Chorus II's, w/active sub driver; Dumb idea?

[wvu80]

I know it's a stupid question, but somebody has to ask the question nobody else cares about.

 

What would happen if someone replaced the passive 15" subwoofer with a powered 15" sub driver?

 

I was looking at Shodrewken C-2's (this picture is from his Chorus II's for sale thread).  

 

Why not drop in a 15" sub driver with a 500 watt plate amp, or use some kind if iNuke to power both speakers?

 

I've got my heatproof jacket on, so flame away at the stupid question! 

[teaman]

I am always thinking along these lines although in your case I think the sub will oppose the woofer. I had debated running a 12 inch passive sub on the rear of the Heresy Gen 1. I figured it gives extra oomph to the KG4, Forte, etc so what could it hurt.

Edited August 22, 2015 by teaman

[Ski Bum]

The Chorus is a reflex enclosure, so your idea of throwing an active woofer in place of the passive is a non-starter.  

 

I suppose it could be done, but that would basically require re-engineering the whole bass alignment to suit both drivers.  For example, you could separate each active woofer by creating internal sub-enclosures, a tall order with all those horns, baskets, and magnet structures getting in the way.  And, assuming that can be pulled off, you would end up w/ basically some sort of franken-heresies in big cabs with built in subs that would likely fall short of the performance of actual Heresies and subs or Chorus in bone stock condition.  This just sounds like the hard way to learn what should be painless lessons concerning the basics of speaker design, and a chance to ruin and already great product.

[moray james]

ok the passive radiators are the equivalent of reflex vents and they perform the same purpose. So re ask the question; should I replace my reflex vent (which tune my woofer in this cabinet) with a second woofer? Answer is no. You barely have enough volume in a Chorus ll cabinet to tune the woofer to 40 Hz if you were to add a second woofer where would the volume come from for that one? This is not a plan. If you want to have deeper bass extension simply add some weight to both of the passives in your Chorus ll and that will retune the system lower. Add 2.5 ounces to the center (inside) of each passive in the form of a couple of flat steel washers held in place with just a small amount of 5-min epoxy you will lower your box tuning point 3-4 Hz which is a nice improvement even though the numbers may seem small. You can't tune any lower that that without running into issues with the passive. This will get you into Forte territory as far as bass extension goes..

Edited August 22, 2015 by moray james

[jimjimbo]

When you say "center" (inside), exactly what does that mean?

[twistedcrankcammer]

I know it's a stupid question, but somebody has to ask the question nobody else cares about.

 

What would happen if someone replaced the passive 15" subwoofer with a powered 15" sub driver?

 

I was looking at Shodrewken C-2's (this picture is from his Chorus II's for sale thread).  

 

Why not drop in a 15" sub driver with a 500 watt plate amp, or use some kind if iNuke to power both speakers?

 

I've got my heatproof jacket on, so flame away at the stupid question! 

In response to your header on this thread, the answer is:

YES!!!

Roger

[wvu80]

In response to your header on this thread, the answer is: YES!!!  -Roger

 

LOL!   OK, let me rephrase, using a new question, but keeping your same answer:

 

"Is the most complex and expensive way to totally ruin the sound of a Chorus II to rip out the passive radiator and install a plate amp and sub driver?"

 

The answer is ... 

[djk]

Something could be done, but at great expense.

 

It would involve buying two more K48, all woofers would have to be the same. A second stereo amp would be needed, similar in output to the main amp. A Linkwitz Transform would need to be designed and feed both the main amp and the second amp. The second woofers and amp would only run below 100hz, but the low frequency cut-off could be extended to below 20hz if desired.

[wvu80]

A scholarly reply ^^^ DJK, thanks.  

 

I've been expecting "what are you, an idiot?  If you want a sub, buy a sub..." 

[Ski Bum]

A Linkwitz Transform would need to be designed and feed both the main amp and the second amp. The second woofers and amp would only run below 100hz, but the low frequency cut-off could be extended to below 20hz if desired.

 

Why bother with a second powered woofer in that case?  You could apply a Linkwitz transform type eq to a stock Chorus (assuming you have a multi kilo-watt amp and the drivers can take the abuse).  And keep in mind that getting such extension via a Linkwitz Transform is not without serious trade offs.  For example, you would necessarily be giving up gobs of SPL producing capability of the driver because of the excursion overhead needed at the lower frequencies.  There is no such thing as a free lunch.  

 

Here is a reputable link explaining some of this better than I can.

Edited August 24, 2015 by Ski Bum