2-Channel Audio

Re: Another active vs passive crossover post

tubes-n-horns — Sat, 04 Jul 2009 13:52:13 GMT

nola:

I figure that if active was that much better, it would be an option offered by high end speaker companies. To the best of my knowledge, it isn't. We have an audio club in New Orleans and although I have never asked about active vs passive xovers over the past year, no one has mentioned using actives. I have heard spkrs well above Klipsch prices, including 13K Maggies and a 45K pair (forgot manuf). Surely the guy who paid 45k for a pr of spkrs can afford a K or 2 more if active is that much better.

NOLA,

Not only the cost to go with the active xover, but addittional two or three or more amps to pull it all together; now the guy who spends 45K on speakers is probably not using $500 amps, if you know what I'm saying.

Have fun in the other LA

Rick

Re: Another active vs passive crossover post

djk — Sat, 04 Jul 2009 10:59:09 GMT

http://www.lansingheritage.org/images/altec/catalogs/1971-monitor/page6.jpg

Re: Another active vs passive crossover post

DrWho — Sat, 04 Jul 2009 05:28:14 GMT

The mass consumer world tends to be about 20 years behind the pro world...active xovers are the norm in almost all powered speaker designs now, which includes some of your highest end studio monitors. It's been that way since the early 90's. There are also many studios running external amps and active xovers too. The list of benefits is real long if you implement it correctly. Check out deqx.com for some modern high-end home audio gear.

Another active vs passive crossover post

nola — Sat, 04 Jul 2009 04:14:56 GMT

Well, sooner or later I was going to have to pop the Q: Active vs passive Xovers......

I am on vacation now and a bit confused by this stuff.

I went to an audio place in LA for Pro Audio, in brief, active only on PA rigs. So......why not in consumer stuff ?????

Here are some anti passive xover URLs found via google. BTW I could not find any that said that passive was better; just that passive is more "convenient" or less expensive or easier to set up. Mind you, I have never heard anyone in a band seriously complain about xover set ups.

http://www.enjoythemusic.com/Magazine/manufacture/0403/

http://sound.westhost.com/lr-passive.htm

"Most people who have read my pages will know by now that I am not a fan of passive crossovers. However, sometimes it is the only sensible approach, or is necessary because of financial considerations or just for simplicity. Before deciding on the use of a passive rather than active crossover, the following article will surprise you - perhaps even enough to make you decide to go active after all."

My journey has included Crites recaps on my 2 AA networks for KHs and LSs and an ALK Uni kit.

I figure that if active was that much better, it would be an option offered by high end speaker companies. To the best of my knowledge, it isn't. We have an audio club in New Orleans and although I have never asked about active vs passive xovers over the past year, no one has mentioned using actives. I have heard spkrs well above Klipsch prices, including 13K Maggies and a 45K pair (forgot manuf). Surely the guy who paid 45k for a pr of spkrs can afford a K or 2 more if active is that much better.

I have read this thread and a couple of others elsewhere in the webesphere with interest tonight.

Given my rig (with addition of ALKs Trachorns and likely Altec 511 pruchase) where does one begin? Maybe with the units mentioned in the thread like the Ashley XR201 (?how many spkrs can 1 unit control) or Behringer ?DCN and DEQ 2496s for xover and EQ? Can these do both 2 way and 3 way active xovers? Can you do passive to the woofer and active between mid and tweeter? How to set these up (that is, real idiot proof instructions for noobs)? Etc.

Oh, have a happy 4th.:))

NOLA in the other LA now

Re: external active crossovers

johnellis — Wed, 21 Dec 2005 02:04:58 GMT

Shawn-

In my system, the crossover points radically changing has not been an issue. None whatsoever. I'v tried Klipsch Type B and the Thunder Bob passive in a traditional configuration. I've also tried Rane, Ashley and Behringer actives. Each had benefits but not one was "it". Like you, at first I was skeptical of this as well. But hearing (and tweaking) made me a believer. Needless to say it's easy to do and well worth a try. Let your ears be the judge. Who knows, you might be surprised!!

John

Re: external active crossovers

sfogg — Wed, 21 Dec 2005 01:07:36 GMT

Ummm.....passive crossovers need to be designed around the impedance they are driving.

The Type B was designed around loads of 8 or 16 ohm drivers.

Your amps likely have 10,000 ohms or much more of load on their inputs. The crossover points are going to *radically* change with loads like that attached to them.

The engineers you talked to were either totally clueless or missed that the crossovers you were intending to use were meant for speaker level connections.

There are certainly ways of doing line level passive crossovers. This isn't it.

Shawn

Re: external active crossovers

tigerwoodKhorns — Wed, 21 Dec 2005 00:58:56 GMT

Interesting, but, may I kindly ask, what is the benefit? Rane and other make active crossovers that are in the $300 - $500 range less. I thougth that the big benefit of an active is a steep slope (24 db/octive)

Re: external active crossovers

johnellis — Wed, 21 Dec 2005 00:34:25 GMT

I am doing something slightly different and it has worked very, very well for me. I have tried both active and passive crossovers and each had thier pro's and con's. As a result, I decided to build a prototype and triamp my system using a passive crossover. A Cornwal Type B in fact. In short, here is how I did it....

1. CD out to preamp in
2. Preamp to out to Cornwal Type B crossover in.
3. Type B woofer out to amplifier in
4. Type B squawker out to amplifier in.
5. Type B tweeter out to amplifier in.
6. Woofer amplifier out wired directly to woofer
7. Squawker amplifier out wired directly to sqawker.
8. Tweeter amplifier out wired directly to tweeter.

