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Post by Deleted on Aug 28, 2015 5:35:19 GMT -5
I think you have was well^^ or have been very close to being banned
But it want for being negative. It was for questioning emotivas marketing strategies and not able to hit a date on anything. Guess they don't like a spade being called a spade.
I'm just sick of Keith spewing things that aren't true with 1000 word essays. When 95% of the time it's false info he doesn't know about the subject well enough to comment.
Sorry for the negativity. I just find people on these boards are very stubborn about learning things that aren't 2 channel related (which eveyones knowledge is much more vast than mine)
But when it comes to home theater and subs. I know what I'm talking about. But some refuse to listen so I get frustrated
But ultimately I apologize. I will use more tact going forward
Rude post deleted
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Post by pedrocols on Aug 28, 2015 10:30:43 GMT -5
Keith is an engineer. Hence, he will explain things from a point of view of, yes you guessed it, an engineer. Same as when you go to your doctor he is going to explain things to you, yes you guessed it again, as a doctor. However, I do encourage everyone to keep an open-minded attitude about home audio whether is two channel or multi channel. By the way Two Channel Rules!
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Post by cheapthryl on Aug 28, 2015 10:55:34 GMT -5
Keith is an engineer. Hence, he will explain things from a point of view of, yes you guessed it, an engineer. Same as when you go to your doctor he is going to explain things to you, yes you guessed it again, as a doctor. However, I do encourage everyone to keep an open-minded attitude about home audio whether is two channel or multi channel. By the way Two Channel Rules!From you guessed it, an audio enthusiast. Hehe  |
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Post by jdubs on Aug 28, 2015 10:57:47 GMT -5
To come back into focus...
I REALLY like the idea of 2, sealed sonotube DIY subs. High power. Probably 10" so it can be in a 12" tube. Fast, tight, etc. I get pretty good room gain, so I think that would be a good set-up. Advantage being, I can build something that's not really on the market (SVS is close, but different design). It'd be cool and I made it myself. Easy to wrap in fabric and make it look decent.
I think Keith does have a good point in that the part express kits posted in this thread are $400. SVS has a bigger, more powerful product for $500 with a break if you buy 2. You get in-home demo with free returns, a strong warranty, and better fit and finish for barely more than DIY. Sort-of my argument from the beginning. But there are advantages (above).
Dayton has some nice, affordable drivers that might fit the bill. I'd probably build them passive and run it with something like a Crown amp.
Speaking of that, I had previously considered doing a couple bucket subs run with a Crown. If I didn't like it I could upgrade the subs and still have the amp. I even considered running them in stereo, IN ADDITION to my REL sub running mono crossed over super low. I think it could sound great if you could get the crossovers to work and not overlap.
One last thing; I've always though 10" was the perfect size for a sub for music. 8" sound great and are fast, but don't extend as low. Seams that 12 and 15" are becoming the norm. I understand the concept of bigger moves more air, can extend lower, etc. For some reason, 10" is still sticking in my mind as best. Am I crazy? Holding on to an older concept? Companies like REL still build 10", but also 12.
Thanks for the replies!
