CurtPalme.com Home Theater Forum

[WanMan]

I misplaced original Paradigm Reference Studio 100 (v2) documentation and Paradigm's online archive doesn't have it for my version (only v4). Maximum power input for the 2x8" woofers + 1x6.5" mid-range + 1x1" tweeter is 300-350 Watts.

When I remove the clips to bi-amp these speakers, one set of posts is for the 6.5" mid-range + 1" tweeter, and the other is for the two 8" woofers. I do not know what the crossover frequency Paradigm designed into this particular model and version.

Problem:

I am going to ASSUME that the bi-amp configuration will result in a maximum power input for the 6.5" mid-range + 1" tweeter is going to be less than 200 Watts. I base this on the fact that the v5 Studio 20's it is under 150 Watts. If I drive the amplifier channels at the same signal level to drive the woofers correctly, I risk running the 6.5" mid-range + 1" tweeter to a dangerous level, no?

Ok, so how do I take a non-amplified signal from a L/R preout (Denon AVR-3311CI) and split it at a frequency that is the crossover frequency of the v2 Studio 100's?

Ok, start the Odd Couple theme ....

[WanMan]

Found some information on Stereophile's website ...

Three-way, four-driver, floorstanding, reflex-loaded loudspeaker. Drive-units: 1" aluminum-dome tweeter, 6.5" mica-polymer-dome midrange, two 8.5" filled polypropylene-cone woofers. Crossover frequencies (slopes): 250Hz (second-order), 2kHz (third-order). Frequency response: 39Hz-22kHz, ±2dB on-axis; 39Hz-20kHz, ±2dB, 30 degrees off-axis. Low-frequency extension (DIN): 25Hz. Sensitivity: 88dB/2.83V/m anechoic, 91dB in-room. Impedance: 8 ohms compatible. Recommended amplifier power: 15-350W. Maximum input power: 210W (typical program source, clipping no more than 10% of the time).

So, I am confused by the recommendation and Maximum power values. BTW, the Stereophile measurements are documented here.

[greg_mitch]

Here is my take...

If you have the clips in and the wiring from the amp is powering the TM & W they are splitting all of the power...equally.

So if you split up the power to the TW & W and still send them an equal wattage...you should be able to calibrate the maximum amount of watts the speaker will take by playing some scenes or audio at reference or near reference volume on your receiver. It will likely be too loud to handle before they exceed their limits....I would think. [disclaimer - I am not responsible for frying your drivers]

You shouldn't have to mess with the crossover either...the TM & W will all have their own internal crossover separately inside.

You cross at 80Hz at the receiver and the internal crossovers will filter the rest before it gets to the drivers.

Example:

From Receiver - 20k to 80Hz
To Woofer - 1000Hz to 80Hz via crossover
To Mids - 3000Hz to 1000Hz via crossover
To Tweeters - 20kHz to 3000Hz via crossover

[Curt Palme]

[Curt Palme]

[WanMan]

I guess my concern is such that the AVR (pseudo-preamp) is sending the exact same kind of signal level for the TM&W. It isn't aware that a) the external amp is working harder for the W and in turn may require a higher signal level to get it to reach a reference point. My concern if the AVR thinks, say, its going to take 95% maximum signal level then this also applies to the amp driving the TM, no?

I guess this really depends on if my ears act as the calibrating device, or some software program (Denon uses the Audyssey software). Maybe I am thinking I run the risk of the TM being over-driven to get the W to level when it might actually be the other way around and the TM will be driven fine and the W being under-driven.

But seriously, doesn't anyone make a simple passive (or even active) one-band equalizer to act as a nice splitter/crossover device?

[dturco]

Sure the do Wan but i think your AVR can be programmed and also that your speakers still use a crossover even when the connector is removed.

I used to use this for tri amping without crossover at all in my Cantons years ago.

http://www.rane.com/ac23b.html

[ecrabb]

[quote="WanMan"]I guess my concern is such that the AVR (pseudo-preamp) is sending the exact same kind of signal level for the TM&W. It isn't aware that a) the external amp is working harder for the W and in turn may require a higher signal level to get it to reach a reference point. My concern if the AVR thinks, say, its going to take 95% maximum signal level then this also applies to the amp driving the TM, no?

[greg_mitch]

Does anyone here bi-amp consumer speakers in their HT?

I never looked into it...do people run 300W to the woofer and then only 100W to the mid and tweeter? I always just assumed you would run the same wattage to both connections on the speaker...but this assuming an internal crossover like most (all?) consumer speakers have like the Paradigms.

[ecrabb]

Greg, yeah - a few people biamp consumer speakers... Most consumer speakers aren't biampable, but some are.

There's really no reason to run the same wattage to the tweets and mids because like Curt said, they require a fraction of the power the woofers do. You can drive a small efficient tweeter and midrange driver cleanly to uncomfortable listening levels with 50-75w. A big woofer might take 3 (or more) times that.

