2 x RB1070 Bridged V's 1 x RB 1080 ?

[bleeding ears]

Hi again guys, looks like I am going to have some time on my hands waiting for my preamp to get fixed so now I am pondering my next purchase.

I am considering using 2 RB1070 amps bridged to power my front speakers.
That should produce about 330 wattts per channel.

However, there is also the RB1080 which does 200 watts per channel unbridged.

Which set up would be best? The costs of each setup would be similar. Anyone tried this out?

I know that distortion level are usually higher with bridged amps, but from what i can gather nobody can tell the difference as long as the distortion levels are below a certain level. Is this correct?

My speakers are rated at 250 watt @ 8 Ohm with 91 -94 db sensitivity.

Any thoughts or info would be helpful.

Also anyone know of any specs or reviews on the 1070 amp when bridged?

thanks Pete.

[csuzor]

I would think a single RB-1080 would sound better than 2 bridged RB-1070. But how about bi-amping the speakers? Maybe 2x 1070s would then be better?

I have 2 systems at home, audio only (based on Rotel 1068 + 1075 + B&W 703) and a/v (based on Denon AVR 90W + B&W 704). Until today, I could not really listen to music on the a/v system, the sound was so poor... well, I connected 2 unused channels on the Denon AVR from the CD player additional L/R outputs, and wired the B&W 704 in a bi-amp configuration... AWESOME. I couldn't believe the difference. It now comes remarkably close to my audio only system, which is not bi-amped. Any remaining difference is due to the 704 vs 703 advantage and room acoustics, but probably not the amp.

Now, in my case, the Denon AVR was seriously under-powered (only 90 "DenonWatts"), but the B&W 704 are not very difficult speakers, so I never thought it would make such a difference. And I know, it's passive bi-amping, which many claim is not worthwhile, and that's another reason why I never tried it. But now, I am sure that the "weaker" amps would all benefit greatly from this simplified speaker load.

So, 2x RB-1070 in a bi-amp configuration anyone?

I wish I could try bi-amping with the 1075, but I need to bi-amp 3x 703 (L/C/R), and the 1075 only has 5 channels... so now, my upgade choice is between another 1075 for a 5 channel bi-amp setup, Vs a 1077 for a classic setup...

[aud19]

Unless you already have a single 1070 and crave more power and also plan to do "proper" biamping by disabling the speakers crossover and adding a crossover in the chain prior to the amplification....just get the 1080

[GregLett]

I agree with getting the 1080. I tried that very configuration using two the RB980BX, and the 1080 sounded better. However the bi-ambing with the
RB980BX in stereo mode, was a little more open than the 1080. I used
one amp to power the LF and one the HF. I would run two 1070's like
csuzor suggested.

[bleeding ears]

Ok guys, I know the 1080 is considered to sound better than the 1070 but there are a few reasons why I thought the 2 x 1070 set up may be beneficial.

1) My speakers cannot be bi wired (one set of binding posts on speakers)
and I do not want to do surgery on my newly purchased Energy's to by pass the crossover, so bi amping is definitely not for me.

2) My Energy fronts are rated at 250 watt, so I would actually like an amp that puts out a bit more than 250 watts, I think this would ensure I am not underpowering the speakers and give a bit of headroom powerwise.
A single RB1070 (130Watt) would leave me wondering if the speakers could do with more, and the RB 1080 is still a fair bit short of the 250 watt speaker rating as well.
This is where I thought the 2 x 1070 amps bridged may be the way to go. I was thinking the 2 x Rb 1070 amps used like a monoblock setup might be good. Eg 1 amp (bridged) to power the left front and the other amp (brdged) to power the right front.

This setup would give 330 watts per front speaker, which is more than a RB1080 and more than the speaker rating which does not leave me wondering if I have enough watts. The cost is similar to buying one RB 1080.
I was thinking that in bridged mode the 1070 may close the gap on the 1080?
However I am not sure if bridging the 1070 is meant for use when powering subwoofers only, where the sound is not so precise and you can get away with a lesser quality amplification?

3) the problems others are having with the RB1080 fuses etc have made me wary of buying one. I am currently experiencing warranty issues with my 1068 preamp and I hear the Rb 1070 is very reliable.(but not many use them bridged)

4)The Rb 1090 is much more (too) expensive and probably overkill (380 watts)

considering all the above, anyone else have any thoughts/ opinions/experience with these units/setups.

Thanks guys Pete

[aud19]

I cringe at the word "bridging" I still vote 1080 PLENTY of power for your C-9's. I mean I'm powering mine with the 1075 and have yet to find myself needing more power. Would I like the extra headroom and insurance of the 1080? Sure but believe me, it's more than enough amp for them. Unless you can get a deal on a dealer's demo 1090 or maybe a used one....? :P :B

[TonyStarks]

Depending if you can be bothered, and how much tim eyou have, how about tasking you're dealer depending on how well you know them, if you can demo these 2 types of setups, its an idea that way you can decide which sounds best to you. If thats a no go, maybe arrange a time (again if you can be bothered) take you're speakers to the dealer and test it out there. Just and idea. At the end of the day its what sounds best to you.

All the best!

