing Jazz. Best Regards, ------------- Elliot Thompson |
Posted By: Dub Specialist Sound
Date Posted: 17 March 2014 at 11:36pm
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I like the way you think my man and your reasoning/knowledge behind it, not just the same ol' them drivers are crap/inferior like you get a lot of time on here! and without any real evidence/experiance to back it up...just an opinion there crap... as you have shown you can get an acceptable/decent sound out of them... nice! ------------- Musical Roots Reggae Vibration is Life! for music is sound...sound is vibration...vibration is energy... and energy begets life. Therein lies my passion!...MUSIC IS LIFE... |
Posted By: _djk_
Date Posted: 18 March 2014 at 12:53am
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http://www.eminence.com/pdf/Legend_CA154.pdf" rel="nofollow - http://www.eminence.com/pdf/Legend_CA154.pdf
This works well in a big box, dirt cheap (about $60 in the USA). ------------- djk |
Posted By: Elliot Thompson
Date Posted: 18 March 2014 at 12:19pm
Thanks. Sometimes you need to ask yourself if you are achieving the sound you desire or, are you just getting what others feel is the right sound for you based on their concepts. You really need to know what you want, and having a good understanding of all the TS Parameters will help tremendously. It allows you to pinpoint on areas others overlook or just don’t care about. If the loudspeaker does not offer TS Parameters, you need to measure the loudspeaker. With the amount of software available on the market today, there is no need to speculate which loudspeaker parameter is correct when you are subjected to get the parameters from others. You also need to build your own design. Too many people think they are designers and cannot even figure out WinISD, which is the most simplistic loudspeaker simulator on the market The keyword here is “You.” If you are not willing to make the effort (get your hands dirty) don’t expect anyone else to do it for you. And of course, the naysayers that get argumentative when you don’t agree with their opinions, which are not based on real world experience, bid them good day and move on. Best Regards, ------------- Elliot Thompson |
Posted By: rish
Date Posted: 18 March 2014 at 2:24pm
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You really need to know what you want, and having a good understanding of all the TS Parameters will help tremendously. It allows you to pinpoint on areas others overlook or just don’t care about. If the loudspeaker does not offer TS Parameters, you need to measure the loudspeaker. With the amount of software available on the market today, there is no need to speculate which loudspeaker parameter is correct when you are subjected to get the parameters from others. You also need to build your own design. Too many people think they are designers and cannot even figure out WinISD, which is the most simplistic loudspeaker simulator on the market The keyword here is “You.” If you are not willing to make the effort (get your hands dirty) don’t expect anyone else to do it for you. And of course, the naysayers that get argumentative when you don’t agree with their opinions, which are not based on real world experience, bid them good day and move on." Best Regards, [/QUOTE] Probably one of the best responses i've read in a long time. agree 100%. well said Elliot. more people should adopt this attitude, then maby they will learn a thing or two. Rish
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Posted By: matt mcginn hi fi
Date Posted: 18 March 2014 at 9:53pm
nice one Elliot I'm going to dig a little deeper and not discount things too quick with my project |
Posted By: Elliot Thompson
Date Posted: 20 March 2014 at 1:31pm
Experimenting is the best means of learning. Best Regards, ------------- Elliot Thompson |
Posted By: Gee136
Date Posted: 20 May 2014 at 11:55am
This has got to be ONE of the most sincere & REAL statement ever written on this board, well done Elliot real Man business Respect.............  ------------- Goverment Sound (weight & treble roots machine) When Goverment ah play, infidels, ginals & masqueraders run away..... |
Posted By: crossed
Date Posted: 20 May 2014 at 4:49pm
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My interest was piqued, I meant to keep an eye on this thread. How did the testing turn out? |
Posted By: Elliot Thompson
Date Posted: 21 May 2014 at 1:48pm
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I completely forgot about those speakers. Bass is the least of my worries. At the moment, I am researching 192 kHz audio interfaces as that will increase the overall quality of the sound than building another sub cabinet. Best Regards, ------------- Elliot Thompson |
Posted By: TmanG
Date Posted: 24 May 2014 at 8:04pm
Hi Eliiot Just wondering how do you protect the drivers from over excursion at low frequencies without a HPF? May have been covered in the other thread but I'm not sure which you mean?
