two 15 in strokers, two RF 500s?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=87552
Printed Date: April 29, 2024 at 11:43 AM
Topic: two 15 in strokers, two RF 500s?
Posted By: cubic
Subject: two 15 in strokers, two RF 500s?
Date Posted: December 20, 2006 at 5:52 PM
Hi Everyone this is my first post. So here is my question. I have 2 old 15 in strokers dual voice coil 2ohm. I have 2 rockford fosgate 500s amps these are 2 channel. I know not near enough power but what i was thinking is just run 1voice coil per speaker . What are my best options here. I would like to bridge the amp 500 watts but I think the amps are only 4 ohm stable bridged. I really need some advise on this. Thanks
Replies:
Posted By: ss-installer
Date Posted: December 20, 2006 at 5:56 PM
if the amps are 4 ohm stable then just series each sub up to 4 ohm and run one amp per sub.
Posted By: cubic
Date Posted: December 20, 2006 at 6:01 PM
Is it possible to use both amps for just one sub? 1amp per coil.
Posted By: haemphyst
Date Posted: December 20, 2006 at 7:18 PM
Yes... perfectly acceptable to do so, as well... You said the amps are only stable to 4 ohms in bridged mode, and the woofers are DVC 2 ohm, so the AMPS won't do it, but otherwise, yes.
Run one channel of each amp to one voice coil of each woofer, and be done with it... You are making it too difficult on yourself.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: cubic
Date Posted: December 20, 2006 at 8:23 PM
I thought about that but that will only give me 250 watts per coil ,there 1200 watt subs 600 per vc wouldnt I be better off sending all 500 watts to just one vc?
Posted By: haemphyst
Date Posted: December 20, 2006 at 8:50 PM
Dude... YOU CAN'T DO THAT, the amps are not stable, bridged to a 2 ohm load. 250 watts per voice coil, is the SAME result as 500 watts to one voice coil, right?
If you use 500 watts to each woofer, that is a total of 1000 watts, true, but you gain 3dB, due to the second diaphragm.
You will have the SAME output - PERIOD - and your amps will be running safely, running 2 ohms per channel.
-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: cubic
Date Posted: December 20, 2006 at 9:15 PM
I ask cerwin vega the same question here is the answer to add short the second coil and the amp will see a 4 ohm load Hi, In my personal opinion I would do one voice coil and put all 500 watts to it. Remember the Stroker 15D2 has will take 600Watt RMS per voice coil. Even if you put all 500 watts you will still be under powering it. :: :: Staling Almanzar : Customer Service :: :: 954.689.8833 x2254 : 954.689.8460 (fax)
:: :: stantongroup.ws :: Cerwin-Vega! : KRK : Stanton
Posted By: haemphyst
Date Posted: December 20, 2006 at 10:45 PM
No, it wont... if you short the first voice coil, and only use the other as a driven coil, it is STILL one voice coil, rated 2 ohms. If you wire them in SERIES, you will present a 4 ohm load to the amplifier, and if you then bridge the amp to the 4 ohm load, your amp will "see" 2 ohms per channel.
I might mention, that if you are going to ask for our opinions then you might actually take the advice...
500 watts to one coil (which you cannot do in any kind of safe method) or 250 watts to each coil (which will work perfectly fine) is still 500 watts to the woofer... either way, (if you want to look at it this way) you are "underpowering" it. Do it the way you want, you obviously know more than I do.
I'll tell you what... Do it the way you want, and with the (either incorrect on their part, or misunderstood on your part) information you have received from Cerwin-Vega, and when your amplifier keeps shutting off because it is overloaded, I want you to come back here and tell everybody I was right, OK?
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: cubic
Date Posted: December 21, 2006 at 9:25 AM
Im not here to be right or wrong just to understand! And just to do somthing because someone else tells me to would be stupid on my part if I dont have a full understanding of why Im doing it. I appriciate your responding. I am learning from your responses. So here I go again. A 2 ohm dvc wired in series presents the full load of 4ohm (In my case shorting the second coil) . A two channel amp 2 ohm per channel bridged, Is 4 ohm stable. So... if Im presenting a 4 ohm load to a 4ohm stable amp... But what you are saying is the amp will still only see a two ohm load. I Thought the point of shorting the second coil was to present the total 4 ohm. Confusing indeed. -------------------------------------------------------------------------------------------------------------------------------------"Those willing to accept an answer and forgo knowledge deserve neither" - cubic
Posted By: haemphyst
Date Posted: December 21, 2006 at 10:37 AM
haemphyst wrote:
Run one channel of each amp to one voice coil of each woofer, and be done with it... You are making it too difficult on yourself.
