Home Theater Forum and Systems banner

1 - 14 of 14 Posts

·
Premium Member
Joined
·
5,798 Posts
Discussion Starter #1
I have JBL 8340A speakers for my surrounds, and was planning on using them for the ceiling but it will be an 11" drop from our 8' ceiling. I see that the JBL 8320 speakers are around 2" or more smaller in every dimension... Does anyone know if these would be a good choice for me for Atmos? They are less than 1/2 the price of the 8340A speakers.

http://www.amazon.com/JBL-Compact-Surround-Speaker-Applications/dp/B009NN4MZO
 

·
HTS Reviewer
Joined
·
1,760 Posts
Assuming your ears are roughly 40-45 inches from the floor when seated, and subtracting let's say 10" more with the speaker installed, your top channels will only be about 3.5ft-4ft above your head. From my experience, that's too close for any surround channel. I can't say whether or not those JBLs would make good Atmos overhead channels, though I assume they'd work perfectly fine. This is a case where I'd strongly recommend flush mounted (if not recessed) in-ceiling speakers. I have read that the Atmos enabled speakers (point up, bounce sound off ceiling) are also better suited to installations with lower ceilings, though I have not personally tested the theory.
 

·
Premium Member
Joined
·
5,798 Posts
Discussion Starter #3
Assuming your ears are roughly 40-45 inches from the floor when seated, and subtracting let's say 10" more with the speaker installed, your top channels will only be about 3.5ft-4ft above your head. From my experience, that's too close for any surround channel. I can't say whether or not those JBLs would make good Atmos overhead channels, though I assume they'd work perfectly fine. This is a case where I'd strongly recommend flush mounted (if not recessed) in-ceiling speakers. I have read that the Atmos enabled speakers (point up, bounce sound off ceiling) are also better suited to installations with lower ceilings, though I have not personally tested the theory.
Problem is I can't do in-ceiling speakers or I lose my whole seal in the ceiling. My ceiling is 8' 3" with my first reflection panels hanging 6" from the ceiling... if I go with the 8320 the speakers will be about 3-4" lower than the panels. Would lowering the level of the Atmos channels make them seem farther away? I don't have a situation where the upward firing speakers would work either as I have JBL 8340A speakers for the surrounds. The surrounds are firing downward (angled) from about 1' from the ceiling. I was hoping I could find some 6" or shallower speakers for Atmos that are 91db or more efficient, Some of the Atmos presentation pictures I have seen use I believe the JBL 8340A (or a similar model), but of course they have high ceilings.
 

·
Registered
Joined
·
919 Posts
I think the audio dispersion area would be one of the top criteria for choosing an overhead speaker in your situation. Does one of those speakers have a bigger, more even dispersion area than the other?

I would not lower volume gain for the overhead speakers, it would throw off the correct balance of surround audio. If the overhead speakers are too close and have a narrow dispersion area, causing hot spots, maybe overhead speakers just aren't in the cards for that setup.

Maybe multiple rows of overhead speakers could disperse sound more evenly. Similar to having multiple rows of side surround speakers in longer/deeper seating areas.
 

·
HTS Reviewer
Joined
·
1,760 Posts
With your surrounds that close to the ceiling, I don't honestly think the addition of Atmos overhead speakers would make a very noticeable difference. I'm not saying you shouldn't try, but don't expect to be shocked by the improvement. You have a few factors working against you.

Ignoring the vertical distance from the listening position, where would the Atmos speaker be located horizontally, relative to the listener? i.e. 2ft in front of MLP, 3ft behind MPL, etc. If they're ahead of the MLP, you'll get some vertical separation between your mains and overhead speakers, which could help make the Atmos objects stand out a bit more.
 

·
Premium Member
Joined
·
5,798 Posts
Discussion Starter #6
With your surrounds that close to the ceiling, I don't honestly think the addition of Atmos overhead speakers would make a very noticeable difference. I'm not saying you shouldn't try, but don't expect to be shocked by the improvement. You have a few factors working against you.

Ignoring the vertical distance from the listening position, where would the Atmos speaker be located horizontally, relative to the listener? i.e. 2ft in front of MLP, 3ft behind MPL, etc. If they're ahead of the MLP, you'll get some vertical separation between your mains and overhead speakers, which could help make the Atmos objects stand out a bit more.
One pair would be about 7' in front of the MLP, and the other pair about 2' behind the MLP. I had planned on all of the Atmos speakers pointing directly downward instead of angled like I have seen some do.
 

·
HTS Reviewer
Joined
·
1,760 Posts
I was re-reading the Atmos installation guidelines. It looks like they've added some details since I went through the process in my HT. Here are some relevant points.

If possible, the height of the rear speakers should be the same as the height of the front speakers. If the room design makes this impractical, or impossible, the rear speakers may be higher than the front speakers. However, we suggest that the height of the rear speakers not be more than 1.25 times the height of the front
speakers.
This will impact the perceived vertical separation between listener level objects and overhead objects. How close will your surrounds be to the top rear speakers?

The overhead speakers should be at least two times the height of the listener’s ear level.
You're on the border here. A few extra inches of height would be good, but I think it's close enough that you're probably ok. I'm assuming about 40-42" seated ear level for you.