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Posted By: Elliot Thompson
Date Posted: 24 May 2014 at 9:26pm
The impedance of the driver rises within 20 – 25 Hz region in the enclosure. This rise is due to how the driver is reacting in the enclosure. As in the impedance rise, the driver resistance increases. The higher the resistance the less voltage loudspeaker will absorb. For example, if an 8 ohm nominal loudspeaker is 35 ohms @ 18 Hz in an enclosure, and, you are feeding the driver an amplifier that offers 89.4 volts (1000 watts) @ 8 ohms, the loudspeaker will not be subjected to 89.4 volts (1000 watts) @ 18 Hz. The voltage will be lower due to the higher resistance. And of course, the lower the volts, the lower the cone movement. So under the given scenario, the loudspeaker would absorb around 42 volts @ 18 Hz on a 35 ohm load from an amplifier that delivers 89.4 volts @ 8 ohms. Measuring (Not simulating) the impedance curve in the enclosure, will tell you where the true impedance peaks lies. Best Regards, ------------- Elliot Thompson |
Posted By: fourway hornloaded
Date Posted: 25 May 2014 at 11:40pm
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The mechanism is real but the explanation is confusing. There is no voltage absorbtion. If the amplifier puts out 89 Volts, the loudspeaker gets 89 Volts. Whereas 89 Volts cause 11,1 Amps in an 8 Ohm load, that same voltage causes only 2,5 Amps in a 35 Ohm load. That's how higher in-box impedance at certain frequencies causes less cone movement. In other words, 89 Volts cause 1000 Watts of power in an 8 Ohm resistance, but only 226 Watts in 35 Ohms. No pun intended, just to make it easier for those trying to grasp the basics. |
Posted By: Elliot Thompson
Date Posted: 26 May 2014 at 3:28am
Sorry that is not correct. I am talking about impedance versus frequency of a loudspeaker. If someone looks at an impedance versus frequency chart of a loudspeaker, it will not show you the amount of amperage consumed by the loudspeaker at particular wattage. What it will show you is the frequency bandwidth, the impedance load at the given frequencies and, at times the phase. By you adding amperage in the equation, it creates confusion for the amperage drawn from the A.C. Receptacle will vary pending on what part of the world you live in. Power Consumption 1000 watts on a 120-volt line source: 8.333 amperes 1000 watts on a 240-volt line source: 4.166 amperes 1000 watts on a 230-volt line source: 4.347 amperes 1000 watts on a 200-volt line source: 5.0 amperes 1000 watts on a 110-volt line source: 9.090amperes 1000 watts on a 100-volt line source: 10.0 amperes 1000 watts on a 220-volt line source: 4.545 amperes This is precisely the reason I did not add amperage in my explanation. Best Regards, ------------- Elliot Thompson |
Posted By: TmanG
Date Posted: 28 May 2014 at 11:22pm
That makes perfect sense to me Elliot thank you for the response. Does the impedance of a bass enclosure not fall back down to normal levels around 10hz? Would in this instance given a strong enough signal in this region, either through subsonic feedback or the music itself, cause concern about over-excursion? Is it the case that electronic processing units rarely let any signal at that frequency pass though at significant level or some other reason that you feel comfortable running your system with no hpf? Just curious is all as I've always operated under the adage that operating an enclosure with no hpf is risky
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Posted By: Elliot Thompson
Date Posted: 29 May 2014 at 4:29am
