For now I'm just looking to get my subs up and running. In the future, I plan some more audiophile choices, but for now I just want to get it hooked running with what I have.
I have two DVC 4-ohm subs in sealed boxes that I plan on running with a mono sub amp that is 1-ohm stable (running parallel/parallel to all four coils). I have everything figured out except the input choice. I plan on (for now) using the speaker-level inputs on the amp since I have a factory HU. Since there is only one channel input, I can just pick a side and plug it in. But, since some songs have differentiated bass L and R, won't I notice some funky reproduction? I usually use a 2 channel amp and bridge it to get stereo converted to mono. Is there a way to "mono" it before it goes to the amp since it only has one input? Any problem if I parallel both speaker channels into one input channel?
Replies (5)
ttocs on 07/16/2009 09:32:04
it only has one high level input? Two wires?
Majority of bass tracks are not recorded in stereo. There are exceptions but for the most part it is mono so it would not matter which side.
swez on 07/16/2009 09:35:45
You can tap off the rear speakers and join the L/R Positives together and 1 ground to the amp in one plug. That will give you A/B channels as input to this Mono amp.
The tricky part is the signal level. (gain settings) you will use to control the bass amp and sub output. You may need an inline attenuator between speaker outs and amp input.
Swez
curtis73 on 07/16/2009 21:41:28
ttocs... one channel input... at least that's what the woofersetc website says, but they could be wrong.
swez... not that I need to know, but; why the gain reduction? I'll still be sending the same voltage even with both channels hooked in, right? I'm not challenging, I just simply don't know. Will hooking the + and - together from each rear channel add stress to the HU? Wouldn't it technically halve the load, or does signal conversion not really have a load? Just curious. My concern is that I'll already be on the low side of gain since I'll be sending 900wrms to two subs that are rated for 400rms each. Will I have trouble dialing it with that much signal?
swez on 07/17/2009 05:35:46
Not sure if you'll have any issues or not. It depends on the voltage from the rear speakers and how the internal preamp side of the amplifier handles the voltage levels coming in.
Example: Say the speakers are getting 15 watts and are 4 ohm speakers. That's about 7.5 volts per speaker. With an AC voltmeter, you can monitor voltage from channel LR alone and then add RR to it. Observe the voltage again with both channels. Since they are in parallel together, I would expect the reading to remain the same if the signals are in phase.
If the combined signal reads 15 VAC, that "may overdrive" the amps' preamp section and require an attenuator circuit to knock down the voltage to a usable range.
I've never had to mess with that as the sub amps I have used or installed had both RCA and Speaker level inputs and never had issues about overdriving the preamp circuits. Try it and see. You'll know immediately that an attenuator is needed if the gain setting is low and output distortion is very noticable at low volumes.
The HU should not have any real issues as the input impedence on the preamp is much higher than the speakers and barely even noticed as a load to the HU.
Swez
PS I have never seen a modern sub amp with only one input channel. The preamp internally accepts A/B channels and sums them automatically and attenuates the signal to a range the amplifier circuits can use. (0.25 - 6.0 volts are typical)
curtis73 on 07/18/2009 17:22:05
Ok, thanks. I'm sure that someone at woofersetc just put the wrong number in the input box when they were generating the sales page for that amp.
I have two DVC 4-ohm subs in sealed boxes that I plan on running with a mono sub amp that is 1-ohm stable (running parallel/parallel to all four coils). I have everything figured out except the input choice. I plan on (for now) using the speaker-level inputs on the amp since I have a factory HU. Since there is only one channel input, I can just pick a side and plug it in. But, since some songs have differentiated bass L and R, won't I notice some funky reproduction? I usually use a 2 channel amp and bridge it to get stereo converted to mono. Is there a way to "mono" it before it goes to the amp since it only has one input? Any problem if I parallel both speaker channels into one input channel?
Replies (5)
ttocs on 07/16/2009 09:32:04
it only has one high level input? Two wires?
Majority of bass tracks are not recorded in stereo. There are exceptions but for the most part it is mono so it would not matter which side.
swez on 07/16/2009 09:35:45
You can tap off the rear speakers and join the L/R Positives together and 1 ground to the amp in one plug. That will give you A/B channels as input to this Mono amp.
The tricky part is the signal level. (gain settings) you will use to control the bass amp and sub output. You may need an inline attenuator between speaker outs and amp input.
Swez
curtis73 on 07/16/2009 21:41:28
ttocs... one channel input... at least that's what the woofersetc website says, but they could be wrong.
swez... not that I need to know, but; why the gain reduction? I'll still be sending the same voltage even with both channels hooked in, right? I'm not challenging, I just simply don't know. Will hooking the + and - together from each rear channel add stress to the HU? Wouldn't it technically halve the load, or does signal conversion not really have a load? Just curious. My concern is that I'll already be on the low side of gain since I'll be sending 900wrms to two subs that are rated for 400rms each. Will I have trouble dialing it with that much signal?
swez on 07/17/2009 05:35:46
Not sure if you'll have any issues or not. It depends on the voltage from the rear speakers and how the internal preamp side of the amplifier handles the voltage levels coming in.
Example: Say the speakers are getting 15 watts and are 4 ohm speakers. That's about 7.5 volts per speaker. With an AC voltmeter, you can monitor voltage from channel LR alone and then add RR to it. Observe the voltage again with both channels. Since they are in parallel together, I would expect the reading to remain the same if the signals are in phase.
If the combined signal reads 15 VAC, that "may overdrive" the amps' preamp section and require an attenuator circuit to knock down the voltage to a usable range.
I've never had to mess with that as the sub amps I have used or installed had both RCA and Speaker level inputs and never had issues about overdriving the preamp circuits. Try it and see. You'll know immediately that an attenuator is needed if the gain setting is low and output distortion is very noticable at low volumes.
The HU should not have any real issues as the input impedence on the preamp is much higher than the speakers and barely even noticed as a load to the HU.
Swez
PS I have never seen a modern sub amp with only one input channel. The preamp internally accepts A/B channels and sums them automatically and attenuates the signal to a range the amplifier circuits can use. (0.25 - 6.0 volts are typical)
curtis73 on 07/18/2009 17:22:05
Ok, thanks. I'm sure that someone at woofersetc just put the wrong number in the input box when they were generating the sales page for that amp.
Copyright ClubKnowledge 2009 * All Rights Reserved