[NonSense]

Bleeding Ears

You might want to try playing your music at lower levels, it might help your condition.

Just kidding!


Note: More wattage does not equal better sound quality.

Also, the very definition if distortion indicates that there is an audible difference. The fact that the resultant audio signal is distorted from the input, indicates the equipment cannot reproduce the signal true to the input. There is no magic line to cross where it becomes audible. Better is always better. (But it's not the only criteria to judge either)

Your amp needs to be able to deliver enough current at your prime listening levels without clipping, and with minimal distortion.
You also, do not need to deliver your speakers their maximum rating to have exceptional sound quality. The majority of the sound pressure level calculation comes from the efficiency of the speaker vs. the wattage of the amplifier. Many have used the 1080 on much less efficient speakers in the 87-89 range with great success. (A 200W amp with a 93dB efficent speaker is like using as 800W amp with an 87dB speaker. Based only on the SPL calculation)

Wattage aside, the 1080 will sound better than a 1070 in bridged mode at reasonable listening levels. Since your speakers are not Bi-Wirable, your choice should be simple if you want the best sound given your two choices.

[bleeding ears]

thanks guys , Aud, do you get the volume up loud with the 1075 amp ?
and do you have a big room?

since you own the same Energy's you would be able to give me the best guide I guess.

My house is open plan (not many doors to close) and my home theatre room space is about 30 feet x 20 feet (15m x 10m) approx.

Yes, I too suspect bridging may not be the best option for whatever reasons eg distortion etc but it did get the wattage up higher than the 1080 for a similar cost.

However as I am finding out low cost, rarely gets the best sound or quality, but thats another story (currently on Club Rotel) and wattage may not be everything, sound quality is important too, not just volume level and composure.

As far as auditioning the setups goes, yes that would be the way to go but I think I already know what the outcome may be, and using a different room with possibly different components and speakers is probably just going to confuse me.

Besides that i dont fancy hauling the 28 kg Energy speakers around, not only may they get damaged but I may get injured as well. LOL

So if the RB1075 does a good job then I guess the RB1070 should do well also? (similar wattages)

the Rb1080 should be better again but, reliability may be a problem? and it costs a lot more in Australia Rb1070 $899 or Rb1080 $1599

I just dont want to wish i had more power down the track.

So Aud how loud on the dial to you usually have it and does it stay composed with heavy rock music? A good test I think?

I wonder if the Energy's (250 watt) are under powered with 120-130 watts per channel.

Anyone else have any thing to add ?

thanks Pete

[bleeding ears]

Nonsense, that was very funny! :lol: well done LOL

You make some good points on efficiency etc.

As is usually the case , I guess we all know the answer is to cough up more cash. LOL

I try to keep the cost down and get the most for my dollar and sometimes it may not be the best way to go.

So, from what you guys have said, I think I will forget the 2 x 1070 amp set up and look at a 1070 or 1080 depending on if they power the Energy,s ok.

As you said nonsense with 91-94 db efficiency maybe a high wattage amp may not be necessary. it s just nice to know you have the watts there if you really want them. It leaves not doubt that you are getting the best out of your speakers.

Unfortunately cost and reliability is an issue always, and that 1080 is scareing me off with its problems.

Anyone run a 1070 with 91-94 db and 8 ohm speakers? I am interested to know how they go?

thanks again Pete

[aud19]

Don't worry much about what speakers' watt ratings are

My room is smaller, only about 15' x 20' but it's split level with half of the rear walls height open to the kitchen behind it. There's also a sizable opening on the right side of the room where the bar and doorway to the laundry and garage entry are.

Generally for movies we keep the volume on my 1066 between 50-60, 2-ch from around 40-65. I've played the Led Zeppelin concert DVD (2nd disc is especially :-y ) with no one else home at 60-70 and it was LOUD and clean Just to see... I tried turning it up closer to 75+ ...I think I barely started to notice some compression closer to 80 but it was so painfully loud that had to turn it down fast! :lol: In other words the C-9's efficiency let's you get away with 120WPC (albiet robust Rotel watts) without much worry.

The 1070 should be up to the task for your C-9's but as you mentioned, down the line you don't want to wish you'd got more power (for a bigger room, different speakers etc). Only you and your wallet can decide that though

[bleeding ears]

Great info Aud, and very funny! Love that little butt rock icon, LOL

Can you tell me which Led Zepplin Dvd it was?

might have to get myself one.

Now that I know 120 Rotel watts does a good job I am not so concerned about getting maximum watts.

So it looks like the 1070 or the 1080 or even the 1075 will do the job for me.

One of these amps should keep my ears bleeding! :lol:

thanks Pete

[aud19]

That'd be this one:



There's a thread here:

http://www.htguide.com/forum/showthread.php4?t=5985&highlight=zeppelin

[Boombox]

Bleeding ears....I've been scratching my head with this as well and posted as similar thread earlier...

http://www.htguide.com/forum/showthread.php4?t=16388

The way to go is the RB1080. This beast does push out 250Watts per channel (according to the Rotel techs here in R.S.A.) as opposed to the rated 200Watts. And because your speaker are not bi-ampable, you should definitely go for the 1080. Plus the 1080 have XLR connectors which the 1070 does not have...(if you are really serious about SQ).