If you mean normal as nominal load of two 8-ohm drivers wired parallel to equal 4 ohms nominal, no. The impedance is higher than 4 ohms nominal at 10 Hertz if we are using the Eminence Alpha 15A woofers in the reflex box played in the videos as a means of reference. Of course, results will vary pending on how the driver(s) are reacting in the enclosure of the design in question. One must also consider the dB ratio comparing 10 Hz to 20 Hz. Almost always there is a significant reduction starting from 20 Hz to 10 Hz from the source (musical content). I might add most audio processors internal HPF starts to activate below 20 Hz and may be around – 1.5 dB to -3 dB @ 10 Hz pending on the audio device in question. Measuring every piece of equipment used in the audio chain will show what is the weakest link starting from the source (musical content) to loudspeaker (woofer). Best Regards, ------------- Elliot Thompson |
Posted By: app
Date Posted: 12 November 2014 at 10:38am
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This is an interesting topic! ET have you already started planning the box for these? ------------- "what!?" |
Posted By: app
Date Posted: 12 November 2014 at 10:49am
Id like to see what the simulation for this would look like.Just to learn a trick or two ------------- "what!?" |
Posted By: app
Date Posted: 12 November 2014 at 1:42pm
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How should the impedance/x-max/transfer function magnitude (?) ratio be read? What I mean is if the impedance is low at lets say 35hz and hi at 65hz and the speaker is given x amount of watts would that cause the frequency range of the speaker to even. Althou it may seem in the transfer function magnitude line that theres not much happening at 35 hz. How should the x-max be in relation to impedance? How do you tune your box so that you can play it without using a highpass filter? edit. b&c sub 18 with 4 different drivers all given their max rms signal. What does the impedance curve tell me? Which one of the lines is the "best"? http://%20imgur.com/fi93gNi" rel="nofollow -  ------------- "what!?" |
Posted By: DMorison
Date Posted: 13 November 2014 at 1:22pm
The amplifier applies voltage to the driver, so the use of Wattage is a bit of a shortcut that masks some of what is going on. The calculation actually assumes a constant Voltage at all frequencies, so where the Impedance is higher, less current will be drawn and the actual (rather than nominal) power dissipated by the driver will be less. All vented Boxes have a low impedance at their Tuning Frequency with peaks either side, and low impedance below the lower peak. This means high power can be drawn even where the driver/box combination is much less efficient, resulting in excess excursion, distortion and heat for both the driver and amp to handle. You don't. Always use an HPF, both for sound quality (reduced distortion) and driver longevity (reduced chace of damage from being pushed too far).
A higher average impedance curve will place less load on the amplifier, giving it an easier job thus less risk of it overheating. It also makes it more likely to be safe to drive multiple speakers per channel. For example, if a driver dips to 5.5Ohms, then 2 in parallel will be 2.75Ohms and that could be a bit low for an amp only rated down to 4Ohms. If the minimum impedance is say 7.5Ohms, then 2 together is 3.75Ohms, much more likely to be OK for even a modest amp.
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Posted By: Elliot Thompson
Date Posted: 30 November 2014 at 4:24am
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app,
Simulators can only give you an estimate on what is supposed to take place in a perfect world. So unless you are planning to go beyond simulators and start measuring loudspeakers, it would be best to use precautionary methods, such as high pass filters and limiters.
My cabinets were designed to play sub low frequencies. My Double Fifteens are good to 25 Hz whereas my Double Eighteens in addition to my Double Twenty-Ones go much lower than that.
