Altec Lansing 19

[electra]

Just purchase a pair of Altec Model 19. I have two Mcintosh Mc2125 SS amp 120w/c and thinking of mono bridge them. Please advice on sound quality between single and biamp.

[CONVERGENCE]

Bi amping is the way to go. You will have more dynamics in the highs with improved harmonics.

These old XO just don't cut it anny more. Theres a second alternative.
Iconic has a new improved XO for model 19. You can check it out.

http://www.iconicspkrs.com/downloads/dn19_8u.pdf


My 2 cents worth.

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[electra]

Do you know the price and will the replacement Xover allow me to do verticle biamping?

[CONVERGENCE]

That's passive biamping. I never tried it that way but did use amps with builtin XO.I would let someone else comment. Active biamping is better and more efficient to my taste.

The price of the new XO I believe to be in the hundreds of $ . Best thing is to contact Iconic Speaker Manufacturing.


http://www.iconicspkrs.com/


Here is a site with an interresting article on passive horizontal;vertical biamping and active biamping.


http://www.audioasylum.com/audio/general/messages/57210.html



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[Mr. Widget]

Horizontal vs. vertical bi-amping is a secondary issue.

With most speakers you can get a better sound from the speakers with an active crossover and multi-amping. However it isn't a simple matter to do it right. You need to carefully set the crossover frequency, slope and balance the amps. Many people do not have the requisite knowledge or patience to do this properly. Some test equipment is really helpful. At least a basic test CD with and a simple SPL meter. An RTA or computer based MLS, sinusoidal or FFT measurement system with a calibrated mic are even better.

On top of that many speakers including the Altec Model 19 there is frequency response tailoring going on in the built in passive network. If you bypass this network, which is necessary to get the full benefit of going multi-amped, you will need to be able to tweak the response curve yourself to get the correct amplitude response.


Widget

[Zilch]

The article says bridging is a bad idea.

The Iconic XO seems to be an updated replica of the original.

Easily accomplished, and probably not big bucks.

I'd probably try that, split and passive biwired (vertical), though 125W/channel seems more than enough to run them full passive....

[Ian Mackenzie]

Horizontal vs. vertical bi-amping is a secondary issue.

With most speakers you can get a better sound from the speakers with an active crossover and multi-amping. However it isn't a simple matter to do it right. You need to carefully set the crossover frequency, slope and balance the amps. Many people do not have the requisite knowledge or patience to do this properly. Some test equipment is really helpful. At least a basic test CD with and a simple SPL meter. An RTA or computer based MLS, sinusoidal or FFT measurement system with a calibrated mic are even better.

On top of that many speakers including the Altec Model 19 there is frequency response tailoring going on in the built in passive network. If you bypass this network, which is necessary to get the full benefit of going multi-amped, you will need to be able to tweak the response curve yourself to get the correct amplitude response.


Widget

Bigger and louder is not necessarily better.:blah:

Perhaps you should re phrase that to read with most loudspeakers you cannot get better sound................based on all those little issues you mention which are quite correct (JBL specificied crossover cards ofr JBL systems being the exception)

[Mr. Widget]

Bigger and louder is not necessarily better.:blah:

Perhaps you should re phrase that to read with most loudspeakers you cannot get better sound................based on all those little issues you mention which are quite correct (JBL specificied crossover cards ofr JBL systems being the exception)I certainly wasn't thinking in terms of bi-amping as a method for getting bigger and louder, but I suppose some might...

I had posted can and you posted cannot... it is the classic glass is half empty or half full viewpoint. I agree that many people will make their system less linear if they bi-amp and some will degrade the quality of their electronics if they insert almost any of these readily available "pro" actives including those JBL units with the correct cards into a system with high quality electronics. That said, if done right, you will get a better sound by removing the passive components between your amp and speakers.

