Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 3 1 2 3
Bi Amping confusion
#165323 04/14/07 01:37 AM
Joined: Jan 2004
Posts: 13,840
Likes: 13
shareholder in the making
OP Offline
shareholder in the making
Joined: Jan 2004
Posts: 13,840
Likes: 13
Ok, I'm trying to understand Bi Amping 80's with seperate monoblock amps. I've read many articles online that talk about "true" bi amping is when you disable the speakers "passive" crossover and use a seperate external "high pass" and "low pass" crossover. See schematic below.



Now, I'm trying to decide if the Axiom m80's have a "passive" type crossover or not, I do not believe they do. Below is a portion of a website that was talking about biamping. You see it mentions most speakers that have dual speaker terminals have a built in "high" and "low" pass crossover design, versus a passive design.

Bi-amping and bi-wiring
It's becoming more common for higher-performance speakers to include dual sets of terminals, usually binding posts. Models with dual terminals almost always also feature a special type of crossover with separate "high-pass" and "low-pass" sections.

Speakers with dual sets of terminals work fine when used with a single set of speaker cables. In fact, they usually come from the factory set up for conventional operation, with "jumpers" installed between the two sets. These jumpers can be easily removed for bi-amping or bi-wiring.
Bi-amping means that instead of driving a speaker full-range with a single channel of amplification through a single set of speaker cables, you actually connect two sets of cables, with each set carrying the signal from a separate amplifier (or amp channel). This way, both low-frequency drivers (woofers) and high-frequency drivers (tweeters) receive dedicated amplification.


Bi-wiring involves connecting two sets of cables to your speakers, like bi-amping, but both sets of cables connect to the same set of output connectors on your receiver or amplifier. Bi-wiring doesn't deliver more wattage to your speakers, so it doesn't offer as dramatic a sonic improvement as bi-amping. Still, many audiophiles find that it offers subtle improvements in imaging and detail.


So since the 80's are the top of the line Axiom speaker, do they have a high and low pass design, or passive? If they are setup with a high and low pass crossover design, they should be able to be "truely" bi amped. I also talked to JC at Axiom tonight and he said if you have seperate monoblock amps that are 300 watts each, you would then be providing the 80's 600 watts, not 300watts like many of you have said would happen?

Thanks, Randy


M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


Re: Bi Amping confusion
SirQuack #165324 04/14/07 01:47 AM
Joined: Jan 2004
Posts: 13,840
Likes: 13
shareholder in the making
OP Offline
shareholder in the making
Joined: Jan 2004
Posts: 13,840
Likes: 13
I used the search function and could not find anything in regards to the 80's, however, I did find this statement by Alan in regards to the 60's.

I agree that in the M60s, it's a low-pass filter to the woofers, a high-pass to the midrange (above 200 Hz), and then another high-pass to the tweeter for frequencies at 2 kHz and higher.

So, I can only assume the 80's have a similar design. With that said, I'm thinking they can "truely" be "bi-amped" using 2 seperate monoblock amps (not multi channel), 2 seperate speaker wires, and removing the gold strap on the speaker terminals? And, you would be "truely" dedicating 300 watts to the woofers, and 300 to the mid/highs?

Thanks, Randy


M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


Re: Bi Amping confusion
SirQuack #165325 04/14/07 01:58 AM
Joined: May 2002
Posts: 10,654
shareholder in the making
Offline
shareholder in the making
Joined: May 2002
Posts: 10,654
No Randy, the requirement for "true" biamping(which might be of no worthwhile benefit anyway)is that there has to be an external crossover ahead of the amplifiers(as shown in that schematic)and any internal speaker crossover(dividing the amps' output in the same frequencies)has to be removed or bypassed. Also, that quoted material contains a liberal serving of drivel.

Re: Bi Amping confusion
SirQuack #165326 04/14/07 03:23 AM
Joined: Jan 2007
Posts: 10,490
Likes: 116
M
shareholder in the making
Offline
shareholder in the making
M
Joined: Jan 2007
Posts: 10,490
Likes: 116
Quote:

So since the 80's are the top of the line Axiom speaker, do they have a high and low pass design, or passive? If they are setup with a high and low pass crossover design, they should be able to be "truely" bi amped. I also talked to JC at Axiom tonight and he said if you have seperate monoblock amps that are 300 watts each, you would then be providing the 80's 600 watts, not 300watts like many of you have said would happen?




Randy,

Page 2 of the manual is very clear. Based on the description in the manual, I would expect the 80s to have two passive cross-overs: one for the bass drivers and one for the mids and tweeters. These are effectively connected in parallel when using a single amp and disconnected from each other when the bridging bars are removed for bi-amping.

You really do need to contact Axiom about power handling however. The 80s are rated to 400W RMS continuous. How exactly this is divided between the drivers when bi-amping is not clear. I know that Axiom claims to drive these at 700W but will Axiom warrant them at these levels? And if so, the question still stands, how is this power divided amongst the drivers? And what exactly is the impedance of each section (I would expect 12 Ohms for the mids and tweeters and 6 Ohms for the woofers; which would translate to 133W for the mids and tweeters section and 267W for the woofers).

So I guess you are considering two MPS-1s ?

Re: Bi Amping confusion
SirQuack #165327 04/14/07 03:39 AM
Joined: Jan 2007
Posts: 10,490
Likes: 116
M
shareholder in the making
Offline
shareholder in the making
M
Joined: Jan 2007
Posts: 10,490
Likes: 116
And if you did feed 300W into each, the total would be 600W. Just make sure Axiom is willing to warrant this.

