preamp bi-amp device? - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 18 Old 01-13-2013, 08:36 PM - Thread Starter
Member
 
Sven26's Avatar
 
Join Date: Jun 2007
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I apologize if this has already been covered but I searched the forms and couldn't find anything...

Is there any sort of device which can be used to split the signal (rca level pre-out) to feed an external amp for bi-amping? My Onkyo 809 can bi-amp the fronts, which sound much better with bi-amping, but I have no option for bi-amping the center. I have considered an external amp but there is only one pre-out, so I have no idea how I'd bi-amp it (let's assume the amp I am considering is a 2 channel and has no option for bi-amping). I have no interest in a DIY solution...does anyone know if there is a product out there for this?

Thanks in advance for any help I get.
Sven26 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 01-15-2013, 05:22 PM - Thread Starter
Member
 
Sven26's Avatar
 
Join Date: Jun 2007
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
nothing?
Sven26 is offline  
post #3 of 18 Old 01-15-2013, 06:08 PM
AVS Special Member
 
Legairre's Avatar
 
Join Date: Feb 2001
Posts: 4,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 58
You would use an RCA splitter out of the receiver. For instance run the splitter off the receiver's left front channel. Then connect your RCA cables to each end of the splitter and connect one to one amp channel and the other to the amps other channel. Then run your speakers wires for the highs from one amp channel and the lows from the other channel. Something like this that you can get at Best Buy or Radio Shack http://www.bestbuy.com/site/Dynex%26%23153%3B+-+RCA+Y-Adapter/9390633.p;jsessionid=46ABCC7F62CBA212C13D2FE8B0F30C7A.bbolsp-app06-20?id=1218097973202&skuId=9390633

"What do you mean it's too loud? My ears aren't even bleeding yet!"

Legairre is offline  
post #4 of 18 Old 01-16-2013, 04:52 PM - Thread Starter
Member
 
Sven26's Avatar
 
Join Date: Jun 2007
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
but that wouldn't separate the high and low frequencies...I thought the benefit of bi amping was driving a narrower frequency range.
Sven26 is offline  
post #5 of 18 Old 01-16-2013, 05:02 PM
585-645-1006
 
jdsmoothie's Avatar
 
Join Date: Sep 2007
Location: Orlando, FL
Posts: 43,961
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 775 Post(s)
Liked: 1433
As with virtually every other AVR on the market, the 809 is simply sending the same exact signal to each set of speaker posts on the FL/FR speakers.

---------------------------------
"JD" – jd@avscience.com ; shop.avscience.com ; 585-645-1006, AVScience - Authorized dealer for AV Gear 
Mon - Fri: 8am – 8pm EST (Sat/Sun too, will return call if I don't pick up)
Call for pricing on Denon, Marantz, Yamaha, Onkyo, Klipsch, Def Tech, Atlantic Tech
** Think the AVR is defective?  Reset the microprocessor 4-5 times. 
jdsmoothie is offline  
post #6 of 18 Old 01-16-2013, 05:15 PM
AVS Special Member
 
Legairre's Avatar
 
Join Date: Feb 2001
Posts: 4,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 58
It is bi-amping but it's passive bi-amping which uses one amp to drive the highs and one to rive the lows if your speakers have the bi-amp bars(removed). It sounds like you want active bi-amping which will involve adding a crossover network. You can read about both of them here. http://www.chuckhawks.com/bi-wire_bi-amp.htm just scroll down a bit. Also since you are using the receiver's bi-amp feature you are "passive" bi-amping your front L/R speakers now because the receiver does not inset a separate crossover network, which is why I posted a passive crossover solution to externally match what your receiver is doing internally (passive bi-amping) by sending the same signal to the highs and lows, but using separate amps to drive the highs and lows.

"What do you mean it's too loud? My ears aren't even bleeding yet!"

Legairre is offline  
post #7 of 18 Old 01-16-2013, 10:35 PM
Newbie
 
hexomega's Avatar
 
Join Date: Feb 2012
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Behringer DCX2496 should do the trick, but you'll need some XLR to RCA cables to interface with non-balanced preamps and amps.
hexomega is offline  
post #8 of 18 Old 01-17-2013, 07:18 AM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 6,034
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Liked: 255
dbx, Marchand, Bryston, etc. all make active analog (Marchand also makes passive) line-level crossovers. The dbx 223 units are fairly inexpensive and would probably work for you. I have one in my system. Available at Sweetwater Sound and a plethora of other places.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #9 of 18 Old 01-17-2013, 07:34 AM
AVS Special Member
 
Theresa's Avatar
 
Join Date: Nov 2010
Location: Minnesota
Posts: 2,430
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
Quote:
Originally Posted by DonH50 View Post

dbx, Marchand, Bryston, etc. all make active analog (Marchand also makes passive) line-level crossovers. The dbx 223 units are fairly inexpensive and would probably work for you. I have one in my system. Available at Sweetwater Sound and a plethora of other places.

