B&w 684 should I amp?

[Jb&w]

I'm running my 684s with an onkyo 805 my question is if I use an amp with 130 watts would these sound better?

[htsteve]

jb&w,

First of all, welcome to the forum! :T


As to your question, my answer is: YES.


Receiver amp sections typically cannot deliver the raw current than an outboard amp can. Part of it is simply that an outboard amp does not have to share any power with any other areas (pre-amp, video, tuner sections, etc.).

Outboard amps can also deliver all their power to all speakers at once. Let's say a recievers output is 100 wpc. Each channel is capable of 100 watts delivery. But typically not all five (or 7) channels can be fully driven at the same time. You can do this with an quality outboard amp. They have the power supply to do this. And they tend to have lower distortion while doing it.

The most noticeable areas of improvement should be bass and soundstage. But all areas will benefit from an outboard amp.


Hope this helps.

[Jb&w]

Thank You it does help. How many watts should I use on these to make them come alive?

[htsteve]

jb&w,

There are a couple of ways to answer your question. First, what do you listen to most of the time: HT or 2 channel?

The 684's will be the most power hungry of your speakers. If you simply want to improve 2 channel performance, I would look at a 200 watt (or so) stereo amp. That will really drive them, plus set you up in case you get bigger speakers later. Something in the 125-150 watt range will also be quite good. You can run the remaining speakers off of the receiver (for now).

If you want to improve your entire HT experience, and 2 channel as well, I would look at a 5 channel amp at least in the 125-150 watt range. Of course, more powerful amps (say 200 wpc X 5) will offer improved performance.

Do you have a budget in mind you can share? Are you opposed to used gear (this can lead to some nice bargains)?

From an ultimate performance perspective, a high powered stereo amp on the mains plus a good multichannel amp for everything else is something to consider. It's what I have today. I did this in two steps. I got the multichannel first and then the stereo amp later.


Hope this helps.

[Jb&w]

I'm ok with used gear I was look at rotel emotiva and parasound. Also onkyo m 501. I'm looking to spend 200 to 300$ for a sterio amp

[ryan.devry]

I do agree with HT steve, however, I would stay with at least a 200W per channel in whatever amp you get. The Onkyo 805 itself isn't under powered for a receiver.

Specs:
130 watts minimum continuous power per channel, 8
ohm loads, 2 channels driven from 20 Hz to 20 kHz,
with a maximum total harmonic distortion of 0.05%
and its a monster at like 50lb


That being said if you get an amp with 125-150 watts per channel I don't know that your going to get much improvement if any. The 805 also goes down to almost 200W per channel at 4 ohm load. So it does push more current than some similar recievers. I just don't think you will get much more improvement from 125-150W per channel amp for the cost. I would definately go with a 200W per channel amp to get the best bang for your buck.....

I hope this helps a little.

[theblue]

you can play the game that I'm playing.

I got a used 5 channel rotel amp which puts out 100 per channel. I currently bi-power using 4 of the channels for my 683s (so it's a lot like a nice 200rms amp) and use the last channel for my center while the rest of my speakers use my marantz which now has an easier load to drive.

later on I'll buy monoblocks or a very nice 2 channels for my mains, and use the rotel for my surrounds (and also probably get a pre that has no amp in it).

don't be afraid to go older with solid state amps because technology hasn't really changed very much over the last decade in the class A and A/B world.

[JustinGN]

I use the 684s at home myself, and I noticed a clear difference after bi-amping using my Marantz SR6003 receiver. Both the 683s and 684s perform a lot better when they have ~200W of power feeding each speaker, which is something the Onkyo just can't do on a single channel. Thankfully, your 805 can bridge the Surround Rear and Front channel outputs into a bi-amp setup, similar to my Marantz. Consult your user manuals about "Bi-Amping", for both the B&W 684s and your Onkyo 805. It's not as simple as plugging in two extra cables and getting more power.

If you'd rather have 200W+ power from a single channel, using an external amplifier (Usually Class AB) is your best bet, as receivers just don't have the space for massive amplifier sections.

[Jb&w]

you can play that game that I'm playing.

