Jump to content

Running six 21sw152 4ohm in parralel on a sp12k amp, doable?


Recommended Posts

Hi guy's, huge fan of this forum (looking at you Mr. Ricci) and I can only hope to contribute to this awesome place down the road

I am wondering if anyone of you has real world experience running three 152s, 4ohm, on a speakerpower 12k amp channel, or on the sp6k at 240v?

How is the actual impedence of this driver when it's in a tapped horn or a band pass inclosure? When I look at the free air charts of the 152 it looks like I'd be dealing with the lowest impedence 70hz onwards if I'm high passing at 30hz

Will I actually be in the 1.33ohm zone? Or will I be averaging closer to 2 actual ohms with 3 per side?

Is this amp too much for only 4 of these drivers going full tilt all night?

 

Also contemplating the ipal route with an external series wiring setup unless that's not a good idea,

thoughts?

Link to post
Share on other sites

I have run subs in series with an external "series speakon adaptor" box I made without any issues.  I think as long as you are using identical subs there shouldn't be any issue running them in series as speakers are fundamentally current mode devices.  This is also why I run the drivers in series in my isobaric subs as this means that the force exerted by each motor should be equal.

Link to post
Share on other sites

Nice, I figured their shouldn't be any issues with an external series setup. as long as the gauge is thick enough I'd assume.

 

I remember reading on here weather or not series vs parallel wiring caused slight phase variances between drivers as they move across different frequencies, most people being proponents of parallel wiring but I'd imagine the differences are so slight, if not non existent with proper implementation.

Any thoughts on weather or not there's a difference in series implementation between the two? The second one being much easier to work with (no secondary speakon on cab) but with longer cable runs...

series wiring setups.png

Link to post
Share on other sites

Those boxes must pound! I figure as long as the subs are getting ample clean power,

something like a series/parralel setup would still come through solid and coherent like you're saying.

I definitely won't shy away from an external series wiring setup in the future to reach the average ohms needed for those pesky Ipals anymore 

Link to post
Share on other sites

I've run plenty of series or series parallel cabs too. Keep the cables as short as possible and use a heavy gauge. Keep the drivers the same model and loading. It'll be fine. There are untold amounts of cabs wired or run in series everyday. 

Three 4 ohm 21sw152's in parallel is probably going to be a min impedance of about 1.2 or 1.3 ohms. The SP amps will "do" it. Might be a smidge low for them but they've run 2 21 Ipal's in series. which is roughly 1.4 or 1.5 ohm. 

Link to post
Share on other sites

The configuration I have used is the right hand side one with a box that has 3 speakon connectors (input and two outputs).  I just used a plastic project box and held it all together with a lot of hot glue.

Link to post
Share on other sites

I figured 6 152's at 4ohm would be pushing it in the end with that amp... I like the idea of option 1 as illustrated if thick gauge and short runs are best, then one could even use the entire cable once it leaves the splitter, dedicate all 4 speakon male/female connectors to 2 beefy 12awg wires within the cable, then use solid 10awg insulated wire in the cabs as you relay back to the 12awg wire, eventually making its way back to the splitter

Main advantage being, it'll produce the shortest and thickest external series cable runs if needed...Now would that be negated by the "thinner" gauge from the amp to the splitter, if say its less then 2ft??

Link to post
Share on other sites

Also, Mr Ricci, what are your thoughts on the Ipal 21 vs the new Eminence NSW6021-6? Running on the sp6k/12k? 

Two of those new Eminence drivers look like they would be a great pair averaging at 3ohms parallel on the amp. If cost wasn't an option, 4 nsw's in parallel or 4 ipal's in series? It seemed like a few people ran into quality control issues with the new eminence driver on this forum if I'm not mistaken. Hopefully it would have been one off defects from what seems to be an awesome subwoofer

Link to post
Share on other sites

Either of those woofers are excellent. The NSW is a lot cheaper here and the impedance is much easier to match amps to with a single or dual drivers. Performance wise the 21Ipal is a bit more efficient and may have a very small edge in power handling because of it but it's probably not enough to be audible. Both are absolutely top tier drivers. I own both. 

Either company is large enough and well established that any sort of mfg defects will be taken care of. There have been some reported issues with both drivers. It happens. 

Link to post
Share on other sites

The speakerpower can do 2+2 so you'll want to try and land a 2ohm load per channel. Look for a driver with a ~5 to ~6 ohm DCR and if you take 3 of them in parallel you're gonna a be right at a 2 ohm nominal load. Perfect for each side of your amp. Are you set on have 6? 4 21's is still a lot and may be easier to deal with.


 

 

Link to post
Share on other sites

Thank you guy's for the awesome inputs, my apologies for the late reply. Much appreciated for side by side comparison of the ipal and nsw Ricci. Although the NSW offers the best bang for the buck, I might try an external series ipal setup, albeit with some thick ass wires. 6 is kinda pushing it for that amp, even with the 152s...specially if I want the damping factor to remain high

 

Been keeping this box on the dl but it's basically similar to the th18 but slightly modified for 21'' woofers, code named the hornicator, I haven't done any measurements on it yet but it sounds hella good and moves some serious air with the 152 and my buddies crappy Inuke, but giving the mouth and 24ft cubic size, I think the nsw or ipal would destroy in this enclosure...weight? Heavy

Th21.jpg

  • Like 1
Link to post
Share on other sites

Thanks man! Huge fan of your designs/subwoofer philosophy. Not quite sure what the low corner is on it. Your standard th18 should do 35hz from what I've read, my goal with this was to keep the same horn style pathway but upsize it for a 21" woofer. Technically it should finish at 34'' deep but I decided to keep the extra 2'' of ply and make a final "bend" at the front as to hopefully, better couple with the air in front of the box.

 

30hz is the main goal, everything else below is a bonus & I think it delivers in spades, giving it's size, it better! lol, it's also overbuilt as a prototype, the first 2 panels, the baffle and front face are both 1", then solid wood wedges were used to create the last front angle, spray foamed the reflector cavities, all in all it probably added 10 + pounds but I think it was worth it.

 

I definitely cant wait to see it's true impedance with the 152 when I finally get to testing it this fall (working on the road till then) I'll definitely/randomly send you the details when I finally get around to it

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...