I'm wanting to do surround sound home theater with active speakers. I have a pair of JBL 308p's and I like their sound a lot. I want to do a 5.1 system with them. I am currently running them 2.1 via my pc and initially I had a hum until I went with balanced cables. So now I am trying to find the best solution for processing my 5.1 (or eventually 7.1 or 7.2) signal to all active speakers with balanced cables. denon dn-500av? Or perhaps an AVR with rca pre-outs and then something like the Behringer HD400 between the avr and monitors? Any suggestions? By the way, I am running an SVS PB16 Ultra.
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Hi
I have an HT built around the LSR 308 (L,C,R) and LSR305 (Surround L and Right). I am using a Denon AVR-X3400-XH as Pre/Pro. I don't use the amplifers in the Denon.
Previously I had an Integra DHC 80.3 .. Great piece of hardware. It stopped functioning after a fall from a shelf ... It had balanced outputs the Denon doesn't. I use balanced cables and simple XLR to RCA converters. I don't have any hum (finger crossed) ... There are a few Pre/Pro with balanced output and all the bells and whistles you can wish for. Some can found there:
Click here for MARANTZ AV-7704
Click here for YAMAHA CX-A5100
I have an HT built around the LSR 308 (L,C,R) and LSR305 (Surround L and Right). I am using a Denon AVR-X3400-XH as Pre/Pro. I don't use the amplifers in the Denon.
Previously I had an Integra DHC 80.3 .. Great piece of hardware. It stopped functioning after a fall from a shelf ... It had balanced outputs the Denon doesn't. I use balanced cables and simple XLR to RCA converters. I don't have any hum (finger crossed) ... There are a few Pre/Pro with balanced output and all the bells and whistles you can wish for. Some can found there:
Click here for MARANTZ AV-7704
Click here for YAMAHA CX-A5100
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I actually just received a Denon AVR-X3100W in the mail yesterday. I had planned on using the pre-outs on it.... Currently I am using the monitors out of my Topping D10/Behringer UMC204HD and I notice a hum with rca but no hum with balanced outs on the Behringer. If I am not doing anything gpu/cpu intensive, the hum is negligible until the amp is cranked up pretty loud, but if I am doing something that draws a lot of power, I get a very loud hum. With the balanced output of the behringer unit, I can do anything with the jbl's maxed out and I hear no hum. This got me thinking.......I really don't like dirty signal.
You should use speakers with similar characteristics as your main speakers; the center should be the same.
There are AV processors with balanced out, they are just more expensive. It may be possible there are no problems with hum when the PC is not connected, so you could try with unbalanced first.
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I seriously considered buying a Denon DN-500AV today and returning the other AVR because of the balanced outs, but then there are some bad things I read about that unit also. Then there's all the features I would be missing out on with the other unit (most of which I probably don't really care about anyway). So I considered going the route of using the Behringer HD400 or equivalent Ebtech or whatever. The concern I have with that is audio degradation... Is there any, and if so, where, and how much etc.
GrimSurfer
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It's easy to do a $hitty job at home theatre/audio. Doing the job once, and to your complete satisfaction, takes a clear set of requirements, planning and discipline.
What is the size of your space (l, w, h)? What is the layout and acoustic features (square, rectangular, irregular, lots of glass, acoustic treatment etc)? What are your sound expectations (life like, organ crushing, etc.)? What sound levels (spl) are you seeking at the listening positions (distance from speakers)? What are your ownership expectations (tech geek... want the newest and am willing to replace components throughout the year until doomsday, moderate... replace every three to five years as major advances occur, conservative... keep some components as long as humanly possible)? What is your budget and WAF?
The clearer you can articulate things in this way, the better the advice you'll receive. There are some really knowledgable people on ASR but it helps if they have enough to get inside your headspace.
What is the size of your space (l, w, h)? What is the layout and acoustic features (square, rectangular, irregular, lots of glass, acoustic treatment etc)? What are your sound expectations (life like, organ crushing, etc.)? What sound levels (spl) are you seeking at the listening positions (distance from speakers)? What are your ownership expectations (tech geek... want the newest and am willing to replace components throughout the year until doomsday, moderate... replace every three to five years as major advances occur, conservative... keep some components as long as humanly possible)? What is your budget and WAF?
