Inspired by the recent "Gone Active" thread...

[jhoak]

Will this work?

Equipment list part 1 - electronics

1) Onkyo P-304RS 2-channel preamp
2) Onkyo P-506RS 2-channel amplifier
3) A pair of Dynaco MK4 monoblock amplifiers
4) Behringer CX231 crossover
5) Behringer DSP-1124P (room equalization)
6) Behringer EP2500 amplifier
7) The usual sources

Equipment list part 2 - speakers

1) Klipsch La Scalas (highly modified)
2) IB SUbwoofer (2-15" AE drivers)

Connections:

All of the sources are connected to the preamp by way of the appropriate cabling
The outputs of the preamp to the preamp to the inputs of the crossover
The low frequency outputs of the crossover to the inputs of the Onkyo amplifier
The high frequency outputs of the crossover to the inputs of the Dynaco monoblocks
The outputs of the Onkyo amp to the woofers of the La Scalas
The outputs of the Dynaco monoblocks to the crossover input on the La Scalas
The subwoofer output on the crossover to the input on the BFD
The output of the BFD to the input on the Behringer amp
The output of the Behringer amp to the IB subwoofer drivers

Additional available equipment:

1) Onkyo M-282 2 channel amplifier
2) Grant Fidelity Tube DAC-09 set to preamp mode

Assumptions:

The Behringer crossover is set to stereo 2-way mode

Questions:

Does it matter to the crossovers in the La Scalas (ALK-Jrs) that there isn't a woofer hooked to them?
Would an additional crossover with both set to mono 3-way be a lot better?
Is this a complete waste of time and resources considering the age related limitations of my hearing?
Is there a better way to hook this stuff up that I haven't thought of? Enlighten me
What am I missing here?

Please keep in mind that this is nothing more than an experiment. I'm 50+ and single so I have a great deal of time on my hands. I don't however have a great deal of discresionary cash to sink in to an experiment. I can spring for another one of the crossovers but not a lot more than that.

[CECAA850]

What am I missing here?

Can't help you on the crossover however I have dabbled in IB's. I doubt that the two 15" drivers in an IB config will keep up with your Lascalas. You've got plenty of amp, but not enough displacement unless you're going to use it primarily for moderate listening levels in a small to medium sized room.

[Coytee]

The outputs of the preamp to the preamp to the inputs of the crossover

check

The low frequency outputs of the crossover to the inputs of the Onkyo amplifier

check

The high frequency outputs of the crossover to the inputs of the Dynaco monoblocks

check (though you might want to know the input sensativies of BOTH amps so you can match if you need to

The outputs of the Onkyo amp to the woofers of the La Scalas

check

The outputs of the Dynaco monoblocks to the crossover input on the La Scalas

check and I also presume you are going to disconnect the woofer from same crossover?

The subwoofer output on the crossover to the input on the BFD
The output of the BFD to the input on the Behringer amp
The output of the Behringer amp to the IB subwoofer drivers

Got me on this stuff...no idea what a BFD is.

Does it matter to the crossovers in the La Scalas (ALK-Jrs) that there isn't a woofer hooked to them?

My understanding of these passives is they have a low frequency circuit, mid frequency circuit and a high frequency circuit....all laid on top of each other using the same inputs. I'd speculate that as long as the crossover doesn't see the woofer and that circuit is 'open' then you'd be ok?? (rank speculation on my part)

Would an additional crossover with both set to mono 3-way be a lot better?

I guess triamping them would be THE ticket with biamping them coming in second place. The mere fact that you can biamp the top half seperate of the lower half (woofer) might alone be an improvement. If you want to hear what might be an even more substantial improvement, look into taking your LaScalas down to a 2-way speaker. I was floored once I realized the difference between the traditional 3-way sound and the 2-way Jubilee. All my life, I had always thought a 3-way was inherently better than a 2-way in every aspect, all of the time with no exceptions. Boy, was I 100% wrong!!

Is this a complete waste of time and resources considering the age related limitations of my hearing?
Is there a better way to hook this stuff up that I haven't thought of? Enlighten me

No idea

I can spring for another one of the crossovers but not a lot more than that

Before springing for anything like that I'd first suggest you make the attempt to hear the LaScala bass bin with a K510 or K402 on top. Seems you already have the electronics? If you liked what you heard, you could sell your unused parts to help fund the transformation.

If you're ever in Knoxville, you are welcome to swing by for a side by side with a 3-way LaScala (30 year old drivers with new extreme slope crossover) next to an actively biamped JubeScala with the K402 on top.

