I need help with building a 7.1 system! (1 Viewer)

[Langotriel]

Right so.. what amplifier do i get ? i need one that feeds 150-200 W at 4ohms and double that at 2 ohms (because the centre speaker will be double the parts)

 

[schan1269]

Why are you running the center parallel instead of series...

And why two centers in the first place?

 

[Langotriel]

Why are you running the center parallel instead of series...

And why two centers in the first place?

All centre speakers i see are bigger and has more drivers than the other speakers.. it has to cover more area so it makes sense to me you gotta remember these rows will be about 18 - 21 feet wide there is a significant space in the middle. If it isn't necessary, why is it always done?

 

[Dougofthenorth]

All centre speakers i see are bigger and has more drivers than the other speakers.. it has to cover more area so it makes sense to me you gotta remember these rows will be about 18 - 21 feet wide there is a significant space in the middle. If it isn't necessary, why is it always done?

When the L&R mains are set up with the center speaker & then EQ'd the 3 work together to produce a VERY wide front soundstage image. Rather than 2 front centers, I would custom make a wider center speakers with 2 opposing woofers (1 on each end) & 1 tweeter in the center top area - match exactly the tweeter & woofers in that with those in the L&R mains.
I had better luck with 2 centers being used in a 6.1 than using 2 at the front as centers

My 3 front speakers are in a 17' wide room 20' deep. all rears are 7' behind listeners ~7 1/2' up, slight downwards position.

 

[schan1269]

I think he's confusing the typical MTM arrangement as "bigger and more drivers"(compared to what, I have no idea).

BIC V830 mains. 3 way, 8" woofer. Center is a DV62clrs, same tweeter, one 6" woofer and a 6" passive radiator.
DCM TF600 mains 2 way with(been awhile since I saw them sockless) 3 tweeters and 1 woofer. Center SurroundScape is 1 tweeter and one woofer(done coaxial).
Polk S6, 2 way with a 6 1/2" woofer and 6 1/2" passive radiator. Center is one tweeter and one woofer.

So...at my house...none of my centers even equal the mains in "driver count".

 

[Langotriel]

Alright so.. what amp will i need? and what exactly should i do with the centre?

 

[Dougofthenorth]

Alright so.. what amp will i need? and what exactly should i do with the centre?

Amp - figure out your loads & go from there
- I answered that in http://www.hometheaterforum.com/topic/329849-i-need-help-with-building-a-71-system/#entry4054003
Yam has a excellent 9.2 (expandable), & 11.2 solutions in various choices & prices with tweakable auto room EQ & many DSP settings

center - use 1 tweeter & 1 woofer or 1 tweeter & 2 woofers it seems many good makers use multiple & many use single, some recommend same as the L&R mains.

 

[Dave Moritz]

I agree that there really is no need to double up on speakers and building them is another story. While mids and tweeters are not effected by the size of the box the woofer and subs are. You could take 10 woofers and put them in the same enclosure but there is a good bet they will sound different. Are you prepared to do a lot of experimenting? Most customers are not willing to wait for someone to play around with speakers till they get it right. This is also getting the right size drivers for the room matched with enough power to fill the room with sound and get it loud enough for the customer. You may want to seriously rethink custom built speakers and buying some from a repeatable speaker company.

There is also alot to tuning the room after the speakers are placed and making sure the subwoofers are correctly placed. One thing some people never think of is that a room tuned with no people in the seats sounds alot different once you get all the seats with people in them.

I have owned Yamaha in the past and they do have good sounding receivers but IHMO they have been passed up with other companies using Audyssey. I would also look at Denon and Marantz and maybe Integra and look at some Yamaha's but the Yamaha is not THX rated and I am not sure if they ever where. You may want to consider a receiver and a power amp combo to give you the power to push all the speakers. I would at least use a 3 channel power amp to power the left, center and right speakers since they will be the most demanding compared to the rest of the speakers. $10,000 may seem like alot but it doesn't take long before that budget is chewed up.

 

[Langotriel]

I agree that there really is no need to double up on speakers and building them is another story. While mids and tweeters are not effected by the size of the box the woofer and subs are. You could take 10 woofers and put them in the same enclosure but there is a good bet they will sound different. Are you prepared to do a lot of experimenting? Most customers are not willing to wait for someone to play around with speakers till they get it right. This is also getting the right size drivers for the room matched with enough power to fill the room with sound and get it loud enough for the customer. You may want to seriously rethink custom built speakers and buying some from a repeatable speaker company.

There is also alot to tuning the room after the speakers are placed and making sure the subwoofers are correctly placed. One thing some people never think of is that a room tuned with no people in the seats sounds alot different once you get all the seats with people in them.