Best Regards, ------------- Elliot Thompson |
Posted By: AndyWave
Date Posted: 23 February 2015 at 4:30pm
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First of all sorry to blow wind to an old thread This is mainly to Mr Elliot Thompson. I'm sorry,but I must disagree, because I have many times used simulation program to design a bass reflex enclosure, and measured impedance graph has followed the simulated one so closely that it's scary accurate. Only thing which is not spot on is tuning frequency, almost every box shows lower tuning in actual build. If i follow your foundings my reflex builds should have point of less excursion above box tuning (iow at the impedance peak above tuning) contrary to this belief there is point where at least in very large cabinets, my drivers bottom out. I have tried JBL and Electro-Voice, are they built with that american legend system you speak about? What would be the driver parameter which makes the use without subsonic filter possible? Suspension compliance?? Huge Xmech comes to my mind also. Before you explain, I simply cannot believe your statement, my experiences with vented enclosures are contrary to yours. Before you ask, I have some 25 years of experience on the subject to back it up. I also have never lost a driver so maybe I'm too careful with something like crest 9001 with clip flickering.... Best Regards, Andy ------------- torturing electrons since ...... |
Posted By: Elliot Thompson
Date Posted: 23 February 2015 at 4:55pm
If the tuning is off, the impedance
rise/dip in the measured box will not co-relate to the simulated response in loudspeaker
simulation software. So how can it be scary accurate? Feel free to measure the impedance curve of the loudspeaker in the box and see how well a measured impedance curve and simulated impedance curve match.
Best Regards, ------------- Elliot Thompson |
Posted By: AndyWave
Date Posted: 24 February 2015 at 3:24pm
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All other aspects than simulated port length are/were spot on. I'm using impedance measurement and driver movement to check port (box) tuning and therefore the actual port length needed. Once the tuning is right, impedance graph correlates between real life and sim. Some of the other aspects I'm refering to are impedance and phase graph,
frequency response, phase response and driver excursion. As said many times in this forum, simulated ports show off some 5-10% longer than actually is needed. To me this means poor modeling of the port, mainly end correction, maybe in too small sized ports the surface friction of air mass to port walls and eddy currents will not be taken account. Have you tried or used winisdpro? There are three additional q-values for box leakage and stuffing (absorbtion), and port loss. Closed box total Q value is maybe the simplest example what happens to driver parameters. What happens after voice coil is driven hot, is primarily qts value growing as Re portion rises but there we're going to the nonlinear region of the driver and small signal data no more holds true. You can use advanced option in winisdpro driver parameters, there are inputs to voice coil temp and VC wire temp coefficient. I'm using horn response, winISDpro and akabak. Have you compared the outcome between different softwares? Maybe akabak is in bit different league as there is possibility to input much more variables and surroundings of the whole box. I have also once found leak inside horn because real life box output and impedance graph didn't compare well with simulation. Found it out when first time giving welly to a new proto...luckily I never "rew cold engine to the max" Rgds, Andy Ps What is that snake oil in american legend, that I'd like to know. You don't specify which parameter we're discussing.... ------------- torturing electrons since ...... |
Posted By: Elliot Thompson
Date Posted: 24 February 2015 at 6:12pm
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You don’t need anything other than connecting the loudspeaker residing in the enclosure to an impedance measurement program and feed the enclosure a sine wave sweep. The results will be the actual tuning frequency of the box based on how the loudspeaker is reacting in the enclosure. I used WinISD before WinISD Pro version was offered, purchased Eminence Designer due to the errors I discovered with the port tuning in WinISD and, tried WinISD Pro once it was offered. Despite being WinISD Pro being superior to WinISD, it is still a simulator. A simulator cannot beat real world measurements when you want to know exactly how the loudspeaker is reacting in the enclosure it is residing in. Horn Response heart and soul is creating horn cabinets. Since I don’t use horn cabinets for bass purposes, it is pretty much pointless to focus on building reflex cabinets in Horn Response when the end results will be no different than using Eminence Designer. I have 14 years of experience with Eminence Designer which served me well. Akabak is good for those who are literally designing the actual loudspeaker (voice coil, spider, etc) to take everything into account. I