Biamping your rig - Crossover - Yes or No

Discussion in 'Amps and Cabs [BG]' started by Ampig, Dec 2, 2004.

  1. Great idea

    8 vote(s)
  2. Waste of money and sound

    8 vote(s)
  3. That depends

    20 vote(s)
  1. Ampig

    Ampig Supporting Member

    What do you biampers do? Does a crossover make your rig more efficient or rob you of power/sound?
  2. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    crossovers are fantastic for pa and have several advantages powerwise, frequency response wise etc. The reason i usually don't like them for bass rigs is that most bass guitar cabinets are designed to handle a pretty wide frequency response. I think 9 times out of 10 you end up with less volume and dont put your cabinets to work for you.
  3. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Biamping works quite well when the two speakers involved cover different frequency ranges. It's far less effective if the speakers overlap though most of their range, and unfortunately that is the case with commercial bass speaker cabs. Biamping a 1x15 and a 2x10 is pretty much worthless as the two cabinets share more bandwidth than not. Biamping the tweeter horn and woofer section of any cab that will allow it works well as the two driver sections operate over distinctly different frequency bands.
  4. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    Good answers. To put it another way: if you want to biamp, be prepared to do a lot of research.
  5. Mud Flaps

    Mud Flaps

    Feb 3, 2003
    Norton, MA
    ***Disclaimer: I have never actually owned a rig capable of biamping. However, I have had the privilege of being able to screw around with around with 50 or 60 biamp rigs on a regular basis for extended periods of time by living in an urban area and living within 20 miles of the largest music store on the eastern seaboard, two massive Guitar Centers, and several local area music stores, not to mention other bassists I have met.

    With the being said, I will continue with my limited understanding of this difficult issue...***

    Bingo! And the research cannot always be done through TalkBass or other online resources, because different rigs sound differently and work differently. In the end, if you do it "correctly", I think you will end up with a better sound; but, it can be almost impossible to do so, or at least take hours and hours.
  6. jawzzz


    May 23, 2003
    Denver Colorado
    I agree with the above. It really depends on the cabs you are using and it takes a lot of fine tuning to get the right sound. I bi-amp two diffent set ups.

    First I use a 410 XLT and a 215 XLT. Crossover is set roughly around 220 Hz.The 215 makes up for the missing low end of the 410 XLT. The 410 XLT is great for the midrange frequencies so it works perfect.

    My second setup is an Aguilar GS 412 with an Aguilar s 210. Crossover is set @ roughly 400 Hz. I mainly do this because I draw too many ampres in bridge mode(1950 watts) with the 412, so I use the 210 and go stereo. The 210 only handles 250 watts, so I prefer to send only higer signal to it to protect it since my amp is 750 watts @ 4 ohms per channel.
    None the less, this setup really thumps.
  7. Passinwind

    Passinwind I Know Nothing Supporting Member

    You can't biamp without an active crossover, so I think your question really is: is biamping worth it? Sure it is, but you need to design the speaker system specifically to take maximum advantage of it. As others are saying, a 1-15 and a full range 2 X 10 aren't the ideal match. OTOH, I have a pair of E-V mid-oriented 10s that sound great for bass biamped with a pair of 15s. The 10s do not want to see low bass, but they go a good bit higher than my 15s, and do it pretty gracefully.

    There's also the possibility of intentionally designing overlap into your active crossovers. The typical ones you see on bass amps don't allow for that, but this approach can sound really good, in my experience.
  8. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    that can actually be one of the most fun and useful approaches. my alembic f1-x had high, low, and full range outputs. I fooled around with running one cabinet full fange, and one with just lows or highs to some degree. in one instance, i sent a full range signal to my bag end 1x15, and i sent the high output to a bag end 1x12, with the crossover set all the way to the left, which i think was about 120 hz or so. the 1x12 was able to be pushed a lot harder without the extreme lows. I also did the reverse, sending full range to the 1x12, and sent lows from about 200 Hz down to the 1x15, which yeilded lots of low end. In the end i still preferred the sound of the full range cabs, but both of these options were cool.
  9. If you're using an ERB then to me it's the only way to go.
    Active is the only crossover to use in this application. With that said I also have to disagree with the comments on 15 and 2/10. In my use that is the perfect solution. I also would suggest thinking PA when biamping a rig. The crossover range on subs would be around 100 to maybe 150 max for the 15. Also good amount of power is needed for a good biamp system. Also since the 15 is usually on the bottom the 2/10 is doing most of the work and usually what you hear. You will feel the sub through the 15, and fill the room with plenty of low end. The great thing with the crossover is the ability to micro tune to your cabs. I hardly use the EQ's on the pre's at all, let the crossover take care of that. Also my 2/10 has a tweeter with an attenuater for additional tweakage.

