Bi-amping Revisited

Early B.

I was talking to a fellow Polkie yesterday (who shall remain nameless 'cause I wanna kick his **** for encouraging me to consider this...:p ) about bi-amping my speakers on my 2-channel system. I've never seriously considered doing it because I felt a better option was to buy more amp than you need. However, I'm thinking about experimenting with a tube amp for the highs or maybe getting another Marsh A400 and bi-amping them. But first, I'm thinking of borrowing my friend's Odyssey Stratos and trying the horizontal bi-amp configuration just to see if it makes a difference.

A few questions -- are there any other members on this forum who bi-amp the speakers on their two-channel systems? If so, how would you characterize the sonic benefits?

How do you adjust for the differences in input sensitivity between the two amps?

Soild state or tubes on the highs?

Is bi-amping a minor tweak or a substantial upgrade? Pros and cons?

Thanks.

Ricardo

I experienced bi-amping with the Tylers using two TAD-60 tube amps. I was very pleased with the results. I used one amp for the lows and one for the mid-highs; The Tylers IMO have the perfect configuration for bi-amping, having the woofers tied to one set of posts, and the mids/tweeter tied to the other. Though I've never tried it, I think that bi-amping a speaker that only has the tweeter in one set of posts would not provide such a marked improvement. Of course I might be wrong.

Early B.

HTrookie wrote: »

I experienced bi-amping with the Tylers using two TAD-60 tube amps. I was very pleased with the results. I used one amp for the lows and one for the mid-highs; The Tylers IMO have the perfect configuration for bi-amping, having the woofers tied to one set of posts, and the mids/tweeter tied to the other. Though I've never tried it, I think that bi-amping a speaker that only has the tweeter in one set of posts would not provide such a marked improvement. Of course I might be wrong.

HT -- how would you characterize the differences between the use of a single TAD-60 versus two TADs?

Ricardo

I really never heard them with only one TAD...but IMO the differences would be the same that you would get by going from a 60 WPC amp to a 120 WPC amp, for a speaker with the stated configurration; I don't think you'd get the same in a speaker that only has the tweeter in one set of binding posts.

I-SIG

I have my SRS vertically bi-amped with a Parasound HCA-1000 on the high end and an HCA-2200 dual-mono on the low end.

I was very pleased with the results. Definitely noticeable. The highs are cleaner and have more air and the mids seem to be faster, cleaner and have more attack. I had a MF A5 Integrated for a few weeks before I did this setup and I think with the 2 Parasounds provide the cleanness and clarity of the MF unit with far more grunt and dynamics.

Also, if you are thinking of bi-amping tweeters only, don't use a tube and there isn't a constant enough signal and can cause the tubes problems. Mark explained it in a thread I did recently.

Wes

engtaz

The hardest part I noticed was balancing the outputs of the amps to not over power the upper or lower frequencies. The high part of some speakers are sometimes a higher or lower ohms then the lower frequencies therefore 1 amp gives more power to one or the other frequency's depending on the ohms. What I would like to know is how others are setting up the amps for balance. I have heard bi amped speakers where the highs became to bright when bi amped.

Thanks
engtas

Ricardo

In my case I used an SPL meter and some test tones, and did not need to adjust at all. I guess the fact that I used the same amp for high/mids and lows helped.

treitz3

Change the input sensitivity on the amps to balance. Or you can swap out different amps that have less power where you need it and more power where you need it. Some amps have the sensitivity control on the front of the amp, like a Carver TFM-55, for example.

My current rig has the M-500t or the M-4.0t [I swap them out often] on the highs and the M1.5t for the bass, augmented with a PSW1000 for the lowest frequencies. With this combination, no sensitivity adjustment was necessary and the end result I am very pleased with.

Early B.

I-SIG wrote: »

Also, if you are thinking of bi-amping tweeters only, don't use a tube and there isn't a constant enough signal and can cause the tubes problems. Mark explained it in a thread I did recently.

Can you provide a link to that thread? Even though I'm leaning towards SS for the highs, I'm interested in learning more about tubes in bi-amping.

Thanks.

I-SIG

Early B. wrote: »

Can you provide a link to that thread? Even though I'm leaning towards SS for the highs, I'm interested in learning more about tubes in bi-amping.

Thanks.

