4 ohm verses 8 ohm??

[deldest]

Well I've got a basic (htib) Sony home theater reciever (SON HTDDW670)that came with several small speakers rated at 4 ohms and some very micro thin wire.

I had wanted to upgrade the speakers (and wire?) but was a little uncertain with the ohm ratings. I have an old (much larger center channel) speaker that I hooked up and it does sound much better than the cheesy little one supplied, it is rated at 6 ohms. I also checked one 8 ohm larger speaker and it also sounded decent (I'm assuming because of the larger cone sizes and better quality).

I believe I understand the basics of resistance, with an 8 ohm speaker (vs. 4) doubling the resistance, thereby cutting the watts in half. And I understand why car sterios always run 2-4 ohm speakers as there is limited voltage, But I have never really understood why with the available voltage in a home, these systems would drop resistance/ohms (maybe just an advertising ploy to say their reciever is 600watts??). Anyways I 'think' I know the effects of running car speakers (2-4 ohm) in your average 8 ohm home reciever - clipping of high/low, distortion, and possible amp overheating. But what would be the effects of running a 6 or 8 ohm speaker on a home reciever that (I'm assuming) was designed for 4 ohm???

I really don't care about a numbers game, so if the amp will now only put out 300 watts, who cares, if it hasn't lost any significant max (db?) volume, especially if the sound was cleaner (no clipping). I would like to get a nice set of speakers, and need to know what my shopping options are. I have heard that people can run with mixed ohm ratings and then tune/balance the volumes via the reciever, but is this just a bad idea, or a common way to get best sound? I think I would/should get a matched set since I would be purchasing pieces. The only speaker I might be looking to keep/use would be that 6 ohm center. Would your 'normal' 8 ohm home speakers work ok??

PS. I'm also assuming this cheesy micro speakerwire came with it to reduce resistance as well, And I'm assuming that I should replace with much thicker for better sound quality (maybe someone could confirm), would this also play a part in what speakers (ohm resistance) to run, as this may contribute more resistance as well??

 

[soniceuphoria]

I'm assuming that your HTIB is a 6.1 system. If that is the case and it is rated at 600 watts then it is probably 100 watts per channel. If the speakers are 4 ohms that came with it and you are going to use 8 ohm speakers, the only difference you will notice is a lower max volume (headroom) as opposed to the original 4 ohm cubes. The only problem that you might come across is that using a 6 ohm and 8 ohm speakers together (mattering on their sensitivity) you might have volume level matching problems. This might make your center channel more dominant than your mains. If you notice a major difference between the original speakers and their replacements then I would use the ones that sound best to you. After all you are the one who it really matters to. I would also suggest replacing your speaker wire also, because the wire that comes with those HTIB systems are inadequate at best. May I also suggest that in the future that you upgrade to a real reciever, I think that you would be a lot more happy with the power and flexability. I hope that everything works out for you. Happy Listening.
Greg

 

[3db]

Hope this helps

Well I've got a basic (htib) Sony home theater reciever (SON HTDDW670)that came with several small speakers rated at 4 ohms and some very micro thin wire.

I had wanted to upgrade the speakers (and wire?) but was a little uncertain with the ohm ratings. I have an old (much larger center channel) speaker that I hooked up and it does sound much better than the cheesy little one supplied, it is rated at 6 ohms. I also checked one 8 ohm larger speaker and it also sounded decent (I'm assuming because of the larger cone sizes and better quality).

I believe I understand the basics of resistance, with an 8 ohm speaker (vs. 4) doubling the resistance, thereby cutting the watts in half. And I understand why car sterios always run 2-4 ohm speakers as there is limited voltage, But I have never really understood why with the available voltage in a home, these systems would drop resistance/ohms (maybe just an advertising ploy to say their reciever is 600watts??). Anyways I 'think' I know the effects of running car speakers (2-4 ohm) in your average 8 ohm home reciever - clipping of high/low, distortion, and possible amp overheating. But what would be the effects of running a 6 or 8 ohm speaker on a home reciever that (I'm assuming) was designed for 4 ohm???