I got a used 5 channel rotel amp which puts out 100 per channel. I currently bi-power using 4 of the channels for my 683s (so it's a lot like a nice 200rms amp) and use the last channel for my center while the rest of my speakers use my marantz which now has an easier load to drive.

later on I'll buy monoblocks or a very nice 2 channels for my mains, and use the rotel for my surrounds (and also probably get a pre that has no amp in it).

don't be afraid to go older with solid state amps because technology hasn't really changed very much over the last decade in the class A and A/B world.
[QUOTE]. If I biwire is it the same as if I was using a 200 watt 2ch amp?

[scanido]

[QUOTE=Jb&w]you can play that game that I'm playing.

I got a used 5 channel rotel amp which puts out 100 per channel. I currently bi-power using 4 of the channels for my 683s (so it's a lot like a nice 200rms amp) and use the last channel for my center while the rest of my speakers use my marantz which now has an easier load to drive.

later on I'll buy monoblocks or a very nice 2 channels for my mains, and use the rotel for my surrounds (and also probably get a pre that has no amp in it).

don't be afraid to go older with solid state amps because technology hasn't really changed very much over the last decade in the class A and A/B world.

. If I biwire is it the same as if I was using a 200 watt 2ch amp?

I agree. You can find some really nice amps from Bryston, Classe, and McIntosh if you are willing to get a generation or two behind. Before i got my current amp i was plaing with a Bryston 4BST and that amp was great for the price!

[htsteve]

If I biwire is it the same as if I was using a 200 watt 2ch amp?

jb&w,

Bi-amping is not really the same as getting a more powerful amp. You can bi-amp with your receiver and might get some improvement.

The problem with a receiver in bi-amp mode is that it is still delivering only the same current to each section. So a 130 watt receiver is still only delivering the 130 watts (and associated current) into each section (high/mids and bass) individually. The bass section draws the most current, so sending the same amount of current to it really will not significantly improve things.

A 200 watt outboard amp will have a significantly better power supply. The engineering and design tend to be better as well. So this kind of amp will be able to deliver all 200 watts (and a LOT more current) to all the drivers, especially the bass units. This is the reason powerful outboard amps bring out the best in quality speakers, which you have.

I've bi-amped twice (with outboard multi-channel amps). And I always came back to a more powerful stereo amp.


Hope this helps.

[theblue]

I think he was more asking if using an outboard amp to bi-power like I am 100w+100w is equal to buying a 200w 2 channel amp.

It's not a as simple as 100+100=200. The real answer is that results/opinions may vary.

I think you'll find that most would agree:

200w monoblocks > 200w x 2 channel amp > 100 x 4 bipowering

but then again, bipowering with 4 x 200w monoblocks > 2 x 200w monoblocks.

(I hope you see what I'm saying)

I offered up the idea as a stepping stone which is what I'm doing with my setup. When I buy monoblocks or a sweet 2 channel amp, I'm going to be sitting in great shape to run a 7.1 setup with loads of power and configuration options.

Thankfully, your 805 can bridge the Surround Rear and Front channel outputs into a bi-amp setup, similar to my Marantz. Consult your user manuals about "Bi-Amping", for both the B&W 684s and your Onkyo 805. It's not as simple as plugging in two extra cables and getting more power.

If you already have the means to bi-power then by all means try it out since it won't cost you a penny.

[Jb&w]

If I put my speaker impedance @ 4 instead of 6 will it hurt my speakers? Also would it sound better at 6. the onkyo put it on 6 when I set it up

[wettou]

If I put my speaker impedance @ 4 instead of 6 will it hurt my speakers? Also would it sound better at 6. the onkyo put it on 6 when I set it up

Good question potentially

[Jb&w]

So I bought an amp today adcom gfa-1a it's rated at 200w a channel and I have to say I really like it

[htsteve]

Excellent!

[Jb&w]

Is adcom a good brand?

[htsteve]

Personal opinion based on talking with others.

Older adcom is pretty good. And the amps are pretty good. Then adcom really expanded the lineup in a fairly short timeframe, and the overall quality sufferred. The local hi-fi shop that carried dropped them as a result.


Ultimately, if you feel you got a good deal on it, and more importantly, it gives you the performance you expected, then this is good for you.
A well built amp will last for years.

I suspect you will begin to notice new and exciting things in various materials.

Enjoy!