I'm thinking about bi-amping; searching for answers

djoutlaw

New DJ
Jun 17, 2008
0
To start out, I would like to say that I have always used one amp to drive 2 or 4 speakers. That is what I’m use to and that is my comfort zone. Now I would like to expand that comfort zone and learn how to bi-amp. However, I am learning that bi-amping is not as simple as connecting an external crossover with two amps—it’s more complex than that. That is why I am here; to find out as much as I can.

With that said, here is what I do know about bi-amping:
•Using two amps with no external crossover is not a ‘true’ bi-amp
•A ‘true’ bi-amp uses an external crossover and two amps
•There are two types of bi-amping: vertical or horizontal.
•In a ‘true’ bi-amp, the internal crossover in the speakers needs to be bypassed

The questions that I would like to have answered are separated by components (speaker, amp, and crossover).

Speaker questions:
•When bi-amping does it matter if the speaker is a 2-way or a 3-way? Is one style preferred more than the other?
Which method (horizontal or vertical) should be used when bi-amping 2 speakers? 4 speakers?
•How can you tell if a speaker has an internal crossover or not without opening it? How do you bypass the internal crossover?
•From what I have learned, bypassing the internal crossover (when using an external crossover) voids the speaker’s warranty—so why bypass? What happens if you don’t bypass the internal crossover when using an external one?

Amp question:
•When bi-amping; are there specific characteristics in an amp that you look for? Or do you choose an amp that matches the speaker’s ratings?

Crossover questions:
•When bi-amping; are there specific characteristics in a crossover that you look for? What are they?
•When calibrating the crossover, where do you go to find the correct frequencies & slopes? What is a slope?

Last question: How does bi-amping increase the loudness (I know the SPL of the speaker can’t be changed) of the speakers? Couldn’t I do that with a more powerful single amp than buying an extra amp and crossover?
 
Well, it's great you are taking the time to learn - but I think you are making something that is fairly simple in to something that sounds much more confusing than it really is.

Ideally, you want to have your system set up with "top" speakers and "subs". Along with that, you will have one amp to drive each, along with an external crossover. The external crossover will direct the correct frequencies to your subs and tops respectively (well, at least to the amp driving each). Your top speaker will actually use it's own internal crossover to separate what goes to the midrange and the horn.

As far as amp size, try and find an amp that will provide 1.5x the speakers RMS, keeping the speakers' ohm rating in mind. Here's a quick example based on what I use, which while bi-amped, I only use a single amp and daisy chain my speakers together, thus cutting the ohm rating on the speakers in half.

My top speakers are rated at 600 Watts continuous, 8 Ohms
My Subs are rated at 800 watts continuous, 8 Ohms
One side of the amp is driving the subs, and the other side of the amp is driving the tops. Since speakers are daisy chained, the Ohm rating drops to 4 Ohms for tops (1200 watts total RMS), and 4 Ohms for subs (1600 watts total RMS).

My amplifier provides 2500 watts per channel @ 4 Ohms. Pretty much 1.5x the RMS for both the subs and tops. See specs...

What amp/speakers are you using?
 

Attachments

drzinc

Trini missing JTV
Jun 7, 2008
2,563
Toronto
www.drzdj.com
Bi amping properly will free your tops to perform at their optimum. If your tops are preforming at their optimum your system will sound more dynamic and hopefully free of distortion and less fatiguing. This is achieved by not having you tops straind by producing bass.

Ok step one look at the specs of your tops and subs and get amps that are 1.5 their rms ratings.
Step two forget about simple crossovers, get a DSP. There are great DSP’s that are about the same price as a crossover and equalizer. A dsp will allow you to not only crossover your tops and subs but it can also protect your system with limiters and other settings.

You do not have to bypass the crossover in you tops to bi-amp
For DJ work the best way to bi-amp is to have your tops run in stereo and you subs in mono or better known as summed.

Now if you tell us what speakers you have and your current amp we can make some suggestions about crossover points and you second amp.
 

Scott Harris

DJ Extraordinaire
Step two forget about simple crossovers, get a DSP. There are great DSP’s that are about the same price as a crossover and equalizer.
Sorry, but I disagree depending on the circumstances. I would says either get a high-end DSP or get an analog crossover and EQ. Most lower priced DSP's sound terrible when listened to critically. A/B compare the sound quality of a clean source (A well mastered CD playing through a high quality CD player or a WAV file created from extremely high quality equipment) connected to a high quality sound system and you will be amazed at the sound differences between low/medium cost DSP's vs a decent analog crossover and high quality (cost) DSPs. A cheap DSP sounds like listening to a 128kb mp3, while analog & high-end DSPs sound clean. You really don't get what you pay for in a DSP, there seems to be an inflection point in cost/sound quality near the $1,000 price point. Most DSPs below this price seem to shortcut quality to attain a price point. The few that I have heard above it sound as good as analog, but then obviously have the richer feature set.

