Bi amping?????? Help

Stilly74

I am new to the bi-amping thing. Recently blew the tweeters in my tsi500's and was told that I "clipped them" guessing under powering them.
Currently running a denon 891 amp. Now how or what is bi-amping to get more power. How do you hook it up?
It the denon even capable of it. What is a good setup for amp/avr.
Recently got some rti12's ( could not pass on price) and will not be running them till I get this whole amp thing figured out.
Any info would be great.
I would use the setup for 50% music in 2ch and 50% movies in 7.1 setup.
Fronts tsi500( have rti 12's now)
Center cs20
Rears tsi 200 and tsi 100 for 7.1
Velodyne eq-max 12 sub

tonyb

No such animal as bi-amping from a receiver. That has been a marketing gimmick that uses that termanology to take the back 2 channels from a 7.1 receiver and add that to the fronts. What that does though is gives less power to the remaining speakers. Considerably less. Your problem is your receiver, I believe we mentioned that already. You need one with preouts and now with the addition of the 12's, you'll certainly need an amp too. If you clipped the TSI's, the RTI 12's are harder to drive and you'll no doubt clip those more easily. So your answer is sell the Denon, get a receiver with preouts and an amp and you'll be good to go.

dkg999

Or just don't listen as loudly.

Stilly74

Yes I understand to get a different avr and a separate amp but what? What is a good starting point. And how do you hook it all up. Stick with denon but get one with pre amps???
Will the rti12 sound that much better than the tsi500? May try them out but at much lower volume levels

rengnath

Alot will depend on your budget. I was in the same boat, with having a receiver with no preouts but I wanted more power. I ended up buying the latest receiver I could afford that had the bells and whistles I wanted and was still brand new. I wanted a receiver that was more powerful than my last one as well, since I couldn't afford to amp all channels immediatly. Buying new was important because I didn't want to risk buying an AVR that was overheated or overdriven.

I went with a Yamaha RX-A800, which isn't discountined yet but it was replaced with the RX-A810 which has network capabilities. It's not high end, but certainly not an entry level receiver. If you're willing to go used, and you can sacrafice HDMI, you can find used high end receivers for under $400. When comparing, look at the weight of them. A 7.1 receiver that weighs 40lbs will have a much better power supply than one that weighs 25lbs, even if the wattage ratings are nearly the same. Find a brand that you like, and start searching and comparing.

When choosing an amp, you choice will depend on how much you can afford. I could only afford an entry level amp, and buying used was a must because everything new was out of my price range. If you want something in mint condition, that will cost you more as well. Alot of amps out there will have scratches, dents, knicks, ect because they can range from 10-30 years old. If you're on a budget, I suggest looking for a 2-3 channel amp and powering your fronts and center, while using the AVR to power everyhting else. I was looking at amps from yamaha, rotel, parasound, and b&k. There are a ton of options though, and everyone has an opinion on what they like.

jviss

tonyb wrote: »

No such animal as bi-amping from a receiver. That has been a marketing gimmick that uses that termanology to take the back 2 channels from a 7.1 receiver and add that to the fronts. What that does though is gives less power to the remaining speakers.

Tonyb, I'd like to understand that assertion; maybe it's not the case for all receivers. My Yamaha RX-A700 claims to have bi-amp capability. When you select the bi-amp configuration you lose the back surround or front presence channels. From my examination of the user manual, it appears there are 7 power amp channels in this receiver, and whether one selects back surrounds, front presence, bi-amp, or zone two (second room speakers) determines what input is provided to two of those amps. For bi-amp, the same left/right front input is provided to those amp channels as the regular front left/right amp channels. Since each of the receiver's seven channels is capable of 90W, you now have 180 Watts assigned to each of your front speakers, 90 to each top half, and 90 to each bottom half. No power is stolen from any of the other speakers. I am pretty certain this is correct, assuming hte Yamaha spec sheet is accurate, and honest. What do you think?

