volume control

[icyveins]

I am looking to have a few different sets of speakers on my ship located a great distance from each other.
what I am trying to do is have the head unit volume turned up a little ways from max volume and then have separate volume controls for each zone. each volume control for there zone will be in separate locations for each person in each zone to control. if someone is sitting at the bar and are trying to have a conversation they don't have to yell over the stereo and can simply turn the volume down in there zone. any thoughts or help would be appreciated.

I have looked up 12v marine volume control and it gives a lot of options for home use, I have not seen much for standard 12v audio setups

 

[Grub54891]

Re: volume control

I'm pretty shure your household radio converts 110 volt to 12 volts inside the radio with the transformer. I'd think the controller your looking at will work just fine. As long as compatible with the radio.
Grub

 

[NYBo]

Re: volume control

Why would you need to worry about 12 VDC vs 120 VAC? Volume controls don't require power. You just need them to have the proper impedance rating and adequate power handling capacity, and water resistance if they are mounted where they could be subjected to rain or spray.

 

[icyveins]

Re: volume control

I guess that answers my question then

 

[sam am I]

Re: volume control

Answer is "L-Pads" ........On the low impedance speaker wire side(house, boat, car) of an amp in the passive world anyway. (no, not potentiometers/rheostats, different beast all together),.

That single volume knobs that you'll see sometimes on the walls in rooms(old school more these days though) at like Doc's/Dentists offices where each room has a speaker/s requiring different levels with one amp turned up max'ish in a closet somewhere driving the lot are L-pads.

These devices are designed to keep impedance's/loads balanced/matched when multi levels are needed and also require adjusting up or down and differ for each area.......Thus, the system stays balanced for the amp and speakers w passive crossovers to all work efficiently and properly.


Not sure if they make remote control ones though, iboats doesn't pay me enough to know that

Let the all knowing oracle known as Google guide you in your journey to stereophonic audiophilia nirvana.

Or? Throw a towel over the things!!

Perhaps A simple series resistor(rheostat) would suffice too I suppose in a pinch. Amp might scream though when it's turned way up and the loads are all high R. Sort of not a good idea.

 

[icyveins]

Re: volume control

I will be purchasing MB quartz speakers here is the information on them,

50 watt RMS
100 watt max
20hz - 20khz
4 ohm minimum load

would this be what I need for each zone...(two speakers)

Amazon.com: L-Pad 100W Stereo, 8 Ohm Rated, 1" Shaft: Electronics

 

[sam am I]

Re: volume control

Yup..those will work just fine. Ideally, with 4 ohm speak's, you'd want 4 ohm L-Pad's(gl finding those) but, your amp(50 watts rms max/ch I presume) in this case, will just see 8-4 ohms as the knobs all go from lowest to highest(8 ohms(l-pad) when the volumes are turned down low/off and 4 ohms(speak's) when turned up high/max and all ohms in between), no biggie.....you're still fine, it'll work nicely for you.

After it's all wired up, have all the l-pads on low, turn the amp up to just around half way'ish, go to each area and max each l-pad out and see if that'll be a high enough level, if not, go add a little more amp, rinse lather repeat.....

 

[bruceb58]

Re: volume control

That's not how L Pads work. L pads will show an 8 ohm load to the amp at all levels that you set the L pad at since the amp output goes across the entire L pad... always.

The purpose of the L pad, besides volume control, is so that the amp output has a load on it. 8 ohms is fine. Doesn't matter what the speaker impedance is.

 

[sam am I]

Re: volume control

You the l-pad cop now? He's not matched....... he's using a 4 ohm speaker and 8 ohm l-pad, read the numbers, do some research, do some math, please!!

I will explain for you, ONCE and yes, I/we know you're an electrical engineer, you've told us all, many times!!.......Wired properly....when the l-pad is turned to max, the speakers impedance is the ONLY reflected impedance to the amp!! 4 OHMS in the case!! Now, think hard here Bruce, how could the speaker get the entire signal with the l-pad turned up to max, if ANY OTHER series resistance was in the circuit?