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Post by tchaik on Aug 28, 2015 12:08:02 GMT -5
In the late 90s/early 2000s it was common marketing propaganda to see large stiffening capacitors used in car audio. They still persist but seem less common. I would not say it is common place to see DIYers overhauling amplifiers with esoteric capacitors though. Usually DIYers simply purchase inexpensive pro amplifiers and call it a day. Sometimes a more quiet fan or a 12V trigger is added but otherwise the amplifiers are run stock for the most part. Unless people are going way overboard with esoteric passive crossover components for DIY mains (not subs) I don't see a lot of other places you can go with over the top stuff for a subwoofer... I guess with esoteric speaker wire or silver speaker terminals, but in my experience DIYers (especially for subs) are usually very budget conscious. Subwoofer, speaker wire, cabinet, finish, amplifier, and interconnects is really all there is to it. It is pretty inexpensive to get good performance DIY. A stereo integrity HT18 can be purchased for $174, make that two for $350. Add a Behringer inuke 6000DSP to power them for $400 and two 4 cubic foot subwoofer boxes from DIYSG for $240 and you are looking at a pretty sweet dual subwoofer setup for under $1000. Compare this to a single SVS SB13 with a smaller woofer, less power, and only one woofer for $1600 I would tend to agree with you that "true DIYers" usually don't add extra power supply capacitance. However, "audio tweakers", who I would put in a separate category, very often fiddle with capacitors. I would say that the two most common tweaks are to replace any electrolytic capacitors in the signal path with polypropylene or metal film equivalents, which may sometimes give a slight audible improvement, and to bypass the electrolytic caps in the power supply with smaller high frequency ones, which may help rejection of high-frequency noise, and probably won't hurt in any case. However, there is a bit of a tendency for DIYers to "use good audiophile capacitors instead of ordinary ones"; and, while this usually won't hurt, it can often waste a lot of money better spent elsewhere. Also, because modern power supply capacitors of a given electrical value are much smaller than their vintage counterparts, I do sometimes see people replacing the originals with modern ones of higher value - but the same physical size (the logic seems to be "more must be better - and it fits"). I would agree with you about the construction of subs, but there are a few fancy drivers out there with die cast baskets and fancy binding posts that, to put it bluntly, make the driver look and feel a lot nicer while you're holding it, but don't contribute to it's actually performing any better once the cover is on. (Thankfully, most of the people who consider amazingly expensive speaker wire with dubious or nonexistent electrical benefits worth buying don't usually extend that to subs.) However, I would caution everyone to always consider actual performance. A lot of what you're paying for in a commercial product is the cost of developing the product, and the knowledge of the designers. I don't know how the performance of the DIY sub you describe compares to the commercial SVS model. It may be better, but it may not. One of the biggest benefits of buying a commercial product is that it is a known quantity. I'm sure you could spend $2000 on drivers and parts and, if you made bad design or construction choices, end up with something that ISN'T as good as its commercial counterpart for half the price. You can read the specs on that SVS sub and be reasonably certain that the unit you purchase will actually meet them. However, I've definitely seen my share of beautifully finished, and lovingly constructed, homemade speakers that nonetheless sounded pretty bad - many of them made out of really nice parts. The trick is to do one's design homework and not fall into the trap of assuming that, if you use really good parts, "you can do no wrong". A well designed speaker made from crappy parts will almost always sound better than a poorly designed speaker made from good parts. (And, although a sub is simpler to design than a multi-way full range speaker, speaker design is still somewhat complicated.) (I would never try to discourage anyone who honestly enjoys building things from making their own sub. However, if the goal is strictly to save money, and acknowledging that a DIY speaker is going to lack things you would get with a commercial unit, like a warranty, and performance that you can reliably predict in advance, then you also need to compare the cost and performance of building your own to the cost of buying a good USED sub. And, if you like fancy woodworking, you might find more satisfaction in buying a good used commercial unit with known performance, and refinishing it to your specifications. The reality is that, while building your own equipment from scratch is a great hobby, especially if you actually enjoy it, it is rarely justified on true price/performance grounds alone. And don't forget, if you're not actually enjoying it, then you need to add the cost of your labor as well.) although what keith has to say is all true, there is a huge network of very skilled diy'ers out there to help in the design of your diy sub and you can get some damn good sound for a reasonable amount of money, and the satisfaction that you built it yourself. for me, diy speaker building is not only a hobby, but is also a means to an end. that end being the design of cabinetry that resembles our amish built furniture and making the wife very very happy. (see picture) personally i like the Dayton 15" ultramax subs in a 3 cubic foot box which gives an f3 of about 34hz with an f6 at about 25hz. quite prodigious bass in an average sized room. i say go for it and enjoy the process. it is like buying a truck. once done you never look back. Attachments:
