Questions on how to power some of these things....(MWM's)

[Coytee]

I have four double MWM bass bins.

 

I was wondering if I could put two of them per side to add some meat to the bottom end?

 

If no, then no big deal.

 

If yes, then how to power them?

 

I have a Crown K2.  Would a single Crown K2 be able to power FOUR of these cabinets (8 drivers)

Have one channel of the Crown go to (double bin) box 1, then jump from that box to the second (double bin) box and do same on other channel?

 

I know I could dedicate a single crown to a pair of bins if I went right channel to one bin, left channel to the other.

 

I've never done this (more than a single double bin) so have no idea how the pros set things up.

 

 

Where I'd like to end up is:

 

2-double bins per side (4 drivers per side, all K33's)

1 Peavy MB-1 per side for mid-bass duty

1 K402/K69 per side for HF duty.

 

Since I don't have enough K510's nor any 1133's, I'm stuck looking at what is at my fingertips.

 

I have three K2's so if I could dedicate one per level, it would work with parts on hand.  If instead, the double/double bass bins would kill a K2 then I need to think of plan B

 

Plan B would the be a single K2 for each double/double bass bin (one channel per cabinet).  Second K2 for each Peavy MB1

 

That's three K2's

 

I could then pull out my dbx BX3 for HF duty.

 

 

Now, I ALSO have two MWM single bins.  Could I make each stack FIVE drivers?  (two doubles and one single stacked)

 

 

Don't you know.....wife is calling...

 

 

[WMcD]

You need a series-parallel or parallel-series connection. Here is one way which assumes each pair is first wired in parallel. This assumes you've got four woofer drivers on each side.

The resulting load on the amp with either is just what a single K-33 (in the horn) will present. So it should be better than the usual parallel set up.

WMcD

[Coytee]

That sir, is exactly what I was looking for, thank you very much!!

 

That suggests that I can indeed, use a single K2 to power all four bins (eight drivers).

 

That simplifies things for me as I only have three K2's.

 

Now I can dedicate one to the MWM's, a second one to the MB units and the third to the K402's.

[WMcD]

Just for some explanation.

There are complicated expressions for putting resistances or impedances in series or in parallel. They can be simplified if we have just one value common to the components. We'll call that "R".

When they are in parallel, we get R/2. When they are in series, we get 2*R.

Therefore in the schematic, the pair of driver in the units, wired in parallel we get R/2.

But then we wire an identical pair in series, and we get (R/2)*2 and that equals R(load on amp). Therefor the amp "sees" a load of just R, even though there are four speaker with themselves having a resistance of R.

The voltage across any one driver is 1/2 of what the amp is producing, so call at Vamp/2. (This is true if you go with a parallel-series or a series-parallel.)

Lets look at power into any one driver.

Power (to one driver) = V*V/R, where R is, again, the resistance of one driver. Be we said that the voltage drop in the circuit gives each driver V(amp)/2.

So we have Power = (Vamp/2) * (Vamp/2)/R. The result is (Vamp/4)/R. This means that each driver is getting 1/4 of the power put out by the amp.

However, we have to consider what power the amp is supplying to given different loads in terms of V(amp)and R(load).

If just one driver was connected, it would be Power = V(amp)*V(amp)/R.

When a parallel wired twin bass bin is connected we get V(amp)/1/2 R. This makes sense because each driver is getting half the power, in theory. There is a big "but" here. Can the amp put out enough current to drive the R/2? Probably not. This is why we see amp power ratings of something like "100 watts into 8 ohms and 150 watts into 4 ohms."

(It should double.) With 4 ohms we're really loading the amp too much. The V(amp) sags. And a protection circuit may shut it down. There is an increase of distortion too.

We could go to absurdity. Someone can say, I'm going to connect 100,000 speakers wired in parallel to my amp with a resulting load of 0.000008 ohms, and it will supply enough power to light up Cleveland. (number? made up) Of course that is not possible.

OTOH, the amp is probably very happy with a load of just R rather than R/2. We really don't need to load the amp to give any high power with our speakers. 1.0 or 10 watts is enough.

WMcD

Edited July 3, 2016 by WMcD

[Coytee]

Twist on the question...

 

I have the two Danley subs sitting in the garage.  I might bring one in.  They have two 12" drivers, out of phase and on each side of the motorboard (or something like that....one fires into the throat and one fires into the mouth with the backwave of one doing something.