I think what you are saying is that most people should not "attempt this at home" unless they are prepared to work really hard at it. It can easily take months to get to a point where you realize you finally got it... there will likely be a hundred times before that where you thought you had it. You may tune your system to sound good with whatever music you listen to the most only to discover that you really haven't moved forward when a friend brings over his favorite CD and it sounds odd. You need to be able to revert the system back to it's original configuration and compare this with your bi-amped system to confirm you have progressed. On the other hand I have visited plenty of friend's houses over the years who had "reworked" their networks or modded them, or gone active and actually reduced the fidelity of their system but were thrilled with the results... I suppose being thrilled is perfectly acceptable... though I personally strive for a linear system.


Widget

[CONVERGENCE]

Hi Electra,

The Xo you would like to have is called a passive line level XO. It has to be customed made by an expert . Since the ouput impedance of your preamp and input impedance of your amp are different . The inductors and capacitors will have a different value than the regular passive XO.

;)

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[Mr. Widget]

The Xo you would like to have is called a passive line level XO...Actually many of the better "audiophile quality" active crossovers that I have used or have known about use a passive section for the high pass and an active section for the low pass. They typically come with extra resistors so that you can match them to the input impedance of your amp. They use this active/passive hybrid because the high pass section is where most of the music is in most systems and they are trying to avoid adding extra crud in there. The crud that comes from the pile of extra op-amps and their related circuits typical of Rane, Behringer, Ashly, JBL, etc. etc. crossovers.

You can build simple passive RC filters to use as a passive crossover at line level (ahead of the amps), but you are right, you need to know the input impedance of your amp and you don't want to load down the output of your preamp.

Of course after deciding to go this route you still need to be aware that all of the hurdles that I mentioned above still remain. You can simply go with a second order 1200Hz network or whatever, but it is highly unlikely that will be the ultimate solution.


Widget

[electra]

Thank you to all the responses. I have decided to trade my amps in for a pair of tube monoblocks. Has any member use a external super tweeter similar to the Onix ERT or the Tannoy ST100 with the Altec 19?

[Ian Mackenzie]

Electra,

Glad you saw the light. Your on the right track.

You might check out Triode Systems or Thomas Dunker's pages for details of that tweeter.

A more elegant route may be to mate the Altec horn with a Tad compression driver.

One of our members Cyclotronguy has used the Tad driver with his Altec horns and it sounded very impressive to my ears..not tweeter required...his amps Passlabs X1 & A60's helped a lot!(goes with the job....)

[CONVERGENCE]

Getting back to Iconic super XO. Here is a quote from Jerry Hubbard.



Jerry Hubbard (Head of Acoustics at Altec Lansign from 1982 to 1992), offers the following;

When designing a passive crossover, many things come into consideration. One aspect, of course, is to correct for any defects in the frequency response of the high and low frequency components in the speaker system itself while maintaining all of the good characteristics it has at the same time. Not as easy to do as one might think..
Another of these is the phase relationship between the two devices, particularly at crossover. In the SUPERCrossovers, as in all the designs Mr. Hubbard does for Iconic Mfg. Co., the key is to design the device correctly so that the low and high frequency devices perform in phase at crossover. If you achieve THAT, then, as Jerry puts it, "You're pretty much done." This is because when you get the two in phase at the crossover point, there is no need for time delay circuitry, as you have achieved your goal. Altec Fan - As far as components in the SUPERCrossovers are concerned, they will utilize, for example, ribbon core inductors: things like that. All super high-quality components.

:)

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[Ian Mackenzie]

To answer electra's original question...

The sound difference of passive and active crossovers

In an ideal world active crossovers are better because they allow direct coupling to the actual driver and this improves various electro mechanical apsects of the driver in real motion. Using a dedicated amp for the highs and lows in theory offers less intermodulation distortion.

This is what people hear, the sound has more snap and clarity when done right. A change in balance asa result of subtle changes in the frequency response.
.
The down side is the added stages of electronics add noise, distortions and there can be a loss of information. These stages usually add odd harmonics and this leads to a change in tonality. The curves created by the active crossover are often not ideal for the actual application as required.

This is what people hear, a hardening of the sound or the intrusion of a sonic glare often referred to a brightness in which the true timbre and musicality are lost.