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Post by Deleted on Aug 28, 2015 12:15:28 GMT -5
Keith is an engineer. Hence, he will explain things from a point of view of, yes you guessed it, an engineer. Same as when you go to your doctor he is going to explain things to you, yes you guessed it again, as a doctor. However, I do encourage everyone to keep an open-minded attitude about home audio whether is two channel or multi channel. By the way Two Channel Rules! Understood. But he is an electronics engineer (for amps etc) just because he is an electrical engineer doesn't make him an expert on al thing that have to do with sound reproduction. Just as a knee doctor may know about my kidneys but I sure as hell wouldn't call him an expert. And a diy 500$ ht18 in a 2' cu box will blow away the 500$ svs in every way shape and form |
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cawgijoe
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Post by cawgijoe on Aug 28, 2015 12:27:26 GMT -5
Keith is an engineer. Hence, he will explain things from a point of view of, yes you guessed it, an engineer. Same as when you go to your doctor he is going to explain things to you, yes you guessed it again, as a doctor. However, I do encourage everyone to keep an open-minded attitude about home audio whether is two channel or multi channel. By the way Two Channel Rules! Understood. But he is an electronics engineer (for amps etc) just because he is an electrical engineer doesn't make him an expert on al thing that have to do with sound reproduction. Just as a knee doctor may know about my kidneys but I sure as hell wouldn't call him an expert. And a diy 500$ ht18 in a 2' cu box will blow away the 500$ svs in every way shape and form First, I want to mention that I have a good friend who I have known for 35 years who has a master's in EE and is also an audiophile. I trust him when it comes to all things audio related. All I'm saying is that just because a person is an electrical engineer doesn't mean he has no knowledge or expertise when it comes to our hobby. The reverse can be true of course. I'll also agree with bmoney that a well made diy sub can easily best a mass market product if the builder knows what he is doing for the cost. |
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Post by Deleted on Aug 28, 2015 12:34:31 GMT -5
Understood. But he is an electronics engineer (for amps etc) just because he is an electrical engineer doesn't make him an expert on al thing that have to do with sound reproduction. Just as a knee doctor may know about my kidneys but I sure as hell wouldn't call him an expert. And a diy 500$ ht18 in a 2' cu box will blow away the 500$ svs in every way shape and form First, I want to mention that I have a good friend who I have known for 35 years who has a master's in EE and is also an audiophile. I trust him when it comes to all things audio related. All I'm saying is that just because a person is an electrical engineer doesn't mean he has no knowledge or expertise when it comes to our hobby. The reverse can be true of course. I'll also agree with bmoney that a well made diy sub can easily best a mass market product if the builder knows what he is doing for the cost. Understood and agreed And a sealed DIY is as easy and basic as it gets. You literally drop the driver in a sealed box and go. Ported in the other hand is a bit more complicated albeit still rather simple. But there is port tune, and DSp programming to make sure the driver isn't over driven etc. Please keep in mind I own 3 Id subs. And wish I knew about DIY and that I actually can build somthing (my Ht for example) from the ground up and it not fall apart hahah. I get very tempted to sell my subs and go DIY. But I wouldn't get nearly what hey are worth due to shipping. So I stuck with what I have. Which is phenomenal. But if I spent what I did on my subs on DIY. There would be no comparison. |
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Post by trevordj on Aug 28, 2015 13:08:23 GMT -5
One last thing; I've always though 10" was the perfect size for a sub for music. 8" sound great and are fast, but don't extend as low. Seams that 12 and 15" are becoming the norm. I understand the concept of bigger moves more air, can extend lower, etc. For some reason, 10" is still sticking in my mind as best. Am I crazy? Holding on to an older concept? Companies like REL still build 10", but also 12. 