 

(pretty technical huh!!?)

 

Anyways, while in Hope, Luther brought up the idea of taking a single Crown K2 (the amp I have designated for the Danley's) and instead of bridging the amp to run both speakers drivers, run a single driver off each channel instead.

 

This would require either wiring them out of phase (no big deal) or, switching them out of phase inside my active crossover (also no big deal)

 

What intrigues me is what does that benefit me over bridging the amp and running the two drivers out of phase?

 

I have the Speakon connector that will allow 4-wire hookup although I currently have it formatted for 2-wire.

Edited July 3, 2016 by Coytee

[ZEUS121996]

Richard,

That was my question, can I double stack 2 dual 15s from the KP-600s and put an EV horn like this on? With the right driver, I think these would sound great

[Coytee]

Once upon a time, I almost snagged a pair of KP600's

 

One of my questions (to Roy) was going to be, can I remove the top cabinet (keeping the bass drivers & subs on the bottom) and simply slap a K402 on top?

 

I never asked and I don't know the crossover point.  I suppose the crossover point of the bass bins will help dictate what you can do on top.

[WMcD]

I had explained this in another post long ago.

 

When you operate an amp in bridged mode, one channel is in reverse polarity to the other, assuming you have an amp set up for that.

 

It means that when fed with a mono signal (this should be part of the bridge arrangement) the left channel is going to plus 1 and the other is going to minus 1 volts (or 10 or 20 volts etc as you turn up the volume).  For a total voltage of 2 volts. Take these to mean the top of the sine wave and the bottom of the inverted (reverse polarity) sine wave.

 

We can think of an 8 ohm speaker as two 4 ohm speakers in series connected as the bridge.  There is a junction between them. The junction is sort of a "virtual ground".  It is always at zero volts relative to the amp chassis or the black output terminals. 

 

This may be a little difficult to visualize.  Just consider.  The total voltage drop across the series is from plus 1 to minus 1 or two volts.  In the middle, at the junction, the voltage must be zero. The voltage drop across the "top" 4 ohm speaker in the series is from 1 volt to zero volts.  The voltage drop across the "bottom" 4 ohm speaker is from zero volts to minus 1 volt.

 

(plus 1 volt) - - (red) 4 ohm speaker (black) -- junction (zero volts or chassis ground voltage) -- (red) 4 ohm speaker (black) -- (minus 1 volt)

 

This means that each channel of the amp is "looking into" a 4 ohm load even though there is (only) an 8 ohm speaker bridged across the channels. Again, we're modeling the 8 ohm speaker as two 4 ohm speakers in series).

 

For this reason, bridging creates a load of lower resistance (4 ohms versus 8 ohms) and more current draw and power draw.  Generally, amps don't like this. 

 

I think you're better off avoiding bridging.  You don't need the power.

 

WMcD

Edited July 4, 2016 by WMcD

[Marvel]

One of my questions (to Roy) was going to be, can I remove the top cabinet (keeping the bass drivers & subs on the bottom) and simply slap a K402 on top?

 

I thought that is what DTEL did in their house. His are singles, though, but yes, that should work.

 

 

Bruce

Edited July 5, 2016 by Marvel

[Coytee]

I thought that is what DTEL did in their house. His are singles, though, but yes, that should work

 

He has MWM's....  I actually switched the subject to the KP-600's, wondering if I could use the two sub bins with the two bass bins and then put a 402 on top of that ensemble.

[Marvel]

Sorry, I read right through that but dropped the switch...

[dtel]

I thought that is what DTEL did in their house. His are singles, though, but yes, that should work.

 

Bruce I have 2 singles on each side, that pic was from I had just one bin finished. Coytee is looking to use 2 doubles on each side,   twice what I use, I wonder if this is for outside ?.  

 

Since you were talking about the 600's, there pretty amazing with subs built in............but I'm not complaining.

 

Bruce, changed it around a little, different tv and redone the stand to fit the center channel for ht.

Edited July 14, 2016 by dtel

[Marvel]

I am pretty sure it would work with the full MWM bins, but... he's switched to the KP-600s.    He was talking about a large gathering at his place... That's close enough that I think I would be able to attend.

 

Bruce

[Don Richard]

Or maybe stay home and listen from the front yard.

[Schu]

Isnt klipsch releasing some new amplifiers soon?