I won't name a brand or model but even a quick listening test with a 256kb mp3 file and using generic headphones in a quiet environment will demonstrate the flaws of what some consider to be the DJ industry standard in DSP technology. Listen for a cymbal crash. Does it sound crisp & natural to you or like a digitized mess? You could save disk space and use 128kb mp3 files if you are using one of these.

That said, most people won't notice the difference in a typical DJ rig in a loud bar so it may not matter unless you listen to it for yourself and let it annoy the crap out of you.... :trimad::trisad::triconfused::trirolleyes:

I suggest that you do not do this test if you already own a DSP!
 

ahoustondj

DJ Extraordinaire
Aug 13, 2007
3,465
Texas
DJOUTLAW,
I agree overall with Scott Harris. DRZINC is correct when stating you should run in stereo for your tops.
I have a couple of questions.
1. In your present configuration, what type of signal are you sending to the single amp, a Stereo signal or a mono signal split with a "Y" connector?
2. Does your present"sub" have an internal filter?

I ask this because I cringe a lot of times when I hear guys say they run mains from one side on the amp and subs from the other side of the amp. You won't imagine how many guys do this the wrong way...namely...taking a stereo signal to the amp and then running the mains on the left side (One half of a stereo signal) and the subs on the left (One half of a stereo signal).
 

ahoustondj

DJ Extraordinaire
Aug 13, 2007
3,465
Texas
Here are a few comments taken from another Pro Forum on DSP/Driverrack.

"The driverack is a fine unit, when set manually. The wizard, unfortunately, is almost a guaranteed 'suck' configuration. I think they did that so you could tell who bought the gear with no clue how to use it versus those that really did know how to set it up."

" I have found it to be quite useful (as long as it has your speakers in its libray) except the suggested gain settings for the amps is always wrong. After going thorugh the wiz, disable the limiters and set your gain structure properly, re enable the limiters, then run the rig against Smaart or something of that nature and then you will end up with something useful..."

No matter what you use or do, sound will still be emitted. Lots of people stop right there. LOL
How you set it up will depend on what degree of excellence you are trying to achieve.
 

drzinc

Trini missing JTV
Jun 7, 2008
2,563
Toronto
www.drzdj.com
I always set my DSP by ear and never use the auto settings.
Driveracks although the industry standard does not sound the best.
I listened to many DPSs before I setteled on the DCX2496 (behringer) although it had a bad rap for breaking down. The first few runs of them did have ribbon wire failures and deserved the bad rap. Once this was fixed it became a fine sounding and flexable dsp, much better sounding than the dbx line. I also have the DEQ2496 eq and together they make a great processing pair that does not have the bad digital sound mentioned above.
 
Outlaw, the guys have given excellent advice. But it would be easier to help you of you would provide a list of equipment that you are working with. Are your speakers already set-up from the factory for bi-, or tri-, amping? Or are you going to rewire them?

It may not be as complex as what you perceive it to be, BUT...there are many variables involved. We just have to narrow it down a little more so you can start playing with your "basic" bi-amp set-up and then start branching out from there.
 

Precisionpower

DJ Extraordinaire
Mar 20, 2007
437
41
Appleton, WI
Could i please remind you guys to use the K.I.S.S. method before replying to some of this stuff??

As you all know, I run a tri-amped system and some of the stuff you guys post confuses me!

Lets try to answer his questions...Not just throw a barrage of other stuff into the mix.

I will agree that the OP is making it out to be a bit more difficult than it needs to be. A nice x-over and the proper amplifiers will be just fine. Keep in mind that Bi-amped tops should almost always be used with a sub of some sorts
 

jokerswild

Chief Bottle Washer
Staff member
Feb 11, 2007
1,272
Elkhart, IN
www.totalimpactdjs.com
Just curious here but is it only considered bi-amping when you are using two amplifiers to power a two-way cab or is bi-amping also when you are using two amplifiers to power a set of full range speakers and a set of subs over a crossover?

I admit I'm a bit confused too.... I am using a DRPA into two amps one powering my tops and the other powering my subs and I use the DRPA to set, among other things, the crossover point in a 2x3 stereo configuration. Am I wrong to call this bi-amping?
 

drzinc

Trini missing JTV
Jun 7, 2008
2,563
Toronto
www.drzdj.com
Just curious here but is it only considered bi-amping when you are using two amplifiers to power a two-way cab or is bi-amping also when you are using two amplifiers to power a set of full range speakers and a set of subs over a crossover?

