Dual Dayton Audio RSS315HF-4 wiring question

[JohnnyNG]

Kind of a beginner question. I'm installing a pair of these single VC 4-ohm drivers in an existing sealed cab. Amp will be a Crown XLS-2000.

Dayton Audio - RSS315HF-4 12" Reference HF Subwoofer 4 Ohm

RSS315HF-4 12" Reference HF Subwoofer 4 Ohm

www.daytonaudio.com

Does it make a difference if I wire them in series for a nominal 8 ohm load and bridge the Crown or run the Crown in stereo with a channel to each driver?

Delivered power is the same in either case: 650 watts RMS per channel at 4 ohms or 1300 watts RMS (mono) at 8 ohms in bridged mode.

I guess the amp would see double the Le in series/mono? Either way preferable?

 

[RickS]

An amp channel for each woofer would be best.

 

[DWPress]

Especially since the RMS is 400W (800 peak) on those drivers + giving them separate channels from the Crown will give you the chance for separate EQ down the road if needed.

 

[JohnnyNG]

An amp channel for each woofer would be best.

Thanks Rick! Are there specific parameters that would optimize vs. series connection?

 

[RickS]

parameters for a box design? not sure what you are asking.

 

[JohnnyNG]

parameters for a box design? not sure what you are asking.

Sorry - wondering what specifically would change with one channel to each driver vs a series connection. I would imagine the amp would see higher inductance in series, for example?

 

[RickS]

Would not worry about the inductance, but am hesitant to advise much more without knowing exactly what your subwoofer plans are.

Should learn a little about the basics first. Suggest searching on "wiring speakers in series vs parallel" on the net. Am not posting here due to rules, but Alpha Sound had a good youtube video. There may be others. This should clarify why I suggested the effectively "parallel" connection for your amp. There may be situations where you might wire the woofer in series, but am going off the limited info you supplied in your OP.

 

[bmc0]

In bridged mode, one channel drives the "+" output and the other drives the "-" output. The two output signals are symmetric and anti-phase, so if we assume perfectly matched drivers, the wire connecting the drivers is held at 0V (the average of the two output signals). In short, each channel sees half the total load, which in this case is simply one driver.

In other words, there's very little difference except: 1) bridged only needs half the speaker wire, and 2) non-bridged allows independent EQ (probably not very useful if the drivers are in the same cabinet). There's some difference in the event of driver failure as well, but whether that's relevant depends on whether you're planning to drive them near their mechanical/thermal limits.

 

[RickS]

In bridged mode, one channel drives the "+" output and the other drives the "-" output. The two output signals are symmetric and anti-phase, so if we assume perfectly matched drivers, the wire connecting the drivers is held at 0V (the average of the two output signals). In short, each channel sees half the total load, which in this case is simply one driver.

In other words, there's very little difference except: 1) bridged only needs half the speaker wire, and 2) non-bridged allows independent EQ (probably not very useful if the drivers are in the same cabinet). There's some difference in the event of driver failure as well, but whether that's relevant depends on whether you're planning to drive them near their mechanical/thermal limits.

Agree, was not considering the voltage increase due to bridging…

Would still like to know a bit more about @JohnnyNG’s design. For example, is he adding a second woofer to the same box volume or what before configuration was vs after.

 

[JohnnyNG]

Agree, was not considering the voltage increase due to bridging…

Would still like to know a bit more about @JohnnyNG’s design. For example, is he adding a second woofer to the same box volume or what before configuration was vs after.

Not much too it, really. Two 4 ohm drivers in a sealed box and a Crown XLS 2000 for power. I see two options for wiring and just wondered if one was preferable and why since power to each driver is the same either way.

 

[RickS]

Not much too it, really. Two 4 ohm drivers in a sealed box and a Crown XLS 2000 for power. I see two options for wiring and just wondered if one was preferable and why since power to each driver is the same either way.

Have you modeled the box? How big is it? are you planning to eq it for lower extension?

P.S.

Do not have hordes of time to help, but happen to have used the same woofer and am using it again right now.

 

[JPA]

Install two pairs of terminal posts in your box, one set per driver. Then you can run speaker wires to both pairs of posts for parallel operation, or if you change your mind later you can connect the posts with jumper wires for series operation.

 

[JohnnyNG]

Have you modeled the box? How big is it? are you planning to eq it for lower extension?

Modeled in WinISD. It's about 1.5ft^3 which is a bit small but will stuff and it's actually about the volume that Dayton recommends. I don't think I'll boost, I get lots of room gain. Don't need very loud volumes but excursion looks good down low.

Just curious about the wiring. The box already has a single set of posts but I'd add another if it made any difference.

 

[JohnnyNG]

In other words, there's very little difference except: 1) bridged only needs half the speaker wire, and 2) non-bridged allows independent EQ (probably not very useful if the drivers are in the same cabinet). There's some difference in the event of driver failure as well, but whether that's relevant depends on whether you're planning to drive them near their mechanical/thermal limits.

Got it, thanks. Not really going to pound on them, it's in the nearfield for a music setup. No need for independent EQ in the same box, agreed.

 

[RickS]

That is cramped. Without eq, your f3 is in lower 50s. Not much of a subwoofer. Why 2 drivers and why not use eq?

 

[DWPress]

You'll get more bang for your buck using separate enclosures that size. Here's a visual for series/parallel speaker wiring:

 

[JohnnyNG]

That is cramped. Without eq, your f3 is in upper 50s. Not much of a subwoofer. Why 2 drivers and why not use eq?

Yeah, somewhat cramped. It's an existing box built to fit in a space and dual 12's worked best. I do use EQ (REW AutoEQ via a MiniDSP Flex balanced, will try Dirac at some point) but don't usually need to boost down low due to decent room gain and no real need for flat infrasonic response. I'll go by as-built measurements and see what's needed at that point.

Anyway, just had that wiring question and didn't intend to take your time with design stuff but I appreciate the help!

 

[Gibsonian]

I’d definitely run them on separate amp channels.

 

[JohnnyNG]

Ok, you people win! I ordered another pair of Dayton binding posts. I was so hoping to get away with being lazy. The Crown doesn't have a "dual mono" mode but I have an XLR splitter to feed both channels.

Thanks all!

 

[bmc0]

The Crown doesn't have a "dual mono" mode

The "Input Y" mode does what you want. Check in the manual under "Crossover Mode" (should be page 4).