Hello all,

New to the board here. I have a 950/770 combination, and am looking to complete building my HT. I have Snell E IV speakers as my fronts and was looking to replace them with Onix Reference speakers (and add a center, rear etc.). The Reference 2 speakers have a 4ohm impedance. Any possible issues to be concerned with?

Thanks,
Vik

1) For cooling, make sure your 770 can breathe easily with plenty of unrestricted space for air entry and exit.

2) Make sure your speaker cable runs to the four-ohm loads are as low in resistance as is reasonably possible.

3) Prepare your room for an available, clean 300W per 4-ohm loaded channel!

[This message has been edited by bestbang4thebuck (edited June 03, 2004).]

I'd say bestbang pretty well summed it up. Item 1 (ventilation for the 770) is of course true with any speaker load, although a bit moreso with a more difficult load like a 4ohm speaker. Proper breathing room for the amp, reasonable speaker wire, and you should be good to go.

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gonk -- 950 Review | LFM-1 Review | Pre/Pro Comparison Chart | Saloon Links

Thanks guys for your quick responses. Any recommended speaker cable. I am currently using the original Monster cable (about 8 years old).

Thanks,
Vik

I have the same same set up you are looking at, except I have Ref 1's all around. With the 950/770 and it sounds great for HT and multi channel music but to me its lacking in 2 channel. I am currently looking for a way to upgrade the 2 channel. I use Onix SP-200 for my speaker wire. If you want to check out my gallery its on the AV123.com forum under the same name.

There have been many thoughts shared on interconnects and speaker cable elsewhere in this forum and in other forums. A lot of debate occurs regarding the advantages of different means to overcome various problems, most of which are minor in the large scheme of things. I think the main point for speaker cables, beyond safety, reliability and proper installation ("Will these things short out?") is resistance. To a much lessor degree come considerations of capacitance, inductance, skin effect, oxidation, etc. But back to resistance ...

If you can glean useful information from wire resistance and gauge tables, I would pick a wire or combination of wires that allow 0.2-ohms or less round-trip for 8-ohm loads, and 0.1-ohms or less round-trip for 4-ohm loads.

See: http://www.epanorama.net/documents/wiring/wire_resistance.html

The 0.2 and 0.1 numbers are my preference and not entirely arbitrary. I did a graph showing a calculation of watts delivered for various wire resistances and speaker loads. I also did calculations of the reduction in amplifier damping (the amplifier’s ability to maintain control over the motion of the loudspeaker’s voice coil) based on the introduction of resistance between the voice coil and the amplifier. The lines of the graph fell off sharply (bad news, in my opinion) if one went much beyond twice the numbers I just recommended.

Loudspeakers near the amplifier pose a smaller problem because the cable round-trip length is not very long.

Slightly off topic, and discussed elsewhere: the passive crossovers found in most loudspeaker systems introduce some non-linear impedance between the voice coil and the amplifier. While the problems introduced by passive crossovers may outweigh most speaker cable issues (why some gunslingers advocate active crossovers prior to bi- or tri- amplification), having a low resistance connection between amplifier and crossover will help the crossover ‘behave’ in the best manner possible for most crossover networks.

---------- Edit ----------

A quick way to use one of the tables presented at the link I posted above:

A table almost halfway down is labeled, “Copper wire resistance table.” Just below the table, the first sentence reads, “These Ohms / Distance figures are for a round trip circuit.”

Looking at the 14-gauge section and rounding off, we can see that a 190-foot cable length between supply and load would introduce about 1 ohm of resistance. So, in order to maintain 0.1-ohms or less using 14-gauge wire, the cable length between supply and load should be 19 feet or less. 16-guage limits the 0.1-ohm length to 12 feet and 12-gauge extends the 0.1-ohm length to 30 feet.

Because most people are more concerned with the best power and control for their main and center speakers, locating the amplifier(s) near the front of the viewing area works out. Having longer cable runs to the side and rear surround speakers means either running parallel cables, heavier gauge cables or accepting just a little less ‘control’ of the surrounds.

I recently helped a friend install a moderate system in their home. I found a reasonably good deal on a 250-foot roll of 12-gauge speaker wire at a large home improvement franchise store.



[This message has been edited by bestbang4thebuck (edited June 03, 2004).]

bestbang4thebuck,

Thanks you for the information. Luckily my front/center runs will be very small - less than 6 ft/per speaker.

Jed,

If you do not mind me asking what did you not like musically about your Ref 1's?

Thanks,
Vik

Sorry, I didn't mean for it to come off like that. I absolutely love the Ref's for music, even more than for HT. I feel the 950 is a great processor for HT, but I feel its shortcoming is how it sounds musically, but the 950's DAC's have been subject to debate in the past. Some people think the 950 is excellent for music and I am no expert, but to me its a bit bright and hollow. Right now I use bypass with my dvd player because that gives me a better, fuller sound IMO. So right now I am looking for a new CD player or maybe something like the P-3A to get more out of my 2 channel experience.

I would say the Ref's are the best decision I have made in a long time. I plan on upgrading to the Ref 2's sometime in the front to improve the HT fullness but I'm still debating if I should hold out for Ref 3's.

[This message has been edited by Jed M (edited June 03, 2004).]

Wait, so we need to take the distance from the amp to the speaker and double it? They count the pos and neg portions of the wire?

Jed,

I felt the same way about the 950 when I first listened to music through it. However over time with some patient tuning, speaker positioning it does sound much better. I recently moved from a Pioneer 525 dvd player to a Denon 2900, and I thing the sound is much improved. There is a difference in bypass v/s using the 950's onboard DAC, but not as much as I experienced with the Pioneer.

But I digress from the original reason for starting the thread.

Thanks all for you help.

Regards,
Vik

JT:

If your speaker cable is 50 feet long, the signal travels 100 feet to make the round trip. If the gauge of the wire is 10 AWG and has a resistance of 1 ohm per 1000 feet, the 100 foot round trip gives a resistance of 0.1 ohm.

In the table I referred to, the round trip resistance is given, so those particular resistance values do not need to be doubled when considering the amp-to-speaker cable run. If you were to read resistance values from a table that did not already take into account the round-trip, then a 50 foot cable run would involve calculating for 100 feet of the conductor.

I have a 7 speaker setup all maggies MMG MMG-C MMG-W(2pr). I just ordered the 950 how will these match with 770?

Just fine.