Connecting 70 volt / 100 volt speakers (Constant Voltage)

How do you connect 70 volt or 100 volt constant voltage speakers that don't have switchable load settings? This simple video will teach you how to connect constant voltage speakers with multiple cables and assist you to calculate how many speakers you can connect to your PA amplifier without overloading it.
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[@colliedogboy]

Well done, Gary. Thank you.

[@GaryDmedia]

+Perry Mike thanks for commenting. Happy the video was of help. I am hoping to answer more questions about 70/ 100 volt speakers in upcoming videos so if you have any questions feel free to ask.

[@rajeshkumar-ob4fr]

Very nice sir out put transformer

[@EMTMZ]

great. I like this . Its new to me.

[@GaryDmedia]

Glad you enjoyed it. Thanks for commenting.

[@nandeesh8]

nice and usefull tips video, I like it and suggest it to somebody

[@GaryDmedia]

Thanks for commenting. I appreciate that you let me know you enjoyed the video.

[@niramasaxena7756]

Sir how to connect Bosch LDB1935/00 240w amplifier to Honeywell EvacPro - G2 and EvacPro mic

[@jonathankeenan80]

hi Gary can you show how to connect paging from phone systems up to a 70v amp thanks

[@GaryDmedia]

Thanks +Jonathan Keenan there are so many variables. Depending on the feed you have from the phone system and the type of amplifier you have. A lot of PA amplifiers have a channel that will override the rest of the channels when a signal is present. These are all things that would have to be considered.

[@ismailparabole9570]

thank you so much

[@GaryDmedia]

Thanks for commenting.

[@christiangonzales7429]

Hi Gary, I have a question. Do the transformers have to be mounted on the speaker drivers? I have two speakers where I cannot attach them to the drivers but I can cut the wires on the wall running to the amp and add a transformer there with some wire nuts. Will it affect sound quality if I have a long amount of wire running between the driver and the transformer?

[@GaryDmedia]

Christian, that is fine as long as the low impedance leads are not too long. The whole idea of constant voltage speakers is to reduce low impedance cables.

[@christiangonzales7429]

@@GaryDmedia Can I send you some pictures to show you?

[@manuelpsia7011]

Say I had 200 watts Amps, with 10 speakers @ 10 watts each, and I added (1) one 100 watts trumpet or Horn speaker, Is this a fair connections or I need amp with more power ? Thanks

[@GaryDmedia]

That would stress the amplifier. It's much better to only load the amp to no more than 80% of its capacity.

[@pbuchta1]

A 70/100v system's speakers should be configured in a parallel circuit. Also, besides never exceeding the amplifier wattage, two other factors need to be considered. These are amplifier headroom (20-30%) and the amplifier's minimum impedance rating.(Usually listed on the amplifier.) Thanks Gary. Very good explanation. Clear and concise.

[@GaryDmedia]

Peter Buchta That is a good point to highlight. Not loading the amplifier to it's maximum in good practice. I appreciate your comments and your input.

[@carlotheatheist]

Are you still active today? Is that suitable for power amplifier? And large voice coil speaker? Because im planning to implant constant voltage transformer to compression driver unit.

[@GaryDmedia]

Mr JN, not sure that a compression drive is suited to constant voltage. The down side with constant voltage is there are some loss in frequency if you use a cheap transformer

[@niramasaxena7756]

My Bosch LDB1935/00 100-0 or 70-0 not showing any voltage on multimeter, what may be the problem sir

[@bjtaudio]

I found also you can use power transformer cores to make up you're own audio transformers too, I was surprised to discover that bandwidth of EI 0.5mm lamination's and toroidal cores can do 20Hz to about 15Khz easy, and as much power as you like. Also can use higher voltages for longer distances and or more power if needed. 70v 100v or even 230V system, I would not go too much higher in voltage as insulation and safety becomes an issue.