Here, as designed, the series pad resister has went to zero as the parallel pad approaches infinity/high resistance. The amp sees 4 ohms, the speaker!! no series resistance else the speaker wouldn't ever get to the level that the amp was pre-set too!!

When the l-pad is turned down all the way, the series pad of the 8 ohm l-pad he is buying is 8 ohms!! and the parallel go to zero, the amp sees 8 ohms!!!

Thus, when ranged from min to max, the impedance the amp sees with a 4 ohm speaker, with an 8 ohm l-pad, ranges from 4 through 8 ohms. If he was using a 8 ohm speaker, it would remain 8 ........ done here.

OP, As it was repeated here again and as I already said, TWICE, "it's fine" with an 8 ohm l-pad, but, PM me if you need.

 

[bruceb58]

Re: volume control

Everything you want to know about L-Pads but were afraid to ask:
L-PADS

I actually agree with you now. The amp will be seeing that 4 to 8 ohm range.

 

[HPLou]

Re: volume control

Very Interesting Topic.
I have 2 speakers on my Arch that does not work and a L-Pad on my Dash same has Icyveins Amazone Link.
I had no idea what was the use for that L-Pad until now. The 2 speakers are located on my arch on top of my Camper Top.
So it makes sense to shut the volume on these speakers when the Camper Top is install.
I guess my L-Pad is defective. I'll replaced it
Thanks Icyveins & bruceb58 for the info.

 

[sam am I]

Re: volume control

OP, your power response analysis with a 50 watt rms amp is in..........You can always wire two 8Ω L-pad's in parallel to make a 4Ω L-pad if that non linear issue keeps you up at night!!

Also, as seen in the plot, the L-pad effective range of the knob will be a little latent(will be a little futher along and have a tad quicker response towards the end travel point)in achieving the same wattage to the speak's when using the 8Ω over the 4Ω as well. Yes, nightmares.

 

[icyveins]

Re: volume control

OP, your power response analysis with a 50 watt rms amp is in..........You can always wire two 8Ω L-pad's in parallel to make a 4Ω L-pad if that non linear issue keeps you up at night!!

Also, as seen in the plot, the L-pad effective range of the knob will be a little latent(will be a little futher along and have a tad quicker response towards the end travel point)in achieving the same wattage to the speak's when using the 8Ω over the 4Ω as well. Yes, nightmares.

View attachment 222121View attachment 222123

english please

 

[sam am I]

Re: volume control

Rock and Roll Veins!!!

 

[icyveins]

Re: volume control

I do not recommend buying 8 ohm controls if your output is 4ohms. The controls are not sensitive at all at low volumes.
when adjusting at what should be a really low volume (its not really low, cant even talk over it) it will just turn off the speakers
I don't know if that is the case for all volume controls but these are not very smooth at all. I guess I got what I paid for

 

[sam am I]

Re: volume control

Re-check wiring plz.........and certainly quality of the l-pad will be a factor here but, something is not adding up here.

It should follow that response curve that shows it should have a nice linear(almost perfect)output as you turn the knob.


The volume should tapper off nicely from loud(whatever the source is set to) to off'ish at about the knobs half way point at around -44db.

 

[bruceb58]

Re: volume control

I did an excel spread sheet and plotted the percent difference between an 8 ohm L-pad driving 4 or 8 ohm speakers and it shows a dip in the center but the ends are pretty close.


Looked at Sam's plot and it jives with his.

Did you wire it correctly? It will do very strange things if you don't.

 

[icyveins]

Re: volume control

I will have to take a look at the way I have it wired. if anyone has a diagram to put up I can compare the way I wired it.

 

[bruceb58]

Re: volume control

Well there are 3 terminals. They should be labeled input from amp, speaker + and speaker -.

or maybe 1,2,3

 

[sam am I]

Re: volume control

off'ish at about the knobs half way point at around -44db.

This is incorrect, apologies...

The output level(voltage) should be approx -20db(or 1/10 the input level) w the knob turned to half way point.......It will be approx -40db(or 1/100 the input level) turned all the way down.

That is, if my math was right.:nerd: