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Jubbed up 5.1 to 7.1 conversion


Cantilope

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Current System = A picture speaks a thousand words.  I am looking for a wall mounted speaker that can get me from 5.1 to 7.1.  You can see where I have the boxes set high in the wall.  I have Jubes as fronts and Belles for rears so losers need not apply.  Anyone used anything that would fit this application?  SQ is of the utmost importance, as they are rubbing shoulders with Jubes... Thanks!IMG_0186.JPG

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Basically, you're looking for timbre match with your stated requirements.  Dispersion isn't really an issue from looking at your picture.  Back surrounds are not full-time independent-channel loudspeakers.  They are used for ambience enhancement and sound effects, like the extra Atmos loudspeaker channels.  You may be surprised how little they add...

 

One option is to look for a used pair of Cornwalls and EQ them a little bit...as I do in my 5.1.  The timbre match is actually quite  good without having to time align them.  They're almost the size of a Belle, but the sound will complement the other loudspeakers in the array.  Cornwalls are almost time aligned except for the length of the midrange horn/compression driver.  This can be physically time-aligned by moving the midrange/compression driver outside of the cabinet if your tastes are more exacting than the as-is sound.  The timbre will be close but not match perfectly unless you're EQing and crossing using an active crossover to  flatten its response a bit more. 

 

I'd also look at the Klipsch KI-396-SMA-II:  http://www.touchboards.com/klipsch-ki-396-w-sma-ii/  That's a two-way with ported 15" woofer and a K-510 horn. I'm not sure what the compression driver is, but I'd guess it's something like a K-69-A...or perhaps even a K-69 (B&C DE750), which is a very good-sounding 2" compression driver.

 

Chris

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A pair of Heresies might also work if you're a little less demanding of timbre match.  You'd have to hang them close to the ceiling in the rear 120 degree quarter areas.

 

Then you could move your Belles forward a bit in front of your equipment rack.

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34 minutes ago, Chris A said:

Basically, you're looking for timbre match with your stated requirements.  Dispersion isn't really an issue from looking at your picture.  Back surrounds are not full-time independent-channel loudspeakers.  They are used for ambience enhancement and sound effects, like the extra Atmos loudspeaker channels.  You may be surprised how little they add...

 

 

Chris

 

Unless you're listening to 5.1 music, then rears become extremely important... (I understand this is the HT sub-forum)

 

I agree with the assessment of heresy's or a nice set of cornwalls.

 

Props for proper rear channel placement... for Home Theater.

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32 minutes ago, Schu said:

Unless you're listening to 5.1 music, then rears become extremely important

If you're talking about correlated rear channel effects, the rears don't do much. 

 

When talking about uncorrelated rear sound effects, you might be surprised how little the loudspeakers more than 120 degrees behind your center (zero degrees at the listening position) contribute...

 

Figure 15-5.GIF

 

Spatial Effect Balloon.GIF

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4781e99ae8ffca5a0124d725dc5d750d.jpg

Ok so looking the other way...

I just happen to have some CWs. Are you suggesting the Belles move forward to the blue chair, becoming mid surrounds and the CWs going between the window and the room treatment? That puts both rear infront if the couch like in B/C of the diagrams. The CWs sit on the floor correct, be a challenge to hang them.

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I found myself unhappy with my rears once I had the fronts and sides all horns (quarter pie bass horns). The direct radiator bass was readily apparent so I wound up going to 5.1 until I built horns for the back. With the quality of your system I think it will bug you too. If you can find a way to keep it all horns it would be best IMO.

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58 minutes ago, Cantilope said:

I just happen to have some CWs. Are you suggesting the Belles move forward to the blue chair, becoming mid surrounds and the CWs going between the window and the room treatment? That puts both rear in front if the couch like in B/C of the diagrams. The CWs sit on the floor correct, be a challenge to hang them.

 

Yes - you can move the Belles to in front of your couch, and the rear Cornwalls close to the rear corner of the room (about 120 degrees from the K-402-MEH in azimuth).  Having the CWs close to the corners will reduce the required movement of the woofer to achieve required SPL on-axis (assuming that you EQ them flat again once you get them into the corners...this is an old PWK trick). 

 

It's worth a try. If the CWs are little too low, you can put solid risers underneath them to raise them a foot or so (as I do). 

 

Chris

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52 minutes ago, tromprof said:

I found myself unhappy with my rears once I had the fronts and sides all horns (quarter pie bass horns). The direct radiator bass was readily apparent so I wound up going to 5.1 until I built horns for the back.

I had this issue with Heresies, but not with Cornwalls. 

 

It really gets down to the level of bass modulation distortion, which gets down to the movement required from the woofer.  Large woofers can sound very horn-like (but not if the group delays near the port tuning frequency become too large--which is a box and port design issue). 

 

Interestingly, Cornwalls in my experience don't sound like Heresies.  I've actually got a pair of Belles sitting in my storage/study, but they don't go as low as the CWs (a big issue in terms of matching timbre with the Jubs and center MEH).  That's why I'm still using the CWs as surrounds. They work quite well.

 

Chris

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50 minutes ago, Chris A said:

I had this issue with Heresies, but not with Cornwalls. 