I have owned Yamaha in the past and they do have good sounding receivers but IHMO they have been passed up with other companies using Audyssey. I would also look at Denon and Marantz and maybe Integra and look at some Yamaha's but the Yamaha is not THX rated and I am not sure if they ever where. You may want to consider a receiver and a power amp combo to give you the power to push all the speakers. I would at least use a 3 channel power amp to power the left, center and right speakers since they will be the most demanding compared to the rest of the speakers. $10,000 may seem like alot but it doesn't take long before that budget is chewed up.

Well... many things have been cleared up.I found a design for the 7 speakers to around AND i am going with dual THT sub boxes.. Can you recommend any specific receivers that can match the A3030? that is the one i am currently considering..And they are not customers.. more like friends.. and i am in charge of the design of everything in the theatre fun fun..

 

[Dougofthenorth]

FACT: Yamaha has been making THX certified AVRs for many many, years - even prior to 2006
- I don't know why anyone would say anything differently ?? - Just Google it for proof

They were also the 1st to provide a THX Ultra2 Plus certified AVR in the Rx-Z11 - as well as other THX modes

The A3030 also has newer THX selections (as well as many of Yam's higher end AVRs) - see the manual or YAM & THX web site

It will do just fine for your application

You will probably find Yam's DSP sound modes work wonderful in your proposed theatre - especially some of the many DSP Cinema Modes - for non 5.1 & up surround formats (IE stereo movies, CDs & TV watching

As for EQ choices - Audyssey, MCACC, YPAO (& others)
- they all seem to need tweaking anyway, after running their auto-setup....

Glad you are making headway

 

[schan1269]

The only area Yamaha is falling behind is...Width.MCACC and Audyssey both have it. Not sure about Sony(and whatever theirs is called...I always forget). NAD nor Anthem have width either.That will probably change once DTS Neo X becomes more prevalent. I can just imagine DTS Neo X w/ rear presence(following along, that would be 13.1).

 

[Dave Moritz]

Sony's room correction and sound fields IMHO are horrid and I personally will not own a Sony reciever, not even an ES!

Previously owned Sony gear, plus my previous HDTV was a Sony Wega rear projection! So not a Sony hater by any means.

Also I may have upgrade my old Yamaha RX-V995 but I still have it and am going to use it for my pc.

http://usa.denon.com/us/product/pages/productdetail.aspx?pcatid=avsolutions(denonna)&catalog=denonna_us&catid=avreceivers(denonna)&pid=avr4520ci(denonna)

http://us.marantz.com/us/Products/Pages/ProductDetails.aspx?CatId=AVReceivers&SubCatId=&ProductId=SR7008

http://www.arcam.co.uk/products,fmj,av-amplifiers,avr750.htm

http://www.rotel.com/NA/products/ProductDetails.htm?Id=502

http://usa.yamaha.com/products/audio-visual/aventage/cx-a5000_black_u/

 

[Dougofthenorth]

The only area Yamaha is falling behind is... Width. MCACC and Audyssey both have it. Not sure about Sony(and whatever theirs is called...I always forget). NAD nor Anthem have width either. That will probably change once DTS Neo X becomes more prevalent. I can just imagine DTS Neo X w/ rear presence(following along, that would be 13.1).

I don't understand why you say this, as the Yam 9. & 11. configs using their YPAO EQing allow for saving multi-positional seating position settings for both width & depth. When used with proper speaker height & width arrangements (& types), handle those issues remarkably.

See http://www.avsforum.com/t/1191582/dpl-iix-thx-select-2-cinema-listening-experience/50_50
for a rather extensive & informative discussion on this...
Beyond that, the Yam DSP choices further the capabilities.

And of course any auto-EQing usually needs tweaking anyway.
The higher end Yam AVRs like the A3030, certainly have extensive OSD menus in that regard.

 

[schan1269]

I don't understand why you say this, as the Yam 9. & 11. configs using their YPAO EQing allow for saving multi-positional seating position settings for both width & depth. When used with proper speaker height & width arrangements (& types), handle those issues remarkably.See http://www.avsforum.com/t/1191582/dpl-iix-thx-select-2-cinema-listening-experience/50_50for a rather extensive & informative discussion on this... Beyond that, the Yam DSP choices further the capabilities.And of course any auto-EQing usually needs tweaking anyway.The higher end Yam AVRs like the A3030, certainly have extensive OSD menus in that regard.

Apparently you don't have the slightest idea what...Audyssey DSX widthOrMCACC widthAre.Those have absolutely nothing, at all, to do with you counter explanation.

