Bi-Amp Khorns

[ssh]

I want to hear my Khorns with a bi-amped configuration. I'm using ALK crossovers. I want to first try the Bogen 230A (25wps) at bass, & the JFL 2A3 (7 wps) at mid/high. The Scott 299A is another option.

I've read numerous active/passive crossover papers, & other "insightful" philosophical articles, but I need some Step 1, Step 2, Step 3 help. I've not seen an explicit description, but I know some of you guys are bi-amping.

Any takers?

SSH

[Dylanl]

Sorry but I can not help you. I just saw your post heading to the bottom of the pile with no answer and thought I would push it back up. I was looking for a similar answer in another thread. I had hoped to get some insight from your post. O well, I guess I will continue to hold my breath.

[mafuta]

This for true bi-amplification as opposed to the foolish trend to "bi amp" whilst keeping the speaker's own crossover in line.

Step 1: Get a line level crossover with appropriate x-over frequency and slopes.This can be either active or a passive. Marchand Electronics (www.marchandelec.com) is reliable,inexpensive and very helpful.Crossover probably 400Hz with slopes from 6 to 24dbper octave depending on your philosophy(I prefer 24db/oct). Cost $500 to $1500. Pass Labs, Krell probably $5000, FM Acoustics around $15 000(I think.For a vintage Marantz 6 (?) you'll have to sell your kids into slavery. Digital crossovers (TACt or some pro brands) are another option if you're not allergic to digital.Also get 2 extra sets of interconnects and an extra run of speaker wire

Step 2.Identify the bass low-pass and mid high-pass sections on the Khorn .Remove these.Throw them away-once bi-amped you'll never go back.Wire the bass amp directly to the woofer and the mid to the mid + tweeter.Make damn sure the mid-tweeter crossover is still in line.

Step 3.Connect the crosover between your pre and the 2 power amps.Turn the level pots on the crossover really low.

Step 4.Say the astronaut's prayer and switch on.Adjust the levels by ear or better with a spectrum analyser.If your computer has a soundcard with in and outputs,a very good analyser with signal generator can be had from truerta.com for 35$. You need a calibration microphone as well. The Behringer 8000 sells for $50. Oh ,you also need a phantom supply.

Sure you want to try it?

Good luck

[Dylanl]

Gasp!!! what! Gasp!!!

Now that I have literally caught my breath, No I do not want to go down this road. Although the thought of selling my children into slavery has croseed my mind.

[ssh]

Thanks, mafuta.

Yes, I want to try it. I hoped to hear from some who are already bi-amping here. I also prefer to use the ALK crossovers. I guess this just doesn't interest Al or other Klipschers very much.

SSH

[Klewless]

I'll add my two cents worth.

1. It is very expensive relative to well designed passive crossovers.

2. It becomes more difficult to deal with individual driver abnormalities.

3. Crossovers do more than just split the signal into bands.

4. As was mentioned, the tweeter must be protected by it's passive crossover unless you have a very, very, very good amp that never hicups while powering up/down (tweeter is a very fragile device).

5. The result whould not sound like the classic Klipsch.

This is just my opinion of course.

I have tried it in the past and didn't get a better sound (to my ears).

6. Damping of the woofer might be too much since the Khorn bass horn dampens the woofer quite nicely.

I do not intend to discourage experimentation. I did and then gave up.

[sunnysal]

my two cents, if you plan to go to the trouble to bi-amp you should tri-amp...why look for benefit between only two drivers in a three driver system? marchand and all the other electronic crossover guys all make three way stereo crossovers for this type of application. DBX and behringer are two more brands of electronic crossover you could consider for this, each has a unit for less than $500...warm regards, tony

[Daddy Dee]

SSH,

Biamping Khorns has been something I've been curious about, but haven't attempted. If I might add another question to this thread, to certainly reveal my ignorance, "What would be the result of running the mid and tweet as usual through an AA or ALK crossover and simply driving the bass bin directly from another power amplifier?

I did find one thread, which referred to this:

http://forums.klipsch.com/idealbb/view.asp?topicID=35528&forumID=68&catID=19&search=1&searchstring=&sessionID={DC8FEC7B-6812-4396-AFB3-2C3291025702}

[ssh]

Dee,

The www.marchandelec.com site has diagrams in their User Guide section that show a bi-amped version using the passive crossover for mid/high. I'm toying with that idea, using their tube crossover.

Lotta money, though.

SSH

[ssh]

Tony,

That would be fun to try, but I want to use the JFL 2A3 at mid/high.

SSH

[mafuta]

Running 2 amps through a passive high level crossover does not really make sense:

1. Both amps still receive the full range signal.Thus the advantage of your 7w Set handling only limited bandwith and not the more demanding bass frequencies is lost.

2.The amps still "see" a complex crossover network and are not directly driving the driver(sorry that sentence sounds silly)

3.You'll have 2 dissimilar amps driving basically a stock speaker.Tonal abberations are certain,especially with the shallower crossover slopes in the crossover.

4. How will you adjust levels relative to one another?You'll have to use a high power L pad or additional line level pots ,cables and connections between pre and power amps-i.e more instead of less.

IMO you'll end up with the worst of both worlds.Then rather stick with a single amp.

Regards

[ssh]

mafuta,

Only 1 amp would feed the mid/high through the passive. The Bogen would drive the bass using the active, just like the diagram on the Marchandelec.com site.

Tony,

I looked @ the DBX. It would be a less costly alternative.

SSH

[mafuta]

I would go for the method you suggesti.e low level bass -mid crossover with 2 amps and retaining the mid tweets as is. Tri amping with a third amp can be problematic and costly.I found in previous systems (Magnepan Tympani) that I prefered bi to tri amping .Having said that I'm about to tri amp my horns again from bi amp,but for reasons not applicable to the standard Khorn.

I use the Marchand XM46 passive line level crossover with great results.You do not have to buy the whole thing with cabinet 'n all.In fact Marchand suggests putting the actual boards inside your amps.The circuitry is really simple-only a few coils,caps and the odd resistor.Being line level the components are much smaller than a conventional speaker crossover.Other advantages.No active circuitry so no power supplies and no noise-important at 104dB/w.

I much prefer these to the Luxman and Krell Active units I used before

Good luck.It's really quite simple with the Khorn and i'm sure it will sound fantastic with your amps

[ssh]

mufata,

Thanks for the post. I'll look at it.

SSH