to bridge or bi-amp?

stevew14 · February 2003

I just picked up another carver tfm 35x and will be using one for each of my two rti150s. I am leaning toward vertical bi-amping, but have also thought about bridging each one instead. Bi-amping would be simpler for me from a cabling standpoint but I am interested in your thoughts on the difference.

Thanks

RuSsMaN · February 2003

Haven't we already done this one? I think George pretty much summed up the pros/cons here:

http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=7670

-Russ

stevew14 · February 2003

Just thought some others might have thoughts on bridging vs bi-amping. Sorry to cause any redundancy issues.

RuSsMaN · February 2003

No biggie, I was just asking. I kind of wish you had the cabling to try both on your particular rig, and report back.

-Russ

mantis · February 2003

steve,
what exactly are you trying to accomplish here?My thoughts of all this I'll call it madness is why not seek a better 2 channel amp?
I never tried this myself,thats why I ask WHY???

Tour2ma · February 2003

For better or worse, I've moved this discussion back over to the "Electronics" area where I think it belongs.

Here's the link:
http://clubpolk.polkaudio.com/forum...=&threadid=7670

George Grand · February 2003

Mantis,

With all due respect, as an audio installer, or salesman, or whatever it is you do PROFESSIONALLY in the field of audio, to call bi-amping/bridging MADNESS, indicates a pretty large lack of audio knowledge. Some speakers are DESIGNED to be bi-amped, and some just plain sound better.

Try the book "Good Sound" by a lady named Laura Dearborn. Exceptionally well written in easy to understand language, it is a good starting point for novices.

I'm out of here for an overnighter to Naval Air Station Lemoore in California.

George Grand (of the Jersey Grand's)

mantis · February 2003

George,
Maddness is slang by man.......and thats how I feel about bi amping speakers in general.I have seen tons of high end systems and no one seems to be doing that anymore,at least the ones I have seen.
When I worked at Soundex up in Willow Grove, Pa......I got to meet alot of high end Audiophiles.I didn't run into any systems bi amped........bi wired yes alot of them do it,hell all of them do it with the B&W N800's,N801's etc in that line.With gear like Audio research,Krell,Mark Levinston,I guess THEY believed they hit the audio nirvana they where looking for.
I never gave bi amping a thought.I'm really not a 2 channel guy anyway.I'm more into Theater Bro.
That book you recommended,I'll have to pick it up being a rookie and all.Thanks for the help.
By the way I'm a Home Theater installer,Programmer.

TroyD · February 2003

Dan, the theory of biamping and biwiring is VERY similar. Take some time and study up on it, go back and reread some of the posts on it.. People have been doing it for years.

BDT

mantis · February 2003

Thanks Troy I understand Bi amping and bi wiring.
I would however will take some time to deeper my understanding as I don't see the need.Bi wiring does improve the sound quality,Without hearing it and I don't care to comment on what I haven't experienced,I do believe sound quality could further be improved.Taking the load off of the single amp and dividing it over 2 amps would reserve dynamic power.
As I said before,I'm not a 2 channel guy.If I was a hardcore 2 channel guy,I would explore this subject further.
George recemended a book called "good Sound" by Laura Dearborn,I'm gonna look for it.

TroyD · February 2003

Maybe I'm missing something here.

Are you saying you don't understand how biamping would be beneficial but you know that biwiring sounds better? The theory is exactly the same. Really, it doesn't matter if your talking 2ch or 10ch, it's the same.

In my own experience, I've found biwiring/amping depends A LOT on your amp. For example, I've tried biwiring my CS400i off my Denon 1801 receiver. No real difference that I could tell. (I recommend replacing the stock jumpers with wire, but that's me). Now, I have also tried it using a Carver amp and can tell you that there is a definate difference. For the record, my center is now biamped off a Carver m0.5t.