My experience with analog electronic crossovers was negative. They degraded the sound. The miniDSP has not degraded the sound of my system.
Theresa is offline  
post #10 of 18 Old 01-17-2013, 09:13 AM
AVS Special Member
 
JHAz's Avatar
 
Join Date: Mar 2009
Posts: 3,924
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 81 Post(s)
Liked: 152
Quote:
Originally Posted by Sven26 View Post

but that wouldn't separate the high and low frequencies...I thought the benefit of bi amping was driving a narrower frequency range.
When you biamp with your receiver, it's passive biamping.

Your speakers already have crossovers. Besides needing to know how to duplicate what the existing crossovers do (crossover point, slope, possibly notches for tweeter resonances) you would have to completely remove or bypass the crossovers in the speakers to actively biamp. Otherwise you will put a fairly deep notch in their frequency response as the line level filters slope the lows going to the tweeter, for example, then the passive speaker level filter further cuts the highs going to the tweeter. A fairly daunting task for a person who lacks experience. Teresa, as I understand it, designs and builds her own speakers, so she has a lot more latitude than somebody attempting to reengineer typical commercial speakers for active biamping.
JHAz is offline  
post #11 of 18 Old 01-17-2013, 09:13 AM
AVS Special Member
 
JHAz's Avatar
 
Join Date: Mar 2009
Posts: 3,924
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 81 Post(s)
Liked: 152
Quote:
Originally Posted by Sven26 View Post

but that wouldn't separate the high and low frequencies...I thought the benefit of bi amping was driving a narrower frequency range.
When you biamp with your receiver, it's passive biamping.

Your speakers already have crossovers. Besides needing to know how to duplicate what the existing crossovers do (crossover point, slope, possibly notches for tweeter resonances) you would have to completely remove or bypass the crossovers in the speakers to actively biamp. Otherwise you will put a fairly deep notch in their frequency response as the line level filters slope the lows going to the tweeter, for example, then the passive speaker level filter further cuts the highs going to the tweeter. A fairly daunting task for a person who lacks experience. Teresa, as I understand it, designs and builds her own speakers, so she has a lot more latitude than somebody attempting to reengineer typical commercial speakers for active biamping.
JHAz is offline  
post #12 of 18 Old 01-17-2013, 11:03 AM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 6,034
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Liked: 255
Quote:
Originally Posted by Theresa View Post

Quote:
Originally Posted by DonH50 View Post

dbx, Marchand, Bryston, etc. all make active analog (Marchand also makes passive) line-level crossovers. The dbx 223 units are fairly inexpensive and would probably work for you. I have one in my system. Available at Sweetwater Sound and a plethora of other places.

My experience with analog electronic crossovers was negative. They degraded the sound. The miniDSP has not degraded the sound of my system.

I'll just say my experience differs and leave it at that. I have only heard one miniDSP system, however.

dbx and DEQx (among others) make digital crossovers, as well as the Behringer unit mentioned earlier, but the value leader certainly has to tbe the miniDSP for a digital unit.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #13 of 18 Old 01-17-2013, 12:11 PM
AVS Special Member
 
Theresa's Avatar
 
Join Date: Nov 2010
Location: Minnesota
Posts: 2,430
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
Quote:
Originally Posted by DonH50 View Post

I'll just say my experience differs and leave it at that. I have only heard one miniDSP system, however.

dbx and DEQx (among others) make digital crossovers, as well as the Behringer unit mentioned earlier, but the value leader certainly has to tbe the miniDSP for a digital unit.

I didn't know dbx made a digital crossover. Sorry smile.gif
Theresa is offline  
post #14 of 18 Old 01-17-2013, 01:24 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 6,034
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Liked: 255
No need, you were right that my post referred to one of their analog models (223). The dbx digital models are the DriveRack series and are nice but much more expensive.

Note dbx, Rane and other pro crossovers generally include XLR connectors for those with balanced IO. I didn't include Rane initially because their "cheap" ($500) models don't go low enough in my application (sub crossover).

This all reminds me that I really need to get a miniDSP just to play around with in my spare time... Soon as I get some!

