Mcintosh MC501 to 802Di's: 8ohm vs 4ohm

[Highroller]

I am wondering about connecting to the 4 ohm taps on the MC501 to my 802Di's. Since the 802Di is rated for 8 ohm can someone tell me what happens when connecting to the 4 ohm taps both from a sound standpoint as well as an electrical standpoint vs the 8 ohm taps? Does more power get send down the wire when connected to 4 ohms to 8 ohm speakers....etc..

Thank you for your help

[mdonda]

If you select the 8ohm tap than you will get the full rated power output at that impedance load, however; you will get less power the furhter away the speaker's load strays from the selected tap. That is the disadvantage of the autoformer and that's why you typically need a much more powerfull Mac amp as compared to a more modern design. The 802d's impedance curve varies quite a bit and the 8ohm nominal rating is just the average. If you select the 8 ohm tap, the frequency range closest to the 8 ohm load will sound its best. You just have to experiment and detemine what sounds best to you.

[htsteve]

highroller,

As mdonda said, you need to experiment. I have 802D's and an MC402. I tried both the 8 and 4 ohm taps. For my room and setup, the 4 ohm connection was better. So that is what I use.



Hope this helps.

[mb225]

If you select the 8ohm tap than you will get the full rated power output at that impedance load, however; you will get less power the furhter away the speaker's load strays from the selected tap. That is the disadvantage of the autoformer and that's why you typically need a much more powerfull Mac amp as compared to a more modern design. The 802d's impedance curve varies quite a bit and the 8ohm nominal rating is just the average. If you select the 8 ohm tap, the frequency range closest to the 8 ohm load will sound its best. You just have to experiment and detemine what sounds best to you.

I often wondered about this since MC makes you select your ohms.

So what happens if your speakers fluctuate between 3 and 8 ohms and you are hooked up on the 8 ohm tap? Does the MC fall short at 3 ohms?

[mdonda]

I often wondered about this since MC makes you select your ohms.

So what happens if your speakers fluctuate between 3 and 8 ohms and you are hooked up on the 8 ohm tap? Does the MC fall short at 3 ohms?

Depends on the power output of the Mac amp. If you're using a 500wpc mac amp, then the difference would be marginal compared to a 250wpc amp. That's why you typically want to use a higher powered mac amp.

[Pio]

I am wondering about connecting to the 4 ohm taps on the MC501 to my 802Di's. Since the 802Di is rated for 8 ohm can someone tell me what happens when connecting to the 4 ohm taps both from a sound standpoint as well as an electrical standpoint vs the 8 ohm taps? Does more power get send down the wire when connected to 4 ohms to 8 ohm speakers....etc..

Thank you for your help

For current hungry speakers that dip to the 3 ohm range like the 802's, you need to select 4 ohm taps.

[mb225]

So this is very odd to me. You would think buying a Mcintosh would get you uncompromising performance. It sounds like the Mac can't handle a large range of resistance. Plus I'm always hearing how well Mcintosh and B&W 800s work together. Yet the B&W have a large resistance range? Are there any amps that are a better fit to drive B&Ws?

Is this a Mcintosh design flaw? I feel like I'm missing something here... :blink:

[mb225]

This really makes me wonder... I'm driving B&W 803s with a Rotel RB-1582.

According to documentation:
B&W 803s - Nominal Impedance: 8Ω (minimum 3.0Ω)
Rotel RB-1582 - Speaker Impedance 4 ohms minimum

So when the B&Ws dip into the 3 ohm range can the rotel support those frequencies? Could this configuration be damaging to the amp or the speakers?

Very interesting... :duh:

[Highroller]

If the 802Di's says 8 ohms (which I think they do), will it cause harm to the speaker to run them at 4 ohms or 2 ohms?

[Kal Rubinson]

If the 802Di's says 8 ohms (which I think they do), will it cause harm to the speaker to run them at 4 ohms or 2 ohms?

I have been running the 802Ds on 4ohms for years.

[wettou]

I have been running the 802Ds on 4ohms for years.

Good evening Kal,

How's the review of the 800Di coming? I am looking to get a pair :B

[Kal Rubinson]

Good evening Kal,

How's the review of the 800Di coming? I am looking to get a pair :B

Just fine, thanks. :W

[Skyblue]

Just fine, thanks. :W

If you post it here first, we can help proof read it ! :T

[wettou]

Just fine, thanks. :W

When does it come out?

[scanido]

803S on the 4ohm tap here as well. Noticed the bass and highs to be more detailed and powerful with a slightly larger soundstage. 8 ohm seemed to benefit the midrange more but lost the bass and high.