    Here's my current rig and how it's setup:
    Alembic F-1X
    Ashly BP41
    QSC PLX1602 500w X2 @4ohms
    Flite 1 15" with 5.5" mid and attenuater 4ohm
    Flite 2 10" with 1" tweeter and attenuater 4ohm

    Bass signal goes into the Ashly, low output of the crossover goes into the QSC. Being a non tube pre I've found the low end much better for the sub. Also since the 15 is crossed over at around 125 the attenuater on the 15 isn't even being used, and the mid speaker is not even used. I got this cab with the mid in case I wanted to use a single cab in small places.

    Stage full range out of Ashly to the Alembic, high output of the crossover into the QSC. I've tried using the full out of the Alembic into the 2/10 and the low end was too much, and the highs were just too mushy.

    The great thing with this setup is the amount of gain controls and tweaking that you can do. For instance to tune the low end you can use the input and also control of the amount of the sub volume in the Ashly crossover, and of course the crossover frequency.
    Then you can adjust the stage out on the Ashly to control the highs. You have input control as well as crossover frequency and amount. Then of course there's the attenuater to handle the horn. Finally I have the volume controls on the QSC for additional tweaking.

    So yes it does take some experimentation to get things like you want it, but to me it's well worth the effort.
    Good Luck,
  10. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    I never thought about putting an x-over in front of a preamp (or preamps).
    Now that you mention it, it would be too cool to run from about 100Hz down into a BBE BMax (SS - with a killer-fast, massive low end) and 100Hz up into a good tube preamp (or a good tube head -- TE V6?), have two channels of amplification (for sure SS for lows) and a really fast sub on the low signal side (maybe a couple of Acme Low B-2W or one Low B-4W) and a good (somewhat full-range) cab on the high side (like one of the older, non-deep Bag End D10X-D w/the coax tweeter).

    You more techie types, would there be phase issues with an approach like this?
  11. spidersbass


    Nov 29, 2004
    Downtown L.A.
    when using a crossover to connect 410's speakers and 2 10" subwoofers, do you need a seperate power amp just for the subwoofers?
  12. Brad Johnson

    Brad Johnson Commercial User

    Mar 8, 2000
    Gaithersburg, Md
    Boom Bass Cabinets, DR strings
    You can biamp without an active crossover.

    And why couldn't a 1-15 and 2-10 be an ideal match? That was one of the first biamp combos I ran. If you did run a active crossover on a two channel amp and sent the lows to the 15 and the rest to the 2-10 (all 2-10s are not created equal of course) that could be just the sound someone was looking for. Or send a full range signal to the 15 and the same to the 2-10 and EQ them differently.

    Biamping is all about increased control over what you send to your drivers. It's neither a good nor bad thing, it depends on what the desired result is. The only requirement is two channels of amplification... that's the "bi" in biamp. That's also why an active crossover isn't required.

    I ran bi-and tri-amp rigs years ago and I wouldn't do either again. Using competent full range cabs eliminated the need for that IME. So in some cases it's not worth it. Most everyone I know who used to do it no longer does. Guess the novelty wore off;)

    Exception being someone like JT who uses a PA sub for lows on an ERB
  13. Finger Blister

    Finger Blister

    Jul 8, 2003
    I've got a built in crossover in my amp.

    It's a waste of resources.

    Besides, you really need another 200 - 300% more power
    on the Low End to do it up right.
  14. Howard,

    The intent of bi-amping is the segregation of components into their optimal operating frequency range. This requires an active crossover somewhere in the circuit to separate the frequency band for the High and Low power amp channels.

    Power is wasted when high frequency energy is applied to a low frequency woofer that cannot reproduce those highs. Conversely, high frequency units are destroyed when they receive low frequency signals. For example, my 15" subs aren't any good above 100 Hz, and my 10" JBL E110s would self-destruct with bass frequencies.

