CWelsh

I do hear what your saying and understand about headroom, peaks vs. continuous, and clipping. All good points. All correct within context. When I'm using the example of an 8 wpc amplifier, my context includes a Klipsch Forte III with 99 dB effeciency. That 99 dB is LOUD by pretty much any standard...loud enough to damage your ears with extended exposure. So, let's say there is a peak in the source material that needs to be twice as loud. That means the amp has to deliver a whopping 2 watts to the speaker. Twice as loud again, 4 watts. Twice as loud again, 8 watts. Now we have to worry about clipping, but we are at 111 dB. And, unless I'm mistaken, an amplifier that can deliver 100 watts will still only deliver 8 watts to achieve that 111 dB. Of course, if we were driving a speaker with 80 dB efficiency, it would be an entirely different context and way more power would be required. Still, how loud the speakers can get is not really the question. Do those additional unused watts (thanks @82 Cornwalls) contribute anything to the overall quality of the sound, or does the output capability strictly affect volume. I'm leaning to the idea that it is only SPL and other factors like current, topology, etc. are responsible for other aspects of the overall "sound".

What an amazing guitar player!

COOL! I want to hear your thoughts!

LMAO!!!

Thanks @geoff. and @Woofers and Tweeters for bringing up the maximum volume issue. I've been thinking about power needs at reasonable listening levels, but this does add another wrinkle, doesn't it? My Forte IIIs are rated at 99 dB/2.83V/1m (just looked this up so I'm correcting my earlier mistake), and have a MAXIMUM of 116 dB continuous. To achieve that maximum requires something a little shy of 64 watts. The specs also show maximum power ratings of 100/400 watts. I assume that means 100 continuous or 400 peak, so we're pretty much in that 2X range. Personally, I have no interest in pushing my speakers to 116 dB, but I suppose in a huge room with a listening position pretty removed from the speakers, that might be somewhat reasonable. I take my measurements from my listening position and consider anything above 90 dB to be really, really loud, but it isn't painful and it sounds quite good. That is still probably below 1 watt of amplifier output. I don't know about the rest of you, but I'm enjoying this discussion. I appreciate the participation.

If I follow your argument correctly, does this suggest that a good, solid, high-end amplifier with high current producing 8 watts should sound the same as a good, solid, high-end amplifier with high current producing 28 or 280 watts into an efficient Klipsch speaker at the same SPL? It makes sense to me that it would but, again, just my assumption.

That is a good question. I would think it should be equal as a function of the speaker crossover network design, but that is just an assumption.

Lot's of interesting comments and information here, but it isn't answering the question that is bugging me. I'll ask a different way... It supposedly takes 1 watt of power from the amplifier to drive my Forte IIIs to an SPL of 98 dB at one meter on axis. A 8 wpc ACA has more than enough power to do that and a 28 wpc Fisher is not going to require more than that same 1 watt to achieve the same SPL. Someone please correct me if this is not true, but it seems to be a law of physics. If this is correct, the question is, what is(are) the benefit(s) of the additional output power of higher output amp? I'm not asking with the ulterior motive of suggesting no benefits exist. In fact, in my response to 82 Cornwalls above, I'm saying I can hear differences that I think of as beneficial...things I don't hear from the ACA at the same SPL. My desire is to understand why. Obviously, it is not all about SPL. Maybe the differences boil down to topology and the output power potential has nothing to do with it, but posts from others supporting the use of higher output amps suggests that is not the case. I'm still curious.

I think I've heard that tubes and Class D SS do a better job of handling impedance swings. I would like to know if that is correct and how that affects what we hear.

Good question. I loaned the Aiyima to my grandson a few months ago, so I haven't tried it for quite a while. And, I've been using the preamp section of the Marantz to feed the ACA, so that hasn't really been used as a full-on integrated for more than a year. My memory is, the sound of the Marantz and the Aiyima are not that far apart. The ACA provides more detail...just a very clear sound. I would describe the Marantz and Aiyima as more of a warm sound. I've only been listening to the Fisher for a few hours. My initial impression is that it sounds very much like the ACA with a touch more warmth and a slightly more expansive sound stage. The big difference is in the bass. I described it to my brother-in-law as more controlled and powerful. Not any deeper, but definitely more robust. I have my listening space in the basement and for the first time ever, I could feel the bass coming through the floor when I went upstairs. I'm sure the Aiyima would do that, too, but I've never played it in this house so I can't compare them head to head.

Klipsch speakers are known for high efficiency. One measly watt of input should be plenty loud for most anyone. Some of us swear by low powered SET or Class A SS amps while others feel they need at least 100 watts if not a couple of hundred. Not being an audio engineer, I don't understand what additional watts can do other than increasing SPL to ear damaging levels, and I would like to learn. Part of my reason for asking is that I've started using my old Fisher x-101-b (28 wpc) instead of my 8 wpc ACA, and I've noticed some significant differences. Is it just the additional output power, or is it the fact that one is tube and the other SS? Or, is it a combination? Or, is it something else all together? Educate me, please!