The clearer you can articulate things in this way, the better the advice you'll receive. There are some really knowledgable people on ASR but it helps if they have enough to get inside your headspace.
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I am only doing a room 12x24x8 roughly, rectangular, not a lot of glass, but there is some, and no acoustic treatment. Organ crushing? No, I am more into life like than I am organ crushing, but I do want it to have the ability to get pretty loud on occasion for music/movies IN THAT ROOM and loud enough to hear it pretty good in adjacent rooms. Also, I am conservative usually. I do like tweaking and messing with electronics often though. I have built a half dozen computers for people this year and done a lot with my own as well.
I just scored a very nice subwoofer unexpectedly. I purchased an SVS PB-2000, but they mailed me the PB16 Ultra. I used it over the weekend, then I emailed the company about it, and let them know what happened. They asked me which model I received and after I told them they told me "Enjoy!" So I ended up with a monster that really isn't going to get used to its full potential, but I don't care because it is awesome.
I just scored a very nice subwoofer unexpectedly. I purchased an SVS PB-2000, but they mailed me the PB16 Ultra. I used it over the weekend, then I emailed the company about it, and let them know what happened. They asked me which model I received and after I told them they told me "Enjoy!" So I ended up with a monster that really isn't going to get used to its full potential, but I don't care because it is awesome.
GrimSurfer
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Cool. You got lucky with the PB16 Ultra, which has massive capacity. Good on SVS for gifting this to you at a PB-2000 price!
Based on your narrative, it seems your after something that can deliver pretty high (but not crazy) spl all day long, yet has the headroom for good clean peaks. ~ 85 dB spl sustained and 91 dB peak at the listening positions might be a way of describing it that might help you choose the amp and speakers.
My view is that the speakers should come first because they have sensitivity ratings and impedances that can dictate amp selection. They also can take up a fair amount of floor, wall and ceiling space. So what are your thoughts wrt atmos (essential/desirable/optional) or height effects layout? How about floor space... are you thinking of towers or satellites? Will the system be used exclusively for movies or for movies/music?
Based on your narrative, it seems your after something that can deliver pretty high (but not crazy) spl all day long, yet has the headroom for good clean peaks. ~ 85 dB spl sustained and 91 dB peak at the listening positions might be a way of describing it that might help you choose the amp and speakers.
My view is that the speakers should come first because they have sensitivity ratings and impedances that can dictate amp selection. They also can take up a fair amount of floor, wall and ceiling space. So what are your thoughts wrt atmos (essential/desirable/optional) or height effects layout? How about floor space... are you thinking of towers or satellites? Will the system be used exclusively for movies or for movies/music?
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Movies and music both, but movies moreso. Also, I want accurate, neutral sound if I have not already mentioned that. I already purchased the JBL 308p studio monitors and also an Integra DHC-80.2 which has balanced pre-outs. Do you think the JBL 308p will sound good for what I am after at a listening distance between 9 to 12 feet? I am not concerned with atmos. I am thinking I will do 5.1 and I will be satisfied with that.
GrimSurfer
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A very quick and dirty analysis....
The most complete specs I could find for your speakers is at: https://www.bhphotovideo.com/c/product/1381118-REG/jbl_308p_mkii_powered.html. The key specs to remember are 92W/dB/m and a peak spl of 112 dB.
An explanation of the THX reference level is at: http://www.acousticfrontiers.com/2013314thx-reference-level/
A calculator for multiple speaker spl is at: https://myhometheater.homestead.com/splcalculator.html
Running the numbers for the JBLs indicates you'll have just enough capacity for 85 dB continuous and as much as 102 dB peak (the THX reference standard) spl. There are some big "ifs" here though... the calculation assumes all speakers will be driven at the same power level. This is rarely the case in 5.x. The other big "if" is whether the JBLs' spec is continuous power... which is likely not the case because the manufacturer would almost certainly specify RMS power.
Now your Ultra 16 is going to add significant spl to the equation, but this will only be between ~20-85 Hz. After that, the JBLs must carry the day... and the way I interpret the specs (assuming they actually meet the specs... not all manufacturer's products do) they might come up a bit short.