Technically, Knoxville IS, "right up the road" []

[Coytee]

though you might want to know the input sensativies of BOTH amps so you can match if you need to

In case they are different... the forumla is 20*LOG(V1/V2)

where V1 and V2 are the different input sensativities. Doesn't matter which one you put on top or bottom AS LONG as you realize one of them will give you the negative of the same number (for example -7.95 as contrasted with flipping the numbers and getting a positive 7.95)

You want to attenuate the more sensative amp (smaller input sensativty number) by that value. in this case, we'd attenuate them by 8 db's and then you have electronically matched the amps inside your crossover.... I am of course, presuming it can do that. I'm not familar with it.

[TNRabbit]

I also downloaded "Room EQ Wizard" online to use in the final tweaking. What you have thus far sounds like a start, but what Coytee said about 2 way is true. One of the reasons I like the Carver AL-IIIs so much is they place the crossover at a LOW 200 hz, in a less critical range. Having a crossover in the mid ranges can make things infinitely more complicated. To go TRULY active, you'd need to pull the crossover altogether & tweak flat response with an active EQ similar to the Rane Parametric EQs I'm using. Taking the crossover out of the loop WILL result in better control of the driver(s) by the amp & reduce power requirements (can't be that much on a sensitive speaker like the K-horns, but there are other positive aspects to removing the crossovers as well). However, you complicate matters quite a bit by taking the passive crossover out, too.

I highly recommend taking a listen to Coytee's system if you can possibly swing it~

Only YOU can tell if it's worth the time/effort. Good luck on your project!

[CECAA850]

Got me on this stuff...no idea what a BFD is.

Behringer Feedback Destroyer. It's an adjustable prrametric equalizer used to EQ subwoofers. In this pic, it's the component between my amps and pre-pro.

[mark1101]

The biggest problem I see............and that I mentioned in the other "gone active" thread is no time alignment. You are going to have a very sloppy bottom end because your sub will be way out of time with your Lascala woofer. You may also have a problem trying to use 1/2 a passive network with no woofer connected to it. I believe those ALK networks are all based on the woofer impedance. Take away the connection to the woofer and God only knows what you have.

I recommend a Behringer 2496dcx so you can learn how to properly assemble and tune an active system, and learn the value of time alignment. Then, if you feel you are successful you can upgrade parts of teh system as you wish.

In fact, I'd go one further and say get the 2496dcx and use it only to delay the sub in the current setup you have now. In other words optimize your current setup first before you try the active approach. I think it will make a big difference if you can provide lascalas with a correctly time aligned sub. That could be outstanding.

I had 2 velodyne subs sitting unused for over 2 years because I thought they sucked and were sloppy. I had tried them with several different Klipsch Heritage setups. When I introduced time alignment I found out how good they really were and I have them in my MCM system now.

[CECAA850]

"Stupid question alert!". Wouldn't the phase adjustment (or distance setting in a receiver) allow you to time align your sub to your system?

[jhoak]

"Stupid question alert!". Wouldn't the phase adjustment (or distance setting in a receiver) allow you to time align your sub to your system?

It should assuming that you're running a modern receiver. In the case that I described there are no such options being largely "vintage" equipment.

[CECAA850]

"Stupid question alert!". Wouldn't the phase adjustment (or distance setting in a receiver) allow you to time align your sub to your system?

It should assuming that you're running a modern receiver. In the case that I described there are no such options being largely "vintage" equipment.

Makes sense now, especially when you combine that with the fact that you'll be running a pro amp with no phase adjustment ala sub amp.

[TNRabbit]

Update?

[jhoak]

I did hook it all up as described in the original post. After a BUNCH of fiddling over a couple of evenings and a weekend I came to the conclusion that that it really didn't offer enough of an improvement over what I was already listening to to be worth the additional complexity.

Perhaps if I were working with a better grade of equipment the results would have been better. As it was I was still running through part of the crossovers (ALK Jrs) for the mid and upper frequencies. I suspect that as suggested tri-amping with 3-way crossovers and eliminating the passive crossovers altogether is the best answer. At this time I do not have the discresionary $$ to take on that project.

I have decided to be content with my current system. At least for a while. It sounds very very nice and I have no real complaints with it. I feel like I've reached that last 5% point where I'm going to need to spend TONS of $$ (that I don't have) in order to hear (or not) anything but marginal improvements.

Also in the "thought hopper" is acoustic improvements to my room. I have a gut hunch that I'd see much more "bang for buck" improvement by simply dealing with the problems in my room. I have done some but I know that there is much room for improvement in that area.

Thanks all for your input and encouragement.

Jeff