I know the thread title says pictures, but I like to know what I'm looking at. 🤩

Rather than switching amps, you might consider replacing your speakers with something with higher sensitivity. I think you would get more bang for your buck. Your RP 500m speakers are rated at 93 dB sensitivity. If your budget can handle it, the RP 8000F II is rated at 98 dB. That is a big difference.

That looks like a very unique double necked Strat. 🤣

I think I may have found part of an answer in a Stereophile review from 2019. "I found that the speaker's impedance magnitude (fig.1, solid trace) dropped below 6 ohms only in the upper bass and in the valley between the twin low-frequency peaks that define the reflex woofer loading. The minimum value is 3.65 ohms at 125Hz. However, the electrical phase angle (dotted trace) is sometimes extreme, and there is a current-hungry combination of 5 ohms and –49° phase angle at 90Hz. Despite its high sensitivity, the Forte III will work best with amplifiers that are comfortable driving 4-ohm loads. And the very large difference between the average impedance in the lower midrange and that in the treble means that the speaker might sound a touch bright with tube amplifiers having high output impedances." I was pretty sure I had read somewhere that the impedance dropped down below 4 ohms at some points. This may explain why the bass sounded tighter with the Fisher vs. the ACA.

I don't understand most of what you're saying, but I'm glad people are engaged with the question. I have the Fisher amp listed for sale on Reverb thinking I could use the funds for other enhancements to my system. However, I'm starting to rethink. We have a shop in town that refurbishes vintage audio equipment and I may take it in for an evaluation. @83 LSIs question of whether it is operating at 100% has me thinking.

A key part of my question that I may not have articulated well is, regardless of the amps rated power, how much of that power is used to drive the speakers to an equal SPL? There was a thread sometime back where a simple method of measurement was described that identifies just how many watts are actually being used to drive the speakers to the desired level. If an equal two amps with significantly different power ratings can drive the amp to the same level, it makes sense to me that the same wattage is being used to do so. And, if that is the case and you are noticing obvious benefits from the higher power amp, I have to wonder if the benefits are from something other than the actual power at the speaker terminals. Please understand, I am not questioning or disputing your experience...others in these forums have said similar things. I'm just wondering if there are factors other than just the power capabilities of the amp that make the difference, or if that extra wattage contributes to more than just the power used by the speakers.

So, I ask a sincere question...not to stir controversy, but out of ignorance on my part. My question starts with the fact that my 8 wpc amplifier will drive my Forte IIIs to what I consider an almost painful SPL. And, I make the assumption that a speaker that is not biamped will have the same amount of power going to the conventional woofer, and the mid and high frequency horns. Am I wrong in my thinking? I can maybe see that higher wattage can provide better control (damping?) of the woofer, but I'm not sure I understand how, exactly. Does the amplifier class (A vs. AB vs. D) have something to do with it?

You might check with Hawkeye Audio in Iowa City, IA. As far as I know, they are the only Klipsch Heritage dealer in Iowa.

The link isn't working for me now, either. It worked when I put it up. I'm checking with the seller, but it looks like he either sold them or took down the ad. Just messaged him. He had set them up so he could demo them if someone was interested, but after listening for a while he decided he wanted to keep them...LOL

I know there has been some stuff posted about using active crossovers, but I'm specifically curious about the Pass designed biamp crossover from DIY Audio. Anyone have experience with it, particularly with Forte IIIs?

Welcome to the club! I am also a Forte III owner (also my first ever Klipsch), and share your enthusiasm.

This is in a Facebook thread I follow. https://www.facebook.com/commerce/listing/1105454427160063/?media_id=0&ref=share_attachment I have no affiliation or interest in this offer. Owner isn't sure, but thinks they are from the mid-80s to early 90s.

It is the big can caps that really scare me. They are buried under a rat's nest of wires and have multiple wires connected to them. I recapped my Marantz 1060 and even replaced a few transistors, but everything is mounted on boards and is clean and easy. If it wasn't such a nice amp, I would try it. I just don't want to mess it up when I know someone with experience could restore it to better than new condition. I've even got all the new caps and am including them in the sale price.

I suspect it may not be working 100%, but I don't have the ability to test it. I've had this amp for more than 25 years and haven't done anything to it. I'm pretty sure it was in storage for at least 5-10 years before that. All of the tubes except the rectifier are Fisher brand, so it is possible they are original. If not, I will bet they are at least 50 years old. Both channels are working and, to my ears at least, sound even. In fact, the sound stage sounds really nice.