View Full Version : Amp specs are they worthless???

05-10-2015, 05:42 AM
Just switched amps in my system i am not going to say brand names because people are bias i will however tell you i use Altec mod 19 speakers and JBL 4311. Ok now about amps one is solid state 200watts with a dampening factor of 800 the other amp is solid state 45 watts with a dampening factor of 40 well the smaller of the amps sounds the best hands down and the bass is better way better and i have no more speaker cone movement with the little amp than i do with the big powerful amp and its 800 dampening factor. And when i run the big amp on the 19's i had no bass so i bought a good Miller Kreisel sub but it never blended in with the big amp. Well i switch to the smaller amp and the sub blended so well it disappeared without changing sub settings. The big amp according to 99% of people online has really good bass that is false and it lacked midrange compared to the smaller amp it really sucks and was a waste of 500 bucks and it's on ebay right now. So my question is how many people pay attention to specs and or reviews and do you think they are accurate? Stereophile gave rave reviews on my big amp they where blatantly wrong so they where either paid to say good things or they where drinking and smoking crack when listening. So do specs really matter??

05-10-2015, 08:05 AM
The big amp according to 99% of people online has really good bass that is false and it lacked midrange compared to the smaller amp it really sucks and was a waste of 500 bucks and it's on ebay right now.
In your experience, which is all that really matters, right?

So why do you continue to ask "which is better" questions? What are you unhappy with in your current set-up?

Ed Zeppeli
05-10-2015, 10:27 AM
It might be technically insightful for those of us not in the know what specs besides damping factor and/or power rating determine control over woofers.

I'd be interested in hearing anyone's thoughts.



05-10-2015, 11:32 AM
If you bought anything based mainly on what Stereophile said then that was your first mistake, except their equipment measurements which may be useful to compare/confirm against manufacturer specs and other review measurements.

Your question of how many people pay attention to reviews, well quite a lot when it comes from "authorities" like pro reviewers, and it seems to often lead to a herd mentality or confirmation bias with gear based on their reviews. It's hard for most people to get their hands on much gear to listen to or compare, even worse now with so few brick & mortar audio shops. You can't always trust user reviews either because everyone thinks what they just bought is a "5-Star" unit...until the honeymoon is over and they begin to hear the flaws but even then, many don't like to acknowledge those flaws.

So yes, trust your own ears, if it works in your system and room that's what counts, and so on.

05-10-2015, 12:57 PM
"....So do specs really matter??

They can act as a guide, sure, but often as not they need some perspective and context in order to mean anything.

Watts per channel is likely the most useful since speaker efficiency varies greatly. As for the highly efficient Altec 19, 45 watts is plenty of power. So in your case does the wattage rating have any real relevance?

Damping factor is calculated by dividing speaker impedance by the amp's output impedance. That says nothing really, as a number on the page, but a higher number does suggest the ability of the amplifier output to better control the woofer's motion. So, the bigger the number the better? Perhaps in the pro world where the amps drive the speakers directly rather than through a passive crossover as we have mostly in the home speaker market. The passive filters really limit the damping effect the amps can provide so there may not be much difference between the amps in damping ability. Not nearly as much as the 40 and 800 numbers suggest.

So reading through your post I would first ask what was wrong with the 200 watt amplifier that it produced "no bass"?

05-14-2015, 01:36 PM
Not worthless, but they don't tell the whole story. You have to go out and listen. Always.

11-20-2015, 10:47 AM
When I had my Altec 19 clones I ran 70 watt tube mono blocks and they blew me away when I first fired them up, I couldn't believe how good they sounded. Bass up the kazoo and plenty of highs.

11-28-2015, 12:58 PM
The model 19 is not the usual case when it comes to amp compatibility because it is rather colored in response. Two of the ways it differs from flat response, at least the examples I have heard, are recessed lower/deep bass and a very bright, harsh even, treble. It is one of those speakers where you are looking for synergy with an amp that is also not flat. The frequency response characteristics and impedance matching, not the rated power output, will determine whether it will be bliss or hell. I have witnessed these quests with the 19 first hand several times, and it was in these instances difficult to go about it scientifically. What they were sure would be an improvement usually wasn't. They just kept swapping out amps until the eureka moment happened. The one thing that always seemed to please was old Dynaco tube units; I liked the Stereo 35 better than the 70, but that was me.

