Toshiba SA7150 and Advent Loudspeakers Stacked

[Doug G.]

Each pair of Advents in my quad system is driven by its own stereo amplifier. Thus, four stereo amplifiers or, in my case, two quadraphonic amplifiers (two stereo amplifiers in one box). I do have four separate amplifiers, also, so that is an alternate option.

Solid state amplifiers really do their best with an 8 ohm load. I have driven two pairs with one amplifier before but at times, it just seemed like a bit of stress crept in at loud volumes and, regardless of claims, a four ohm load does stress an amplifier more than an 8 ohm load. More current flow, more heat, with a lower impedance load.

The stacks are up off the floor about two feet.

As to stacked Advents in a two or four channel system, they're both good.

And yes, they do sound amazing in my quad system.

Doug

 

[spark1]

Each pair of Advents in my quad system is driven by its own stereo amplifier. Thus, four stereo amplifiers or, in my case, two quadraphonic amplifiers (two stereo amplifiers in one box). I do have four separate amplifiers, also, so that is an alternate option.

Solid state amplifiers really do their best with an 8 ohm load. I have driven two pairs with one amplifier before but at times, it just seemed like a bit of stress crept in at loud volumes and, regardless of claims, a four ohm load does stress an amplifier more than an 8 ohm load. More current flow, more heat, with a lower impedance load.

The stacks are up off the floor about two feet.

As to stacked Advents in a two or four channel system, they're both good.

And yes, they do sound amazing in my quad system.

Doug

Who has made such claims about the effect lower impedance loads vs higher?

 

[Doug G.]

I have. Oh, and Echowars here on this forum if you don't respect my opinion (and it's not really opinion, it's fact). It's simple physics. More current flow, which is what happens with a lower impedance. More heat produced by output devices which, of course, is more stress on them.

Doug

 

[Bernardz]

Learning about speaker efficiencies,
I found this old clip about the Advent OLA’s.
It’s states the speakers produced 90 db at 2 volts input . Would that be classed as a low or high efficiency loudspeaker .

 

[spark1]

Learning about speaker efficiencies,
I found this old clip about the Advent OLA’s.
It’s states the speakers produced 90 db at 2 volts input . Would that be classed as a low or high efficiency loudspeaker .

The correct term is sensitivity.

That is a non-standard measurement.

The Advents are not particularly sensitive.

 

[Bernardz]

Thanks for the clarification. There is much for me to learn in the audio world. But it’s a fun journey .
Bernard

 

[Doug G.]

90dB sensitivity is about in the average range. Not high, not low.

Doug

 

[spark1]

90dB sensitivity is about in the average range. Not high, not low.

Doug

90dB with 2V into a 6 ohm load translates to a standardized sensitivity of nearly 93dB with one watt of input. I'm pretty sure the Advent's actual sensitivity is quite a bit below that...more like 88dB. The Advents I've owned (both NLA and OLA, and 5002's) sure weren't 93dB!

 

[spark1]

I have. Oh, and Echowars here on this forum if you don't respect my opinion (and it's not really opinion, it's fact). It's simple physics. More current flow, which is what happens with a lower impedance. More heat produced by output devices which, of course, is more stress on them.

Doug

Of course it does. If you had read any of my earlier comments, you would see that was what I was explaining to the OP. Sheesh.

You said that "regardless of claims", lower impedance result in additional heat. So who has claimed otherwise in this thread? Who's making these claims that you referred to? Where? That was my question.

You act as if you are the lone light in the darkness. Yet I see no evidence of anyone questioning the impact of higher current draw. Again, sheesh.

 

[Doug G.]

90dB with 2V into a 6 ohm load results in a sensitivity of nearly 93dB with one watt of input. I'm pretty sure the Advent's actual sensitivity is quite a bit below that...more like 88dB.

Still pretty average. Advents can be driven to very high levels with surprisingly little power.

Doug

 

[Doug G.]

Of course it does. If you had read any of my earlier comments, you would see that was what I was explaining to the OP. Sheesh.

You said that "regardless of claims", lower impedance result in additional heat. So who has claimed otherwise in this thread? Who's making these claims that you referred to? Where? That was my question.

You act as if you are the lone light in the darkness. Yet I see no evidence of anyone questioning the impact of higher current draw. Again, sheesh.

Sorry, I misinterpreted your post. The way it's written, I thought you were challenging that impedance makes a difference in amplifier operation. I see you were asking who has claimed it doesn't. I wasn't implying anybody in this thread was claiming that but have seen others claiming an amplifier rated for 4 ohm impedance doesn't experience differing stress than with 8 ohm impedance.

Of course, there are some amplifiers designed to mitigate such differences but the typical solid state amplifier is affected.

Doug