williamgauci

Not going to speak for tonyb, but what your Yamaha manual is describing is passive bi-amping. It's not true bi-amping which involves physically separating the crossovers in your speakers and powering the low freq. from one amp and mid-high from another. The frequency crossover is electronically separated before the amplification. In your 7 channel amp, you'll never see 90w out of all 7 channels at the same time for any amount of real time. By reassigning two of your channels to the fronts, you're still sending "90w" to the speaker, you don't add the wattage. In the end, the more channels you're powering at once, the less power you have available. Yamaha and others play fast and loose with their ratings. Running your Yamaha in 7 channel stereo say, is probably only providing half it's rated wattage in real continuous power. I have tried the passive bi-amping with my Yamaha and I found no appreciable difference either way really.

apachec

looking for an interconnect cable SRS 2.3Tl

jviss

williamgauci wrote: »

Not going to speak for tonyb, but what your Yamaha manual is describing is passive bi-amping. It's not true bi-amping which involves physically separating the crossovers in your speakers and powering the low freq. from one amp and mid-high from another. The frequency crossover is electronically separated before the amplification. In your 7 channel amp, you'll never see 90w out of all 7 channels at the same time for any amount of real time. By reassigning two of your channels to the fronts, you're still sending "90w" to the speaker, you don't add the wattage. In the end, the more channels you're powering at once, the less power you have available. Yamaha and others play fast and loose with their ratings. Running your Yamaha in 7 channel stereo say, is probably only providing half it's rated wattage in real continuous power. I have tried the passive bi-amping with my Yamaha and I found no appreciable difference either way really.

Thanks William. While I understand what you are saying, and the configuration is in all probability passive bi-amping, in that the same line-level signal is presented to the power amps that drive the upper and lower parts of the speaker cabs, there is no reason to believe that Yamaha is cheating on the power output of the channels. Do you have a reason to believe that it is so? Further, it's simplistic to expect '90W at the same time,' since the program material doesn't drive the amp at a constant output level. It's only important that the headroom exists, and the amp can respond to the transient demands up to that level. I don't think what you say negates the assertion that there are now 2 amp channels driving each front cab, and that, at least according to yamaha, the channels are capable of 90W each. If you think Yamaha is fibbing, that's another topic.

williamgauci

It's fairly common knowledge that most receiver manufacturers play fast and loose with watt/channel ratings on their integrated receivers.
Do a quick search for 'Yamaha bench tests' and you'll find lots of quotes like this excerpt...

Power results otherwise were generally fine, though 5- and 6-channels-driven tests fell well short of the unit's single-channel/stereo spec of 90 watts, suggesting that total power-supply current is not sufficient to service all channels fully at the same time even when unchecked by the protection circuitry. This is not uncommon among all but the most expensive receivers, and the fact that I observed ample power in listening tests confirms that such all-channels tests, while a useful benchmark of overall potential, are not a particularly real-world model.

http://www.soundandvisionmag.com/article/test-bench-yamaha-rx-v661-av-receiver?page=0,1

I basically agree with everything you're saying, but the fact remains that if my manual says 100w/ch. I'd expect to be able to see that out of all 5 channels at once and that's not the case with the majority of the receivers out there. The people who have a casual interest or don't do their research on what they're buying are under the impression that they're pumping full power to all their speakers. I was under the impression that my Yamaha was capable of pushing 120w/ch. until someone pointed out the reality of receiver ratings to me.

jviss

Hi William,

I udnerstand what you are saying and I do not doubt that it is the case. A receiver with five or seven power amps that could put out 90 or 120 Watts per channel continuously would be an expensive and large proposition, in transformer and power supply filter bulk, not to mention thermal considerations. My view is that these components are rated for intermittent output at maximum power, which can be considered a statistical allocation of resources. That they can go all the way intermittently is important, in terms of dynamic range of source material, that is, headroom. But practical application of these receivers is not going to require continuous maximum power output. That said, I have not made any quantitative measurements of my bi-amped configuration, and I'm not sure I can hear a difference; it seemed louder and clearer, but that is just as likely due to the placebo effect as the actual bi-amping. I do know it cost more in cable, and I lost the presence channels, so in the end it probably wasn't worth the trouble.