am not commissioning a loudspeaker manufacture to create my own OEM Loudspeakers so Akabak would not serve any use for me. ARTA has served me well for nearly 10 years for giving me the answers I am seeking. I don’t drive my speakers ragged. I put down that type of abuse over 20 years ago. The name of the game is having more than enough to get the job done and not screech by hoping your drivers will make it by the end of the event. So the heating of the voice coil to point it gets hot does not apply to me anymore. A lot of people worry about maximum SPL out of one box. I don’t concern myself maximum SPL for I am going to get a lot of SPL due to carrying quantity not only in subwoofers but amplifiers as well. Let me explain something to you. When you design a loudspeaker enclosure, you are custom designing it for your requirements under the given conditions. You must know everything about that design to the point you can set up, walk away and not worry about anything failing throughout the event. This comes from not only researching the loudspeaker’s measurements in the real world but, knowing exactly how much power the driver is going to receive from a frequency standpoint based on the impedance curvature of the loudspeaker measured in the enclosure. Your subwoofer system is supposed to be designed to work with your sound system and designed around your system’s characteristics. Now, if you are building loudspeaker enclosures in order to sell them to the public you will take precautionary methods for you have no clue how the speakers are going to be used from the customer. Since I am not selling my designs, I can build them based on the sole end user… Me. Best Regards, ------------- Elliot Thompson |
Posted By: odc04r
Date Posted: 24 February 2015 at 8:02pm
It'll give you the small signal behaviour, I assume you don't test with more than a couple of V - and that's really only one step better than the simulated model (whichever simulator you use) but with some error removed. Bet you your reflex cabinets don't behave the same when you stick 50W into them over some time, let alone 500W. Voicecoils will warm up and parameters will shift, if you know your margins here then job done. If not then at this point you are effectively guessing albeit an educated guess.
It is really so much more than that - the one thing Akabak offers over HR (even with horn cabinets) are variable assignments. I'd have to go dig out some scripts but when I was playing with tapped horns I wrote scripts that used the effective dimensions of the cab to work out horn length and taper (or vice versa) then placed the driver at variable points along the horn/pipe (depending on taper). Using designed experiment techniques I could then produce a surface response of my inputs vs simulated responses and clearly see what was driving what. Would have been a lot trickier to do that with HR.
How hot do you think your voicecoils get even under moderate useage conditions? I have pondered this question before a few times and I don't have an answer but I think we might both be surprised what even a few 10s of W can do to temperature, especially in a midrange driver which does not have excursion enhanced cooling. |
Posted By: nickyburnell
Date Posted: 25 February 2015 at 9:30am
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This whole thread reminds me of an argument I had about trucks not needing syncromesh . People have forgotten the real science, absolutly wonderful Elliot, an insight and a lesson. I don’t drive my speakers ragged. I put down that type of abuse over 20 years ago. The name of the game is having more than enough to get the job done and not screech by hoping your drivers will make it by the end of the event ------------- It's everything, not everythink! |
Posted By: Elliot Thompson
Date Posted: 25 February 2015 at 10:51am
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Even if a shift occurs per frequency when you feed the loudspeaker more voltage the impedance cannot go lower than the loudspeaker’s resistance it can only go higher. Usually, the vented back plate works as a cooling system to keep the voice coil temperature cool when the piston is moving back and forth. So the change of the resistance is not huge unless you are using one or two speakers to cover a large area and driving your woofers ragged with minimum excursion involved. The majority of woofer repairs are based on electrical damage not mechanical damage. As the old saying goes, “There is strength in numbers.” A lot of issues you read on the Internet are from users toting two to four enclosures housing a single driver. Those issues do not apply when you are carrying four or more enclosures utilising two or more drivers in each enclosure. The workload is minimised a lot hence, minimising heating issues. I’ve conducted a lot of tests in the 1990s with sacrificial drivers. I believe if you are in this business long enough, you need to have sacrificial loudspeakers at your disposal. I recall when I used Scoops (1990s) I took two boxes, connected them to a 200 watt per channel amplifier, drove the amplifier into