At first, there was a slight hum. This problem was solved by grounding the Type B crossover back to the preamp. For testing, I spliced one end of el cheapo RCA interconnects and used the center wire (hot-red) for input/output and external wire to ground. I should also note that before doing this I spoke with Crown engineers and gave them the specs for the type B as well as what amp I was using. I was told that there would not be a problem doing this. My mids are driven by tubes therefore I contacted engineers @ Conrad Johnson and they said the same thing as the Crown engineers. Once again, no problem. Anyway, I hooked everything up and the sound was marvelous!! The bass was extremely tight, mids extremely clear. I also noticed that the attact and dynamics were lightning fast. The sound was also very, very open. In short, it was, by far, the best my system had ever sounded.

After running my system in this configuration for a number of months, I then decided to upgrade the stock Type B crossovers to 8 guage inductors, mundorf capacitors and a universal transformer. I also replaced my spliced interconnects with Cardas connectors and silver wire. Once again, this modification was also a giant leap forward. For me, this configuration has given me the best of both worlds as far as triamping is concerned.

Anyway, I just thought I would throw this in.

Re: external active crossovers

sunnysal — Tue, 20 Dec 2005 22:54:37 GMT

Thanks Shawn,
I'm gonna print that one out, I can always count on you for useful information!
Warm regards, tony

Re: external active crossovers

sfogg — Tue, 20 Dec 2005 22:51:50 GMT

Tony,

"You are right there are preamps out there that can drive it BUT at lowish volumes you will not be driving the input DACS sufficiently."

There is no difference there between consumer and pro levels. Any time you turn down the volume ahead of the unit you are using less then the full A/Ds resolution. That is why it is important to setup the system such that the loudest material you listen at at the loudest you listen it just below clipping the A/Ds. Where you see people complain about these things is when they haven't gotten the levels through the units done well.

"the crossover should ideally see constant voltage for optimal sound,"

Never going to happen. Volume in music changes... voltage changes. Ideally you should feed the crossover digitally if possible.

"volume should be controlled after the crossover ideally. right?"

Optimally, but that doesn't mean it can't work well ahead of it if you set levels properly. A room is going to limit the systems SNR far more then lowered levels into a digital crossover will. If one has a 50dB noise floor in their room and listens at a peak level of 100dB they have 50dB SN in their room. The Behringer is rated at 113dB SNR. If you setup levels well through the unit you could likely get close to that for your peaks. Even if you turn down the pre-amp (50dB of attenuation) to the point where music is lost below the noise floor in your room you still have around 60dB SNR through the Behringer. (About the same amount of what the best vinyl can give you)

"that is what is marvelous about the DEQX, volume in digital domain. "

Digital volume control reduces resolution too. Digitally you attenuate the signal... which means it is closer to the noise floor of the DAC. End result... less resolution.... lowered SNR.

"with these other units one should have a singe channel passive volume control after the crossover and before the power amps IMHO."

For tri-amping a pair of K'Horns they would need a six channel control. If you do L/C/Rs you need a nine channel control. Not a lot of options there.

Even with a the less then ideal setup IMO the advantages of the crossover far outweigh the negatives.

Shawn

Re: external active crossovers

sunnysal — Tue, 20 Dec 2005 22:33:58 GMT

Shawn,
I was thinking more about the inputs. You are right there are preamps out there that can drive it BUT at lowish volumes you will not be driving the input DACS sufficiently. the crossover should ideally see constant voltage for optimal sound, volume should be controlled after the crossover ideally. right? that is what is marvelous about the DEQX, volume in digital domain. with these other crossovers units one should have a six channel passive (or digital, MSB makes one) volume control after the crossover and before the power amps IMHO.
regards, tony

Re: external active crossovers

sfogg — Tue, 20 Dec 2005 22:30:22 GMT

Chris,

Yeah, the locked volume controls on the Yamaha are certainly a nice feature of it if one was to use them for overall system volume control.

The lower resolution of the A/Ds and D/As on the Yamaha will make getting signal levels proper into it even more critical.

Shawn

Re: external active crossovers

sfogg — Tue, 20 Dec 2005 22:28:05 GMT

Tony,

Even with consumer level outputs and horns you are still going to need attenuation between the crossover and the amps to get things optimal.

Getting to full voltage on the input may or may not be an issue depending upon what one is using for a pre-amp. Some will be able to drive it to full level easily.. most any tube unit could for example.

Shawn

Re: external active crossovers

sunnysal — Tue, 20 Dec 2005 22:27:15 GMT

Chirs that unit is one of the best out there for consumer use, I love the fact that once levels are set you can lock everything together and use one volume to control everything at once. I also remember it has a level control switch either in the back panel or inside, remember to use consumer levels and not pro or you will not drive the dac sufficiently to get top sound quality. regards, tony

Re: external active crossovers

tigerwoodKhorns — Tue, 20 Dec 2005 22:15:01 GMT

Dr. Who,

Check out the Yamaha D2040 four channel divider. I bought one on Griffinator's reccomendation. This is a pretty serious piece of gear that can be configured in a number of fashions. I will be able to tri amp, send a full signal to a center channel and a subwoofer, time delay, use the linky/(whatever) correction at the crossover frequency, add parametric EQ if needed, and select the crossover frequency at an exact point. I hope it lives up to my expectations.

http://www.sweetwater.com/store/detail/D2040/

Needless to say, I picked one up used on eBay. I don't think that I could explain the $3,000 to my wife.

Before deciding to go digital, I was going to use this Ashley unit:

http://www.sweetwater.com/store/detail/XR2001/

http://www.sweetwater.com/store/closeup/XR2001--Main

Not as many features, but affordable and a really nice unit.

Chris