"Slam"--what is it, is it really accurate?

Thanks much for all the replies. I'd like to ask if you think my McCormack DNA-1 has the cojones to produce slam with reasonably efficient speakers? I think it is rated at 150 watts/channel into 8 ohms, and 300 watts into 4 ohms. My speakers are the(fairly old now) Legacy Audio Signature II, which are supposed to be very efficient, but I have never found them to produce significant slam on drum shots, or be all that dynamic on transients in general.

What I don't have a clue about is whether the Signatures are capable of slam/dynamics given a much more powerful amp, or if I would benefit more from a new/different set of main speakers. Any thoughts much appreciated.

"What I don't have a clue about is whether the Signatures are capable of slam/dynamics given a much more powerful amp"

Looking at specs of SE version of your Legacy speakers (can't find same for IIs), and assuming they are similar, I'd say, yes they should definitely be capable of "slam" in most rooms if in good working order.

I'd also say that given the power recommendation from Legacy for SE version, assuming similar to yours, of up to 300 watts, a bigger and beefier amp would yield additional dividends in the slam department.

Most vendors underrate the maaximum power handling of their speakers in order to play it safe and so as not to scare off buyers, but in general, I would tend to throw the kitchen sink amp power wise at speakers like those. A good quality 500 w/ch into 8 ohm Class D amp is what I would try. I landed on mine for my big OHM speakers for exactly the same reason. 250 w/ch Class D should deliver nice dividends as well.

I use my 500w/ch Class D amp even with my tiny similarly efficient Triangle Titus monitors, along with all my larger and more power hungry models.

As long as you listen to your ears for any signs of stress or breakup with more challenging recordings at a particular volume before going louder, you are not likely to damage most good quality speakers that are in good condition.

Your more likely to damage a speaker by blowing a tweeter if you attempt to crank up an underpowered amp too high and clipping occurs.

More power keeps clipping out of the equation. That creates dynamics and slam and is also easier for most good speakers to digest to boot.

@ Mapman,

Thanks much for the thoughts. Just for grins, could you name a starting point in the way of a class D amp? It would be interesting to compare a state of the art class D amp to my McCormack DNA-1 rev. A. And even if I were to find an increase in slam/dynamics with the class D, I would want to make very sure that I did not lose any of the mid and high frequency "niceness" that this McCormack has.

Lots of info here on various threads regarding Class D amps.

I've been using Bel Canto ref1000m monoblocks for a few years now and think those to be rock solid still and a very good value used. That's really the only ones I can vouch for based on extended listening. I've heard other good ones as well in recent years from Jeff Roland and Audio Research. Other that would be of interest for me due to value potential would include Wyred4Sound and DSonic. I would probably avoid older Class D amps in order to access current possibilities in that the technology continues to advance significantly still.

Hypex Ncore technology has really upped the performance standard for Class D. I have a pair of monoblocks for sale right now here on Audiogon if you're interested.

But I would caution that amp power, while important to deliver slam, is not the only precondition. You also need clean and dynamic source electronics capable of driving the amps well. Since slam is about dynamics, if you don't have high resolution and low noise signal, it will blur the dynamics and detract from the slam. We are always fighting some level of dynamic constriction in recordings, some worse than others with the loudness wars, but even really well recorded stuff is much less dynamic than real life. Such is the nature of recording vs live. In order to maximize dynamics, the entire signal chain needs to be clean and clear, and electronics need to have good impedance matching with each other so they aren't strained and have enough "drive" to create that realistic slam. A good preamp is often key to giving that last bit of drive and dynamics to the music.

I also think clean power into all electronics is highly critical. Good in restrictive power conditioning like the Pi Audio units and power cables that do a good job of rejecting and filtering noise can really reduce the noise floor of your system, which in turn increases dynamic contrasts and slam. Of course it also greatly improves imaging, soundstage, and micro dynamics as well, so it's not either/or when it comes to slam and other audiophile characteristics.

Finally, I would say proper management of bass resonance and nulls in your room are vital to slam in the bass frequencies. Untreated rooms are a horror show of bass anomalies that produces varying levels of boom and suck out at different frequencies. If you can use room treatment, multiple subs in a distributed array, EQ, and/ or combinations of these to even out the room response, your system will be capable of producing clean and even bass that will then slam rather than booming.