# New House..new 70v speaker system



## AllenS (Dec 6, 2011)

Hello all! New to the forum and not familiar with 70v systems...I bought a house a year ago and it is wired with Bose ceiling speakers and an outdoor speaker. I am finally getting around to trying to hook it up (wife is tired of asking) and I was hoping someone here could help.

The house has two speakers in the living room for surround sound and they have their own L & R hookups, but the den, dinning room, kitchen and patio have a speaker with individual volume controls and one 70V hookup in the wall.

My question is, how do i hook up my TV to this...what amp do i need...etc.

Attached are pictures of the hookups and the volume control.

Thanks in advance!!!
Allen


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## tonyvdb (Sep 5, 2007)

You will need a special amp designed for use with the 70v speakers. There are many that will but you need to search them out. Do a search for "70v amplifiers"


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## AllenS (Dec 6, 2011)

I have, but not sure exactly which amp I would need or how to hook it up to the single 70V connection...sorry...just pretend like you are talking to a child...


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## tonyvdb (Sep 5, 2007)

By the looks of the picture the connection is an "rca" connector?


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## AllenS (Dec 6, 2011)

That is correct.


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## tonyvdb (Sep 5, 2007)

Ok, thats easy then, all you need is the proper amp (you wont need much for output power) probably less than 100watts and understand that its a mono system not stereo.
Just hook up the output of the amp to a speaker cable and attach an rca connector to the one end (positive is the center pin).


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## AllenS (Dec 6, 2011)

How do I go about hooking up my TV to the amp or do I need to go from the TV to a receiver? I purchased a small 40watt amp from Radio shack, but could not get it to produce any sound. I ran rca cables from the sat. box to the amp and then used a split RCA cable from the 70V and COM on the amp and pluged it into the wallplate.


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## AllenS (Dec 6, 2011)

By the way...thanks for your help on this Tony! Sorry for all the questions!


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## tonyvdb (Sep 5, 2007)

Thats no problem 

You will need to get an amp that has a built in mixer (a small sound board) on the face. Or you can use your existing Receiver and use the zone 2 output as well if your TV is connected to it.


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## tonyvdb (Sep 5, 2007)

This 70v amp/mixer would work for you


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## AllenS (Dec 6, 2011)

This is what I had, but not sure I was hooking it up correctly.

http://www.radioshack.com/product/index.jsp?productId=2103829


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## tonyvdb (Sep 5, 2007)

unfortunately that does not support a 70v system the impedance is incorrect for the speakers on a 70v system and can not use a "normal" amplifier.


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## AllenS (Dec 6, 2011)

It did have a COM, various omhs (2,6,8 i think) and 70V for hookups in the back. I tried running an RCA cable from the STB to the Phono hookups in the back and used a split end RCA cable from the COM and 70v to the wallplate...but got nothing.


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## tonyvdb (Sep 5, 2007)

Hmmmm, Im not really sure then as it should have worked unless the STB was not outputting a signal? Thats not saying that there is not something wrong with the wiring to the transformers on the rheostat or the speakers.


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## AllenS (Dec 6, 2011)

Any easy way i could check the kwiring to the transformers on the rheostat or the speakers?


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## tonyvdb (Sep 5, 2007)

you can send a line level signal from the rca input and just use a small speaker or even cheap headphones and attach the headphones to the wires at the transformer to see if you have any signal


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## AllenS (Dec 6, 2011)

Ok. Before I climb up in the attic and move all the blown insulation, I will see if it is a signal from the STB. I know the previous owner was using them when we were looking at the house. Just so I am 100% on the connections from the amp...see pics.

On the first one the cable I am using for the 70v connection is an RCA to tin ends...


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## AllenS (Dec 6, 2011)

Just revisiting this...it has been six months and I have not done anything to correct this yet. What a waste of Bose speakers!!! Now that the summer is hear, I would really like to get this working (like to use the outside speaker). Can someone take a look at my pics and let me know if that wiring looks correct before I purchase that amp (Atlas Sound AA35 35W Mixer-Amplifier) or if there is a better amp I should get.

Thanks
Allen


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## DeuceTrinal (May 7, 2012)

Allen,
The pictures don't quite match the radioshack link, but it seems like that amp may work for running your 70V house speakers. It most likely won't work for running both your house speakers and your surround sound L&R speakers at the same time. 