My point here is that biwiring is not a gimmie in terms of improvement. I think it depends a lot on your sources. I also belive that there is a lot of psychology involved as well. It MUST sound better, right? Anyway, that's my .02

BDT

mantis · February 2003

ToryD,
I think it's in my logic that my thinking "thinks"this.Bi wiring helps seperate the frequencies,so the wire doesn't have to carry all of them.Using 2 amps would do the same thing,your right.But I think using a better quality amp would yield better sound performance then using 2 of the same amps.
I own the Rotel rb960bx dual mono amp.I thought of buying another one and bi amping my mains(Russ found it on E bay).But I didn't go for it for a lack of drive for it.I'm all for better sound Bro,This road I never traveled.Bi wiring I have a couple of times on my own and Hundred of times in the field.
Speaking of in the field,I haven't ran across bi amping yeat.I have been an Installer for over 3 years now and I have done tons of jobs,2 channel as well......no bi amping.So You know what????For the Hell of it, when time allows,I'm gonna play with the Idea in the store and see whats what...........
What else have you done with Bi amping Troy???I'd like to read more about your experience.
Thanks dude.

Gary Robertson · February 2003

Hey Mantis...
Where do you work. Maybe i could buy something from you..does the store do mail orders and a catalogue?? i could use some upgraded speaker wire--do you have Tara's or Transparants" or Monster ? etc.

TroyD · February 2003

How does the wire figure into the equation? The theory behind biamping/biwiring has NOTHING to do with wire.

The logic is in the crossover. In a nutshell, the benefit is derived from the highs and mids/lows being powered independently of each other. Because the mids/lows require more power, they can draw more power without at the same time drawing more power to the tweeter. See the theory?? Incidentally, that's why you can't biwire the RT1000i's because the binding posts don't correspond to the crossover.

If you follow that logic of powering the highs and the mid/lows independently than it would follow that biamping would make even more sense, would it not? You like the sound of your speakers biwired? Imagine having (if you use identical amps) twice the power available going into each speaker.

For the record, I've also tried the same thing with my B&W 601's with similar results. IMO, from a midline reciever, the benefits of biwiring are a subject of debate. I don't see the night and day difference. IMO, I think you are better off just making a decent jumper to replace the stock one.

Again, just MY .02.

BDT

TroyD · February 2003

Gary,

www.tweeter.com

BDT

dcarlson · February 2003

Troyd, I'm not sure you understand the theory behind bi-wiring. If you use some high quality speaker cable you'll notice difference between mono-wiring and in my case "Mantis wiring".

You seperate the lows from highs which does make a difference. Wether the difference is good is up to personal preference.

Here's a link for ya.

http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/biwire/Page1.html

George Grand · February 2003

Mantis,

What I am trying to point out here is this HYPOTHETICAL SITUATION:

You either sell or install equipment. You are asked by a customer if he should bi-amp a speaker. The speaker has provisions for bi-amping. These provisions were included for a reason. The speaker designer is a HIGHLY RESPECTED speaker designer, with many great accomplishments to his credit. The customer just might be aware of that. YOU tell the customer, "Madness this bi-amping!" The customer has every right to question YOUR judgement. He or she may well even think a lot less of any other "advice" you may have provided. Think about it.

It has NOTHING to do with 2 channel alone, as one could bi-amp in home theater multi-channel set-up's as well.

Get the book friend.

George Grand (of the Jersey Grand's)

TroyD · February 2003

Carlson,
I'm SURE I understand the theory.

Re-read it again. It only serves to validate my point. The wire is only a conduit. The magic lays in the crossover, not the wire. If you understand that, than you will understand why everyone says that you cannot biwire your RT1000.

Using your logic, if I took a non-biwirable speaker (say, an RT7) and ran a double run of each wire than that would be biwiring? How about if I doubled the gauge? Instead of using 16awg, 8awg?? No, of course not.

Look, guys, this isn't a pissing contest over a subjective issue. The science here is cut and dry. We can argue and scream all you like but facts are facts. If you don't understand it, well, I'm sorry but there isn't much else that I can do.

BDT

mantis · February 2003

George,
Point taken.If one of my customers asked if he/she should bi amp there speakers,I would reply exactly like this"Sir/mam The speakers can be bi amped,We can go ahead and order you 2 more amps.We will need to add another pair of audio cables and if need be Y adapters to spit the audio signals.In theory, this should make for cleaner sound quality.
My point is I wouldn't tell anyone not to do this,I'm all about better Hi fi.As I said before,I never traveled down this path to better my personal system,and I haven't ran into it in the field.I work for Tweeter and I don't see our customers trying this,there has been some that could maybe travel the road of bi amping,but the percentage is less then 5%.
Over at Soundex,when I worked there,The percentage was alot higher,like 70 to 80% of the customers there knew exactly what they where buying,have been into audio forever and upgraded all the time.To tell you the truth,I am suprised I haven't run into anyone bi amping there speakers.There is this one guy who owns about 1 million dollars of aduio gear.He has 2 listening rooms in his basement.He owns just about everything Soundex carries.He even had a pair of the orignal Natulis B&W speakers,the one's that looked like a sea shell.He didn't bi amp anything.He used Mono blocks of all different kinds to power his fleet of speakers.You would like this dude,he has a closet of just wire.Man when he showed it to me,he has hangers in there with wire hanging from them.That closet must be worth 60 grand......sick I'll tell yeah.
Well I'm not going to beat this into the ground.My question to steve was why he wanted to do this?what was the goal?Thats all,I'm not knocking Bi amping.
I plan on doing some experimenting myself with the idea.At the store we have B&K amps I can try this out with.

