Which set should I buy ? SRS 2.3 NON tl,or SRS 3.1tl

Get the 3.1TL's.

Everyone tells you to buy the 3.1TL's, yet you get the lesser model.

bassfann wrote: »

The 2.3's aren't the lesser model,but they definitely will cost more to mod.

Ah, but they are and everyone told you so.

I see your angle. However, I dont think you fully understand what it would take to turn 2.3's into 2.3TL's. It would be a major expense.

They become hypersensitive after being tripped numerous times.

More power at this point will not help, the polyswitches need to be replaced with .5 ohm Mills 12 watt resistors.

As for power, you want high current and you do not want a Carver SS amp.

bassfann wrote: »

I know the switches have to be replaced.

Not so much "replaced" as "eliminated".

bassfann wrote: »

I'm not sure which amp to go with. I have the Krell,but it needs overhaul, not sure if I want the expense.

Had the lid off? Krell isn't too fond of outside repair--they want everything shipped to them. Therefore, no service manuals or parts sales. Even so, a clever boy might be able to figure out what's wrong.

F1nut wrote: »

Still looking at watts when you should be looking at current.

Don't the two go hand in hand in most applications? High current is mentioned often but I am not sure I understand the differences. Care to share the 101 basic course on watts vs current for myself and any others who might be interested?

"Watts" is merely Volts X Amperes. The problem is that you can get a high-watts figure suitable for advertising in big, bold print by using a heaping helping of volts (very inexpensive) and hardly any amperes (amperes are expensive)

Now, at some point physics raises it's ugly head. The "industry standard" for loudspeaker load is 8 ohms. Of course, most speakers do not maintain their nominal load over the full frequency range. An 8-ohm speaker can easily dip to 6 ohms or lower at certain frequencies, and perhaps 20 ohms or even much higher, at others. And then there's loudspeaker/cable reactance which is a concept way beyond what I can write here, except to say that reactance makes hash of rated power, because rated power is performed using resistors, but the loudspeaker load has capacitors and inductors in addition to resistance.

So as it turns out, it's cheap to get high voltage out of an audio amplifier, but high current requires care, thought, typically lots of copper in the transformer, lots of aluminum for heat sinks, and lots of silicon (or glass) in the output devices. There are designs that get around that--but they tend to have other problems.

So if your speakers are a fairly benign (mostly resistive, little reactance) 8-ohm load, your amplifier has a fairly easy job. Dropping the load from 8-ohms to 4-ohms doubles the current required. This makes the amp work MUCH harder, requires heaps of heat-sinking, numerous output devices, and a big transformer with big storage capacitors. Drop the speaker impedance to 2-ohms, and the current required doubles again. Very few amps are rated for 2-ohm loads, and they're all "expensive"--relatively speaking.

Advertising got TOTALLY out-of-control during the '60s. Every manufacturer had a different way to rate the power of their products, so it was impossible to compare the power of one brand to another. The FTC stepped in, and produced a procedure, and a requirement for advertising the FTC "Rated Power" in bold print, to be more prominent than any other rating. Consumers were fairly well-served with this rating system except it only required one power spec, not a series of specs at progressively-lower impedance. An amplifier can rate well with an 8-ohm load, but fail miserably at 4-ohms.

Of course, manufacturers found ways to "cheat". One of the more popular now is to provide a switch on the rear panel to go between "high impedance" (8-ohm) and "low impedance" (6- or 4-ohm) loads. The switch engages circuitry that strangles the power supply, so the marginal heat sinking, under-sized transformer, and scanty output devices can't overheat and set fire to the equipment.

The short story is that Polk SDA speakers were advertised as "easy to drive" (moderate reactance) except for the lowish nominal impedance. A nominal 4-ohm load was common,for early Polk SDAs, later speakers ended up closer to 6-ohms--but both early and late had considerable variation dependent on frequency.

Any amplifier that's nearing it's amperage limit at 6-ohms is going to sound strained driving a Polk SDA. An amp rated for continuous 4-ohm duty should be OK. Ideally, you'd want the amp to be capable of driving a 2-ohm load or lower, at least in intermittent duty.

Never, in the history of home audio, have there been more speakers sold, or more speaker models available, that have a nominal 4-ohm impedance or lower, yet at the same time, the flood of Chinese or other Asian bottom-feeder amplifiers/receivers are entirely unprepared to deal with low-impedance loads.