'tis a myth that smaller subs are somehow "faster." A well designed subwoofer in a proper sized enclosure with appropriate power, equalization, and time alignment can sound "fast" and "tight" regardless of size. In fact, it is easier to achieve this with larger subwoofers as they move air more efficiently than their smaller counterparts, all other things being equal. Further, "snappy" bass actually usually has more to do with midbass in the 80-160Hz range. This will come down more to the capabilities of your fronts than your sub (not to mention capable midrange and tweeters also have a surprisingly large contribution to the experience of tight, snappy bass). Similarly, the myth persists that sealed subs are "tighter" and "more controlled" and "better for music" which is not necessarily true. Well designed ported enclosures are perfectly usable for music and are more efficient. The "well designed" portion of that statement is key though and probably beyond the scope of this discussion. The second part of your statement is generally true: The larger the woofer, the deeper is can play all other things being equal. There are some large woofers optimized as midbass or midrange drivers, however. Larger, more efficient woofers with less moving mass will not extend as low. For example, I am currently building a set of "bookshelf" (quotations as I use this term loosely) two way speakers with a 12 inch midbass woofer and a horn loaded ribbon tweeter. If my preliminary tests are any indications these will produce a tremendous amount of tactile midbass. These 12 inch drivers are unable to play much content below 60hz, more realistically 80hz. In general it will always take a larger box and more power to get deeper bass regardless of the woofer being used. To get a speaker with lower resonant freqeuncy (Fs) more moving mass must be used which necessarily results in a decrease in efficiency (hence more power required to do it). www.data-bass.com/myths |
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Post by KeithL on Aug 28, 2015 14:31:11 GMT -5
As I mentioned before - if you want to compare "actual cost", and aren't doing it because you enjoy it, then do be sure to count all the time you spend researching, ordering parts, and building it - at your normal hourly wage. Personally, I find that woodworking tends to eat up a lot of time, not to mention the time spent cleaning up and buying tools. (Again, if you have a well stocked workshop, and you use it regularly, then this may not count. However, if you don't, you have to add not only the cost of painting, but the cost of the paint and the paintbrush, and the time it takes to go buy the supplies, and the cost of the time it takes to clean up afterwards. I find that these tend to add up rather quickly.... especially if you actually count the weekend you spent on the project as "two days pay" - which I do.) It is in fact true that, in the old days, 10 inches was considered by many to be the ideal tradeoff between the ability to move air and making a cone that was both light and stiff. (If the cone is too heavy, it stores more energy; since that stored energy takes longer to dissipate, the cone tends to ring and produce sound after the actual stimulus is gone, so the bass sounds muddy and "slow".) With modern drivers, this and many other older "rules of thumb" are no longer true. I think some folks also need to study the math a bit more carefully. For example, if I were to start with a 12 inch driver and an 8 inch driver, both with the same free air resonant frequency, and all else being equal...... 1) The 12 inch driver will be able to make more bass at a maximum because it can move more air 2) But, if I put them both in the same sized box, the 8 inch woofer will have a LOWER cutoff frequency (because its cone is smaller, the volume of air in the box will act as less of a spring, so it will have a lower resonance in the box) This means that, without eq, in the same box, the 8 inch driver will go lower and be slightly more efficient (but it will start to distort sooner if you play it very loudly). And you can "trade off" on the 12 inch woofer, and get it to go equally low, but with more output capability, and a reduction in efficiency (but you'll need to use active EQ to counteract the rolloff due to its higher resonant frequency). (And characteristics of the driver itself, including several electrical parameters, will determine whether you'll get a flat response and a gradual roll off, or a nasty bump and a sharp drop, with a given cabinet, and a given amount of stuffing.) (Which all means that, if you're designing a small speaker, with a limited cabinet size, and you don't need it to play loudly, you'll actually get flatter bass that goes lower with a SMALLER woofer.) My point here is that, even with a "simple sealed cabinet" there are still tradeoffs that you need to be aware of..... so, yes, you CAN "screw up a simple sealed sub" if you pick the wrong sized cabinet for your driver, or you over or under stuff that cabinet, or you don't brace it correctly. Which is why, if you don't understand ALL the math yourself, you should stick with the box size recommended in a well thought out DIY project plan (or recommended by the manufacturer.) To put this in the context of your last sentence...... You can lower the free air resonant frequency of a driver either by adding mass or by reducing the spring constant (of the driver itself) - either is equally effective. Now, when you put that driver into a sealed cabinet, the mass of the cone remains the same, but the spring is increased (the air spring of the cabinet is added to the spring of the spider and surround). This causes the in-cabinet resonant frequency to be higher than the free-air resonance. However, since the spring constant of the cabinet is inversely proportional to the size of the cabinet, you can minimize this effect by using a bigger box. (Adding stuffing in the cabinet also reduces the resonant frequency - because stuffing "increases the effective volume of the cabinet" by up to 20% to 30%.) You could also use a smaller woofer with the same free air resonance (because a given sized cabinet will raise the resonant frequency of a smaller driver less). You;ll find all of these formulas, as well as the rather more complicated ones for designing tuned-port speakers, in any decent speaker design book. One last thing; I've always though 10" was the perfect size for a sub for music. 