weavercr · February 2003

IMO Bi amping make more of a difference than Bi wiring. Since the highs and lows are amplified in different amps un like bi wiring where the lows still effect the highs inside the amp.

Tour2ma · February 2003

Weaver, I was just going to ask a question related to your post when it popped in. It was to George and Troy, but chime in if you can please. It is:

George, Troy,

First, I think you know I believe bi-amping has value. A few honest questions though

For full benefit wouldnt you want the crossover before the amplification stage, i.e., between the pre-amp and amp? Seems that asking both amps to amplify the entire signal only to have the speakers crossovers filter out the portion that is not usable by the drivers they serve, is a waste. Especially seems so in the case of the HF amp (or channels).

Do the amps themselves address this via receiving feedback of the unused signal? (I thought feedback loops were strictly internal to the amp, but may be wrong.)

Is it possible to downsize a speakers crossover for this service by simply scaling down the components for the low voltage signals present before the amp? Does anyone do this?

Aside to Troy, good to see you posting. Still thinking of yall over there.

An aside to all,
Id like to point out that in dcarlsons link, Figure 3 is in essence a diagram of bi-wiring with jumpers left in place. A lot of misinformation on this being damaging to amps and speakers in another thread. Taint so

TroyD · February 2003

Tour,

Excellent questions. I don't know that I have the definitive answers. I have read though (and can see the logic) that having a crossover in a vertical biamp set up is the ideal situation . To be honest, my experience with vertical biamping that I don't think I'd want to offer an opinion.

I will say, and in a perfect world, my preference (in theory) would be for a vertical biamp setup, like RonP has. In this case, each channel of the amp see the same information so the chance of bleed through or any other unwanted consequences is pretty much eliminated.

BDT

dcarlson · February 2003

This is the last time I post anything on bi-wiring, I promise.

This is taken from What HIFI.

Biwiring involves the use of two runs of cable between an amp and a suitable pair of speakers, and works because the return feeds between the speakers and amplifier aren't carrying full-range signal, but only that relevant to the appropriate part of the speaker.

Right? The RT1000i has a fixed sub crossover at 80Hz. Anything at or below 80Hz gets processed through the internal subwoofer amp in the speaker. The signal coming from the receiver/amp to the speaker is still being separated at a crossover point. It may not be separating the tweeter and the midrange drivers but it's still separating something. Is it the best term to use? I don't know, but bi-wire means 2 wires, it's not called crossover-wiring.

That's it, I'm done, never again.

I'm sorry if I've upset some people, it wasn't my goal. It all started because I noticed a difference when (I'm not going to use the term) I ran 2 sets of wire to my speakers and wanted to let people know that I did notice a difference.

TroyD · February 2003

Carlson,

No worries mate! Your not upsetting anyone but you aren't getting what biwiring and biamping really involves.

Okay, lemme try this one more time.

In a standard speaker, take the RT35i. There is a crossover which essentiall directs the signal to the appropirate driver. Well, for the RT35i, there is only one pair of inputs (binding posts) connected to the crossever so you hook up one pair of speaker wires and away you go.

Now, take the B&W 601's that I have. There are TWO sets of binding posts which means that you can drive the upper frequencies independent of the lower ones. You can either hook up the speaker with ONE set of wires with some type of jumper in place or with a biwire/biamp type setup. If you run ONE set of cables to ONE set of posts and remove the jumper you are only going to get sound out of either the tweeter of the mid/bass (depending on which one is connected). See how this works?? This allows you to drive the high frequencies independent of the low frequencies which has all sorts of benefits.

