Horizontal vs Vertical Bi-amping

organ

Anybody here tried both before? The way I see it is that there is benefits to both set ups. With horizontal, I can see the delicate current for the tweeters being produced in a seperate box which should give you cleaner highs. With vertical, the result may be better. If the amp has one transformer for both channels, the channel driving the woofer could borrow some extra power because the channel powering the tweeter will use very little current. In a way, I think horizontal bi-amping may be a waste of power because the tweeters require so little power compared to the woofers.
Anybody have experience with both types of bi-amping? What kind of results did you hear? Bi-amping is something I'd really like to get into after I get my turntable. Oh yeah, they will be two identical amps.

Maurice

burdette

For what reason do you want to bi-amp? If the concern is current, then you'd go vertical, using two identical amps. If you believe one particular amp is better for lows and a different amp is better for highs, then you'd go horizontal.

Edit.. noticed your comment about two identical amps. Don't know why you'd consider horizontal given the amps are the same and one is not 'better' on the high end. That completely ignores the supposed benefit you'd be after. Two identical amps would leave vertical as the only logical choice.

gidrah

I've tried both (same speakers and amps) on a limited basis. The vertical bi-amping seemed to broaden the soundstage and tighten up the imaging a little. Then again these were the results I was expecting so it may have been psychacoustic as the results were not very dramatic.

organ

Thanks for the response guys.
Burdette,
I forgot to mention that it will be another NAD C270. The C270 is equipped with their Impedance Sensing Circuitry. The amp constantly scans the impedance of the load and adjusts it's power supply to provide the best power transfer. In a way, I see this as a good thing for horizontal bi-amping. The current being sent to the tweeter is very delicate(even into the micro Amps). This way, when the amp is just focussing on the tweeters, those tiny amount of current will make it to the tweeter much easier because the amp is hardly doing anything. IMO, the softest passages should be more audible than having both the woofers and tweeters connected to the same amp.
The reason I would horizontally bi-amp with two identical amp is because the gain will be the same on both. If the gain on both amps are different, the result may really suck.
Gidrah,
I don't think it was the placebo effect that you experienced. When doing vertical bi-amping, it's a lot like using mono blocks. You won't receive any cross-talk between the L and R channels. IMO, cross-talk may still occur if the op-amp in the source is of poor quality. I'm sure what you heard was real(better soundstage, more focused imaging, etc).

Thanks again for your answers. It should be fun to try both. I'll be sure to let you guys know when I get another amp.


Maurice

madmax

I've tried vertical biamping and had good results. Too bad I didn't make a comparison to horizontal, it could have been helpful.
madmax

burdette

Well, organ, if the amp would be different in the way it handled driving two tweeters vs. driving a tweeter and a mid, then I'd think you'd be in the territory of considering horizontal, i.e. different performance. The information I relayed is general. You can always play around for fun.

Razz

Guys,
I am exploring the world of BiAmping and have a newbie question and would appreciate some guidance. Apologies in advance if I am in the wrong forum for this, but this was the best one that came up when I googled "Bi Amping help". Here goes:

I understand the following as the difference between Vertical and Horizontal Bi Amping:

Horizontal Bi Amping is when you power the Woofer and Tweeter/Midrange through seperate amplifiers. For this to happen, the pre amp should have either 2 pre-out sockets or you need to use the RCA Y connecter to split the signal (any drawbacks??). The speakers must have a biamp capability i.e. the cross overs should be isolated and the Woofer and Tweeter/Midrange should be capable of being driven independently.

Vertical Bi Amping is basically a dedicated amp for each channel, serving the entire frequncy range, i.e. when you power all drivers of a left channel speaker with a dedicated amp for the Left channel and likewise for the right speaker.

I hope my understanding is correct. A question I have is - for Horizontal Bi Wiring, is it necessary to have Low Pass and High Pass filters between the Pre and Power stages so that the Power amps only amplify the frequency range needed for their relevant drivers? or can the same results be acheived without the filters? Are such filters are available commercially?

I have just bought the NAD C272 and C162 Pre and would like to experiment with BiAmping.

Many thanks
Ali

Polkitup2

Unless you have the NAD C372 to go with your C272 you won't be bi-amping. You need two amps to bi-amp. I have vertical bi-amp'd my NAD c370 and c270 with good results.

unc2701

One thing I think that should be mentioned here that hasn't been: Semi-active horizontal biamping. Lets say your speakers cross over at 1000hz. Put in a high pass active filter at 500 hz and a low pass at 2000hz. The tweeter amp only see freq's above 500hz, then the speaker's passive network cuts out the rest. Opposite for the mid-bass amp. In addition to the amps seeing an easier load (less phase shifts & impedence dips @ crossover point), there's less strain producing frequencies that would just be filtered out anyway. You have to go well outside the actual crossover point since depending on the slope, the drivers do still produce sound.

This won't make a huge difference in the bass, but the tweeter amp (esp. tube amps) can greatly benefit from having those freqs filtered out.

Early B.

Where's treitz? He should have some input on this topic.

Razz

Guys,
Thanks for the input. I have Vertical biamped just yesterday using the NAD C162 Pre and two NAD C272 Powers. Currently using Paradigm Phantom V3 - looking to upgrade to Speakers that can be BiAmped. The sound is very good, however I do think it's time to look at different speakers. I am in Dubai for the moment therefore my choices are limited. So far, I have not been able to locate Polk Audio here. I know this is Club Polk, and I have always been a fan, so at the risk of being politically incorrect - any suggestions?

Cheers
Razz