In a typical system, where you run into trouble with exceeding the amplifier's power capability, the woofer is sucking the lion's share of the amplifier power... The amp starts clipping the waveform and in the process, that waveform starts looking more and more like DC current than a nice oscillating AC wave... If that happens long enough, the tiny windings in the tweeter's voice coil heat and eventually just burns up. Bye bye little tweeter voice coil!

So, in the biamp configuration, your tweeter/mid stays cleaner longer because the amp driving those can be loafing along even if the amp driving the woofer is approaching clipping.

SC

[WanMan]

In this case I would have to wonder why companies like Paradigm offer it as an automatically available option. Heck, even the center channel in this series and version can be bi-amped.

Anyway, to me it seems that if I can why not? I have two five channel amps rated for 200 WPC. The dirty deed was already done on that purchase.

[greg_mitch]

When people say bi-amp is it exclusive to feeding the TM & W separately without crossovers like Curt was talking about? I always attributed "active crossover" to that method...I didn't think that had anything to do with bi-amping.

I wired up my speakers to be able to feed the woofer (via crossover) separately from the tweeter (via its own crossover). I was under the understanding this was what people referred to as bi-amping.

I guess I did it because it was relatively easy and cheap...but now that I think about it...it sounds like it is more trouble than it is worth.

It would be a complete pain the ass to level match the tweeter and woofer if you were feeding them different power levels...you would need to take measurements.

The fact that I am running 200W to both the T & W is what is confusing me right now about the power split between the two.

I think I need to read the Loudspeaker Design Cookbook
Amazon Link.

[greg_mitch]

[ecrabb]

Greg, it's not complicated... In the Paradigms and in most other biampapble speakers, the crossover networks are designed in such a way that there are essentially two separate signal paths from the terminal cup; one path feeds a low-pass filter to the woofer, and the other feeds a high-pass filter to the tweeter/midrange. A bar on the terminal cup simply ties the two together if you're not biamping.

But, regardless - biamping isn't relegated to passive or active filtering, nor is it limited to line-level or high-voltage filtering... It's simply using two amplifiers to power a set of drivers making up a full-range speaker; one amp to drive the power-hungry LF driver, and another to drive the HF drivers.

There is a bigger benefit to biamping with active filtering in that you don't have the power wasted in a typical speaker crossover network. But, unless you were using speakers with no filtering (crossovers) at all, you can't do that. That's typical in pro-sound speakers, but not any home speakers that I know of.

SC

[greg_mitch]

[WanMan]

[Curt Palme]

Sure, any car stereo crossover. Add a 12 volt power supply and you're done. Dirt cheap too.

Don't forget that a number of people biwire their speakers, ie. run a separate wire from the same amp output connectors to the tweeter and the woofer input.

THis was discussed over at avs years ago, and I can't remember if it was Kal who said that his system sounded better with biwire, but to me it's a crock, it's just an excuse to sell more speaker wire.

Kal, was it you that said biwire sounded better?

[Curt Palme]

Sure, any car stereo crossover. Add a 12 volt power supply and you're done. Dirt cheap too.

Don't forget that a number of people biwire their speakers, ie. run a separate wire from the same amp output connectors to the tweeter and the woofer input.

THis was discussed over at avs years ago, and I can't remember if it was Kal who said that his system sounded better with biwire, but to me it's a crock, it's just an excuse to sell more speaker wire.

Kal, was it you that said biwire sounded better?

[ecrabb]

Wan... I wouldn't even consider buying any sort of line-level active crossovers (especially some cheap car stereo crossover!) and putting it in your signal chain before you try using the speakers the way Paradigm designed them! By putting a line-level device into your signal chain, you have way more chance of screwing up the sound than you do improving it... Do you know what the crossover points should be? How about the slope? No? Then, don't mess with it! Other than level-matching, you're not really gaining anything by doing that, anyway! Like I said, you don't have any level-matching when you don't bi-wire, so why are you worrying about it when you are?

Quit worrying about it and just hook the damn things up and see how it all sounds, will ya?!?!!

SC

[beun]

Wan,

My perspective from an electrical engineer point of view.

1) Unless you can remove the internal speaker cross-over filter, adding an extra line level one will only ruin the frequency response.

2) With the shorting bridge in place you are supplying the same voltage to the woofer and the mid/high section. So if you want you can use two amplifiers with identical outputs to supply the woofer and the mid/high section separately with the same voltage, its the same difference.

3) You don't actually supply power to the speakers, you supply a voltage and the speaker consumes a certain amount of power depending on its impedance. In the crossover schematic you posted the tweeter path will show a high than 8Ohm impedance to the amplifier and is attenuated on top of that. Therefor the power dissipated by the tweeter speaker itself will be well less than supplied by the amplifier.

4) Your ears will automatically limit the actual power dissipated by the speakers because it gets too loud (I hope).

5) Having an amplifier with the capability supply a higher wattage may actually help in keeping your tweeter alive, more tweeters die from clipping amplifiers than from ones supplying clean power. Do remember that 90% of the power is in the first 3kHz bandwidth anyway, very little actually goes to the tweeter.


So in short, if you want to bi-amp go ahead with any decent amplifier it won't make much of a difference but it is worth the experiment.


Kim