Totally Bi-Amping

[fnordlyone]

Many a musician at talkbass said it wasn't worth the hassle-- that there are great light new full range cabs, and cute new small heads.
Maybe. But what I've got is old school.. 2x12 ported box tuned down to 30hz and a sealed cab (2x10) that is tuned to around 48hz.

So, with all the hassle of two patch chords (instrument cables): BiAmp achieved. The Peavey Mark IV has two outs for bi amp. One, I send straight back into the Mark IV's power amp in (conveniently right next to the High out); so the Peavey's power amp section sends everything above 50hz to the sealed 210. This is the lowest crossover point which goes to all the way to 500.

The Low out, I send to one of the channels of the qsc rmx1450 power amp. Now, this channel receives all and only the lower than 50hz signal from the Mark IV. AND, this qsc channel is set only to receive signals Above 30hz-- much more efficient use of wattage in the low zone which uses up the most head room. The 2x12 is only doing 30-50hz and the 2x10 is handling all the mids and highs.
Sounds awesome compared to what I was doing: sending all frequencies to both speakers. Guess I thought the speakers would figure out how share the load
Now, I really need a 2x15 and an 18 to see what the REAL old School is all about!
f nor d !
All this old gear is staying quiet as a mouse with the shielded basses. It is so INCREDIBLE to hear everything without noise. Everyone! shield your basses!

 

[Munjibunga]

Many a musician at talkbass said it wasn't worth the hassle-- that there are great light new full range cabs, and cute new small heads.

Guilty.

 

[Downunderwonder]

Fun init!? My own cabs sound great doing it but the schlepping is too much not fun.

 

[Rick James]

Biamping makes sense if you do it the right way. Using twelves only up to 50 hz and using tens for midrange isn't the right way. Using the twelves up to maybe 500 hz and sixes above that is the right way. The same would apply to using eighteens on the bottom.

 

[Mr. Foxen]

Picking frequency band by speaker diameter is the wrong thing.

 

[Abrahampost]

Hey if it sounds good and you don't mind shlepping gear have at it! I messed around with bi amping and finally decided matched cabinets sounded better/cleaner to me. Now wet/dry rigs I love, but can't get myself to try it at a gig. Nothing like a dedicated clean bass signal underneath your effects.

 

[Downunderwonder]

Hey if it sounds good and you don't mind shlepping gear have at it! I messed around with bi amping and finally decided matched cabinets sounded better/cleaner to me. Now wet/dry rigs I love, but can't get myself to try it at a gig. Nothing like a dedicated clean bass signal underneath your effects.

see the current fx thread on Wounded Paw v3. Have cake and eat it with highpass effects reblended to low pass clean lows.

 

[dincz]

Biamping makes sense if you do it the right way. Using twelves only up to 50 hz and using tens for midrange isn't the right way. Using the twelves up to maybe 500 hz and sixes above that is the right way. The same would apply to using eighteens on the bottom.

Exactly. The thread title should be "Partially biamping".

 

[Munjibunga]

Picking frequency band by speaker diameter is the wrong thing.

Very true. I had a couple EAW SBX220 subs each with two 12s in them, and I crossed them over at about 90 Hz. Tightest and best subs I ever had. But heavy (105 pounds).

 

[Rick James]

Picking frequency band by speaker diameter is the wrong thing.

There are much better ways of deciding on where to cross over to the next smaller speaker, like using polar or axial response plots to find the -6dB at 30 degrees off axis frequency, but for a simple rule of thumb the speaker cone diameter is OK, you don't want it larger than one wavelength.

 

[Mr. Foxen]

Freq response has no relation to speaker diameter, so there is no such rule of thumb.

 

[callofcthulhu]

But he picked the frequency band based on the tuning of the port (30Hz) not the diameter of the speaker.

 

[Mr. Foxen]

But he picked the frequency band based on the tuning of the port (30Hz) not the diameter of the speaker.

He picked by diameter right here, in these posts I replied right under:

Biamping makes sense if you do it the right way. Using twelves only up to 50 hz and using tens for midrange isn't the right way. Using the twelves up to maybe 500 hz and sixes above that is the right way. The same would apply to using eighteens on the bottom.

There are much better ways of deciding on where to cross over to the next smaller speaker, like using polar or axial response plots to find the -6dB at 30 degrees off axis frequency, but for a simple rule of thumb the speaker cone diameter is OK, you don't want it larger than one wavelength.

 

[Rick James]

Freq response has no relation to speaker diameter, so there is no such rule of thumb.

Dispersion is related to the size of the speaker. It's the only result that is directly related to speaker size, its the reason why midranges are smaller than woofers and tweeters are smaller than midranges, not frequency response. Not using a speaker into the range where it starts to beam is why multi speaker systems exist, and you can ballpark where beaming will happen with no more data than the diameter of the cone. It's not as precise as having axial response charts or polar plots, but you don't need those to know that a 13 inch cone in a 15 inch speaker is going to beam above 1,000 hz. Unless you're a guitar player, they still haven't figured it out.

 

[Mr. Foxen]

Diameter and beaming frequency only relate if you assume the speaker has no compliance. Speakers have compliance.

 

[Rick James]

Diameter and beaming frequency only relate if you assume the speaker has no compliance. Speakers have compliance.

I'm not an authority, but even I know that dispersion and compliance, T/S spec'd as Cms, are unrelated.

 

[Mr. Foxen]

Cones are not infinitely stiff, so don't act pistonically, so diameter doesn't relate to dispersion.

 

[callofcthulhu]

He picked by diameter right here, in these posts I replied right under:

Sorry, you didn't quote so I assumed you were responding to OP.

 

[Marko 1]

Crossed at 50hz, about all you're gonna actually hear is the top cab.

 

[SteveC]

Way back in the day I beamed with a Peavey TNT and a powered Peavey 210HP cab. Ran the lows to the 15" Black Widow in the TNT and the highs to the 210/horn powered speaker enclosure. Crossed it over around 150-200 using the built in cross over in the TNT. I don't know how it sounded but it looked cool and I was cool as I "bi-amped" and no one else did.