I really don't care about a numbers game, so if the amp will now only put out 300 watts, who cares, if it hasn't lost any significant max (db?) volume, especially if the sound was cleaner (no clipping). I would like to get a nice set of speakers, and need to know what my shopping options are. I have heard that people can run with mixed ohm ratings and then tune/balance the volumes via the reciever, but is this just a bad idea, or a common way to get best sound? I think I would/should get a matched set since I would be purchasing pieces. The only speaker I might be looking to keep/use would be that 6 ohm center. Would your 'normal' 8 ohm home speakers work ok??

PS. I'm also assuming this cheesy micro speakerwire came with it to reduce resistance as well, And I'm assuming that I should replace with much thicker for better sound quality (maybe someone could confirm), would this also play a part in what speakers (ohm resistance) to run, as this may contribute more resistance as well??

The loudness level is more a function of the speaker's senstivity than the ohm ratings. If the impedance (resistance applies only to DC) of the speaker is too low, it may cause a huge current draw on the amp/recievier which would trip its protecttve mechanism if so equipped and temporarily shutdown the receiver. Your receiver would have actually have an easier time trying to drive a higher impedance speaker than a lower one.

The skinnier the speaker wire, the higher the resistance, the thicker the speaker wire, the lower the resistance. Its an inverse relationship but it makes sense. The thicker the wire, the more copper you have available to conduct the current with. Think of a garden hose analogy. The bigger the hose, th emore water can run thru it.

 

[j_garcia]

The only problem that you might come across is that using a 6 ohm and 8 ohm speakers together (mattering on their sensitivity) you might have volume level matching problems. This might make your center channel more dominant than your mains.

Impedance has nothing to do with the level the speaker plays at, only the amount of current it will draw to achieve that level. So matching impdance between speakers is sort of a non-issue.

With the HTiB, the problem isn't how much current your home has, but how much the receiver can actually deliver to the speakers. An 8 Ohm speaker of similar size and specs will be easier for the receiver to drive. Most likely the HTiB receiver wasn't designed to use a 4 Ohm speaker, they just used one that doesn't draw a lot of current and they used the lower impedance to up the output of the receiver for those channels.

 

[jcPanny]

Speaker Wire

Get the largest gauge wire that the connections (probably speaker clips) on the back of your HTIB will accomidate. 12 gauge or 14 gauge will work well, but I would only bother buying wire for speakers that you upgrade.

It is normal to adjust the volume level and distance setting for each speaker. These volume settings can very greatly depending on the efficency of the speakers and the adjusts allow for an even front and rear sound stage.
In car audio, the Front/Rear and Left/Right adjustments do the same thing.

 

[deldest]

Thanks guys for all the replies....

I do plan on upgrading to a better reciever eventually, and was hoping to be able to get a decent set of speakers (or two) now, and work my way up. It sounds like I can go 6 or 8 ohm with little problems (aside from proper sound leveling which would be done anyway). If the only issue is 'headroom' or max volume I think I will be ok (the 6 ohm actually sounded louder to me), I'm thinking the better speakers may have an easier time making the sound. And when I upgrade the wiring too, I'm hoping/guessing this might help offset any real loss of headroom.
I did have another other question. This is for a dedicated basement theatre room, but the room does open to other areas (bar and pool table well rear and left/right). I will be keeping the (5.1 for now, hopefully better later)speaker arrangement appropriate for the theatre seating area, but was thinking of possibly using these cheap sony 4 ohm speakers as sattelites for the other two areas (for parties and such when movie surround is not really important). Is this reasonable, and what would be the proper way to connect them??
I was thinking of tapping into the left and right fronts (w/add switch and in series or parallel?) as I think this is what the reciever drives when in sterio mode. Is this correct or should I just run any extra off the center (or even rears)?
I'm thinking one speaker in either area would be enough for ambient sound, but as I may have extra lying around, if I went four (two each other room) would it be appropriate to run two (each) in series (then match the 8 ohms)? Am I even being "reasonable", or would I just be better off adding a second (straight sterio) reciever and splitting the input, driving two sets seperately with the same input (or would this create synch issues)??

Thanks in advance.

