biamp with tweeter, no Xover for main driver?

[OllBoll]

Hello there!

I've read some about the advantages of biamping, of how the bass is improved since damping factor isn't limited by series inductor... but what if there is no inductor or filter on the main driver, only the tweeter is crossed?

Is there still advantages to be made if biamping or is it unnecessary overkill then?

// Olle

[Charles Darwin]

You would need to find a woofer which is free from cone break up modes and rolls off smoothly before it starts beaming to make that work well.

[OllBoll]

What made me get the thought is that i plan to build a speaker (OA5 MMX)

The speaker crossover has an inductor in the filter, but the woofer is really a full range driver and when looking at the measurements i realized that the point of the main driver crossover isn't really to cross it to prevent it of playing too high frequencies and thus distort, but simply to flatten it's frequency response between 2 and 10 khz where it otherwise gets stronger than meant to. But that should be doable through an EQ instead shouldn't it?

[konut]

You could use a line level low pass/EQ filter on the woofer as long as your amp has enough gain to account for insertion loss of the filter.

[OllBoll]

Yes, but that would need two amps... what i basically wonder is if i really need two amps and true biamping for optimal sound quality in this case or if the removal of the Xover for full range driver makes biamping unnecessary and improvements miniscule.

The tweeters are are to be crossed at about 5 khz with a 12db filter.

// Olle

[konut]

I misunderstood. I thought you were biamping and were just wondering whether to roll off the woofer or run full range. Biamping is unnecessary if your sources or drivers lack resolution and cannot hear the improvement. Otherwise only you can determine whether the added expense and complexity are worth the improvement.

[AEIOU]

Originally Posted by OllBoll

Hello there!

I've read some about the advantages of biamping, of how the bass is improved since damping factor isn't limited by series inductor... but what if there is no inductor or filter on the main driver, only the tweeter is crossed?

Is there still advantages to be made if biamping or is it unnecessary overkill then?

// Olle

Typically when biamping you use an electronic crossover before the amplifiers.
The signal is split with treble sent to the tweeter amplifier and bass and midrange sent to the woofer amplifier.

[Jonathan Bright]

The benefits of bi-amping can apply to the amplifier too. One serious book on speakers rates the FIRST benefit of bi-amping as the reduction of intermodular distortion in the amps because each is handling a smaller bandwidth.

Another article says that even with a 3k Hz cross-over the improvement can be heard. Reading up on IMD in power amps is a good encouragement to consider bi-amping.

Cheers, Jonathan

[ByronInLawrence]

Greetings,

Who wrote that an inductor in series with a woofer will decrease bass? I would question this person's expertise, because plenty of excellent speakers with great bass have been made using passive crossovers with an inductor in series with the woofer.

As far as the cost vs. benefits of bi-amping: as Konut wrote, only you can decide whether or not the added expense of bi-amping is worth the sonic improvement. However, I predict that you will find your suspicion that the improvement would be "minuscule" to be correct. I suggest that you build the OA-5-MMX with the passive crossover designed for it, and see how you like it. You can always buy or make a second amp and active crossover in the future.

Good Luck and Happy Listening!

[CityPooh]

I use biamping for years, crossover is passive, 6dB on 5 drivers per channel, other two drivers have 12dB xover.(i m "no crossover is best crossover" character). No need for active crossover.
For pre i use tube DAC with two 6N6P tubes.
Reason is simple.
One amp is tube amp, other is older top model of Yamaha transistor power amp.
We all know, that tubes better reproduce harmonics enjoyable to human ears(they slightly "enlight" and lift them), but they do have roll off in bass area, where transistors have better control.
Sum of both amps working together are impeccable transients and control, because speakers never lacks power.
Sound is still more tubelike, transients are fast and precise, bass tight and very detailed in upper bass area. Nice sounding "bastard".

I was just curious in the start, if my simple reasons for biamping, that i underlined, will work in that way and i must say, that it works so darn good, that i will never use just one amp anymore, because they cant beat combo like this..
Only minus, is big consumption of electrical power.
In fact, developing something like this, means few years of experimenting, of developing "special trickery blending", not only because speaker drivers in my DIY set are from 86dB to 91dB, important are also, for sonic charcter of the system, proper sounding passive components in amp, DAC and speakers and also bypass caps.