Passive crossovers have series and parrellel passive elements conected to the drivers to create the desired crossover functions. These elements interact with the electro mechanical charactertics of the dynamic drivers in complex ways and this can lead to non linear distortions.

This is what people hear, passive crossovers tend to sound more soft and loose and lack the tactile dynamics of the actively driven drivers.

Active crossovers are very useful for crossover points below 400 hz because the above issues become more of a real problem. At 800hz or above with a really good passive crossover and with a really good power amp the gains and complexity of an active system would need to be carefully considered.

Speaker builder/designers find a fully active system useful when analysing and configuring a proposed loudspeaker system.

Ian


Here is an example of a high quality active crossover that I built recently. There are no integrated circuits, no 3 pin chip regulators and no electrolytic capacitors in the signal path on premium audio grade Auricaps. Class A discrete dual-J fet/Bjt buffers are used in all active stage. All signal path wiring is teflon coated OFC copper, potentiometers are expensive precision conductive plastic audio grade types. Seperate signal and power earth systems using star ground virtually eliminate noise from entering the signal path.

The crossover can has 10 selected crossover points, 6, 12, 18 or 24 db slopes and 5 filter Q settings.

As a rule I don't like digital active crossovers....the less A/D and D/A conversions the better. Even an optical as opposed to coaxial digital cable is an audible degredation in sound quality.

They are great though for "quick and dirty" experiments prior to settling on the parameters of a proper passive network.

[sura]

For those interested in the cost of the crossovers from Iconic, here's what Jim sent me in an e-mail last February:


The Improved or "R" (formerly U) unit uses excellent MPF Capacitors, Non-Inductive Resistors, Gap and Aircore Inductors. Both the Low Pass and High Pass sections have load stabilizing and equalizing networks.

The Supercrossover, or "S" unit has the same circuitry as the "R" but is made with more expensive Audiophyle grade Capacitors, Resistors, Aircore and Foil inductors.
The "S" model is somewhat more transparent and detailed in response than the "R' model, this refinement comes at somewhat increased cost.

Our usual crossovers with the set levels sell for the following, your price is NET. :

Unit Net each List each

DN-19R 255.00 340.00
Model 19 pattern, no Lpads, Improved Unit, exceeds performance of original

DN-19S 352.50 470.00
Super 19, better inductors, HF caps, HF resistors

If you desire the Control Add-on, add $90.00 to the cost of two crossovers. This includes 2 trim plates, labels, 4 controls and wiring. connected to the crossovers. , For example DN19S X 2= 705.00 +90.00 = 795.00 This prices does not include shipping or if you are a Washington State resident, State Sales Tax.

Thank you for your inquiry, if you have any questions, please ask. JIM

[Cyclotronguy]

Hiya Ian,

Thanks for the accolades! For what it's worth; my wife painted the big JBL's and placed them in a proper Asian environment... now they sound much better. LOL:bouncy:

Cyclotronguy

[garyl]

I am probably a bit out of my league here in regards to your question.
I was faced with a similar question when I began building my Model 19 clones.
After much discussion with Bill at GPA and Gary Jones at Altec, I decided to go with their recommendation for XOs.

I can't answer if they can be bi amped or how they might perform for your needs. I can say with out hesitation that these XOs are absolutely gorgeous in my 19s and every bit as nice as the original 19 XOs. I can also say I spent a great deal less then the offering by Iconic.
I questioned the crossover point set at 1500Hz and was told this could be a blessing in disquise for the 802s and it has proven to be a very nice yet almost unnoticable difference.

Worth looking into I would say.

http://img.photobucket.com/albums/v722/Gamalot/AltecXover.jpg

http://img.photobucket.com/albums/v722/Gamalot/N1500005c.jpg

[spkrman57]

Biggest item of difficulty I found was setting the mid and HF controls to sound best.

Ron

[garyl]

I know exactly what you mean on this but I also have the same difficulty with the stock 19 and 15 XO settings.
I alway figured this was an idiocyncrisy with my ears rather then a defficiency with the controls.
I completely wore out the grill tabs on both my stock speakers so when I built the clones with this XO I mounted them on the back rather then behind the grills.

Gary