8" sound great and are fast, but don't extend as low. Seams that 12 and 15" are becoming the norm. I understand the concept of bigger moves more air, can extend lower, etc. For some reason, 10" is still sticking in my mind as best. Am I crazy? Holding on to an older concept? Companies like REL still build 10", but also 12. 'tis a myth that smaller subs are somehow "faster." A well designed subwoofer in a proper sized enclosure with appropriate power, equalization, and time alignment can sound "fast" and "tight" regardless of size. In fact, it is easier to achieve this with larger subwoofers as they move air more efficiently than their smaller counterparts, all other things being equal. Further, "snappy" bass actually usually has more to do with midbass in the 80-160Hz range. This will come down more to the capabilities of your fronts than your sub (not to mention capable midrange and tweeters also have a surprisingly large contribution to the experience of tight, snappy bass). Similarly, the myth persists that sealed subs are "tighter" and "more controlled" and "better for music" which is not necessarily true. Well designed ported enclosures are perfectly usable for music and are more efficient. The "well designed" portion of that statement is key though and probably beyond the scope of this discussion. The second part of your statement is generally true: The larger the woofer, the deeper is can play all other things being equal. There are some large woofers optimized as midbass or midrange drivers, however. Larger, more efficient woofers with less moving mass will not extend as low. For example, I am currently building a set of "bookshelf" (quotations as I use this term loosely) two way speakers with a 12 inch midbass woofer and a horn loaded ribbon tweeter. If my preliminary tests are any indications these will produce a tremendous amount of tactile midbass. These 12 inch drivers are unable to play much content below 60hz, more realistically 80hz. In general it will always take a larger box and more power to get deeper bass regardless of the woofer being used. To get a speaker with lower resonant freqeuncy (Fs) more moving mass must be used which necessarily results in a decrease in efficiency (hence more power required to do it). www.data-bass.com/myths |
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Post by KeithL on Aug 28, 2015 14:43:39 GMT -5
If I was going to build my own sub, I would definitely go with Sonotube. It's relatively cheap, very strong and stiff, yet still internally damped; and the cylinder shape itself is very strong. And, with a shot of black paint, and a nice simple spandex "sock", you avoid all the time-consuming woodworking. (It is cardboard, so I would be sure to paint or Varathane it, just to seal out any possible moisture, even if you aren't going to see it.) And, along with all its other benefits, it stands up very neatly in a corner. Regardless of the shape, though, you do want to stick with the overall volume and amount of stuffing recommended by the manufacturer of the driver if you have those. Depending on the electrical characteristics of the driver itself, too much or too little stuffing can result in a premature bass roll off - or a significant bump followed by a sharp roll off. There is an optimum amount of stuffing for a given driver and enclosure volume. If you don't have any specific recommendations there, just don't seal the speaker up until you have a chance to listen to it. That way you can add or remove stuffing to tune it. (And, yes, depending on other factors, it may or may not make much difference - but better safe than sorry.) With drivers, be sure to look at the Xmax - which is how far the cone can move. The amount of air a speaker can move depends on how big the cone is and how far it can move without distorting. (An 8" cone can move just as much air as a 12", but it has to move twice as far to do it; but some drivers can move ten times as far as others, so consider both things together.) To come back into focus... I REALLY like the idea of 2, sealed sonotube DIY subs. High power. Probably 10" so it can be in a 12" tube. Fast, tight, etc. I get pretty good room gain, so I think that would be a good set-up. Advantage being, I can build something that's not really on the market (SVS is close, but different design). It'd be cool and I made it myself. Easy to wrap in fabric and make it look decent. I think Keith does have a good point in that the part express kits posted in this thread are $400. SVS has a bigger, more powerful product for $500 with a break if you buy 2. You get in-home demo with free returns, a strong warranty, and better fit and finish for barely more than DIY. Sort-of my argument from the beginning. But there are advantages (above). Dayton has some nice, affordable drivers that might fit the bill. I'd probably build them passive and run it with something like a Crown amp. Speaking of that, I had previously considered doing a couple bucket subs run with a Crown. If I didn't like it I could upgrade the subs and still have the amp. I even considered running them in stereo, IN ADDITION to my REL sub running mono crossed over super low. I think it could sound great if you could get the crossovers to work and not overlap. One last thing; I've always though 10" was the perfect size for a sub for music. 8" sound great and are fast, but don't extend as low. Seams that 12 and 15" are becoming the norm. I understand the concept of bigger moves more air, can extend lower, etc. For some reason, 10" is still sticking in my mind as best. Am I crazy? Holding on to an older concept? Companies like REL still build 10", but also 12. Thanks for the replies! |