[@GaryDmedia]

+bjtaudio Yes the toroidal core transformers are much more efficient and this is why the better amplifier manufacturers use them to step up the voltage as an output transformer. It gets a little expensive if you want to use them to step down voltage at each speaker in a big installation. I really appreciate you taking the time to comment. Thanks for that.

[@markgalluccio724]

I have a Solance 100W sub woofer that runs on a 70 volt system. (I no longer have the satelites. I want to use the sub on my current audio receiver with 4 other speakers. I have a subwoofer port on my receiver. can I bypass the 70v transformer on the Sub Speaker and use it directly from my receiver? Can I add in a Sub Woofer Amplifier?

[@bjtaudio]

For you're information: The idea of the audio transformer is to step-up the voltage of an audio amp for long distance transmission of PA sound over ordinary 0.5mm2 fig 8 speaker wire, with very little power loss. Also allows multiple speakers and at different power levels to be all connected to the one line in parallel. The idea works in exactly that same way ac power is transmitted with step-up and then step down transformers. The audio output of the amp is not constant voltage as such, the constant voltage refers to transformers transmission winding line voltage.

[@GaryDmedia]

+bjtaudio Thanks so much for your informative comments. It's is so good to have others share their experience in this field.

[@johngil2848]

Nice video. 100V speaker line feed (also 50V and 75 V are common) requires that the amplifier is specially designed for that, as it is loaded with abnormal inductive and capacitive loads that can generate instability (oscillations and motor-boating). Otherwise it is a question of correct inpedamce matching. Use very good line transformers. Poor quality line transformers degrade the frequency response and increase instability. This transformers use special quality iron and special wire wound technics.

[@GaryDmedia]

+John Gil Thanks so much for contributing. Appreciate it.

[@evanmulvihill9651]

What I'd like to know is what would happen if you connect an 8ohm speaker to a 70v amp, or a 70v speaker to a non 70v amp. Fire, I know. But why?

[@GaryDmedia]

Connecting an 8 ohm speaker to a 70 volt amplifier will short out the amp. You can connect a 70 volt speaker to an 8 ohm output amp. It just won’t be very loud. Note a 70 volt speakers resistance (impedance) is 1000’s of ohms.

[@bahnundansagen2718]

You can add a transformer and then put it into speaker!

[@franciscopereira-grupodisc9269]

Hello. Please, what problems should I have if I connect the output of a 100v amplifier to a 70v speaker line?

[@GaryDmedia]

The only problem Francisco is that the speaker system will drawer more wattage than what is written on the speaker transformer. For example a 70 volt speaker that has 5 watts written on it may load the amplifier to 8 watts. Even so, with this knowledge you can still use 70 volt speakers on a 100 volt amplifier, you just have to remember not to overload the amplifier.

[@franciscopereira-grupodisc9269]

@@GaryDmedia , thanks a lot for the information.

[@spanishescapes]

Hi mate. Would it be safe to use 100v line speakers on a 70v line output amplifier? Thanks in advance

[@GaryDmedia]

Yes definitely safe. 100 volt speakers are a higher impedance so they will sound quieter. You just have to lift the gain of the amp a little. Raise the volume that is.

[@spanishescapes]

@@GaryDmedia thanks for the reply mate

[@jazzmood2383]

Very clear explanation about constant voltage speakers. Nice work!

[@GaryDmedia]

More constant voltage vids coming. I spend a lot of time installing these systems. Thanks for sharing your comment.

[@Dhaif_El-Jaber]

Dear i have been installed as following : one amplifier 240 watt 4 speakes Bose each one 10 watt i connect from first speaker to second .........ect then i need to add new two speakers but i asking you how to add cable join from last speaker or no problem if i am going to join from any section of cable ?

[@AA-uz7su]

Can you use speakers that are on 1 watt mode and other speakers on 2 watt mode on the same 70v system?

[@GaryDmedia]

Yes definitely Arturo, that is the best feature of using a 70v speaker system. Thanks for adding your question.

[@rafaelrivera5779]

Como conecto bocina jbl 8128. Tiene 5 cablecitos y no se cuales tomo

[@GaryDmedia]

Si está utilizando una salida de 100 voltios, utilizará las conexiones negras y marrones del altavoz.

