First off I have 2 Sony Xplod GTR120L 12" 1300watt(380rms) subs and a Sony Xplod GTX1302 800watt amp.

I know thats my problem I have XPLODS!!!

I had the subs in a ported box that measured 34x13.25x14.25

I never had a problem with the amp overheating and powering down and the hit in that box but they hit so hard that the box rattled apart and gave that nasty wood rattle.

So I built a new box that measures 36x19x14.5 and its a I for get the name but its ported and sealed the front of the subs face towards the sealed the back towards the ports.

Also the subs dont hit half as hard as they did when in the smaller ported box. Now I have not touched the gain or bass boost on the amp or changed anything anywhere now the amp overheats and powers down. Is this due to the now box being bigger and better? Please help. I am looking for a bigger amp now but until then I want this to work.

Thanks

 

You've got two separate issues going on here most likely. First off is your new enclosure, is it a prefab or did someone design it and you built it? The type of enclosure you're using now is a single reflex bandpass enclosure and they are not easy to design. Even worse is the fact that the prefab ones are built and tuned to get loud, with a narrow band of efficiency. That means they have poor response in the low and upper bass regions. I would imagine that your new enclosure has to do with the poor response.

Now, onto the amp overheating. Your subs are 4 ohm SVC and your amp is a 2 ohm stable 2 channel amp. The amp is ONLY 2 ohm stable in stereo mode, or in other words with the 2 ohm load on each channel. If you have your subs connected to the amp bridged AND connectec in parallel for a final 2 ohm load you're overloading the amp. When you bridge an amp it sees half the nominal load on each channel. If you connect a 4 ohm load to the amp bridged then each channel is seeing 2 ohms. With your two 4 ohm subs connected parallel to the amp bridged you have a 2 ohm nominal load which means each channel is seeing only 1 ohm. If it's not corrected soon it will burn up.

 

I had it designed and built. So your saying I should wire them seperately? They are in a series now going from +sub to +sub to +amp and -sun to -sun to -amp. I am soon getting a GTR 2202 1300 watt Xplod to help. It is also a 2 channel.

 

Here is what it is.

 

That's parallel, not series. Here's a couple of diagrams to help.

This is PARALLEL, what you described as it's wired now.


This is SERIES. However, one sub on each channel is the best way for you to go. No other way of wiring it is going to get you more power to your subs from that amp.



The GTR-2202 isn't going to gain you any real difference at all in power to your subs, it would ultimately be a waste of money, really. If you HAVE to keep it Sony then I would suggest the Sony XM-ZZR3301. With your subs wired in parallel on that amp they'll each get 300wrms which should make a noticeable difference from your current amp. If you don't mind going with another brand of amp the PPI P1000.1, MB Quart OA1000.1, and Hifonics BRX1100.1D would all power your subs with right at/around their rated power for less money than the Sony options. The PPI is a GREAT amp for the money and while I'm not super fond of MB Quart or Hifonics (both owned under the Maxxsonics umbrella, they ruined MB Quart and Hifonics) they're great options for somone in your shoes.



Yessirree, that's a single reflex bandpass box. Unlike a regular sealed and even a regular ported enclosure the calculations have to be perfect and the build also done perfectly in order for them to function correctly. Even then that doesn't mean the designer designed it correctly. Bandpass enclosures have their uses but in almost all cases a person is better off with a standard ported or sealed enclosure. There are too many compromises to bandpass to make them useful for most people. The biggest compromise is the relationship of the frequency response to efficiency. A bandpass can be more efficient or louder than a ported enclosure with ease, the problem is that in order for that to work the frequency response suffers. The name bandpass describes exactly what the enclosure does, it passes or plays a certain band of frequencies tuned by the size of the sealed section and the size/tuning of the ported section. If you want one to get loud, it's easy enough to do, but it will have a short frequency range before it rolls off on the low and high end. For example to get a good gain over your ported enclosure the designer may have designed the box to peak at 45hz. That means everything that is 45hz will be super loud, but anything below or above it will roll off, or get quieter the farther away from 45hz you get. Making deep sub bass weak and the upper bass ranges almost non existent. On the other hand a person can design one to get a great frequency response with good range down into the super deep bass ranges (25hz) and well up into the upper bass ranges (80hz), HOWEVER that bandpass box would have LESS efficiency than a standard ported enclosure with similar tuning, it just wouldn't get as loud. Bandpass enclosure's have to be designed SPECIFICALLY for the drivers being used as well. It your box wasn't directly designed around the Theile/Small parameters of your subs then it's completely useless to you in the first place. They're VERY tricky enclosures to design and utilize, VERY.

I would HIGHLY suggest getting a good design on a standard ported enclosure and going back to that type of enclosure. I could help you with that if you wanted. Sony recommends 1.13cuft per sub, I can verify that with some software and make a recommendation and design up for you.