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Post by trevordj on Aug 28, 2015 15:25:00 GMT -5
It is in fact true that, in the old days, 10 inches was considered by many to be the ideal tradeoff between the ability to move air and making a cone that was both light and stiff. (If the cone is too heavy, it stores more energy; since that stored energy takes longer to dissipate, the cone tends to ring and produce sound after the actual stimulus is gone, so the bass sounds muddy and "slow".) With modern drivers, this and many other older "rules of thumb" are no longer true. I think some folks also need to study the math a bit more carefully. For example, if I were to start with a 12 inch driver and an 8 inch driver, both with the same free air resonant frequency, and all else being equal...... 1) The 12 inch driver will be able to make more bass at a maximum because it can move more air 2) But, if I put them both in the same sized box, the 8 inch woofer will have a LOWER cutoff frequency (because its cone is smaller, the volume of air in the box will act as less of a spring, so it will have a lower resonance in the box) But... in your second scenario, all other things are not equal . In this example, the 12 is necessarily relatively underdamped compared to the 8. I realize it is impossible to change one small signal electrical parameter (in this case Sd) without affecting others. In addition, in this example, while the 8 may have a lower F3, the 12 would may or may not have more absolute output at any given frequency compared to the 8 depending on how relatively underdamped it is... no matter the case, it would require more power to achieve a given level of output compared to the 8 which, again, all things are therefore not equal . Absolutely, like you said, if you don't need it to play loudly. The best way to go about it is, of course, use modeling software, build a test enclosure, measure in room response, rinse, lather, repeat. It is a labor of love and to get it right certainly takes more time. Vance Dickenson's Speaker Design Cookbook is an excellent resource for all of this stuff. I have read through it a couple times and still use it as a reference. I still like to read it cover to cover once every few years. |
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Post by garym on Aug 28, 2015 16:47:52 GMT -5
Nice job, tchaik!
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Post by jdubs on Aug 28, 2015 19:57:55 GMT -5
What's the danger in using a car audio driver if I wire it up for the proper impedance?
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Post by jackpine on Aug 28, 2015 20:44:46 GMT -5
What's the danger in using a car audio driver if I wire it up for the proper impedance? No danger, I've heard of people doing it before using JL subs. I wouldn't recommend though unless you fully understand all of the drivers specs. A driver designed for use in a car will be built to withstand a harsh environment. This may affect the performance of it in negative ways, every design choice is a compromise. |
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Post by trevordj on Aug 29, 2015 0:03:13 GMT -5
What's the danger in using a car audio driver if I wire it up for the proper impedance? There is nothing magical about speakers that makes them "car audio" or "home audio" specific. Dayton, Scanspeak, Dynaudio, Morel, Stereo Integrity, and Acoustic elegance speakers are frequently used in both car audio and home audio applications. Use a speaker modeling program to simulate the response of the speaker in an enclosure close to the size you desire/have available and go from there. Infinity 1260w and 1262w are a few budget drivers marketed for car audio that are frequency used in budget home audio applications. There is an entire online forum that originated out of the desire to assemble high quality, lower cost car audio systems using home audio drivers as a way to save money (DIYMA). There is no problem with taking this concept the other direction, although car audio drivers are notoriously overpriced for given performance levels/features. For example, Alpine used to market a set of very high end component speakers called F#1, they were simply Scanspeak midbass, midrange, and tweeters rebadged and marked up 50-75% |
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Post by millst on Aug 29, 2015 12:23:16 GMT -5
What's the danger in using a car audio driver if I wire it up for the proper impedance? A proper car audio driver will be designed with a small environment in mind; say 200CF and have high Fs/Qts. This is not optimal for a larger home environment of 2000CF. The price is likely to be higher since the car environment is harsher and the car driver must endure it. Of course, there are some car audio drivers that this isn't true for and they can be used for home designs, but I'd argue they aren't really proper car audio drivers (sub-optimal for a car). You can always use a driver that's less than optimal, of course. Regardless, you need to model it and and understand the compromises being made. -tm |
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Post by jdubs on Aug 29, 2015 14:11:57 GMT -5
Lots of great info and sources listed here; thanks! I'm starting to formulate a plan.