CoolJazz

jviss wrote: »

... That they can go all the way intermittently is important, in terms of dynamic range of source material, that is, headroom. But practical application of these receivers is not going to require continuous maximum power output. ...

Another factor in these cases is that even though you present a full range audio signal to a power amplifier section, if you're driving a speaker section that includes a crossover as part of the load, then you are not pulling the same current through the output stage.

Let's say that in easier to understand English... The amplifier hooked to the high frequency section of the speaker is going to pull FAR less current than the amp section hooked to the woofer section!

The crossover in the high freq side presents a high impedance to the amplifier. So even though full range information is present to the amp output stage, it isn't asked to make any current, so that amp section is stressed very different than in a full range connection.

Often this "fools bi-amping" and so on misses this important distinction!

CJ

jviss

CoolJazz wrote: »

Another factor in these cases is that even though you present a full range audio signal to a power amplifier section, if you're driving a speaker section that includes a crossover as part of the load, then you are not pulling the same current through the output stage.

Let's say that in easier to understand English... The amplifier hooked to the high frequency section of the speaker is going to pull FAR less current than the amp section hooked to the woofer section!

The crossover in the high freq side presents a high impedance to the amplifier. So even though full range information is present to the amp output stage, it isn't asked to make any current, so that amp section is stressed very different than in a full range connection.

Often this "fools bi-amping" and so on misses this important distinction!

CJ

CJ, I'm relatively new to the discussion of bi-amping, but I have a pretty good foundation in electronics; so the comment on current is discordant to me. What I mean is that if you build a network that presents an 8Ω impedance to the amp, it doesn't matter that there's a tweeter woofer on the other side, the same current will flow for the same amp voltage output. The energy not used by a tweeter that would be used by a woofer will be dissipated in the crossover network. Is that not so?

Now, in practical terms, the characteristic impedance of speakers, and, indeed, of the crossover networks varies with frequency, so it may not play out like this in real life. But without knowing what that is, it's no possible to say what the current might be.

tonyb

Think about what an amp is. It stores power. It doesn't put out it's rated wattage/current at full bore all the time. Thats why it's important to have a power supply/amp that has the capabilities to feed the speaker the power when those quick transients come into play such as bomb explosions in movies for example. Look at the caps in a receiver, then look at the caps in an amp and tell me which one can store more power. Lots of variables here guys. Your source material, how damanding that is, the speakers capabilities, design,load, and the amps capabilities. Most standard entry level receivers have a 350-450 watt power supply for 7 channels, look at the specs. Now, the heavier the load, the more that power supply is stretched. Doesn't matter how you dice it up in a receiver, your using the same power supply for everything. Your source material tells the speaker to produce sound at x level depending also on the volume, the higher the volume, the more is asked of the speaker, the speaker then asks the power supply to give it what it wants at x volume it's being asked to play at, when the limits are hit, the receiver says it's done, got nothin' left. You clip the receiver, fry a tweet or two then call Polk and say you have a defective speaker. I also believe that if you feel a need to bi-amp, in most cases, you bought the wrong speakers for your size of room and are trying to reach SPL's that are simply not possible with the gear you have.
The problem as I see it anyway, and is played out here on the forum time and time again, is some will eventually want to upgrade to those big towers they were drooling over. Some make a gradual step up, some go from bookies to RTIA9's, but never consider that the heavier load they keep putting on the 450 watt power supply and that will come back to haunt them in the way of blown tweeters because they have these nice big speakers and imediately want to crank the volume dial, sending the receiver into clipping. So as you progress in your upgrades, keep in mind the load you are representing to that receiver. We always say around here that the electronics should improve also as you keep stepping up the ladder. Unfortunately thats not the case as I see some still wanting to drive big towers in 7 channels from the receiver they had with the HTIB unit from last Christmas. Everything has it's limits gents.

F1nut

Excellent post, Tony.