OK, NOW, in YOUR case, with the RT1000i. Yes you have TWO sets of binding posts which would lead you to believe that you can biwire/biamp these speakers. It's just not so. There is NO crossover associated with the binding posts. One set feeds the tweeter and midbass and one is simply a high level sub input. I know it's confusing but if you give Ken Swauger a call, he can explain to you, much better than I can , why this all makes sense.

BDT

weavercr · February 2003

Hey Troy why dont you use RT55i vice B&W 601s in your examples.

TroyD · February 2003

I own the 601's and not the 55's

Charlie,

Do me a favor, swing by my house from time to time and run my stereo rig, would ya? It PAINS me to think if it just SITTING there and I know Wendi won't ever turn it on. There is beer in the fridge in the garage, help yourself.

BDT

Tour2ma · February 2003

Originally posted by dcarlson
This is the last time I post anything on bi-wiring, I promise.
This is taken from What HIFI.
Biwiring involves the use of two runs of cable between an amp and a suitable pair of speakers, and works because the return feeds between the speakers and amplifier aren't carrying full-range signal, but only that relevant to the appropriate part of the speaker.
That's it, I'm done, never again.
I'm sorry if I've upset some people, it wasn't my goal. It all started because I noticed a difference when (I'm not going to use the term) I ran 2 sets of wire to my speakers and wanted to let people know that I did notice a difference.

DC,
Dont quit on us. I/ We absolve you of your promise. No ones upset, annoyed maybe, but not upset.

kidding

Not sure where your not called cross-over wiring comment came from, but if it was around my aside on the jumper wires, I was just addressing another thread discussion. It was nothing back at you. My 2 Ch rig has been bi-wired with jumpers for a long time. At minimum Id expect the impedance reduction in adding the second run could make a difference. To what degree depends on the gauge wire employed, the length of the run and the power youre pushing. So even if your Polks crossover wiring does not lend them to true bi-wiring. A difference could be noticed.

To my mind bi-amping carries all the bi-wire benefits, since it requires four speaker wire runs, with the potential for more. Were all happy you noticed a difference with your bi-wiring. Me, Im trying to learn here, and the Q&A and debate all leads to that. And on that note

The What HiFi quote you posted makes no sense to me. How could the speaker return feeds only carry the part relevant to the appropriate part of the speaker to the amp? Isnt that the part it used? Seems to me the unused part, intended for the other set of drivers, is what, if anything, would be returned. Again, not a challenge here, just an attempt to understand

MxStYlEpOlKmAn · February 2003

Couldn't you biamp all your biampable speakers in your HT? Say you biamped your center - surrounds - mains - side surrounds - rear center......wouldnt that b alot of amps? eh?

Ron-P · February 2003

I have my mains and center bi-amped, 3 stereo amps is all that is needed.

Peace Out~:D

dcarlson · February 2003

Tourma,

The crossover-wiring comment came from TroyD's definition of bi-wiring (What I take from it anyway and agree with, partially), where you bi-wire based on a cossover point between the highs and the mids/lows.

I say, what does it matter at which frequency the crossover point is at? Between highs/mids and lows or highs and mids/lows it's just the crossover points and the wiring is still separating the signals between the binding posts.

What I take from the What HIFI quote is this: a speaker is going to draw what it needs to produce sound. If you have a 2 way speaker bi-wired, the tweeter will only draw the signal the crossover will allow it to see. The woofer will also only draw the signal the crossover will allow it to see. Thus separating the Highs from the Mids/Lows in the wire run.

I'm definitely not giving up on this forum, I thought I was done with bi-wire topic. I think I've said my peace...but I guess I just broke my promise.

gidrah · February 2003

Bi-wiring has benefits, bi-amping has these same benefits with the potential for more.

Bi-wiring separates the hi&low, but the connection at the amp is a mix. If it's together at the beginning it'll be together at the end. Why not just buy better cables and replace the jumper.

Bi-amping separates the hi&low at the amp. With a separate channel driving each. Each channel gets the same input, but the draw on each is separated. Also there is the benefit of more surface contact at the terminals.

Then there is the crossover prior to amplification. Good call Tour2ma! This is where the possibilities really take hold. You're only driving each channel within a limited freq. range which can extend your dynamics considerably, you can tailor your amps to the range desired, and you can experiment with different cables and drivers.

P.S. Who's got an extra active X-over laying around.

to bridge or bi-amp?

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