Good day everyone. Im here to make some query which I believe a delicate one.
I have a dolby pro logic amplifier rated at 70w/ch into 6 ohms at stereo mode, speaker requirement is 6-16 ohms as indicated at the back panel. I bought a 6.1 channel receiver and I want that old amp to drive a 4-ohm passive subwoofer. I thought of having 4 ohms resistor in series with the sub to make an 8-ohm load. My questions are:
1. Is my idea just ok?
2. Is the word "ohms" of a speaker has the same meaning as the ohms of a plain resistor?
3. Is it ok for a subwoofer out to be routed directly to an integrated amplifier's CD or other input?
4. My new receiver has mono sub out. Is it ok to split it using Y connector, making two lines connected to amplifier's left and right CD or other input? (The idea is to utilize the amplifier's left and right power, since the sub can accept two speaker level inputs from two channels)
5. Will it increase volume output compared with just single line from sub out to the amplifiers left channel input only?
The answer to questions above will be of great help for me. I hope you guys could share me your knowledge regarding this matter. Thank you very much.
Derek
Posted on
It sounds like you only have one woofer.
1. You would probably be OK without the resistor. It will match the impedence but it will waste half of your power.
2. Yes.
3. Yes.
4. If you only have one woofer, you wont gain anything by splitting the line-out. You MAY load down the receivers line-out which could change its frequency response...
5. See 4.
NOW, if you have two woofers or a duel-voicecoil woofer, you should wire them in series - that would equal 8 ohms.
Thanks Derek. Yes, the subwoofer has dual voice coil(as ive said, it can accept two speaker level inputs, only each into 4 ohms). Connecting the two coils in series would give 8-ohm impedance but requires only one channel(70 watts) to drive it. What I want, if possible, is to drive the two coils separately, to optimize the use of 2x70 watts power of the amp. Derek, is my idea before safe to the amplifier? Again, can I attain higher volume output? Thats my only purpose. Thanks.
Derek
Posted on
Not realy. Driving the two drivers with resisters would throw away 1/2 of each channels power (as heat) and you will have aproximately 2 times 35 watts or 70 watts. If you use one channel, there will be 1 times 70 watts. Except you will only be drawing power from the wall to produce the 70 watts. The other way, you will be drawing twice as much and heating two resisters. If you don't have the greatest power supply in the amp, it will produce even less power.
Hope this helps..
dong rodriguez
Posted on
Ok Derek. I understand the best way is to connect the two coils in series giving 8-ohm impedance and use only one channel to drive it. But 70 watts (maybe lesser now) of power for a subwoofer is, I think, quite small. Doubling that maybe better. Would you suggest on using two subwoofers of that same kind, this time utilising the two channels? Will it serve my purpose? The woofer is rated at 200 watts maximum. Any possibility of overload?
Again, thanks a lot.
Derek
Posted on
That should work.
I don't think you will be able to overload it because that's probably 200 watts per voicecoil.
dong rodriguez
Posted on
I mean, overload on the part of the amplifier. The woofer is rated 200 watts/voice coil. No specified minimum wattage. Isn't that relatively high power woofers draw more current from the amp, making it overloaded?
Derek
Posted on
The woofers' power rating has no baring on amplifier load. You can try to turn the amp up to reach 200 watts but it will clip the audio at its maximum and severaly distort the sound.
Ok Derek. Just for final confirmation. I have to split the sub-out using Y connector, route each line to amplifier's left and right CD input respectively then connect one subwoofer to the amplifier's left speaker out and one to the right. Please confirm this set up.
Thank you very much and more power.
Derek
Posted on
That will work but that takes us back to the beginning. It will be louder but MAY overload your amp.
You should sent a single patch cable to one channel of your amp and connect both voicecoils, in series, to one channel of your amp.
Sorry I didn't get it. What do you mean "send a single patch cable to one channel of my amp?"
dong rodriguez
Posted on
Derek, I just wanna ask a final favor. Please give me instruction, step by step, how to set this up so that I can utilize my old amp and that subwoofer, avoiding another expense for a new subwoofer.
Thank you very much.
Derek
Posted on
Instead of using two patch cables (Left and Right), just use one (your choice).
Hi Derek, I bought a kenwood vr6050 which uses 8 ohm 100 watt speakers. Can i use my existing 1 sharp 6 ohm 60 watt speakers for centre and surround rear. 2. akai 8 ohms 50 watt speakers for front L & R
Thanks,
VK
Derek
Posted on
Yes
Ben Costello
Posted on
If this all has to do with home theater, you should stick with 8 ohms for everything, being that it is most common with newer style amplifiers. What you could also do is use a combiner for the two amp outs to the sub, series the two coils, and then your ohms match, and you've got the power that you need
Hi, Im installing a subwoofer into my car however there is no sub out on the stereo. Ive heard you can take a wire of each channel which wires are these?
I have a Sony STR-DE875 amp. I have TWO sets of front speakers (Bose 601's and Bose 301's). The receiver does NOT have the A&B speaker outputs, I've just twisted the wires together (one set of spkrs in one room, another set in the living room).
The speakers are 8 ohms, and I've heard that I can damage the receiver if I set it up like this. The receiver has a switch to allow 8 or 4 ohms. But have I created 4 ohms? Or 16 ohms? (are ohms additive? or inverse?)