 

It really gets down to the level of bass modulation distortion, which gets down to the movement required from the woofer.  Large woofers can sound very horn-like (but not if the group delays near the port tuning frequency become too large--which is a box and port design issue). 

 

Interestingly, Cornwalls in my experience don't sound like Heresies.  I've actually got a pair of Belles sitting in my storage/study, but they don't go as low as the CWs (a big issue in terms of matching timbre with the Jubs and center MEH).  That's why I'm still using the CWs as surrounds. They work quite well.

 

Chris

 

Very well could be. To me the rear pair are invisible (or should be). If not on I will notice their absence but usually not their addition (with the current all horn setup). I had a pair of KPT-200(?) in the back, and I think I also tried Fortes, but was never happy as I could hear their addition negatively as opposed to the seamless integration of the current horns.

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Thanks!  Sounds like I really just need 4 more MEHs...

 

I'll do some playing around see if the wife will help me carry down the CW's, I new collecting one of each would come in handy one day.  See if that sates me.  But, I am pretty sure I'll want it all horn loaded, that's what got me here to begin with...

 

Joe

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The group delay occurs down around tuning.  This should not be a big problem with HT.  It will effect some explosions and thing down that low.  But, we are talking quick peaks.  Chris, the chart you posted was from 2002.  My rear speakers are very active in a majority of newer movies.

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13 hours ago, derrickdj1 said:

Chris, the chart you posted was from 2002.  My rear speakers are very active in a majority of newer movies.

The two charts that I posted aren't related to time and industry practices but rather the inherent abilities of the human hearing system.  It doesn't change over time.  Those plots will still be good 100 years from now. 

 

The observation that your surround rear loudspeakers might "be active" is something that is unrelated to the relative auditory contribution that loudspeakers at that azimuth from your screen can make. 

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23 hours ago, Chris A said:

When talking about uncorrelated rear sound effects, you might be surprised how little the loudspeakers more than 120 degrees behind your center (zero degrees at the listening position) contribute...

 

Chris, can you provide links or citations for the charts that you showed? I'd like to read them in their entirety.

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https://docs.google.com/file/d/0B_l73GVBBlIUYjIwZGI3ZWItYmJlZC00NmM0LWFiMGUtNTcyMWY4MTUxYmM4/edit?pli=1

 

I really recommend buying the book (which is available at Amazon) since Toole really outdid himself, and having the book in paper format also helps to serve as a much better place to scribble in gloss style in the columns your own comments and observations.  I know that my copy of Toole's book is now very "personalized".  The pdf version, above, is good when you want to find something that you've already read, via online searches. 

 

That book is excellent.

 

Chris

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  • 1 year later...

Finally made some forward progress and captured myself a set of La Scalas for rear/rears. I have cleaned them up, replaced the horn to driver gaskets and replaced the caps in the original AA xovers. I rescued these from a shop that cuts granite and they were pretty grungy, they are much nicer now than they appeared when I picked them up.

 

I am glad that I stuck with horn loaded all the way around, although as you can see it took awhile to collect the right parts worth the wait. The conversion from 5.1 to 7.1 has been worthwhile as the extra rears just add that much more immersion into the movies. I also have a pretty deep room they help with that as well. Since this last post I have also replaced the single THT with (2) F20 horn loaded subwoofers. This is what the LS sit upon. I am very happy with the pair of F20s as well. The bass in the room is tremendous but effortless and they blend in very well with the Jube Bass bins. I love, love, love horn loaded bass. I also sit upon a concrete floor so added some bass shakers to the theater seats. These I have come on at the lowest of lows and they add just a but more to the experience but don't add any distortion to the audio.

 

So a quick run down of the current gear:

 

L/R = 2016 Jubes running from a DIY 6 channel class D amp made from 3 TI TPA3255EVM boards.

C = 2016 DIY K402 based MEH (ChrisA) w/ (2) 15" Eminence woofers also connects to the EVM boards

SUR = 1978 Klipsch Belles, ALK xovers, Crown D75A amplifier

REARSUR = 1978 La Scalas, AA xover, Crown D75A amplifier

Sub 1&2 = Lil Mike F20, Crown XLS 2502 amplifier

Bass Shakers = Crown XLS 1000 amplifier

I use an Oppo 105D for the front end and a Xilica 4080 for xovers, delay, and speaker balance.

 

FIY those are audiophile/hospital quality high definition, triple quasi gold plated yellow wing nuts. They give better bass.

 

IMG_6776.thumb.jpg.096e4dd652410a9a71599b837232f181.jpg

 

IMG_6775.thumb.jpg.9ffc86cb100df5781ffddffb3da9d2fd.jpg

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53 minutes ago, Cantilope said:

FIY those are audiophile/hospital quality high definition, triple quasi gold plated yellow wing nuts. They give better bass.

You need to try the semi-gold plated wing nuts.  They have more transparent synergy than those old fashioned obsolete quasi plated models you're using.  :lol:

+++

 

Those F-20's make the La Scalas look like small bookshelf speakers!  :blink:

+++

 

Would you care to describe a bit more what we are looking at with regards to your amps?  I'm not sure what your per-procsessor is.  I see a rack in the left rear, a tube amp on the left side Belle and I'm not sure what is on the right side Belle.

 

It really looks like you are really getting that room dialed in.  :emotion-21:

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