I'm not really looking for a "budget build". My point was I didn't want to spend so much on components that I could have gotten a tried and true product from a manufacturer. If I could spend $1000 or so and build 2 quality subs that can keep up with and compliment my system, great. If it costs much more than that I'll get 2 PSA subs and call it a day. BUT, the plan that's forming looks like it will work. I will update this thread soon!
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KeithL
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Post by KeithL on Aug 29, 2015 14:20:33 GMT -5
Everything you've said is entirely correct, but I would still exercise a little caution before using a "car" driver for a home speaker, or vice versa - because a few of the design considerations are a bit different.... 1) A car is a pretty tough environment for a speaker, and car speakers are exposed to a lot more dampness, and much higher operating temperatures (and lower ones) than home speakers. While the cone, surround, and other construction materials used in many speakers are very resistant to all of those things, it's more of a necessity for a speaker intended for use in a car. You don't want a cardboard cone that will mildew, or absorb water on damp days and get soft, and you don't want a plastic cone that will get soft in a hot car in the summer, or adhesive that will get brittle in winter so the voice coil falls off. (In short, a car speaker needs to be a little bit more "rugged" and "weather proof" than a home speaker. 2) Speakers in cars tend to be subjected to very abusive pressure conditions (the air pressure in the car jumps when you slam a door). This can actually break the cone, or damage the surround, on a speaker not designed for it. A speaker designed for use in a car should have a tough cone, and the suspension should be designed so that the cone is stopped by the suspension, or even a "bumper", rather than the cone bending, or the voice coil slamming into the magnet when you slam a door. Some home speakers meet this need, but others have... limited survival prospects.... if you use them in a car. 3) Car speakers are also more likely to be subject to being overloaded (you may not do it, but lots of people turn the volume up far past where it distorts in a car, even though they may not do so with the stereo in their living room). The reason you need to consider some of these things is that, if a speaker is designed for in-home use, it may not survive the rigors of life in a car, and so may fail very quickly. And, in the other direction, many car speakers are designed with more consideration for ruggedness than for sound quality, so using a driver intended for use in a car in your living room may get you extra ruggedness you don't really need, while costing you sound quality you'd rather have. This is not at all to suggest that some home drivers won't work very well in a car, or vice versa, but you should pay particular attention to the specific design factors that might make a driver tend to work better for one or the other when considering using one "off label". What's the danger in using a car audio driver if I wire it up for the proper impedance? There is nothing magical about speakers that makes them "car audio" or "home audio" specific. Dayton, Scanspeak, Dynaudio, Morel, Stereo Integrity, and Acoustic elegance speakers are frequently used in both car audio and home audio applications. Use a speaker modeling program to simulate the response of the speaker in an enclosure close to the size you desire/have available and go from there. Infinity 1260w and 1262w are a few budget drivers marketed for car audio that are frequency used in budget home audio applications. There is an entire online forum that originated out of the desire to assemble high quality, lower cost car audio systems using home audio drivers as a way to save money (DIYMA). There is no problem with taking this concept the other direction, although car audio drivers are notoriously overpriced for given performance levels/features. For example, Alpine used to market a set of very high end component speakers called F#1, they were simply Scanspeak midbass, midrange, and tweeters rebadged and marked up 50-75% |
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KeithL
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Posts: 10,273
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Post by KeithL on Aug 29, 2015 14:35:04 GMT -5
The best way to go about it is, of course, use modeling software, build a test enclosure, measure in room response, rinse, lather, repeat. It is a labor of love and to get it right certainly takes more time. Vance Dickenson's Speaker Design Cookbook is an excellent resource for all of this stuff. I have read through it a couple times and still use it as a reference. I still like to read it cover to cover once every few years. All agreed.  My point there was that, unlike what someone else had suggested, "even designing a simple sealed sub" really is rather more complicated than "just sticking any good driver in a box" - at least if you do want really good performance. (And, for anyone not up to the task of doing the calculations themselves, or not interested in spending the time and effort to do so, they're more likely to get the best bang for their buck by buying "a kit" from someone like Parts Express, which includes recommended parts and construction details, and not changing anything like box volume unless they understand all the factors involved.) |
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