Actually it was Chuck. Here ya go:

Madmax on tubes on tweeters

Wes

Systems

HTrookie wrote: »

I guess the fact that I used the same amp for high/mids and lows helped.

This an important point when bi amping with the internal passive crossover.The ampflifiers must have the same gain or you will have an imbalance between the woofer and tweeter.

schwarcw

I have my SRS 2.3's horizontal biamped. I'm using two Parasound Halo A21's. These amps are rated at 400 wpc into 4 ohms. I've got plenty of power into the 2.3's. Originally, I had one Halo A21 powering both. What I noticed was an overall improvement in image and detail. The soundstage is very large, even at low volumes. I'm very pleased with the results. I don't have a tube pre, but I do have a Sony Modwright that has a tube output. I am very please with the level of detail, clarity and without the harsh or fatiguing experience.

hearingimpared

Early B. wrote: »

I was talking to a fellow Polkie yesterday (who shall remain nameless 'cause I wanna kick his **** for encouraging me to consider this...:p ) about bi-amping my speakers on my 2-channel system. I've never seriously considered doing it because I felt a better option was to buy more amp than you need. However, I'm thinking about experimenting with a tube amp for the highs or maybe getting another Marsh A400 and vertically bi-amping them. But first, I'm thinking of borrowing my friend's Odyssey Stratos and trying the horizontal bi-amp configuration just to see if it makes a difference.

A few questions -- are there any other members on this forum who bi-amp the speakers on their two-channel systems? If so, how would you characterize the sonic benefits?

How do you adjust for the differences in input sensitivity between the two amps?

Soild state or tubes on the highs?

Is bi-amping a minor tweak or a substantial upgrade? Pros and cons?

Thanks.

EB I've had my 2 ch rig bi-amp'd since March. It made a major difference in sound quality.

Here is the link I posted here on the topic.

One of the things I considered before bi-amping was the slew rate. Now there are some here that think slew rate is an irrellevant number. I don't believe it is. I also considered using a tube amp on the highs and a sand amp on the lows. It was recommended that I don't do this although I am going to try down the road.

If you read the thread you will see where others chimed in and stated they have their rig bi-amp'd too.

hearingimpared

engtaz wrote: »

The hardest part I noticed was balancing the outputs of the amps to not over power the upper or lower frequencies. The high part of some speakers are sometimes a higher or lower ohms then the lower frequencies therefore 1 amp gives more power to one or the other frequency's depending on the ohms. What I would like to know is how others are setting up the amps for balance. I have heard bi amped speakers where the highs became to bright when bi amped.

Thanks
engtas

Roy this is irrellevant. Woofer's and mid-woofers always draw more power than the tweeters whether they are bi-amp'd or not.

amulford

I haven't yet but I plan on doing it with four identical monoblocks...

Early B.

Thanks for the feedback, fellas. This is very helpful.

I also found additional info:
http://www.polkaudio.com/forums/archive/index.php/t-9652.html


I'm convinced to at least try it someday. I'd like to either get another Marsh A400 and vertically bi-amp, or a Marsh A200 and horizontally bi-amp. I don't think I'd want to fool around with a different amp for reasons mentioned here already. KISS principle.

This will be an expensive "tweak." After purchasing the amp, ICs, and speaker cables, the cost would be about $1,000. Oh, and I'd need y-connectors on my pre (yuck).

jdhdiggs

I-sig: Must depend on the type of speaker/design of tube amp. I have had zero issues with tube's only pushing tweeters.

Amulford: Bet it will sound exactly the same as using two but for twice the cost....

I-SIG

jdhdiggs wrote: »

I-sig: Must depend on the type of speaker/design of tube amp. I have had zero issues with tube's only pushing tweeters.

Please expound on that.

Also, that was from Madmax's experience, so maybe call him out.

Wes

hearingimpared

jdhdiggs wrote: »

I-sig: Must depend on the type of speaker/design of tube amp. I have had zero issues with tube's only pushing tweeters.

Amulford: Bet it will sound exactly the same as using two but for twice the cost....

Yo Bro, do you have speaks bi-amp'd?

Polkersince85

Anybody tried bi-amping 2.3TL's using an active crossover between the pre and amps. I've got two TFM-55's and a preamp with dual outputs. I can adjust the output on the high end. Seems like a good match. Would this create problems with the SDA imaging?