If you take the plate with the L&R and 70V jacks off the wall, what does the back look like (pic?) If the 70V connection is an RCA, there was probably another location in the house that had a 70V amp, and this plate was used to feed it low level (non-amplified) signal. If there is heavy gauge wire (18-14 gauge) wire connected to the back of that RCA, it was probably directly driven off a 70V amp, the a non-standard connector was used (RCAs are typically only used for low-level applications). You can solder a RCA to speaker wire to connect to the COM and &_)V terminals of your amp in that case.


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## AllenS (Dec 6, 2011)

I will pull the plate off and take a pic tonight and post it tomorrow. Ignore the radio shack link...I think I am going to go with the Atlas Sound AA35 35W Mixer-Amplifier..unless you know of a better amp at a reasonable price.


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## AllenS (Dec 6, 2011)

Ok...to my surprise, there are 4 wires spliced to the RCA wire for the 70v plug and a wire each to the L & R plugs...(see pics)

Guess this will change what amp I should use and how to wire it...any suggestions? I want all the speakers to be hooked up to the TV (each room i can turn down) to play music throughout the house.


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## DeuceTrinal (May 7, 2012)

Ok, so they used an RCA for speaker connection - not the right one, but probably functional. You could use it as is if you really want, by soldering speaker wire to a male RCA and plugging it in. 
Here's what I'd do if it were my house:
I'd replace whole plate, and use proper binding post inserts.
I'd run heavy speaker wire (14-12 ga.) to each splice of red and black wires, and I'd solder the joint instead of just a wire nut. 
I'd pull one of the ceiling speakers grills off, or the speaker out (or look at the back from an attic) to identify the model and find out how many watts it draws (important on 70V systems). It might be determined by the vlume controls, look up the model number of those too if needed. 
Add the watt rating of all speakers, buy a 70V amp with adequate head room (rated for at least as many watts continuous, not peak or max). 
Hook 70V amp to new binding posts on the wall, plug source into 70V amp, and you should have music. 
Make sure to turn down all the volume controls before testing! 

If you happen to already own an amp, you can buy a 70V transformer that will let a normal amp work with 70v speakers (70v amps have this built in).
Parts express has everything you need, either way.


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## AllenS (Dec 6, 2011)

Ok...are you saying you would splice all the reds together and all the blacks together and use heavy speaker wire to two separate binding post? What would the hook up be from the 70v to the binding post...com to black...70v to red?


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## DeuceTrinal (May 7, 2012)

AllenS said:


> Ok...are you saying you would splice all the reds together and all the blacks together and use heavy speaker wire to two separate binding post? What would the hook up be from the 70v to the binding post...com to black...70v to red?


Yep, exactly. Not the two surround sound speakers, just the house distributed audio speakers. I'd keep the surround sound rears as separate pairs of binding posts, to hook up to your receiver (something like these, which fit in these)
You'd hook up the com or negative terminals to the black, and 70V or positive terminal to the red, with that same heavy speaker wire.


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## AllenS (Dec 6, 2011)

Ok. I pulled one of the speakers out (not the surround sound two in the living room) and it is set at 8 watts. So assuming all of them are set the same, we are pulling 32 watts with these four speakers. See pic below for the speaker type. (Bose model 32). The vol. controls did not have anything that I could use to determine type (see first page for pic). Last thing I need is a suggestion for a cheap amp and a diag. on how I would hook up my cable box, dvd player, tv, and amp all together. The surround sound speakers do not have a volume control in the room, so those will need to be controlled by the amp / tv. The others do and therefore everything can be run through all 6 speakers and then I will simply turn off the volume in the other rooms. If i could run the surround sound through one channel and the other four through another, that would work also. Keep in mind for the amp I am looking to say between $100-$200. Again...thanks for all your help!!!


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## DeuceTrinal (May 7, 2012)

OK, assuming the 32W number is correct, I'd be looking for a ~40W or bigger amp. If it were my house, I'd either check all the speakers wattage setting or get an amp big enough to handle any that were set higher. 
The two surround speakers in the living room are most likely normal 8 ohm speakers (I'd check before spending money), and need a dedicated amp channel each to be used. So you'll need two separate types of amps, or an amp with a zone 2 output that is 70V (you can use a transformer). 

