Von Schweikert VSX: 14 Ohm & only 8 Watts?

[nightflier]

I read that the Von Schweikert VSX on wall speakers were rated at 14 Ohms and could be powered by a measly 8W amp (the SonicImpact T-Amp?). First of all, is this a typo on their website or can an 8 W amp actually drive these speakers? Also, what does the 14 Ohms spec mean? I have amps that are stable to 2 ohms, but I don't know what it means to go in the other direction. Does that mean that my 250W @ 8 Ohms will only be pushing out somewhere around 125W at 14 Ohms? Is this safe for my amp? If so, then that would mean that the T-amp isn't going to cut it, right?

[topspeed]

VSA puts their average ohms as their rating. You'll notice that he states min. ohms as 7 ohms, which is still really high and a very easy load to drive. This, no doubt, is why he welcomes SET amps even though at 87dB's efficient, 8 watts aren't going to achieve window shattering spl's.

Every dynamic speaker presents a reactive load to the amplifier that varies depending on what it's being asked to do. Different frequencies will present different loads. Generally speaking, the higher the ohms, the easier it is to drive. The easier something is to drive, such as the VSX, the more options you have from an amplification standpoint. IOW, at 14 ohms nominal, it's very likely you could drive these speakers with a SounDesign rack system from the '70's.

[nightflier]

Any idea how these VSA on-wall speakers sound?

[Geoffcin]

I read that the Von Schweikert VSX on wall speakers were rated at 14 Ohms and could be powered by a measly 8W amp (the SonicImpact T-Amp?). First of all, is this a typo on their website or can an 8 W amp actually drive these speakers? Also, what does the 14 Ohms spec mean? I have amps that are stable to 2 ohms, but I don't know what it means to go in the other direction. Does that mean that my 250W @ 8 Ohms will only be pushing out somewhere around 125W at 14 Ohms? Is this safe for my amp? If so, then that would mean that the T-amp isn't going to cut it, right?

The T-amp can power 4 ohm speakers. I've actually driven maggies with it. NO it didn't play loud, but what was there sounded quite nice. The T-Amp would deliver about 5 wpc before clipping into the 14 ohm load.

You also have this correct;

An amp that delivers 250 watts into 8 ohms will also deliver 125 watts into 16 ohms. Powering a high impedance load is not a strain for an amp. Headphones are often rated to 300 ohms, and several flea watt amps have been modified to power them.

[RGA]

The Sonic T-amp ran the Audio Note K/Spe fairly well - this speaker is 90db sesntive though where it was positioned I would susect closer to 87db, The AN K is actually tougher than the speaker you note because the K is a 6 ohm speaker (min impedence not mentioned but it's lower than 6). The K was in a room too big for it and the SOnic Impact played to more then sufficient volume levels. The sonic Impact I heard was rated as 5 watts.

I was not overly impressed with the sound (it was modified and runs about $300.00) but for the money it was certainly good enough. Everyone in the room including the fellow who brought his over $1000.00 Musical Fidelity agreed that the SI sounded considerably better than his MF. So how you view the SI will depend on the relative experience you;ve had listening to pricey amps. The SI could seem like a giant killer (which I suppose in our session it would be tough to argue against -- I also felt it was every bit as good (but different) than a Celeste rig that was brought to the session). Though with the tougher to drive Gershman speakers my opinion would change.

[basite]

why do they actually make speakers rated @14 ohms? quite hard to find a normal amp that can do that (good)

[RGA]

why do they actually make speakers rated @14 ohms? quite hard to find a normal amp that can do that (good)

The question should be reversed -- 14 ohms a clock radio could drive - any amp can drive 14 ohms. Not every amp can drive 3. Most all 8 ohm loudspeakers will dip and rise well beyond and below 8 ohms. They could be anywhere from 3-30ohms - nominal is simply selected by the manufacturer to mean where it usually is. The easier the speaker is to drive the more amplifier options you have to choose from. A 2 ohm 81db speaker pretty much rules out all SET amplifiers and most tube amps and some very good low powered SS amps.

[nightflier]

While I don't want to knock VSA, I have a hard time believeing that these speakers can reach down to 40Hz. This certainly would take more than 8W. Bass response is where all on-wall speakers seem to falter and I wonder if there is any solution besides adding a sub. Has anyone heard these or are there any reviews of them anywhere?

[RGA]

nightflier

I don;t know anything about whether the speaker can reach 40hz but how many watts the amp has has nothing to do with bass response. A 1.5 watt SET amp with a K-Horn or either of my speakers will easily reach 40hz

[topspeed]

Dude, you're in Newport. Drive an hour to San Diego and hear them for yourself at the shop.

[superpanavision70mm]

Ok, dumb question...

What if you are driving your speakers by using the pre-outs on your receiver and then into an amp? Are you only powering them through the amp or are you also getting some power from the receiver as well?

[Geoffcin]

Ok, dumb question...

What if you are driving your speakers by using the pre-outs on your receiver and then into an amp? Are you only powering them through the amp or are you also getting some power from the receiver as well?

In this case the preamp section of the receiver is powering an outboard amp. This is very effective, and I use TWO outboard amps in my setup.

[nightflier]

Dude, you're in Newport. Drive an hour to San Diego and hear them for yourself at the shop.

I didn't realize how close they were. Do they have a showroom?