Since you're so close to the edge here, I suspect that distortion may become an issue. There's no way of knowing this without seeing more data on the speakers' performacne. My gut feel is that better speakers may be required by those placing a high priority on "accurate" and "neutral" sound but you should be able to reach 85-90 dB which is plenty loud even if it falls short of the THX peak.
The most complete specs I could find for your speakers is at: https://www.bhphotovideo.com/c/product/1381118-REG/jbl_308p_mkii_powered.html. The key specs to remember are 92W/dB/m and a peak spl of 112 dB.
An explanation of the THX reference level is at: http://www.acousticfrontiers.com/2013314thx-reference-level/
A calculator for multiple speaker spl is at: https://myhometheater.homestead.com/splcalculator.html
Running the numbers for the JBLs indicates you'll have just enough capacity for 85 dB continuous and as much as 102 dB peak (the THX reference standard) spl. There are some big "ifs" here though... the calculation assumes all speakers will be driven at the same power level. This is rarely the case in 5.x. The other big "if" is whether the JBLs' spec is continuous power... which is likely not the case because the manufacturer would almost certainly specify RMS power.
Now your Ultra 16 is going to add significant spl to the equation, but this will only be between ~20-85 Hz. After that, the JBLs must carry the day... and the way I interpret the specs (assuming they actually meet the specs... not all manufacturer's products do) they might come up a bit short.
Since you're so close to the edge here, I suspect that distortion may become an issue. There's no way of knowing this without seeing more data on the speakers' performacne. My gut feel is that better speakers may be required by those placing a high priority on "accurate" and "neutral" sound but you should be able to reach 85-90 dB which is plenty loud even if it falls short of the THX peak.
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GrimSurfer
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Since you want to move up to 5.x, which will require the purchase of new satellites/centre speaker, this would be the most logical time to upgrade from the 308p.
GrimSurfer
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Using the same calculator indicated to me that five 308p speakers, operating near max spl, would hit the peak from 12 feet away. The problem is that this calculation is based on all kinds of inaccurate and unproven assumptions.
One issue is that 5.x doesn't send equal levels to all speakers. It sends less to the rears... sometimes considerably less. So overall spl will not be 5 x dB. It will be 3 x n dB + 2 x (n dB x 0.x), the x being the percentage of power sent to the rear speakers by the audio board in your AV Controller.
Another issue is my inability to find a graph showing the frequency response for the 308p. If the response isn't ruler-flat (and at that price point is unlikely to be), then you may only reach the desired spl in a narrow part of the mid or higher frequency ranges. In other parts of the audible range, spl could easily be down 3-6 dB or more.
None of the is likely to occur from 20-80 Hz or so because your SVS Ultra 16 is extremely capable.
One issue is that 5.x doesn't send equal levels to all speakers. It sends less to the rears... sometimes considerably less. So overall spl will not be 5 x dB. It will be 3 x n dB + 2 x (n dB x 0.x), the x being the percentage of power sent to the rear speakers by the audio board in your AV Controller.
Another issue is my inability to find a graph showing the frequency response for the 308p. If the response isn't ruler-flat (and at that price point is unlikely to be), then you may only reach the desired spl in a narrow part of the mid or higher frequency ranges. In other parts of the audible range, spl could easily be down 3-6 dB or more.
None of the is likely to occur from 20-80 Hz or so because your SVS Ultra 16 is extremely capable.
GrimSurfer
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I need to see a graph. These simple specs aren't terribly useful for the kind of calculations we're making.
The reason for this is that the FR could be down -3 dB from 45-100 Hz (which wouldn't matter very much because your PB-16 Ultra could be trimmed to make up for this without breaking a sweat) or it could be down in broad swaths in the middle and high frequencies (where it would be significant and, quite possibly, prove to be an insurmountable challenge).
Now some of this might not matter with room correction software but even that has its limits. At the end of the day, the pre amplified signal reaching your powered speakers cannot exceed ~2.0 volts or distortion is likely.
Please keep in mind that I'm being rather careful and deliberate. I could say "yeah, should work" and leave you to buy three more 308ps... only to have you lament the purchase if you hit a performance bottleneck.
Achieving "accurate" and "neutral" sound at THX reference levels from 9-12 feet back isn't something that one would normally associate with entry-level powered speakers.
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