how much space plus the 705 or 805

[mailman23]

I am considering an onkyo 705 or 805. Later(6 months to a year) I plan to add a multi channel amp.First, is the 805 worth paying the extra $250.00, and second, how much space should be given for the receiver to cool. I have a sony sxrd stand that is open in the front and the back, but only gives 3/4'' of clearance above.The 705 is a little smaller, with about 1/2'' more space. If this space is not efficient I may have to buy a new a/v rack which would destroy my budget with the wife.

 

[Nomo]

The new Onkyos reportedly run pretty hot, as does my Yamaha. Ideally you should have at least 4 inches above for ventilation. As an alternative you could install a small fan to supplement the lack of space.
I can't comment on the 805 over the 705 other than to say they are both fine receivers.

 

[MDS]

The manuals for the 705 and 805 suggest 4 inches on both sides and the back and 8 inches above. That's a pretty tough requirement to meet unless you are using a wide open audio rack.

1/2 to 1 inch clearance on top is probably not sufficient.

 

[Rickster71]

Can you somehow move the shelves?
If not, can you make new shelf supports that would allow you to move shelves?
With so little clearance, I don't think a fan would be as effective as it could be.
Sounds like you need a new rack.

 

[mailman23]

yep, i guess I'm getting a new rack. What a shame! Now to the other question. The 705 or 805?

 

[sh0]

I have the 805 so my experience is only the with that. So far I've been happy with it.

When I was researching, it seemed that the biggest difference was the THX certifications resulting in the 805 having a better amp section. Supposedly the 805 also has better DACs and I believe it also has one more optical input and better multi-zone options.

One other difference that I never confirmed: In the 705 manual, it appears that the manual speaker level adjustments are only in 1 db increments. The 805 can be adjusted in 0.5 db increments. The manual may not be correct though and I didn't confirm the information on the 705.

Regarding the certifications, the 805 is THX Ultra2 while the 705 is THX Select2. There's an article here on AH discussing THX Ultra2 but it is comparing it to THX Select (not Select2) so I'm not sure the comparison is relevant. The information on THX Ultra2 could still be useful.
THX Select and THX Ultra2 Certification General Questions

The AVS Forums are a good place to look too. There are threads on both the 705 and 805 that discuss differences in the models. That's where I did most of my research.