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
post #15 of 18 Old 01-18-2013, 05:13 AM - Thread Starter
Member
 
Sven26's Avatar
 
Join Date: Jun 2007
Posts: 49
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks for all the info. I didn't realize that my receiver was just duplicating the signal to both posts. I did notice an improvement in the sound (hopefully real, and not imaginary like the placebo effect mentioned in the linked article) perhaps due to more power being provided to the speakers.
Sven26 is offline  
post #16 of 18 Old 01-18-2013, 05:47 AM
AVS Addicted Member
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,336
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 711 Post(s)
Liked: 1153
Quote:
Originally Posted by Sven26 View Post

but that wouldn't separate the high and low frequencies...I thought the benefit of bi amping was driving a narrower frequency range.

As others have pointed out, passive biamping does not fully separate the high and low frequencies. Both sets of amplifiers amplify the same signals.

Separating the amplification of high and low frequencies would only have an audible advantage if the amplifier had audible intermodulation distortion. Good modern audio gear doesn't have this problem.

Your education about the benefits of biamping seems to be simplistic. The major benefit of biamplification is the use of active crossovers and the elimination of passive crossovers. Active crossovers can be more fully optimized to maximize system performance. The separation of signals into narrower frequency ranges is a secondary effect, not the major goal.

Many home audio systems do use active biamplification, and the benefits that we see in those applications are very instructive. The most common application of biamping in modern home audio systems is the use of powered subwoofers.

When we use powered subwoofers:

(1) We use active crossovers that route high and low frequencies through different amplifiers with different power ratings that are tailored to the needs of different speakers and installations.
(2) Our powered subwoofers use amplifiers that are themselves tailored by professional engineers to meet the needs of the exact speaker driver that they are used with.
(3) The use of active crossovers enables easy selection of crossover frequencies to meet the varying needs of different installations.
(4) Because our active crossovers split the frequencies up, they can make more efficient use of available amplifier power, since the power amps don't have to amplify signals that the speaker they drive aren't handling.

As you can see, this is so different from passive biamplification that there is simply no comparison.
arnyk is offline  
post #17 of 18 Old 01-18-2013, 05:55 AM
AVS Addicted Member
 
arnyk's Avatar
 
Join Date: Oct 2002
Location: Grosse Pointe Woods, MI
Posts: 14,336
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 711 Post(s)
Liked: 1153
Quote:
Originally Posted by Sven26 View Post

Thanks for all the info. I didn't realize that my receiver was just duplicating the signal to both posts. I did notice an improvement in the sound (hopefully real, and not imaginary like the placebo effect mentioned in the linked article) perhaps due to more power being provided to the speakers.

The fact that most people hear differences when they implement passive biamplififcation may be real or just an illusion. If it is real, it happens because the high/low frequency balance of the speaker is being changed from what it was designed to be to some other thing that was probably chosen at random. The change was actually an unintended consequence because the actual change, if well-executed and theoretically speaking, should have no audible benefits at all.

If you think about all of the testimonials that you have read about people making changes to their audio system, almost 100% of the time an improvement is claimed. If you actually do serious work with audio systems you quickly find that it is very easy to make changes that have no audible effects, and some of the time the changes actually make things worse. The fact that almost 100% of the reports claim improvements is actually an indictment of the reports themselves. Real work with audio technology is simply not always that rewarding. What you are more likely to be seeing is the fact that people tend to be self-affirming. They would like to believe that everything they do is good and helpful. Life is often a bit more complex than that!
arnyk is offline  
post #18 of 18 Old 01-19-2013, 02:19 PM
AVS Special Member
 
DonH50's Avatar
 
Join Date: Feb 2010
Location: Monument CO
Posts: 6,034
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 150 Post(s)
Liked: 255
Quote:
Originally Posted by Sven26 View Post

Thanks for all the info. I didn't realize that my receiver was just duplicating the signal to both posts. I did notice an improvement in the sound (hopefully real, and not imaginary like the placebo effect mentioned in the linked article) perhaps due to more power being provided to the speakers.

If you have a single 100 W amp driving full-range, highs and lows, and then hook up two 100 W amps, one driving the lows and the other the highs, there is no net power increase. It is not the same as using a single (or two) 200 W amplifier. You have just split up the frequency range over which the amplifiers operate. If you want more power, you need to get a more powerful amplifier.

Plus all that Arny has said... Bi-amping, passive or active, is generally not about more power.

"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley
DonH50 is offline  
Reply Receivers, Amps, and Processors

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off