# Questions about building front towers



## swong46 (Feb 15, 2010)

Hey all, I come from car audio and am new to home audio. I am building front towers/shelf speakers. I have a set of car components that I want to use but they are 4 ohm.

I want to run the speakers off a home audio 5.1 receiver but I am on a budget for receivers that are 8 ohm stable. Are there any cheap 4 ohm stable receivers?

Now here is the MAIN question, can I get some 4 ohm speaker and add a crossover to it and run it in series with my other speaker making the total load 8 ohms? I will build its own chamber and what not. I just want to know if this is a bad idea or not?


Thanks!
Sheldon


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## jackfish (Dec 27, 2006)

There are many sources for speaker building information. It sounds like you need to start with something like http://www.amazon.com/Speaker-Building-201-Comprehensive-Course/dp/1882580451


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## RBTO (Jan 27, 2010)

Firstoff, check the specifications of the receiver you're using. A number of receivers are spec'd for 4 Ohm operation. If that isn't the case, yes, you _can_ run two speakers in series to total 8 Ohms, but the speakers should be similar to each other or you'll have additional complications in power handling, frequency response, etc. You can also place a 4 Ohm resistor in series with your 4 Ohm speaker to get 8 Ohms, but this is a last ditch effort since it will affect the damping of your speaker and thus affect its sound reproduction (also the 4 Ohm resistor will dissipate power that should be going to audio - this is not a good way to go).

Assuming your receiver won't handle 4 Ohms, your best choice is to get 8 Ohm drivers or a new amp that will handle the 4 Ohms. Drivers might be the lower cost option (there are exceptions), but if your receiver/amplifier is old, it might be a good time to upgrade it. There are differences between car and audiophile speaker drivers, so going to different drivers could be worthwhile as well. The final choice is yours. Check with Parts Express for driver options.


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## swong46 (Feb 15, 2010)

Any recommendations to a cheaper receiver that is 4 ohm stable?

What I wanted to do was run a small 3-4 inch that barely uses any power and run it in series. Is that bad?


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## RBTO (Jan 27, 2010)

If you have regular drivers and connect them in series with a really small driver, you may have a problem with the efficiency differences. By the time the larger driver is sounding good, the smaller one may be distorting or be driven into clipping. Usually smaller speakers have power ratings less than their larger cousins, if you feed 10Watts to the pair, each would get 5W. The standard driver would be ok but if the smaller one is rated at 1W or so (might be typical), it is fried. No problem if both are the same speaker. Each would get 5W and assuming they are audiofile quality, that would not be a problem. It depends on what you chose for your "smaller speaker".

I don't have any suggestions for a low cost, 4 Ohm capable, receiver. Again, it depends on what you mean by "cheaper". Cheaper than what? There are 4 Ohm amplifiers (not receivers) available for under $100. You'll just have to shop around and look at the specifications before buying. Go to amazon and type in "Receiver" and you'll get lots of hits for a base to start from.


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## swong46 (Feb 15, 2010)

Any 4ohm stable receivers for $300 ish?
I looked at separate amps and they seem to be mostly 8 ohm aswell...


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## RBTO (Jan 27, 2010)

I'm way out of my league here. There are a lot of Home Theater Shack folks that can better advise you as to a good sub-$300 receiver, but go here:

http://www.crutchfield.com/g_10420/Receivers.html?tp=179

Crutchfield is one of many places to shop on-line and they offer a good tech support call-in line that you can use to get additional info. The Dennon DRA-297 receiver comes in well below your top dollar number and it handles 4 Ohm speakers. There are many others. You just need to find what you want in terms of features - then look into the manufacture's specifications to see if 4 Ohm output is supported. A lot of dealers list the specs along with the receiver that's being shown, but you can always Google the item for more info.


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## swong46 (Feb 15, 2010)

Any 5.1 receivers for around 300 ish? I asked crutchfield and shopped around, and they told me the cheapest one was Onkyo TX-SR707 which is 550-600 used. I know this stuff is expensive, but I just don't have the money now


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## swong46 (Feb 15, 2010)

I found the ONKYO TX DS797 and Denon AVR 2802 to be good. I only want to run 4 ohms on the front left/right channels and I can use 8 ohm for the rest of the speakers. Are any of those 2 good?


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