I just bought a used PMC Twenty5.23s. Bass feels very light compared to my previous speakers (Amphion Creon). Bass is fast and accurate, but it feels weak in the lower frequencies. The mids and highs are fine. Are these speakers too much for Uniti Atom?
Pmc transmission line speakers should provide easy to drive great bass even at low volumes - do you know why the previous owner of yours was selling? Perhaps they have a fault… I have a pair of 25-26 and sent them to pmc thinking they had begun to sound weak, pmc found that the bass drivers were beginning to fail, once replaced the speakers sound great again. It would also be worth checking that you have connected the speaker wires correctly so that the pair are in phase
Obvious things I guess but are you sure they aren’t connected out of phase and are securely spiked to the floor? Have you tried moving them around a bit for example changing the amount of space behind them?
I’d choose fast and accurate bass over soft and flabby any time. I wonder if it feels ‘less’ because actually it is more sophisticated and subtle than your old speakers, or just ‘different’? I should say I have no experience of either.
The Atom should drive them OK in my view. I’d be wary of changing that or adding a power amp until you are sure the speakers are right for you.
Bruce
Yes, they are too much for the Atom. It’s just not powerful enough to drive the speakers well. A Nova would be a much better fit.
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Hello and thanks for your answer. Speaker wires are connected correctly. I don’t know why the previous owner has sold them. I bought them from shop.
I’ve got the same speakers driven by a Star and they sound really good, plenty of bass
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Hi and thanks for the answer. Speaker wires are connected correctly. I have also tried to change the amount of space behind them and tried to find the optimum place. Bass sounds good at low volumes. It also sounds very good with most music. Maybe it’s just more sophisticated than my previous speakers, as you said? If I listen to music with a lot of bass (e.g. Tyga’s Rack City), I can hear how the bass drum starts and ends quickly, with the previous speakers it sounded like a continuous bass between the bass drum beats. A bit like if I listen with my ear closed to the output of a transmission line. Another question: if I listen at a higher volume, should the bass element move? It doesn’t move at all. At least the eye can’t tell it. And how about air flow from the transmission line outlet? You can barely feel it with your hand, but no significant air pressure comes out of it, even at high volumes. Is that ok?
Maybe everything is fine and the Atom is enough for these speakers? Maybe the case is that speakers are just more sophisticated and accurate than the old ones. Or what do you think?
An alternative route would be to convert the speakers to active and then swap the Atom for the HE version.
Roger
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…or borrow a 250 and use the Atom as a preamp to see what difference that makes.
Bruce
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Correction to the previous one: you can see the bass driver move at a higher volumes.
I was trying to avoid the ‘buy what I’ve got’ cliché but yes, that would be a good option and almost certainly better than swapping the Atom for a Nova. Two 100W amps in each speaker will certainly get them going.
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I’ve two pairs of PMC Twenty5.23s in different rooms. One on a 250dr, the other pair on a 65w TEAC. They don’t sound like the same speaker at all. The latter just can’t drive them well. It can can volume but it’s fairly thin.
They need a better amp.
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And almost certainly better than using the Atom alongside a 250.
Roger
What sort of sound level do you mean by higher volume? At a very rough estimate the cones of the 12" bass drivers in my PMCs would only be visible moving on bass peaks of 100dB (@1m) upwards - perhaps 1mm or so on bass drum. 109dB peaks would be maybe 8mm. The driver in the 25-23 will only have maybe 1/3 to 1/4 of the piston area, so 3-4 times the movement, maybe 1 mm movement on bass peaks in mid 90s decibel range.
Thank you for the answer. I looked closer and yes they are moving. Decibels probably less than 100.