That is still the best answer I can give you!
OK, here's the misunderstanding/miscommunication... You are not shorting ANY voice coils. You are wiring them in series, and although it may SEEM as though it is one voice coil, it is still TWO... The amp will see one load. 2 ohms in series with 2 ohms equals 4 ohms - you are right about that. The current (power) goes through BOTH coils. You are still using two (as in BOTH) voice coils, not one. An amplifier, bridged to a 4 ohm load makes the SAME POWER as an amplifier wired in stereo mode to (2) TWO OHM LOADS. As I have said several times, you CANNOT USE JUST ONE VOICE COIL ON THE WOOFER AND BRIDGE IT TO THE AMPLIFIER. It will not be stable. An amplifier running bridged to a two ohm load is "seeing", electrically ONE OHM PER CHANNEL, which your amps are not stable to.
If you wire the coils in series and bridge the amplifer, you are still going to get EXACTLY the same amount of power to the woofer, as you would if you wire one voice coil of each woofer to one channel of each amplifier.
I still need you to understand this: once wired in series, you will be still feeding 250 watts to each voice coil, which will be EXACTLY THE SAME, both output and thermally, as wiring one channel of each amplifier to each coil...
Here are your wiring options, but only the second one is safe for your amplifier. Again, the second diagram will present the same load and the same power (and therefore the SAME OUTPUT, with less confusion possible) as wiring as wiring one channel of each amplifier to each voicecoil. ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: cubic
Date Posted: December 21, 2006 at 10:57 AM
Ahhh.... Now that makes sense. Thanks for your paitence. So Guess the question is, is 250 watts to each coil enough to move these speakers? And what amps would you suggest I buy to power these speakers? I think mabey I need to puchase proper size amps To get the total benifiet. Suggestions would be appriciated.. Thanks for helping me out
Posted By: ss-installer
Date Posted: December 21, 2006 at 11:50 AM
get 2 Memphis MCD1000. one per sub at 1ohm. should be plenty. parallel the subs for 1ohm.
Posted By: haemphyst
Date Posted: December 21, 2006 at 11:52 AM
Here... Probably expensive, as most of the Zapco stuff is, but it'll make those things jump out of their baskets!
A pair of Eclipse DA7232's (stereo, and not a bridgeable amplifier) with one channel to each woofer coil would knock your socks off, too... ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: stevdart
Date Posted: December 21, 2006 at 12:00 PM
haemphyst has provided great advice, as always. Now for the above question...1 watt will move those subs. 1 watt. If your goal is to compete with these famous one-note wonders, upgrade your amps. Use two mono amps capable of 1 ohm, wire the coils in parallel to make a 1 ohm impedance for each sub, leave the subs separated, and feed each sub up to its rated RMS. One mono amp per sub. Look at mono amps whose rating is 1000 to 1200 watts driven into 1 ohm. It doesn't have to get too costly doing it this way, just in case you're not made out of money. IC above, as ss_installer likewise said. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: cubic
Date Posted: December 21, 2006 at 1:47 PM
Thanks guys, Im not wanting to compete but the subs are going into a winning show and I want the system to be as impressive as the van. So Im going to look into the mono amps, and for now Im going to wire one channel to each coil. Ive included the box size from cerwin vega if anyone would every need them. STROKER-15D2 Specifications POWER HANDLING: 1200 Watts RMS (600 Watts per coil) FREQUENCY RESPONSE: 36 â€" 200 Hz SENSITIVITY: 95 dB IMPEDANCE: 2 Ohms per coil MSRP: $800 CIRCA: 2003 Parameters Fs: 36 Hz Qts: 0.217 Qms: 9.120 Qes: 0.223 Vas: 3.11 cu. ft. Xmax: 0.9" (+/- .45â€) Re: 1.7 ohms per coil Sd: 130.82 sq. in. Driver displacement 0.27 cu. ft. For 40 Hz Tuning; SPL The optimum enclosure is 5.0 cubic feet (total internal volume) with two 6†diameter round ports that are 16.17†long each. For 35 Hz. tuning; Sound Quality High Power The optimum enclosure is 5.0 cubic feet (total internal volume) with a 44 square inch port with a port length of 16â€. For 35 Hz. tuning; Sound Quality The optimum enclosure is 4.5 cubic feet (total internal volume) with one 6†diameter round port that is 9.25†long. SEALED OR BANDPASS ENCLOSURES ARE NOT RECOMMENDED. www.cerwin-vega.com
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