    I use a Rane active crossover with my SWR/QSC bi-amp rig. It is far superior to passive crossover components in both signal quality and control.
  15. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    dude, no offense but you've got to stop asking the same questions in 20 different threads hoping soemone will give you the answer you want. Just stick to one thread that you started and keep the discussion in there.

    Hey Dirk, I want my alembic back!!!!
    j/k, (well not really), i'm glad you're digging it.
  16. Passinwind

    Passinwind I Know Nothing Supporting Member

    My comments were regarding full range 2 X 10 cabs. It can sound good, but you're leaving something on the table, dig? Arguably, if they're mushing out, they're not really full range.

    Another fun trick with biamping is to insert the crossover before a dual compressor, and use different compression settings on highs and lows.

    Brad, I agree that there are possibilities for using passive elements before the amps, and some audiophile types also advocate "passive biamping", which runs multiple amps full range, and uses passive crossovers on the speakers. The former approach is something I haven't seen much in many years, and the latter doesn't really conform to any textbook definitions of biamping that I've seen. I'm open minded though; results are what counts anyway, more than semantics.:cool:

    In any case, I too gave up on biamping my bass rig years ago, but Dirk convinced me to give it another try, since I had all the right stuff lying around anyway. I really, really liked the result, and am looking forward to my next electric bass gig to try it on stage.

    OTOH, last night I had a soundman who insisted on pumping my EUB up in the 60-80 Hz range through the house subs. My pitch definition was completely hosed, ouch. :bawl: Pesky biamping! :ninja:
  17. Fuzzbass

    Fuzzbass P5 with overdrive Supporting Member

    The compressor I own is the Rane DC-24, which is a dual compressor plus crossover: highs and lows are compressed separately. IME it's more transparent than the single-band compressors I've tried within that price range ($400 or so).

    I could use the DC-24 biamping, but I've always set it to recombine lows and highs. One of these days I'll have to try a biamp rig, but I've been happy enough running my speakers full-range.
  18. Brad Johnson

    Brad Johnson Commercial User

    Mar 8, 2000
    Gaithersburg, Md
    Boom Bass Cabinets, DR strings
    That's why I said :"Using competent full range cabs eliminated the need for that IME".

    Biamping is great for stuff that can't hang on it's own, full range. The thing is, it's very easy to find full range stuff these days that alleviate that problem.

    I didn't say anything about passive elements before an amp:D.

    You don't necessarily "need" an active crossover to biamp. You don't "need" a passive crossover either. If you're running two channels of amplification you "can" biamp. This isn't semantics, it's about what biamping actually is. It allows you more control over two drivers, in whatever configuration they might be. There are people that actually think you have to run a low pass and/or high pass to biamp... some of them are
    in this very thread. You don't.

    You can use a mono or stereo equalizer as a crossover if you want. That would allow you to control one side of a biamp (mono) or both sides (stereo). You can match the gains between cabs of differing efficiencies with a biamp. If you're doing something different with two channels, guess what?

    You're biamping. Stereo is biamping. So is mono into two amp channels.

    I have what I consider one of the better off the shelf preamps for biamping, the Yamaha PB-1. It has two crossovers, which addressed the problem of single crossovers creating a sonic hole at the crossover point. As nice as it is, I seriously doubt I'll ever go back to using it. My ThunderFunk or Amplified Music Products amps sound great, especially when paired to my Nahas 1-15/1-12 cabs. They match each other very well and I don't need a two channel amp.

    See? It's an option... but you may still be hampered by the nut behind the wheel;)

  19. Sundogue


    Apr 26, 2001
    Wausau, WI
    Well, if you don't use a crossover, then you have to use some kind of filter for bi-amping. There must be something in the signal chain that allows for the frequencies to be seperated. As you pointed out, you can use a dual channel EQ and cut all the lows out of one side and all the highs out of the other, but either way, you have to use something to seperate. Otherwise you are just running full range to both cabs, regardless if they have their own dedicated amp.
  20. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    in the spirit of what brad was saying - the other thing i experimented with was using my alembic superfilter after the preamp but before the poweramp to give two different signals to the 15 and the 12. on the 15 i added a low pass filter, and i used a band pass filter to add soem percussive midrange to the 12, or used a high pass filter on it. in both cases i was sending a full range signal to both cabinets, but eq'd the signals differently. that definitely had some cool effects as well.