CoolJazz

jviss wrote: »

CJ, I'm relatively new to the discussion of bi-amping, but I have a pretty good foundation in electronics; so the comment on current is discordant to me. What I mean is that if you build a network that presents an 8Ω impedance to the amp, it doesn't matter that there's a tweeter woofer on the other side, the same current will flow for the same amp voltage output. The energy not used by a tweeter that would be used by a woofer will be dissipated in the crossover network. Is that not so?

Now, in practical terms, the characteristic impedance of speakers, and, indeed, of the crossover networks varies with frequency, so it may not play out like this in real life. But without knowing what that is, it's no possible to say what the current might be.

You've pretty got it jviss. But in this case, and not spelled out in my comments, is that what's being discussed is a bi-ampable speaker. So you've got seperate inputs to the high side and the low side. Usually jumped.

The high side will be rated as 8 ohm load to the amp and the low side will also be an 8 ohm load. Either jumpered together or seperately. The reason why is the crossover. Otherwise the two 8 ohm drivers would run full range and be a 4 ohm speaker. But the crossover raises the impedance very high for the "underdesired" portion of the range.

So the high side for instance, presents a very high impedance to low frequencies and as a result presents very little current load to the output stage.

In a true bi-amp configuration, the crossover is prior to the amps and the speaker crossover is bypassed or removed. So each amp is only presented with a portion of the audio spectrum. This minimizes intermod between notes and is better in that way.

But the point I was making, and believe is sometimes missed, is that when presenting an amplifer section with full range information this does not necessarily make the PS deliver the same current to the amp as when the condition exists of the amp driving a crossover in the speaker. The output for the high section is unloaded from heavy current demands of the low frequencies even when the full range information is present.

Hopefully this will now make sense! Good topic!

CJ

rebuy

I agree with Tony, common sense.

GregKopp

I'm going to have to ask about this as well. I just got a set of TSi500's and I'm considering biamping them.

Right now I'm in a 7.1 configuration on an Onkyo TSX-806 receiver. Is it worth it to lose the rear channels and bi-amp the mains?

tonyb

In short, no, your receiver has plenty to drive those speakers to their full potential hooked straight up.

Richd82

Good post tonyb, well said.

GregKopp

Thank you, simple and easy answer.

rebuy

tonyb wrote: »

No such animal as bi-amping from a receiver. That has been a marketing gimmick that uses that termanology to take the back 2 channels from a 7.1 receiver and add that to the fronts. What that does though is gives less power to the remaining speakers. Considerably less. Your problem is your receiver, I believe we mentioned that already. You need one with preouts and now with the addition of the 12's, you'll certainly need an amp too. If you clipped the TSI's, the RTI 12's are harder to drive and you'll no doubt clip those more easily. So your answer is sell the Denon, get a receiver with preouts and an amp and you'll be good to go.

I bi-amp from an avr with good results. Have you ever done it?

tonyb

rebuy wrote: »

I bi-amp from an avr with good results.

If you say so.....and yes I have tried it. In 2 channel their was little benefit if any, in 7 channel it sounded worse.

I find this particularly funny comming from a guy who thinks using the metal straps on a speaker is bi-wiring.

Look, we can sit here all day and throw darts at each other if you want. If you like it, bi-amping from a receiver, who am I to tell you otherwise. Knock yourself out. If others ask for an opinion, I'll give mine and your certainly free to express yours too.

rebuy

That's nice that you try to discredit me with your snide remarks. Typical when you can't present a valid point but since I have not done this to you, keep showing me your true colors.

Tell me Mr. know it all, what do you call the configuration Polk uses to hook up their speakers, Is it a type of bi-wiring or does the signal go into the speaker directly can go through the crossover. If it goes thru the crossover, you don't need, binding straps, jumpers, or bi-wires for the top end. Or does Polk require you to do a basic bi-wire configuration to activate a second network inside the speaker. Do you know the difference in these two types of configurations or are you just to busy trying to insult people to look at what you are working with. Put on your thinking cap and keep your insults to yourself.

F1nut

rebuy wrote: »

I bi-amp from an avr with good results. Have you ever done it?