I own a 1070 and it drives a 93dB Boston VR2 speaker in bi-wire config. The amp is extremely stable and does not heat up much (I listen to a lot of jazz/funk/fusion and at times rap, with the ugliest ceiling rumbling, window shattering, bass) especially during heavy (deep bass) rap sessions (max 40-50 volume level). I love the "simplicity" of the 1070....all it needs to do is amplify, nothing fancy.
I'll be getting another RB1070 soon (couple of weeks) and I'll be going the passive bi-amping route. I've found that (to my ears) vertically bi-amping (1 amp per speaker) my speakers (260Watts/speaker) and 1x1080 sound "the same"...what made both configs shine was when a R30 000 (US$4000) CD-player was used as a source 8O. This was what made the biggest and most significant SQ difference. This solved my SQ problems...unfortunately I can't afford a R30 000 cd player yet, but I at least know how much better my stereo can sound (even without the second 1070)!! :T

Regards,

[miner]

I drive my B&W N804 & ASW800 with my RB-1070. This weekend I had some visitors from IL. My friends wanted to audition the system listening to Pink Floyd's 'Wish You Were Here'. I had the volume on my RC-1070 pre at about the 2 o'clock position. It was really blasting clean, clear music - the loudest I have had the system. The B&Ws opened up effortlessly. I, too, was contmeplating upgrading or bi-amping but now I am contnent - for now.

[aud19]

Plus the 1080 have XLR connectors which the 1070 does not have...(if you are really serious about SQ).

While it's good to have the added feature, the 1080 is not a "true" blanced design and hence there's no real bennefit to using the XLR connections. Unless you enjoy paying extra money for cables for no reason? :B Generally, IMO you're better off putting that extra money in to better quality RCA cables or other components, unless the equipment your connecting together are "true" balanced designs and/or you have long, noisy runs. Otherwise it's a waste of time and money.

[Boombox]

Thanks for that aud19....
I did consider the 1080 heavily because of these connectors.....still it is good to know this...will splash out on some decent RCA (although my current pair are quite decent) for my twin 1070s..

[Jurgen]

This reply is al little late and you already have good answers on your questions. I'll just throw in my $0.02.
Since your not able to bi wire, bi amping is also out of the question and there is little doubt that a single 1080 will perform better than a single 1070 and I will go as far that bridging 2 1070's can sound worse than a single 1070. At least that was the case with my speakers: really awful sound.
Bi amping however offered a spectacular improvement. Really night and day difference.

[csuzor]

Yes, bi-amp whenever possible, that is my new recommendation. I finally did try bi-amping the L/R 703 from the 1075, and the difference is awesome. See post in B&W section. Too bad there are not 6 channels in the 1075! Now looking for a 2nd 1075 to bi-amp 5 channels.

[Dmantis]

I vote for the single rb1080. Sweet amp and well worth the asking price.

mantis

[bleeding ears]

thanks for the info guys, never too late to learn more.

Jurgen, its good to know that bridging 2 x RB1070 amps did not give a good result. I think I will forget that idea totally.

Why do you think you got such a good result with the bi amping set up?

Do you think your speakers needed it for some reason or benefited from more wattage?

I could be wrong but I think it was Dynaudio that did not believe in bi wiring or possibly bi amping?

Obviously Energy must think along these lines also?

Any ideas why this might be?

Also any idea how decent quality mono blocks compare against the other amps and set ups?

Pete

[soundhound]

bleeding ears, good question, and your'e probably on the right path. A 1080 would have paid divedends as well as biamping with the 1075. Even while biamping w/ an active crossover, (removing jumpers on binding posts) your'e still at the mercy of the passive crossovers in the cabinet, so the net was to pick up some extra power for the frequencies that needed it.

[aud19]

Also different speakers (drivers, crossover design etc) respond differently to bi-amping beyond the obvious addition of power That's is why some companies don't offer dual posts IMO. Not that they don't believe in bi-amping in general but that with their specific components/design they found it made little or no difference and decided to reduce manufacturing costs (hopefully passing some savings on to the buyer) and/or putting that money elsewhere in the design.

[bleeding ears]

Ah! right, so could it be said that if your speakers do have double binding posts, then the manufacturer may have designed the speaker in such a way to give a better result with bi amping Vs single amp/ wiring?

This would perhaps explain why some get good results with bi amping.

Or to put it another way could it perhaps be said that if your speakers do not have double binding posts the manufacturer designed the speaker to perform best or equally well without bi amping?

If very expensive speaker manufacturers dont provide double binding posts perhaps cost is not the consideration, perhaps the internals of the speaker are designed to operate at optimum performance without any noticeable benefit from bi amping or bi wiring?

I could see this issue going the way of speaker cable discussion (ie never ending and perhaps inconclusive) but is very interesting and I am sure could instigate some good comments from others. Could warrant a new thread?

Pete

[aud19]

I think you summed it up pretty nicely there. ESPECIALLY the last sentence! :lol:

[Jurgen]

I think you summed it up pretty nicely there.

:agree: