Home Theater Subwoofer Plate Amplifier

Home Theater Subwoofer Plate Amplifier

Home Theater Subwoofer Plate Amplifier

Moving beyond the capability of the amplifier, there is one other question to consider: do you want a plate amplifier or an external amp? While plate amplifiers have the benefit of allowing an all-in-one-box solution, there are a lot of reasons to consider an external amplifier. First and foremost, you can buy a lot of power for cheap in the form of a pro-style external amp. If you’re building multiple subwoofers, wiring is a lot easier as you don’t need a power outlet adjacent to each subwoofer. Last but not least, it’s much easier to replace an external amplifier, as a new/different plate amplifier may require different cutout dimensions in your enclosure.
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Home Theater Subwoofer Plate Amplifier

As mentioned, a DIY subwoofer primarily consists of a driver, enclosure, and amplifier. Of course, there are a few additional ingredients that are worth considering as well. Measurement suites like Dayton’s Omnimic or XTZ Room Analyzer coupled with a sophisticated EQ system like miniDSP will enable you to shape the response of your subwoofer. This is especially important when it’s time to actually use your subwoofer in your room. Without any sort of EQ, even the best subwoofer will have ugly peaks in the response that are a recipe for boomy bass. EQ will also let you shape the low end of your system; depending on the amount of room gain your space exhibits, you may be able to achieve flat response well below 20Hz with little more than a low shelf filter. However, one should be careful in boosting system response, as this requires more amplifier power and excursion from the driver. Remember, a 6dB boost equals 4 times the power and 2 times the driver excursion, making it easy to run out of headroom in a hurry.
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Home Theater Subwoofer Plate Amplifier

There are three basic components needed to build a sealed subwoofer: the driver, the enclosure, and an amplifier. Building a successful subwoofer requires some design work in terms of matching the driver to the enclosure, and specifying an amplifier that delivers enough output for your needs without the risk of smoking a voice coil or bottoming out the driver. Back in the good old days, this kind of work was no small feat. Today with modeling software like WinISD, real world data from sites like data-bass, and a little guidance, it’s a lot less complicated. So where do we start?
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Home Theater Subwoofer Plate Amplifier

On the face of it, picking an amplifier seems like a simple task; more power is better than less, right? However, this is an area where great care must be taken, as too much power can quite literally break your subwoofer, either by burning up the driver’s voice coil or by beating the driver to death via over-excursion. At the same time, an amplifier needs to be powerful enough to deliver the output you’re looking to achieve into the impedance load that your driver presents. Getting this balancing act right is the key to maximizing performance without putting your investment at risk. This is also an area where commercial subwoofers have an important advantage; through the use of customized DSP limiters, they can keep a woofer out of trouble while still having a boatload of power on tap.
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Home Theater Subwoofer Plate Amplifier

The Dayton Audio SPA250 subwoofer amplifier produces 250 watts of clean power output, and combines with a host of flexible user options to make it an unbeatable choice. A user-configurable bass boost circuit creates a 6 dB peak at 35 Hz, which allows sealed subwoofer designs and certain ported enclosures to achieve their optimum bass extension and maximum “flat” output.
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Home Theater Subwoofer Plate Amplifier

Need 2ohm stable dedicated subwoofer amp. I am looking for a dedicated subwoofer amp to power a couple of subwoofers I have. Something similar to the Velodyne SC-1250. The only problem with that amp is that it is not 2 ohm stable. I have two JBL GTi MKII’s in a sealed enclosure so I will need two amps. I really like how simple a dedicated subwoofer amp would be vs using a pro amp and then having to add a DSP. Issues arise, when you add more components to a system. I’ve read that some add noise to the system and others don’t have enough output voltage for the pro amp. I need a minimum of 750 watts per sub and my budget is right around $1,200 but I am willing to spend a bit more if I find the perfect solution.
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Home Theater Subwoofer Plate Amplifier

Note that some drivers utilize dual voice coils, which allow the end user to change the impedance of the driver as seen by an amplifier. For example, if a driver has a pair of 2 ohm coils, wiring them in series gives you an impedance of 4 ohms, while wiring the coils in parallel nets you a 1 ohm load. We recommend avoiding wiring for a lower impedance (<3 ohms), since this will place great strain on a partnering amplifier.
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Home Theater Subwoofer Plate Amplifier

Are you a serious bassaholic on a tight budget? A DIY subwoofer might just be the fix you’re after. For not a lot of cash it’s possible to build a sub that can compete with the very best subwoofers on the market. Beyond that, you will have the pride in knowing that you built an integral part of your home theater, and the knowledge that you have a unique piece of equipment that Joe Sixpack can’t just pick up at the local big box store. However, realizing the value proposition of DIY requires great care, both in terms of getting the design right, as well as the implementation. Don’t forget the age old tip: measure twice, cut once. Are you a DIY subwoofer enthusiast? Make sure to share on our forums, including pictures of your build.
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I am looking for a dedicated subwoofer amp to power a couple of subwoofers I have. Something similar to the Velodyne SC-1250. The only problem with that amp is that it is not 2 ohm stable. I have two JBL GTi MKII’s in a sealed enclosure so I will need two amps. I really like how simple a dedicated subwoofer amp would be vs using a pro amp and then having to add a DSP. Issues arise, when you add more components to a system. I’ve read that some add noise to the system and others don’t have enough output voltage for the pro amp. I need a minimum of 750 watts per sub and my budget is right around $1,200 but I am willing to spend a bit more if I find the perfect solution.
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For those who only have a passing interest in woodworking, flat packs sold by Parts Express and others are also a viable option. A flat pack is to subwoofers what Ikea is to furniture. You get a bunch of pre-cut pieces to build an enclosure, which you assemble at home. Needless to say, this can save a bunch of time and effort, but they may not fit your exact requirements, i.e. building a tall, shallow subwoofer versus a basic cube.
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Here we’ll look at how to design and build a DIY sealed subwoofer. Sealed subwoofers have a few important advantages for the DIYer. First and foremost, they’re relatively easy to build compared to a vented box or a more exotic alignment like a tapped horn or transmission line. The sealed alignment is also relatively tolerant of minor changes in box volume and driver-to-driver manufacturing variations. Last but not least, they need less protection than ported subs, which can quickly overload below their tuning point. On the down side, without a port to augment system output, you need a meatier driver to achieve solid deep bass.
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The first step in building any subwoofer is selecting the driver, as this will determine how large an enclosure you need as well as what you need in terms of amplification. You can find a dizzying array of raw drivers from companies like Parts Express and Madisound, as well as from smaller shops like iST and Stereo Integrity. Driver selection is all about what you’re looking to achieve. If you want enough deep bass to rattle grandpa’s dentures you’ll need a lot of displacement, which is a fancy way of saying a large driver with a lot of cone area (aka Sd) and linear excursion (otherwise known as Xmax). If you’re living in an apartment where high SPL is a surefire way to get an eviction notice, a 10” – 12” driver might be more appropriate.
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Of course, there’s a lot more to the driver than just size. Basic frequency response is one important consideration that can make or break the sound quality of your subwoofer. Thiele/Small parameters like Fs (resonant frequency), Qts (total Q of the driver at Fs), and Vas (equivalent compliance volume) will also determine how a driver will perform in any given box. Sensitivity and impedance are also critical considerations, since these will help determine your amplification requirements.
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Thankfully, subwoofer builders have a happy medium to choose from with a Qtc of 0.707. This alignment is typically referred to as maximally flat, since it provides the most extended response before the system begins to roll off. The enclosure volume of 2.7 cubic feet is by no means ultra-compact, but it’s not something you’d mistake for a refrigerator either. It’s not as efficient in the deep bass as a larger box, again blame Hoffman, but the payoff here is that the driver is at far less risk of over-excursion as well. Finally, while the design isn’t “critically damped”, ringing is nonetheless reasonably well controlled relative to a high Qtc box.

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