 

[j_garcia]

If this receiver doesn't support a second "zone" or have an A/B switch for a second set of speakers, then it can get a little tricky. I would wire series, as parallel will probably overload the receiver due to even lower impedance by combining the speakers. I would also keep the number of speakers on any given amp channel to a minimum when wiring this way. When you do upgrade your receiver, look for one that has a Zone 2 output, which will be ideal for what you are talking about doing.

Check that 12ga fits first, because it generally does not fit in to the spring clip type connections. 14 should fit in most and should be plenty for just about any HT.

 

[deldest]

If this receiver doesn't support a second "zone" or have an A/B switch for a second set of speakers, then it can get a little tricky. I would wire series, as parallel will probably overload the receiver due to even lower impedance by combining the speakers. I would also keep the number of speakers on any given amp channel to a minimum when wiring this way. When you do upgrade your receiver, look for one that has a Zone 2 output, which will be ideal for what you are talking about doing.

Check that 12ga fits first, because it generally does not fit in to the spring clip type connections. 14 should fit in most and should be plenty for just about any HT.

So realisticaly, it might be better at this point to just use a second reciever than to try to tap extra speakers in? That may make upgrading the reciver higher on the priority list. I could always resign the Sony reciever to the secondary/ambient role. It don't know if it will drive much more, and at least then it would drive the speakers it came with.
As far as speaker wire, I understand that thicker/lower guage is generally always better, but would 16ga be ok? Last time I was at the store the were trying to sell 18ga, so I bought some 16 (thinking It was better than what they were selling) and have some left over.

 

[j_garcia]

Not sure why they would push 18 ga as it is too small for the typical HT. 16 will work for shorter runs (should be fine for your main speakers), but if you have anything over 50', it'll be easier to go with 14 or 12 everywhere and buy in bulk.

Current 7.1 receivers can generally power a second set of speakers in zone 2 and still allow you to use 5.1 in the main area, and also play two different sources in each of those zones if one so chooses. They can typically also send a line level (RCA) signal to another amp/receiver to power the second zone as well. I think the idea of using the HTiB as the second zone is a great idea.

 

[deldest]

Not sure why they would push 18 ga as it is too small for the typical HT. 16 will work for shorter runs (should be fine for your main speakers), but if you have anything over 50', it'll be easier to go with 14 or 12 everywhere and buy in bulk.

Current 7.1 receivers can generally power a second set of speakers in zone 2 and still allow you to use 5.1 in the main area, and also play two different sources in each of those zones if one so chooses. They can typically also send a line level (RCA) signal to another amp/receiver to power the second zone as well. I think the idea of using the HTiB as the second zone is a great idea.

My equipment closet IS centrally located, so I think my speaker runs should not exceed 30-40 (theatre runs should be about 25), but still maybe I will check out some 'bulk 14ga'. know any reasonable price/quality places?

As far as the 7.1, your description sounds GREAT, and seems to fit perfect for what I'm looking to do (and I thought 7.1 was just extra rears, DOH!). Is that description for most/all the 7.1 recievers, or just the most expensive ones?? Maybe I will have to start a new thread (and start shopping) on a nice reasonable 7.1 system, but feel free to make any suggestions here. The idea of running split sound (not mono/sterio) in my secondary areas does seem appealing.

 

[j_garcia]

I can't say all 7.1 receivers can power both zones, but all receivers that have zone 2 capability (regardless of the number of channels) will have preamp outputs for zone 2. Something to be aware of, when using a zone 2 from the primary receiver, zone 2 will be stereo only, and is usually for analog inputs only as well; meaning a DVD or CD player connected via digital will not work for zone 2 even in stereo mode.

7.1 does apply to the use of 7 speakers in the main system, but the ability to use 5.1 in the main room and have the extra channels used to power another zone is sort of a side benefit that can be very useful when another amp/receiver isn't an affordable option. Now, when using the preamp outputs, that means you can run the separately powered speakers in zone 2 AND still have 7.1 in the main room, since the channels are not being used to power the other zone. Another benefit of "zones" is that you can listen to two different sources such as DVD in the main area and CD in zone 2 (like a patio), at the same time.

www.partexpress.com has bulk wire for decent prices, in both in-wall (UL/CL-3 rated) and standard speaker wire. There's another place that gets recommended here often, but I haven't used them and I can't recall the name off hand.