clip while, playing an audio cassette for 90 minutes (Auto Reverse Enabled). After the test, one 18 inch driver survived while the other offered signs of voice coil rubbing. The magnets on both woofers were hot. The next test was using one double fifteen inch sub and driving the woofers beyond their rated power (The woofers were rated 150 each and I was feeding each driver 600 watts) with an excess amount of sub low content (32 Hz and below). It took an hour or so, but eventually, the woofer’s cone ripped to shreds to the point the voice coil was bobbing up and down without a cone. After the test, I checked both drivers. Despite the ordeal, the magnet and, voice coil was not hot but Luke-warm. The final test was feeding 200 watts (clipping time to time) of continuous music to a 15 inch driver playing mid-range (100 Hz on up) for 6 hours with the dust cap off. This allowed me to check the heating temperature every hour. After the 6 hours was complete, the voice coil was warm and the magnet was Luke-warm. The driver was not damaged during the test. It is these little tests I’ve conducted decades ago which allows me to not worry about thermal or mechanical drawbacks. Once you use quantity, more SPL and very little to no driver failure will always come into play. Best Regards, ------------- Elliot Thompson |
Posted By: odc04r
Date Posted: 25 February 2015 at 12:49pm
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All of that is common sense really backed up with a bit of theory which fits nicely. I think we can summarise it as: Headroom is good Drivers that move more will as a general rule cool better. but run the risk of mechanical damage eventually The opposite is also true, if you let MC Shoutalot run straight through your midtops constantly then you may well find your mid voicecoils fusing together. As you say when a voicecoils temperature rises impedance can only increase, which gives rise to power compression and again this can be avoided by using more drivers and less power per driver. All good. But in this context we are talking really about impedance as a pure resistance and we are not considering phase shift. If we really want to understand what safety margin we have as a function of voicecoil temperature then we need the whole picture of what happens to the Qts of the system and specifically if the width of resonance widens or gets thinner. Because in turn this affects the region of the box operation where voltage and current are not in phase and has implications for how much reflected power the amplifier must sink if nothing else. Also as you mentioned in another thread (maybe this one?) if you design a crossover point close to the resonance region of a box then when it all heats up the resonance region may widen and now you are seeing a phase shift at that crossover point which was not there before. What we are missing here is some proper data on all of these effects, I'm sure it is out in the literature somewhere if I searched. But one day I will build that realtime+real load condition impedance analyser that I am always thinking about and then I will know for sure! |
Posted By: Elliot Thompson
Date Posted: 25 February 2015 at 4:13pm
Have you checked out ARTA? There are various things you can do with this software that will help you get closer to the answers you are pondering about. http://www.artalabs.hr/" rel="nofollow - http://www.artalabs.hr/ Best Regards, ------------- Elliot Thompson |
Posted By: odc04r
Date Posted: 25 February 2015 at 4:39pm
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I haven't as it happens, it's been on the list of things to try for quite a while but again never got around to it. I have an idea for a real time system in my head which I doubt arta will do, but I will check it at some point soon when I've got the current crop of work off the desk. Edit: Just had a look and I don't think it will do what I am after which is real time monitoring of a loudspeakers voltage and current independent of each other in real time with automatic level switching. But I will still have a play with it one day |
Posted By: Elliot Thompson
Date Posted: 26 February 2015 at 2:43am
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What you are prescribing sounds more to wards software embedded in an amplifier’s DSP. Best Regards, ------------- Elliot Thompson |
Posted By: odc04r
Date Posted: 26 February 2015 at 9:23am
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Yes similar for sure, ultimately I do want to make measurements over real world conditions and time spans. Acquiring the data and then processing using a PC would give a lot more flexibility than an onboard amplifier DSP I would have thought (curve fitting and parameter extraction etc). Certainly it allows you to brute force algorithms to an extent when prototyping and enables logging of data. It's just a bit of fun really but right now I have a CNC to finish and a somewhat complicated analog filter to design and build too, then a distinct possibility of having to move house. So maybe when all that is done.
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