I admit I'm a bit confused too.... I am using a DRPA into two amps one powering my tops and the other powering my subs and I use the DRPA to set, among other things, the crossover point in a 2x3 stereo configuration. Am I wrong to call this bi-amping?
A speaker can be bi-amped or a system can be bi-amped both would use 2 amps.


What you are describing is bi-amped system. If you bi-amp your tops and also run a sub then you have a tri-ampd system.
 
I ask this because I cringe a lot of times when I hear guys say they run mains from one side on the amp and subs from the other side of the amp. You won't imagine how many guys do this the wrong way...namely...taking a stereo signal to the amp and then running the mains on the left side (One half of a stereo signal) and the subs on the left (One half of a stereo signal).
I assume this wasn't directed at me when I said I do EXACTLY what makes you cringe. :tribiggrin:The DSP built in to the Crown I-Tech HD is among the best out there. The DSP takes care of the stereo signal I feed the amp, and trust me - my speakers and subs are receiving more than half a signal.

This can be done the correct way, when using the proper equipment, but I do agree - I have seen this done horribly wrong as well!:trirolleyes:
 

ahoustondj

DJ Extraordinaire
Aug 13, 2007
3,465
Texas
Just curious here but is it only considered bi-amping when you are using two amplifiers to power a two-way cab or is bi-amping also when you are using two amplifiers to power a set of full range speakers and a set of subs over a crossover?

I admit I'm a bit confused too.... I am using a DRPA into two amps one powering my tops and the other powering my subs and I use the DRPA to set, among other things, the crossover point in a 2x3 stereo configuration. Am I wrong to call this bi-amping?
Bi amp means two separate signals one for Mid/Highs and one for Lows powered by two separate amps.

When one has a two way cabinet that can be bi amped, what that means is that you can bypass it's passive crossover and feed two separate signals usually low and mid/hi to that cabinet.

Tri amping means three separate signals one for Highs, one for Mids and one for Lows powered by three separate amps.

The signals fed to the amps usually come from an Active Crossover or a DSP with active crossover built in.
 

djoutlaw

New DJ
Jun 17, 2008
0
Well, it's great you are taking the time to learn - but I think you are making something that is fairly simple in to something that sounds much more confusing than it really is.

Ideally, you want to have your system set up with "top" speakers and "subs". Along with that, you will have one amp to drive each, along with an external crossover. The external crossover will direct the correct frequencies to your subs and tops respectively (well, at least to the amp driving each). Your top speaker will actually use it's own internal crossover to separate what goes to the midrange and the horn.

As far as amp size, try and find an amp that will provide 1.5x the speakers RMS, keeping the speakers' ohm rating in mind. Here's a quick example based on what I use, which while bi-amped, I only use a single amp and daisy chain my speakers together, thus cutting the ohm rating on the speakers in half.

My top speakers are rated at 600 Watts continuous, 8 Ohms
My Subs are rated at 800 watts continuous, 8 Ohms
One side of the amp is driving the subs, and the other side of the amp is driving the tops. Since speakers are daisy chained, the Ohm rating drops to 4 Ohms for tops (1200 watts total RMS), and 4 Ohms for subs (1600 watts total RMS).

My amplifier provides 2500 watts per channel @ 4 Ohms. Pretty much 1.5x the RMS for both the subs and tops. See specs...

What amp/speakers are you using?
I have two amps (behenger ep 2500 & ev cp3000s
I have three sets of speakers (2 cerwin vega 153, 2 peavy pr 15", 2 tour x tops and 2 tour x subs)
 

djoutlaw

New DJ
Jun 17, 2008
0
Bi amping properly will free your tops to perform at their optimum. If your tops are preforming at their optimum your system will sound more dynamic and hopefully free of distortion and less fatiguing. This is achieved by not having you tops straind by producing bass.

Ok step one look at the specs of your tops and subs and get amps that are 1.5 their rms ratings.
Step two forget about simple crossovers, get a DSP. There are great DSP’s that are about the same price as a crossover and equalizer. A dsp will allow you to not only crossover your tops and subs but it can also protect your system with limiters and other settings.

You do not have to bypass the crossover in you tops to bi-amp
For DJ work the best way to bi-amp is to have your tops run in stereo and you subs in mono or better known as summed.