 

[Dougofthenorth]

Apparently you don't have the slightest idea what... Audyssey DSX width Or MCACC width Are. Those have absolutely nothing, at all, to do with you counter explanation.

Well, Apparently you don't have the slightest idea what...I know or do not know
& that the A3030's YPAO & custom tweaking can provide that in several ways, other than having dedicated
width speakers, as clearly explained in the linked discussion.
If there is no problem with that, or prevalent need for that, then I don't see that as "falling behind", in something that they feel is not needed - at this stage ...

It wasn't a "counter explanation" - I was merely providing the OP with useful information, further to his preferred choice of the A3030

 

[schan1269]

And numerous "powers that be" in the audio world have said...Width is more immersive than height(which I don't adhere to that thought).So, Yamaha not having width puts them behind those that would prefer width...or DTS Neo X.Hence why I said...Imagine if Yamaha added DTS Neo X to rear Presence. I'd be first in line.

 

[Dougofthenorth]

And numerous "powers that be" in the audio world have said... Width is more immersive than height(which I don't adhere to that thought). So, Yamaha not having width puts them behind those that would prefer width...or DTS Neo X. Hence why I said... Imagine if Yamaha added DTS Neo X to rear Presence. I'd be first in line.

Or as you previously stated 13.1 or 13."X"

Widths & heights - go for all extra 6 speaker options

However, you have the enviable position of having an extremely large area.
Heck, you could do the 22.2 (Hamasaki 22.2) with all that room.
Not to mention a hybrid multiple speaker Circle Surround system.
- Which toured at exhibitions in North America, years back in a dome with a 360 degree screen
- a lot of viewers got vertigo though - including me!

90%+ of normal folks - would have a hard time finding space for the floor standing width speakers.

Mind you, media for other than 7.1 (still scarce - getting better) & below is all that is practical for most...
I think Expendables 2 was "optimized" for Neo X - not really discreet & needed a Neo X decoder compatible AVR

But, as R. Dressler & T. Holman "agreed" to (sarcastically), in a discussion several years back
in response to a statement of; 'an infinite number of speakers in an infinite number of positions'

 

[Langotriel]

I am starting to realize that 7 of the speakers that I plan to build might not be loud enough.. Even if we build the room a little smaller and rearrange the seats. However if we DO change things up a little and build 9, Then that's all good right? the A3030 does power 9 channels with 230W at 4ohms (at least that is what it says on the European versions.. no mention of it on the US one)So? 9 actual speakers being fed about 200W each plus 2 THT subs being fed 200 each as well (at least i am told that is enough to pulverize people in the room.. lol )That is a combined 2200W .. That should fill the room nicely? EDIT: Added some pictures that I made in Sketch up quickly. It is kinda sorta maybe to scale . The screen is around 160 inches and is a 2.35:1 screen. I only added the subs and the front and center speakers. Maybe this helps visualize what i am going for. The steps have no seats but are there for reference. 4 rows, 7 seats each. 28 seats total should fit there.So imagine 9 of those speakers around that size room.. plus 2 very loud subwoofers... Yes? no?

 

[Dougofthenorth]

Manual for all specs are at http://www.pcrichard.com/images/manuals/RXA3030BL-manual.pdf
read through it to see & for extra presence speaker set up

BTW "loud" has essentially nothing to do with SQ
Same with 2 pulverizing SWs blasting

ALL of the speakers have to properly interact with each other
&
then with the room & then with the contents & bodies.

Same as do the drivers in each of your homemade boxes.

You may have to EQ the room again with people sitting in seats
Saving different EQ programs for different situations

I am in the process of building a 20 X 20 X 10H HT addition with 11.1 config
Using known brand speakers with known responses/characteristics
I am having the setup computer modeled first. Then when all is built.
So I will build walls to best specs with proper construction & wall treatment materials (& ceiling & floor)

For example

The A3030 is capable of handling a room of that size, when it is properly optimized.
As previously discussed using the 9 would help- as would 11

 

[Langotriel]

"BTW "loud" has essentially nothing to do with SQ"

Normally i would agree however, sound quality is often affected if speakers are constantly pushed to their limit and if nothing else, over time the SQ will deteriorate. With a room of this size, it would be pushing the physical abilities of the 6.5 inch drivers to fill the room with just 7 (talking SPL here) so we would have to play it loud to get the proper cinema experience... with 9 i just figured that the volume of each individual speaker could be a little lower and in turn, the speakers would last a little longer.

As for the subwoofer.. same thing.. loud at low wattage means that they last because we don't have to push them to their limits.