[@nimashali9076]

Please help me with this, im struggling. I Have 10 speakers (100volts) and a amp with 250W output power. The speakers has 3 outputlevels, 10w, 5w and 2.5. I want to use 10W for all the speakers. So if i understood this video right, i have to connect one speaker to the amplifire first then start adding speakers pararell with the first speaker? Example: step 1, for the first speaker i choose COM and 10W from the speaker and connect it to 100V and COM output on the amplifire step2 I plug the remaining speakers in parallel with the first speaker Or should i just plug all speakers in paralell then connect them to the amplifire?

[@GaryDmedia]

+Nima Shali There is a good document that may be what you need. It has a good illustration that shows you how to connect to a power amplifier. Hope this will help you. adn.harmanpro.com/site_elements/resources/860_1425410780/Guide_to_constant_Voltage_systems_original.pdf

[@nimashali9076]

Hi Gary, that illustration confused me. Im not really good at this but i made a sketch on how i did my wiring, i get full sound from my speakers but im worried over the wires, i dont want them to heat up. Please look at the image and let me know where i did wrong.. imgur.com/S9oNoc6

[@GaryDmedia]

+Nima Shali I understand your problem. Please send me a photo of the back and front of your speaker so I can understand what your connecting.

[@nimashali9076]

Speakers: imgur.com/BWQJmBi Amplifire: imgur.com/a/Xp8BQ Thank you Gary! i really dont know who to ask! I appreciate you doing this for me!

[@GaryDmedia]

+Nima Shali No worries, I will check it out.

[@mattheww3116]

Does anyone have an answer? I don't understand why the amplifier has 20 more watts? Thanks

[@GaryDmedia]

+MatthewW As long as the watt rating on the amplifier is more than your calculated load it will be fine. With the same speaker system on the video you could connect to a 250watt amp and it would be OK. If you connected a 35 watt amplifier it would be overloaded. It is best to have at least 20% spare wattage as a safe zone. Hope that helps.

[@mattheww3116]

+Simple Audio Tips Thank you! :)

[@hoangquyennguyen3201]

Can I have the parameters and the name of the other impedance sub product?

[@rickbarber6758]

Can the standard 8ohm receiver be converted to 70 volt output?

[@GaryDmedia]

Yes definitely. You just need a line transformer like one on the back of 70 volt speakers. The down side is that you will be limited to the load wattage if the transformer. 15 watt transformer can only safely transfer 15 ways of power.

[@DiamondDog_]

@@GaryDmedia my question is if the speaker has a power of more than 1000W can this method be used? and also there is something called passive crossover is there any difference if using it simultaneously. sorry for my bad english🙏🏻

[@mrjn5786]

Hey can i used that in some speaker like 12 inch speakers?

[@GaryDmedia]

+Mr Jn You will only be able to use this setup if the speaker has a transformer attached to it. There are very few if any 12 inch speakers with CV transformers attached. Most 12 inch speakers are wired using the 8 or 4 ohm connections.

[@ajnebiwazeer8439]

How am I connect 6 watts 16 speakers to amplifier. In 100 volts line

[@GaryDmedia]

I'm not quite sure what you mean by 6 watt 16 speakers. Do your speakers have a transformer on the back?

[@ajnebiwazeer8439]

Siry sir my English is weak.I have 16 speakers with back transformer. In 4 inch size and 6 watts and100 volts. How in connect these speakers with amplifier?

[@GaryDmedia]

You use the same method. Connect them in parallel. All of the + together and all of the - together. The amplifier will have to more than 100 watts to use this method.

[@ajnebiwazeer8439]

Gary thank you very much. Its OK.

[@dennyfarrell4388]

Thank you Late Night Chicago Radio

[@sergiojoseph650]

Good video!!

[@GaryDmedia]

Thanks +Sergio Joseph I hope to create more content to assist with constant voltage systems in the future.