Re: Bi Amping confusion
Mojo #165328 04/14/07 03:59 AM
Joined: Feb 2007
Posts: 43
G
buff
Offline
buff
G
Joined: Feb 2007
Posts: 43
The mids and tweeters should handle less power than the woofers. In two-way prosound active speakers you typically see 300 - 400 watts provided to the woofer and 100 watts to the tweeter/horn. 300 to the mids and tweeters seems like alot.


M80,VP150,QS8,ERD-1,XPA-2,XPA-5,UMC-10,PS3,XBOX360,Dish VIP622,PB13 Ultra,Panasonic PT-AE3000U
Re: Bi Amping confusion
gmeyer #165329 04/14/07 04:12 AM
Joined: Feb 2007
Posts: 43
G
buff
Offline
buff
G
Joined: Feb 2007
Posts: 43
You could run the mids and highs off of your Denon and the lows off the MPS-1 the passive crossovers in the M80's will protect the drivers from unwanted frequencies, But both amplifiers will waste energy amplifying the whole frequency range which the passive crossovers in the M80's will dissapate as heat. Not as efficient as an active crossover system which prevents the amplifier from wasting power on frequencies that are not used by removing them before the amplifier.


M80,VP150,QS8,ERD-1,XPA-2,XPA-5,UMC-10,PS3,XBOX360,Dish VIP622,PB13 Ultra,Panasonic PT-AE3000U
Re: Bi Amping confusion
gmeyer #165330 04/14/07 01:59 PM
Joined: Mar 2007
Posts: 79
K
old hand
Offline
old hand
K
Joined: Mar 2007
Posts: 79
Hi all, MoJo is correct in that the manual states how to bi-amp and mentions nothing of external x-overs. The reason they include the dual binding posts is because of the speakers abilty to be bi-amped in this manner without any external devices.

When you bi-amp you are still ONLY running 300wpc (in this case) into each section of the speaker, i.e. tweeters, mids, woofers. You are in effect increasing power overall but not in each section as it were. 300 wpc into the bass section is 300wpc not 600.

Next point, speakers that are rated at 400wpc are in no way limited to this size of amp, in fact most companies will tell you the more power the better. One is far more likely to damage speakers by trying to drive them too loud with a small or under rated amp and clipping the amp which really frys speakers in a hurry. This is why I cringe when I see folks on here telling people"yeah that receiver will drive those 80's no problem" this is ill advised for MOST Avr's. I agree there are exceptions but they are limted. There is currently posts here dealing with this exact problem and is forever an ongoing issue with the uninitiated.
NOTE: if your speakers make popping, rattling, or are making distorted type noises, they are telling you...hey dummy! turn that amp down I'm hurting over here. Unless you are deaf its unmistakeable when a speakers is in severe ditsress. However, soft clip may be much harder to detect to the untrained ear and this is why good amps have protection circuitry, to protect your speakers!

Randy, I would go ahead and try bi-amping, its not possible to hurt your speakers in this manner and as I said last week I think it will really boost your output, just try one speaker even and see what happens, you have the amps in your cage already. Good luck.

These are all my opinions only of course and are from what I have learned in 31 years of serious audio gear playing.

Regards, Chris

Last edited by KlipschGuy; 04/14/07 02:06 PM.

Emotiva DMC1, MPS-1 ,M80v2 ,Klipsch RC64,Mirage Omni260 surrounds,Paradigm PW2200 sub
Re: Bi Amping confusion
KlipschGuy #165331 04/14/07 03:11 PM
Joined: Jan 2007
Posts: 10,490
Likes: 116
M
shareholder in the making
Offline
shareholder in the making
M
Joined: Jan 2007
Posts: 10,490
Likes: 116
Quote:

This is why I cringe when I see folks on here telling people"yeah that receiver will drive those 80's no problem" this is ill advised for MOST Avr's.




I agree and maybe we should be qualifying these kinds of statements with quantitative results based on our own experience. Something like "My room is 4000 cubic feet, very live, I sit 8 feet away from my M80s and during music I achieve an SPL of 80 dB with less than one watt input per channel using the Denon AVR2105 which is rated a clean 90W into 8 Ohms.".

Re: Bi Amping confusion
Mojo #165332 04/14/07 05:40 PM
Joined: Aug 2004
Posts: 6,379
Likes: 7
axiomite
Offline
axiomite
Joined: Aug 2004
Posts: 6,379
Likes: 7
When we say "XYZ receiver will drive M80s no problem" we mean "the receiver will not artificially shut down at low output levels when driving 4 ohm speakers because of protection circuitry or overheating", not "the reciever will drive the M80s to their full potential".

There are a number of receivers out there which seem to run into problems at *lower* SPLs with M80s than they would with M60s or another good 8 ohm speaker. Those are the ones we try to steer people away from...

I guess we could make this more clear, and probably should.

Last edited by bridgman; 04/14/07 05:43 PM.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8
Page 1 of 3 1 2 3

Moderated by  alan, Amie, Andrew, axiomadmin, Brent, Debbie, Ian, Jc 

Link Copied to Clipboard

Need Help Graphic

Forum Statistics
Forums16
Topics24,940
Posts442,457
Members15,616
Most Online2,082
Jan 22nd, 2020
Top Posters
Ken.C 18,044
pmbuko 16,441
SirQuack 13,840
CV 12,077
MarkSJohnson 11,458
Who's Online Now
0 members (), 565 guests, and 1 robot.
Key: Admin, Global Mod, Mod
Newsletter Signup
Powered by UBB.threads™ PHP Forum Software 7.7.4