Bi-amping requires each amp to have its own power supply. Your AVR shares one power supply between all the channels. Therefore, it's not capable of bi-amping.

tonyb

Last thing I ever claim to be is a know it all.

The 2 sets of posts represent the lows and the high end of the speaker build. The straps connect the 2 sets of posts. Those straps are made of cheap brass so if you think the signal is better humming along brass,than copper, cool, run with it, but you'd be in the minority with that. Both sets of posts are connected to the crossover, you can't run with just one set of post for the speaker to work without the straps connecting them, or 2 sets of wire going to all 4 posts. More benefits obviously when bi-amping, but even then the purist in this hobby will say you have to have an external crossover. The 4 posts are there for bi-wire,bi-amping, nothing more,nothing less. Bi-wiring eliminates that brass jumper, and most just use regular good quality speaker wire to replace it. Some feel that sending a signal, uninterupted to each set of post garners some benefit over sending the signal to one set of posts, along a brass jumper or speaker wire, to another set of posts. It's about keeping the signal as direct as possible.

Now wether that whole shabang is audible or not is up for discussion. Some say yep, some say nay, guess it all depends on your ear, and the gear involved.

BTW- I don't need a thinking cap, my tinfoil one works very well. But....if you have a Carmel, California hat laying around, I'd be happy to take it off your hands.

Tankman

F1nut wrote: »

Bi-amping requires each amp to have its own power supply. Your AVR shares one power supply between all the channels. Therefore, it's not capable of bi-amping.

+1.rebuy,tonyb and F1nut are some of the most knowledgable guys in here and they are usually spot on.

Tankman

tonyb wrote: »

Think about what an amp is. It stores power. It doesn't put out it's rated wattage/current at full bore all the time. Thats why it's important to have a power supply/amp that has the capabilities to feed the speaker the power when those quick transients come into play such as bomb explosions in movies for example. Look at the caps in a receiver, then look at the caps in an amp and tell me which one can store more power. Lots of variables here guys. Your source material, how damanding that is, the speakers capabilities, design,load, and the amps capabilities. Most standard entry level receivers have a 350-450 watt power supply for 7 channels, look at the specs. Now, the heavier the load, the more that power supply is stretched. Doesn't matter how you dice it up in a receiver, your using the same power supply for everything. Your source material tells the speaker to produce sound at x level depending also on the volume, the higher the volume, the more is asked of the speaker, the speaker then asks the power supply to give it what it wants at x volume it's being asked to play at, when the limits are hit, the receiver says it's done, got nothin' left. You clip the receiver, fry a tweet or two then call Polk and say you have a defective speaker. I also believe that if you feel a need to bi-amp, in most cases, you bought the wrong speakers for your size of room and are trying to reach SPL's that are simply not possible with the gear you have.
The problem as I see it anyway, and is played out here on the forum time and time again, is some will eventually want to upgrade to those big towers they were drooling over. Some make a gradual step up, some go from bookies to RTIA9's, but never consider that the heavier load they keep putting on the 450 watt power supply and that will come back to haunt them in the way of blown tweeters because they have these nice big speakers and imediately want to crank the volume dial, sending the receiver into clipping. So as you progress in your upgrades, keep in mind the load you are representing to that receiver. We always say around here that the electronics should improve also as you keep stepping up the ladder. Unfortunately thats not the case as I see some still wanting to drive big towers in 7 channels from the receiver they had with the HTIB unit from last Christmas. Everything has it's limits gents.

+1,this is why i hang out in here.Really nice post Tonyb!.

WilliamM2

Tankman wrote: »

+1,this is why i hang out in here.Really nice post Tonyb!.

So you think that amps store power? And that large tower speakers are harder to drive than small bookshelf speakers? Any other misconceptions of his you agree with?

Tankman

http://www.audioholics.com/education/amplifier-technology/10-things-about-audio-amplifiers.For those who need too know.Hope it helps.

Tankman

http://www.audioholics.com/education/amplifier-technology/10-things-about-audio-amplifiers.This link should work.