my Sierra-1 et al story

[GirgleMirt]

Wow crazy! Nice pic and setup!!!

Nice that four speakers retain the 8 ohms What is it, 2 parallel speakers in parallel?

Could you do 3 series of 3 in parallel for a tower of 9 speakers at 8 ohms? At less than 10000$ for a pair, who wouldn't do it! Though maybe you'd get a volume discount at that price! hehehe

[Eddie Horton]

Dave F., I'd like to hear what you think of this setup. Have you, yourself tried it? What are it's strengths and weaknesses, etc.?

[jvillas]

I think the hook-up is in series,rather than parallel. As far as I know that is how to keep the 8 ohm rating. If I am correct there is a drop in voltage.

I am delighted to see a stacked configuration. Awesome!

I run my speakers stacked (parallel hook-up) in both my 2 channel setups.
Never tried a triple or a quad set-up. Though I have heard triple Large Advents years ago.

Running Stacked for me thats the way to go.

[Mia & Lana's dad]

Here's my in room FR for each channel as measured and calibrated by Audyssey MultEQ XT. It is averaged from 8 positions. Despite Integra's implementation not allowing for a "flat" curve. To me, the high frequency roll off seen here does not impact the HT experience. For music, I used to listen exclusively in Direct mode for SACD/DVD-A. With the new front stage, Audyssey finally sounds better for music when using a THX mode that does not roll off the top end.

Dave knows what it sounds like because he ran the full gamut of tests and measurements to determine its feasibility and wouldn't let these out if it didn't pass his stringent standard of quality and performance. For me, there was no gamble - I trust Dave. He said it would be incredible. I am finding out that he was speaking conservatively.

[Mia & Lana's dad]

I hope Dave will chime in, but here's something I held back and did not include with the hints dropped last week:

4 horizontally stacked Sierra-1 proved to be quite impressive. They must be wired up in a specific manner to maintain impedance, but this is simple. In fact, to my surprise, nothing about their performance is compromised but you gain lower distortion, greatly increased dynamic capabilities and all the output that even you could want

As you can see, if I copied and pasted that word for word - there would not have been the great reveal and the ensuing dénouement which make forums so much fun.

[GirgleMirt]

I think the hook-up is in series,rather than parallel. As far as I know that is how to keep the 8 ohm rating.

Well 8 ohms rating of the Sierra is the impedance rating. wikipedia says:

The total impedance of any network of components can be calculated using the rules for combining impedances in series and parallel. The rules are identical to those used for combining resistances, although they require some familiarity with complex numbers."

So series should get added: 2 sierras in series would give 16 ohms, four 32 ohms. 4 ohms drivers are usually used for MTM speakers, in series, which results in the normal 8 ohms impedance. So to get 8 ohm should be 2 parallel speakers in parallel.

Anyway I'm never wired so many speakers together so am not totally sure if it would be the way, I'm also curious if the 9 speaker solution would be doable, or if something (crossovers?) wouldn't make it work...

[davef]

Hi Guys,

The wiring was simple --

It is series-parallel. Each pair of the stack are wired in series, thus creating 2 16 ohm loads. The two 16 ohm loads were then wired in parallel, creating an 8 ohm load.

Ron, your measurements look good, lots of room gain down low but Audyssey cleared that right up. The high-frequency roll-off that you see might be the cinema-EQ or even the microphone. What mic are you using?

What is interesting about the measurements is that the frequency response closely matches the single speaker measurements before Audyssey, which is a good thing. In addition, notice the dip on the single speakers (surrounds) at the 180Hz range -- this is floor bounce. With the stack, that dip is eliminated due to the having much tighter vertical dispersion (greatly reduced floor and ceiling bounce)

I will say, I am very impressed at the improvements the MultiEQ XT made to the subwoofer response. With regard to what I mentioned in the subwoofer thread -- this is the proper way to handle auto subwoofer room EQ.

In a room like Ron's and to meet his demands for output and impact, this was a very good solution!

[Mia & Lana's dad]

That's it right there, just hook everything up into the pre/pro, laptop and presto.

I had dialog with lead Audyssey Installer Services Supervisor as well as Chris Kyriakakis, Audyssey CTO - the high frequency roll off is definitely their defacto target curve tailored for HT/Movies, Cinema EQ on the nose. Not the mike. They tell me the unit supplied along with its calibrated preamp works like the $2500.00 Behringer.

[davef]

I had dialog with lead Audyssey Installer Services Supervisor as well as Chris Kyriakakis, Audyssey CTO - the high frequency roll off is definitely their defacto target curve tailored for HT/Movies, Cinema EQ on the nose.

Interesting, is there any way to bypass that option or input your own target curve? I am impressed with the results, but I don't like the idea of someone else telling me that I need to listen to my speakers with a high frequency roll-off. Personally, I find cinema-EQ a bit annoying -- I am not looking for reproduction that sounds the same as a theater, I want realism and accuracy all the way.

[Mia & Lana's dad]

There are three target curves to select from, I presume all Cinema EQ high frequency roll off:

Target 1 - small to medium (least amount of roll off

Target 2 - medium to large

Target 3 - Approximates 500 seat theater

Unfortunately one cannot tailor their preferred response for the time being.

The THX modes restore the top end but it isnt available for 2 channel without applying processing. I like THX Games with PLIIx for regular CD's.