Now if you tell us what speakers you have and your current amp we can make some suggestions about crossover points and you second amp.
What are some good DSP's?
 

djoutlaw

New DJ
Jun 17, 2008
0
Sorry, but I disagree depending on the circumstances. I would says either get a high-end DSP or get an analog crossover and EQ. Most lower priced DSP's sound terrible when listened to critically. A/B compare the sound quality of a clean source (A well mastered CD playing through a high quality CD player or a WAV file created from extremely high quality equipment) connected to a high quality sound system and you will be amazed at the sound differences between low/medium cost DSP's vs a decent analog crossover and high quality (cost) DSPs. A cheap DSP sounds like listening to a 128kb mp3, while analog & high-end DSPs sound clean. You really don't get what you pay for in a DSP, there seems to be an inflection point in cost/sound quality near the $1,000 price point. Most DSPs below this price seem to shortcut quality to attain a price point. The few that I have heard above it sound as good as analog, but then obviously have the richer feature set.

I won't name a brand or model but even a quick listening test with a 256kb mp3 file and using generic headphones in a quiet environment will demonstrate the flaws of what some consider to be the DJ industry standard in DSP technology. Listen for a cymbal crash. Does it sound crisp & natural to you or like a digitized mess? You could save disk space and use 128kb mp3 files if you are using one of these.

That said, most people won't notice the difference in a typical DJ rig in a loud bar so it may not matter unless you listen to it for yourself and let it annoy the crap out of you.... :trimad::trisad::triconfused::trirolleyes:

I suggest that you do not do this test if you already own a DSP!
I don't own any crossover or dps--that is what I'm trying to figure out here on this thread--thanks for the help/advice.
 

ahoustondj

DJ Extraordinaire
Aug 13, 2007
3,465
Texas
I assume this wasn't directed at me when I said I do EXACTLY what makes you cringe. :tribiggrin:The DSP built in to the Crown I-Tech HD is among the best out there. The DSP takes care of the stereo signal I feed the amp, and trust me - my speakers and subs are receiving more than half a signal.

This can be done the correct way, when using the proper equipment, but I do agree - I have seen this done horribly wrong as well!:trirolleyes:
When I say "Half a signal" what I actually mean is half the spectrum of the music program not the signal voltage.

Not saying you do but I have known some people to assume that any one side of a stereo signal is considered mono. Are you engaging a mono switch on your mixer or are you sending a mono signal out from your laptop/soundcard?

I do know that if you are running tops on one side of the amp and subs from the other side than that final output is no longer stereo. Am I correct in that conclusion?
 

djoutlaw

New DJ
Jun 17, 2008
0
DJOUTLAW,
I agree overall with Scott Harris. DRZINC is correct when stating you should run in stereo for your tops.
I have a couple of questions.
1. In your present configuration, what type of signal are you sending to the single amp, a Stereo signal or a mono signal split with a "Y" connector?
2. Does your present"sub" have an internal filter?

I ask this because I cringe a lot of times when I hear guys say they run mains from one side on the amp and subs from the other side of the amp. You won't imagine how many guys do this the wrong way...namely...taking a stereo signal to the amp and then running the mains on the left side (One half of a stereo signal) and the subs on the left (One half of a stereo signal).
Right now I'm using one amp in parallel to run 2 tops and 2 subs
As for sub having a filter--I don't know that answer--where would I look to find it?
 

djoutlaw

New DJ
Jun 17, 2008
0
Outlaw, the guys have given excellent advice. But it would be easier to help you of you would provide a list of equipment that you are working with. Are your speakers already set-up from the factory for bi-, or tri-, amping? Or are you going to rewire them?

It may not be as complex as what you perceive it to be, BUT...there are many variables involved. We just have to narrow it down a little more so you can start playing with your "basic" bi-amp set-up and then start branching out from there.
I have posted what amps and speakers I have on another post in this thread
 

ahoustondj

DJ Extraordinaire
Aug 13, 2007
3,465
Texas
Right now I'm using one amp in parallel to run 2 tops and 2 subs
As for sub having a filter--I don't know that answer--where would I look to find it?
Like Precisionpower stated K.I.S.S
It does not matter what you were doing before. Look ahead to what you need for what you want to do.
Here is my suggestion #1. (No Brand Names)
To Bi-amp
Stereo Equalizer
Stereo Two Way Electronic Crossover
Two Amplifiers
(One amp will run your tops/mains the other will run your Lows/subs)
The amp running your subs can be run as two channels/stereo or you can sum the signal out from the crossover and then bridge the amp)


Suggestion #2

DSP/Driverrack (This includes EQ, Limiters, Crossover etc)
Two Amplifiers
(One amp will run your tops/mains the other will run your Lows/subs)
The amp running your subs can be run as two channels/stereo or you can sum the signal out from the crossover and then bridge the amp)

I hope this helps. The amps you need will depend on the power ratings of your speakers. Its advised to have ample headroom on the amps to eliminate peaking/clipping.