 

Ok lets address your first issue. The way you currently have your subs wired is actually considered "Parallel".
"Series" wiring is as follows... Ex: Amp "+" to Sub #1 "+"
Sub #1 "-" to Sub #2 "+"
Sub #2 "-" to Amp "-"
"Series" wiring is setup to lower the ohm load between your subwoofers. So say you have two 4Ohm subs, wiring them in series will take your Ohm load down to 2Ohms which is where you want to be for low resinance bass. When you wire in "Parallel" you raise the ohm load taking your 4Ohm subs to 6ohm or even 8ohm which is the load you want for regular speakers. Having your subs ohm load high on an amplifier specified for 2ohm or 4ohm load will cause the amp to over heat and clip. Also the bass wont be as low, try changing your your wiring setups to how I described above and you will hear a difference in the bass.
Ok on to your next question, as far as the bass being not as loud in your new box is linked to the style box you had built. Your box is whats called a Bandpass box, these box's give you a little of both worlds "Sealed" and "Ported" (Notice how I didnt say "The BEST of both worlds"). These boxs are good for evryday use for someone that just wants a solid system that doesnt slam and vibrate mirrors loose. If you want hard hitting competiton level bass you need to go with a "Slot Ported" box that is tuned correctly. I have made a lot of boxs for different applications, and no matter how I configure them nothing hits harder than a quality tuned "Slot Ported" box. For example I have a "Slot Ported" box tuned to about 36hz - 38hz. I am running three Kennwood KFC-XW10's and a Kenwood KAC-8104D 1000watt Mono with a 2k Farad cap. My system slams enough to wobble mirrors on the door and push the doors out when windows are up and doors are closed, also I flex roof. I cant 100% remember but the dimentions are about 12"h x 38w x 15.5"d, with a port that is 34" long and allows for a 4" channel all the way to the opening. Now my system is loud but will be a lot louder when I get my 3000 watt amp consider the subs I have are 300rms each and my amp only pushes 500-700rms through one channel. My subs are wired in a series and my Ohm level is around 1ohm-2ohm. Before in my earlier systems I didnt know the difference or the whole deal with Ohms and wiring, resulting in fried amps by hooking them up wrong and my systems just sounded ****ty. Now that I got the ohm loads figured out they sound great. Btw I own a 97' 4-door blazer.
Also one last little tip, it doesnt really matter what kind of subs you are using a subwoofer is a subwoofer. If they are not setup correctly and are not in the correct box you doomed from the start. I can make any sub sound good. For example my cousin has a 93' single cab S-10, he picked up an 8" Lanzer sub and a 300watt Lanzar amp. He is about 6'1 so we coudlnt build a box to go behind the seats since he had to have them all the way back so I made a custome center console box not too much bigger than a factory console size considering this is a beater truck. That system would hit like he had a 10" subwoofer in the truck. It all comes down to the box your subs are in.

 

Take note of what's bold and red, I'm afraid you have that backwards. When you think of series, think of it like batteries in a flash light. Being put end to end, + to - adds the voltage together so that a 3 D cell maglite is operating with 4.5v (1.5 + 1.5 + 1.5). Parallel can be more complicated when figuring total circuit resistance with different values, but when they're all the same it's simply the value of resistance divided by the number of loads. For example with if you had ten 500 ohm resistors in parallel the total circuit resistance is 50 ohms (500 / 10). This is basic electronics and ohm's law.

As for the rest of your information I feel you've pretty well got it right.

 

Yeah sorry i got the series parallel thing mixed up. Thanks guys I think ill go back to a ported box and try both running in series and parallel.

 

Would you like help with a design for the new ported enclosure? It's not big deal to run the T/S parameters of those subs and design you a really good box.

If you keep your current amp there's no need to play with the series/parallel wiring of the subs. There is no combination of wiring that's going to be more advantageous than simply wiring one sub to each channel. The amp is rated 130wrms x 2 @ 4 ohms, 170wrms x 2 @ 2 ohms and 340wrms x 1 @ 4 ohms. You have single voice coil 4 ohm subs so 2 ohms stereo is not an option, it's physically impossible as is a 4 ohm load on the amp bridged. For bridged you can only wire the subs to either 2 ohms (which the amp can't handle) and 8 ohms. Now 8 ohms is fine for the amp but it has absolutely no advantage for you as far as power is concerned. Technically speaking, in most cases when you double impedance you'll cut the power that can be applied by half. So if you connect the subs in series to the amp bridged the power output would be somewhere in the ~200 watt range (170 being the mathematical figure). That's only ~100 watts (85 being the mathematical number here) per sub. At that point you'd be better off just leaving them wired to the amp in stereo, or one sub on each channel.

Now, if you were to get the Sony mono block I listed, or one of the others then you would definitely want to connect the subs in parallel to one of those amps. The 2 ohm final load on the amp would be the rated power you're looking for and there would be absolutely NO reason to connect them to the amp in series.

 

Yeah I am getting that mono amp and have a guy that builds competition boxes that I work with give me one of his. He built one for a guy and he didn't pick it up. Ill run them parallel to the mono amp and see which box is the better way to go. Oh the box he is giving me is ported rated to 32 hertz and 3/4 inch birch at 3.6 cubic ft total.