If the chosen overhead speakers have a wide dispersion pattern (approximately 45 degrees from the acoustical reference axis over the audio band from 100 Hz to 10 kHz or wider), then speakers may be mounted facing directly downward. For speakers with narrower dispersion patterns, those with aimable or angled elements should be angled toward the primary listening position.
I'll admit a general lack of understanding of horn-loaded driver dispersion, but I think this may be a factor in the case of your top front channels.
 

·
Registered
Joined
·
356 Posts
Problem is I can't do in-ceiling speakers or I lose my whole seal in the ceiling. My ceiling is 8' 3" with my first reflection panels hanging 6" from the ceiling... if I go with the 8320 the speakers will be about 3-4" lower than the panels. Would lowering the level of the Atmos channels make them seem farther away? I don't have a situation where the upward firing speakers would work either as I have JBL 8340A speakers for the surrounds. The surrounds are firing downward (angled) from about 1' from the ceiling. I was hoping I could find some 6" or shallower speakers for Atmos that are 91db or more efficient, Some of the Atmos presentation pictures I have seen use I believe the JBL 8340A (or a similar model), but of course they have high ceilings.
I wonder if changing the distance settings (setting them higher than they actually are) in the processor would be a possible solution to low ceilings.

Sent from my iPhone using HTShack
 

·
Premium Member
Joined
·
5,798 Posts
Discussion Starter #9
I was re-reading the Atmos installation guidelines. It looks like they've added some details since I went through the process in my HT. Here are some relevant points.


This will impact the perceived vertical separation between listener level objects and overhead objects. How close will your surrounds be to the top rear speakers?


You're on the border here. A few extra inches of height would be good, but I think it's close enough that you're probably ok. I'm assuming about 40-42" seated ear level for you.


I'll admit a general lack of understanding of horn-loaded driver dispersion, but I think this may be a factor in the case of your top front channels.
My rear surrounds will be the same height as the side surrounds...like my surrounds were sitting on top of my front channels as large tweeters (a little above but not too much, and they will be angled toward the MLP).


My ear level is 36" in the front row.

The dispersion is 90-100 degrees from 400Hz to 12Khz.
 

·
Premium Member
Joined
·
5,798 Posts
Discussion Starter #10
I wonder if changing the distance settings (setting them higher than they actually are) in the processor would be a possible solution to low ceilings.

Sent from my iPhone using HTShack
Don't know.
 

·
Registered
Joined
·
919 Posts
I wonder if changing the distance settings (setting them higher than they actually are) in the processor would be a possible solution to low ceilings.
Changing distance settings would change timing and (similar to changing gain settings) would throw off the correct balance of surround sound.
 

·
HTS Reviewer
Joined
·
1,760 Posts
Although you're at the limit of a couple of the Dolby guidelines, I think your strategy is a good one. The 8320 will be nicely matched to your other speakers, which is always good. Mount them as planned and let your AVR do the calibration. I don't suggest changing the level or distance settings on the overhead speakers once the room correction has been done. It sounds like your listener level speakers are in a good position given the dimensions provided. I think your top fronts are far enough from the MLP - 8ft+ (line of sight) based on my estimates. You may end up wanting to angle them toward the MLP a tad. I'd say if the AVR compensates with an extreme level boost on those, make use of the built-in 20 degree mounting angle to aim them. You may also notice localization from the top rears, in which case I'd say it would be ok to manually dial back the level on those just a bit.

Looking forward to hearing your impressions once you're up and running. I'm sure I missed it somewhere... what AVR are you using?
 

·
Premium Member
Joined
·
5,798 Posts
Discussion Starter #13
Although you're at the limit of a couple of the Dolby guidelines, I think your strategy is a good one. The 8320 will be nicely matched to your other speakers, which is always good. Mount them as planned and let your AVR do the calibration. I don't suggest changing the level or distance settings on the overhead speakers once the room correction has been done. It sounds like your listener level speakers are in a good position given the dimensions provided. I think your top fronts are far enough from the MLP - 8ft+ (line of sight) based on my estimates. You may end up wanting to angle them toward the MLP a tad. I'd say if the AVR compensates with an extreme level boost on those, make use of the built-in 20 degree mounting angle to aim them. You may also notice localization from the top rears, in which case I'd say it would be ok to manually dial back the level on those just a bit.

Looking forward to hearing your impressions once you're up and running. I'm sure I missed it somewhere... what AVR are you using?
I am currently just using a Krell Showcase 7.1 preamp until I find a AVP with balanced outputs (true differential), HDMI 2.0, HDCP 3.2, Atmos, and DTS-X. I figure it will be sometime next year before I can complete the jump. For the time being I am just getting the amp, and speakers all setup. I also will have to decide if I want to add another DDRC-88A or just eq the Atmos channels.

I can't wait to get the setup tuned with the DDRC-88, and the new JBL surrounds.:T
 

·
Registered
Joined
·
1 Posts
Did you use the 8320 , i have these as rears and they are working very well. very good dynamics and extend very low to 65hz at -3b. they have good directivity index so I think they will work very well. I see many people use the volt 10lx or 6/8lx but I doubt that they will be much better they provide more dispression so in case you have a few sitting row it may be a better speaker. I am being lazy as I have done a lot of DIY and can't be bothered with more speaker DIY.
 
1 - 14 of 14 Posts
Top