very loud internal sounders

[ross94]

what? what? ehh?, right joking aside it was as easy as just moving the speaker I would of done it by now and we would not be having this conversation. My house is very awkward to run cables around without causing major disruption. ie lifting chipboard floors channeling finished walls ect its just too much hassle and not too mention the missus will kill me.

so back to the question will an 8ohm make a difference over a 16 ohm. serious answers only please.

 

[bernardgreen]

If the power source is constant voltage output and near zero internal impedance then an 8 ohm load will take more current than a 16 ohm load. Twice as much current. If the load can handle that extra current then it might produce twice as much output.

But a power source that feeds sound power into a loud speaker doe not have a near zero internal impedance and the internal voltage drop across the internal impedance will increase as more current is taken by the load. So the output voltage will be lower with an 8 ohm speaker as the load than it will be if the load is a 16 ohm speaker.

Whether fitting an 8 ohm will make more sound than a 16 ohm depends on the size of the internal impedance.

The 8 ohm speaker may be louder than the 16 ohm speaker ( low internal impedance )

The 8 ohm speaker may be not as loud as the 16 ohm speaker ( internal impedance greater than 16 ohms )

The most sound will be when the most power is transfered from source to speaker. ( assuming the speaker can handle the power without the coil burning out or the cone rupturing )

The most power transfer occurs when the internal impedance is equal to or less than the impedance of the speaker.

Find out the internal impedance of the driver and then you can tell if the 8 ohm will be any louder than the 16 ohm.

There is the other consideration. Can the driver provide the extra current without over stressing its component when loaded with an 8 ohm speaker.

 

[ultomoat]

My house is very awkward to run cables around without causing major disruption. ie lifting chipboard floors...

I can 110% recommend these floorboard holesaws: http://www.toolstation.com/shop/Pow...+Bits/sd1120/Solid+Board+Access+Cutter/p36742 I bought one a couple of years ago when I needed to run cables under the floor, and have used it several times since for plumbing and wiring.

Toolstation also sell plastic discs to fill the hole you've drilled - which provide a handy access point in the future.

 

[ross94]

hi there ultomoat. the panel says it can drive 2 16 ohm speakers in parallel if that helps thanks.

 

[bernardgreen]

hi there ultomoat. the panel says it can drive 2 16 ohm speakers in parallel if that helps thanks.

Then it should be able to drive one 8 ohm speaker without overloading ( maybe damaging ) the driver. But as I said it depends on the internal impedance whether the sound power into an 8 ohm load ( one 8 ohm or two 16 ohms ) will be greater or even as great as that to a single 16 ohm speaker.

 

[ross94]

sorry bernardgreen I thought that was ultomoat who was explained about the impedance. I will try an 8 ohm speaker see how that goes. if that does not work then I must be going deaf, only 25 years old and going deaf lol, too much concerts I think.

funnily enough I can hear the smoke detector and doorbell no problem and they are only 85 decibels alledgedly. yet the sounders I have bought in the past says they are rated at 110db or even 120db hmm

 

[secureiam]

I am surprised at the 110 and 120db sounders not being loud enough, either they are not set up correctly or you don't have enough power to drive them? Or you are going deaf.

If you are going deaf I would see your GP about the possible cause given your age, if you haven't battered your ears too much with loud music there could be other issues that need looking at urgently.
(If that didn't scare you enough, an uncle of mine started with hearing issues and turned out it was brain tumour at the time was only in his early 30's, so seriously having hearing problems get it checked out.)

I would be surprised if they 8ohm or 16ohm speaker would generate greater than the 110 and120db sounders already tried.

 

[ross94]

would an elmdene 500 or 600 work? they say they are 120db but that could be bs. can you recommend a decent loud internal one that will wake me up and the way to set it up. thanks

 

[secureiam]

yes they are loud, 108db @ 1m according to the pdf I have, but there is a low volume e/e trigger and a high volume alarm sounder.

 

[EightyTwo]

If you can't hear the soint 2, the extra 3dB (perhaps) from an 8 ohm speaker isn't going to make much difference. Moving the speaker/sounder would be a much better option. Could you run a new bit of cable from the panel? Or could you break into the existing bell cable somewhere? I still think that your best bet is to get it on the landing or in the hall. Could you drill through the wall behind the existing speaker?

Leave the kitchen door open...

 

[ross94]

HI guys again sorry for the delay. just thought I would let you know it was my hearing playing up. just did a sound test today with my original elmdene 16 ohm speaker. very loud downstairs and quite loud upstairs even with bedroom doors shut. This will definatelly wake me up which is good.

all that running finding louder sounders when all this time it was just temporary hearing damage. what a plonker eh.
I guess I keep more to the back row in future when going to concerts lol. anyway thanks to all who assisted. cheers