This is all assuming you intend to use the speakers in the living room as rear surrounds in a 5.1 surround sound system (which is what I assumed because you called them surround sound speakers). You'd also need a left, right and center speaker next to your TV. 

My recommendation would be to get a surround sound receiver with a powered zone 2, and a 70V transformer to run the zone 2 into your house speakers. That will let you connect all of your sources to a single unit, which will run both the living room and the whole-home audio. This will be the simplest and probably cheapest effective solution. Unfortunately, you'll probably be pushing the limits of the budget. However, I am not at all familiar with the current options for inexpensive gear, so I could very well be wrong about that. 

This is a basic audio-only reciever that would work, along with a 70V transformer.
With this you'd probably only get one channel (left or right) of sound to the rest of the house, as the output will be stereo.


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## AllenS (Dec 6, 2011)

So if I get the 70V transformer, I can use any receiver? If that is the case, and I open up my budget a little, would the Onkyo TX - NR709 be a good choice for this 2 zone set up? I am only going to use it for Blue ray, TV, and maybe a gaming system in the living room and then pump a separate feed through the 70v speakers (can i pump the same feed if I wanted to?)


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## DeuceTrinal (May 7, 2012)

Yup! That receiver looks quite nice too! You should be able to select any analog source in either zone, including the same source simultaneously. That means anything you want to listen to in the zone 2, needs to have analog (RCA or headphone) audio outs. Other than that limit, it should work great. The main 5.1 room can listen to any source, digital or analog.


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## AllenS (Dec 6, 2011)

Would I run the wires at the plate to 10 guage speaker wire, then to the 70v transformer, then to the receiver?


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## DeuceTrinal (May 7, 2012)

Exactly. Some transformers have pre-attached wire leads, others have just terminals for spade connectors or soldering (soldering preferred). Either way, the output of the zone 2 left or right (not both) from the amp goes to the input terminals of the transformer, and then the output of the transformer goes to the wall plate.
10 ga wire is overkill, it'll work fine if you already own it, but 14 is _plenty_ for the power you're sending to those speakers.


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## AllenS (Dec 6, 2011)

how would this take the stereo of zone two and put it into mono? by taking only the left or right from the zone 2 on the amp?


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## DeuceTrinal (May 7, 2012)

It wouldn't. Using a conventional receiver, you get right or left, not both. If you want both, you need to use an external amp and use a y cable on the zone 2 out of the receiver. Or, if the receiver has a mono mode of some sort, that would mix it for you. Many receivers do have mono modes, you'd have to check on particular models to find out how they handle that for zone 2.


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## AllenS (Dec 6, 2011)

Since the surround sound speakers are 4ohms, can i just use my Sony Home Theater DVD player and hook them up to the R&L rear speakers and then pick up a mid range 60W 70v amp?


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## DeuceTrinal (May 7, 2012)

If the "Sony Home Theater DVD player " is one of those all-in-one setups, and has speaker level outputs for rears, then the answer is _maybe_. Not all receivers/sound systems can handle 4 ohm speakers, especially cheap ones. What is the exact model of the sony system? Does it mention minimum impedance (usually 6 or 8 ohm, sometimes 4) anywhere on the back or in the book?

If your sony system has an audio out, then you can use that for signal to the 70V amp, and be able to play the same thing everywhere. Or you could get a 70V amp with built in mixer (pretty common) and just run your sources to both systems, maybe digital to the sony and analog to the 70V.


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## AllenS (Dec 6, 2011)

it is the sony dav-hd277wc and the speakers are 3 ohms


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## DeuceTrinal (May 7, 2012)

Then you should be able to hook up the in ceiling rears just fine. No telling how they will sound, some of those system-in-a-box setups have some weird eq on the outputs to compensate for cheap speakers. I've setup others that did just fine with better speakers though, so you'll just have to see. Don't crank the volume right off the bat, test first.


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## AllenS (Dec 6, 2011)

k...so i pick up the Onkyo TX-NR515 and plan on using the zone 2 for the house speakers. Just want to be sure that when I hook up the receiver to the 70v line transformer and then to the speakers, it will not burn out my brand new receiver...


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## DeuceTrinal (May 7, 2012)

It won't burn anything out if you've hooked it up properly. Start at very low volumes and work your way up, checking every room to make sure it sounds right. Even if a speaker or volume control was blown from the previous owner and shorted out, the receiver should protect itself. If you're really concerned, hook up any old radio/receiver/tv with speaker outs and test with that. 
Be aware that the NR515 is rated for 6 ohm minimum speaker impedance, so if you intend to use the 3 ohm speakers from the sony system, you risk overheating the Onkyo (not recommended). 
Have you read the wikipedia page on constant voltage speaker systems? It might help make sense of the advice I've been giving =)


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## AllenS (Dec 6, 2011)

I just realized the 6 ohm issue...should i be concerned since the speakers in the ceiling are 4 ohm? I can always return it and get a different receiver (still in box).


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## DeuceTrinal (May 7, 2012)

Yes, you should be concerned. _How _concerned is a tougher question. Will it work? Yes, definitely. At low volume it could probably run for years just fine. 
The issue is that a lower impedance speaker draws more current from the amp. If the amp can't deal with the extra heat generated, it will overheat, sometimes catastrophically. Alternatively, it's possibly to just pop a FET or other small component with a current surge, and the channel(s) just die(s). At best, the receiver will be working harder and running hotter to drive 4 ohm speakers. That may or may not kill it fast, but it will push it harder, and increase the likelihood of premature failure in some manner. Personally I'd get one rated for 4 ohms or swap the rears to run within published spec, for the warranty if nothing else. (Running 4 ohm speakers probably voids the warranty - not intended use or some such)


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## AllenS (Dec 6, 2011)

I went ahead and got 2 Boston Acoustics HSI 250 ceiling speakers, 2 Boston Acoustics A26 bookshelf speakers, and a Boston Acoustics A25C center speaker to complete the 8ohm set. Just so I understand watts...the zone 1 will be driving all of these speakers and zone two will have a 70v 100w step up transformer on it and drive 4 speakers for a total of (8+8+8+10) 34 watts. The amp is rated as follows:

Power Output	130 W/Ch (6 ohms, 1 kHz, 1% THD, 1 Channel Driven, IEC)
Dynamic Power	180 W (3 ohms Front) 165 W (4 ohms Front) 100 W (8 ohms Front) 

Does this mean that I have 130watts per channel so the cable box can drive 130w to both zone 1 and zone 2, or will it only drive 130watts to both zones, split 35watts to zone 2 and 95watts to zone 1?


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## DeuceTrinal (May 7, 2012)

Nice! A voice-matched system like that should sound better than a mis-matched one anyway, and I'm pretty partial to Boston's gear myself =)

The wattage rating (which you should *always* take with a tablespoon of salt, they are often inflated for marketing by changing the testing in various ways) is per channel, so the amp is rated for 130W x 7 channels = 910W. 

What this means is each speaker will have that much power available to it. Most of the time, it's actually using a much lower amount of power (basic tv news dialogue in a quiet room is probably <5W peak, for most systems). The power varies directly with the volume, so is constantly changing. 
So you'll have 5 channels x 130W going to your main room, and 1 channel x 130W going to your 4 zone 2 speakers (they only draw what they need, so they'll only take the 8, 8, 8, or 10 watts they are tapped at).


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## AllenS (Dec 6, 2011)

Perfect...I plan on putting in a pool next year, and was going to run some more speakers off of the zone 2...sounds like I have plenty of watts left for that!

Once I get it into setting it up, I might have a question or two...but I will reply with a final pic so all can see!

Not sure if it helps the site, but I bought stuff from Parts Express and Accessories4less...advertized on this site.


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## phreak (Aug 16, 2010)

Wouldn't you be using the zone 2 preouts to your 70v amp? The 70v amp will be supplying the wattage to those speaker, lightening the load on your AVR. It will be powering zone 1 and merely supplying a signal for zone 2.


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## AllenS (Dec 6, 2011)

I went with a 70v step up transformer rather than a 70v amp. I might consider getting a nice 70v amp down the road when i put the pool in so I am not limited by the 100w transformer or the 130w channel on the AVR.

I will run the zone two speaker (High Left I think) into the transformer and then to the speakers.


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