I never witnessed anyone EQ-ing the darn thing. If it worked, that would be easier for sure then looking for amps, but there was probably more going on than what an EQ would fix.

11-28-2015, 02:11 PM
Those dynaco's were exactly what I had hooked up!

01-06-2016, 02:23 PM
I have found it often to be the case; the smaller, well designed and built amps (especially in a big line like the famous and ubiquitous Semi Valley "22xx" series Marantz receivers), to have a sweeter, richer and fuller sound to them than their bigger siblings

Same experience with tube amps smaller 6BQ5 stuff has often bested (well regarded and good sounding) KT88/6550 types here in my house in the "euphony" and subjective bass departments More inner detail too

Stromberg-Carlsons definitely come to mind

The only moderately "big" envelope that I enjoy is the original incarnation of the 7591 and even they are only modest as for output if run within sane limits (I love my old Fisher which I have dialed back considerably to try and cool things down a bit)

This observation being true when mating with reasonably appropriate loads, but still, the smaller guys always seem to have a more pleasant sound to my ears even when paired up with less than optimal speakers (on paper)

I know this proves nothing, too many variables and certainly not "scientific", but today I will definitely consider smaller machines that years ago I used to reject out of hand (if it wasn't 100wpc or better, I wouldn't even consider them) I was proven wrong too many times now. 100wpc was a magic number for a teenager in the late '60s early '70s, like some sort of grail with bragging rights

Obviously they run out of steam sooner than the big guys and you have to be careful not to clip, but for plenty good levels in my living room (satisfying and plenty loud going by my Radio Shack SPL meter) I now have no problems with a good sounding 20 watter

Live and learn (and I might still have more of my hearing if I had learned this truth sooner)

Ian Mackenzie
01-07-2016, 02:46 AM
Some scientific reasoning and different perspectives.

The Altec 416 woofer used in the model 19 is. Low Q woofer and relatively sensitive.

These two facts tell me the model 19 would be sensitive to damping factor and may sound over damped when driven at low levels compared to monitoring levels where the Fletcher loudness curves brings bass into perspective a loud levels.

I have heard the model 19 in a large room with a 300 watt a side amp and it sounded great right up to the point where a pipe organ poled the woofers shorting the voice coils and destroyed the amp.

( this was a demo by Rank industries when the model 19 was released)

Under these conditions the dynamics of the bigger amp come to the for.

The other consideration is that big amps in general are at their worst sonically at low levels where a hardness can be fatiguing. We are talking less than a watt.

There are exceptions like my Pass labs 250.5 power amp which has single ended class a biasing up a to watt or so then is push pull class A to maybe 20 watts then it's class A/B. The effect is extreme resolution and a hint of warms at low levels and brilliant dynamics

The big amp may well be close to a wire with gain and will present a warts and all situation of the source further up the food chain.

The stock model 19 was good in its day but as Clark says has some short comings. Don had the model 19 for while and l think he voice comment on what it did well and less well.

Introducing some coloration or warmth from a
typically smaller amp may bring about a listenable but not accurate presentation.

You could insert a o.1-0.2 ohm power resister in series with the speaker leads to evaluate the change in bass response.

This would lead to a small but audible rise in the response below 100 hertz so the response is less over damped. A 100 0hm resister across the woofer damps the reactive aspect of the bass impedance and will have the effect of damping the upper bass. JBL do this with their more recent networks where the dcr of the L induction on the woofer is designed into the bass tuning.
This is what makes audio so subjective.

02-10-2016, 02:26 PM
What I look for: is the output capacitance (stage) . I need a lot of microfarads !

05-05-2016, 12:40 AM
This may come as a surprise: Exept from the 930 using Japanese transistors, look at the schematic of the main amp and it will be obvious according the schematic the 930 main amp is exactly the same as the Citation Twelve one.