Running auto Calibration - MCACC

falcon

Well, here is my system; speakers: Polk Audio LSi15, LSiC, and LSiFX. Sub, HSU VTF-3 MK 2. AVR Pioneer Elite 72TXV and Rotel RMB-1095 amp. Very happy with my setup. The process of building this system was a bit confusing, but in the end I am very happy with my choices.

Here is the question. I have run auto MCACC and the system has selected all speaker as large and sub on. In the manual for the speakers it says to select Center and surround as small, so the fronts and sub manage the base. Which recommendation is correct? If I change the speakers to small, will any of the MCACC setup be affected?

Thanks.

Frank Z

Just to make sure we're clear on this subject, the physical size has nothing to do with the Large vs. Small setting. Large vs. Small relates to the frequency response capability of the speaker it self. A full range speaker (20-20k Hz.) can be set to large and won't have any problems reproducing the signal it receives from the source. A speaker that is not rated for full range response will struggle to reproduce the lower frequencies and sound muddy. Clipping is a concern and so is damage to the speaker.
Your LSifx's and the LSiC are both rated at 40Hz - 27kHz and the Lower -3dB Limit is 52Hz. Although they do go rather deep they aren't exactly full range (large) speakers.
Setting them to small with the appropriate crossover point will put less of a load on them and allow them to handle the mid and upper frequencies with easy. You've got a sub that is designed to do one thing and one thing only, take advantage of it. Yes you'll need to run your MCACC set-up again but it will be worth it. You might want to try setting up your system with an SPL Meter as well and see which sounds better to you
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falcon

Frank just to make sure, you are suggesting for me to run it again and set the Center and surrounds to small and let the sub handle all the bass. I have to check, but I think I will have to go to advanced MCACC setup to be able to provide specifics. Will the crossover be handled by MCACC setup once I change the speaker size or will I have to specify? If I have to specify, do I specify per manual specs or something else?

Sorry, I think you should know that you are dealing with a complete newbie here. This detailed setup and terminology is pretty new to me. I have upgraded from JVC DD receiver with satellites all around. This is pretty big step for me in terms of the equipment of what the equipment can deliver.

Thanks

Frank Z

Yes you should set the center and surrounds to SMALL.
I'm not 100% sure on the MCACC features, but I believe it will automatically default to a crossover point of 80hz which is the THX standard.

Sorry, I think you should know that you are dealing with a complete newbie here.

No problem, we were all newbies at one time or another.

Download a copy of the Polk Audio Home Theater Handbook and get busy reading. There's some really great info in it and whatever is unclear can be clarified by a lot of the folks that frequent this site.

adam2434

My MCACC also sets all speakers to large with my current speakers (see my signature). In the past, it set my NHT Super Center to small (it only went down to about 85 Hz). The MCACC use some low freq criteria to set speakers to large (my guess is somewhere in the 50-60 Hz range).

On my 45TX, I don't think you can rerun the MCACC with different size settings - I'm pretty sure the MCACC will just reset them all to large based on what it's "hearing" in the test tones. You could do it manually with a meter.

I play around with the following settings, sometimes during a movie or concert to get the best out of a given soundtrack.
1) Fronts/center/surrounds all large, sub on
2) Fronts large, center and surrounds small with 50 Hz crossover, sub on
3) Fronts large, center and surrounds small with 80 Hz crossover, sub on
4) Fronts/center/surrounds all small with 80 Hz crossover, sub on

I tend to like 1) and 2) with concert DVDs and 3) and 4) with movies. With 2 ch music, I run the fronts full range with no sub, bypassing the Pioneer altogether and using a separate preamp.

I'd say play around a little and see what sounds best to you.

As a sidenote, one thing I've always been curious about is the actual bass content in the front/center/surround chs of a DVD sountrack with a LFE ch. I would think that the engineer would put all the low freqs in the LFE ch, that's what it's there for. This begs the question, "how low do my speakers really need to go to be able to produce all the freqs in a soundtrack when all speakers are set to large?". I wonder if there is a standard for this, or if the engineer can put low bass in the front/center/surrounds if he/she so chooses.
It would be cool if someone actually measured what bass is in the front/center/surrounds of typical DVD soundtracks. This kind of info could really be helpful for speaker size purchase decisions and crossover settings for systems that are primarily HT geared.

Adam

mantis

Allow the MCACC to decide which setting is correct. It measures the speakers and sets the crossover correctly.

A Rotel amp with a Pioneer Elite receiver as a Preamp. I can see why you would want to use it over the rsp1068 as it's about featureless and alittle behind the times now.Pioneer has been doing a killer job over the years and this year is no different.

Dan