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HCA-1000A

heeman

heeman

PRETTY HAPPY.........
Famous
Jamhead had asked a question on what amplifier(s) I was using to drive the C1's. I answered that over on the Speaker Thread however someone suggested that I start a thread here.

I am using the Parasound HCA-1000A amplifier. I have been in touch with Parasound and they indicated that this amplifier had been replaced by the Halo A23. They indicated that the HCA-1000A has a slight edge over the A23 (Retail $995).

So my question is..........................is the Parasound HCA-1000A adequate to drive the C1's to full potential.

Here are the spec's:

Parasound HCA-1000A
-------------------------------------------------------------------

Continuous Power Output - Stereo:
125 watts RMS x 2, 20 Hz - 20 kHz, 8 Ω, both channels driven;
200 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, both channels driven
Continuous Power Output - Mono: 400 watts RMS, 20 Hz - 20 kHz, 8 Ω
Current Capacity: 45 amperes peak per channel
Slew Rate: >130 V/µsecond
Power Bandwith: 5 Hz - 100 kHz, +0/-3 dB at 1 watt
Total Harmonic Distortion: < 0.03% at full power; < 0.01 % typical levels
IM Distortion: < 0.03 %
TIM: unmeasurable
Dynamic Headroom: > 1.5 dB
Interchannel Crosstalk: > 80 dB at 1 kHz; > 60 dB at 20 kHz
Input Sensitivity: 1 V for 28.28 V, THX Reference Level; 1.1 V for full output
Input Impedance: 33 k Ω
S/N Ratio: > 116 dB, full power; > 96 dB, THX Reference Level
Damping Factor: > 800 at 20 Hz
Power Consumption: 500 watts
Dimensions: w 17 1/4" x h 3 1/2" x d 13 1/4", h 4 1/8" with feet
Net Weight: 22 lb

* Edit - I'm adding the C1 Platinum Specs (Batman)

Sensitivity: 85 dB (2,83 V/1 m)
IEC Power Handling: 170w
Impedance: 4 ohms
Freq. Response: 45Hz - 22kHz (+/- 3dB)
Crossover Freq. 1800Hz
 
That is probably fine.

In every aspect other than peak power output, that is an ideal amp. You might benefit from more power, but that means getting double the power, minimum, to achieve any real results.
 
Yup. Depending on your volume level, and distance/size of room, you should be fine. That amp is stable to less than 4 ohms (and I believe your speakers are actually 4ohm minimum.....at least the Contours are).

I use an amp rated at approx. 300 watt/ch in 4ohms and have never had an issue. Not much difference between 200 and 300 watts.
 
I listen Loud, some on here can confirm that! :music-rockout: :music-rockout:

However, my room is small, 12.5 x 17.5 x 8 Sealed.
 
For the uninitiated ...

Can someone give us the digest version in how to take those amp specs and determine that they are nearly ideal except maybe peak output power? What are you looking FOR and what are you looking to AVOID?
 
Does the inverse square law about the output loss over distance apply at the same rate for adding a second speaker?

The C1 is rated at 1W = 85 dB at 1m. Keith sits 8.5 feet from it. So 1W at 8.5 feet is going to yield 66dB, which is a 19dB loss over that distance. But the rating and calculation is for one speaker. Does adding a second speaker offer a 19dB increase in output?
 
Adding a second speaker and amp playing a mono signal will increase the output by 3dB SPL, but a peak output capacity increase of 6dB SPL.

But, in a closed room, the inverse square law does not apply the same way. In fact, even in real life it doesn't work because we always have the ground reflecting sound, so the output would be 3dB to 6dB higher than the inverse square law defines.

So, in a closed space (which can also be calculated fairly accurately) the loss per doubling of distance is less than 6dB.

Still, even with your calculations, 125W with a speaker rated at 85dB SPL at 1w/1M from 8.5 feet (or 66dB) will be about 97dB SPL. Add about 6dB for the room reinforcement (which will vary from frequency to frequency) and the output would be more like 103dB SPL.

Ultimately, I think an amp with a clean and solid output capacity of more than 250W would be better, but the 125W from the HCA-1000A should be pretty sufficient most of the time.

A Parasound A21 would be more ideal.
 
One other question:

How does setting the X over at 80Hz effect this? That is where I have the Pre/Pro set.
 
heeman said:
This amp has a 200W rating at 4 ohms, does that factor in?
Click to expand...

Not in the answer I just gave to Zing.

It is a sign that the amp has a very ample current output capability, which is one of the many reasons this is a very, very good amp for your speakers.
 
it's be better with some unobtanium shielded 4" diameter cables with hydrostatic induced atom separated urethane spacers to keep them off the floor. I can sell you a magnificent set for $4500.....and that's at an 80% discount.
 
How does setting the X over at 80Hz effect this? That is where I have the Pre/Pro set.

I would think that it would since the demand on the amp will not be full range.

Can someone that understand this explain in more detail.
 
-B- said:
it's be better with some unobtanium shielded 4" diameter cables with hydrostatic induced atom separated urethane spacers to keep them off the floor. I can sell you a magnificent set for $4500.....and that's at an 80% discount.
Click to expand...

I'll take 10 pairs........................... :happy-smileygiantred:
 
heeman said:
This amp has a 200W rating at 4 ohms, does that factor in?
Click to expand...

When I was looking at amplifiers, I used Soundhound's description to help evaluate "what makes a good amplifier". One of the criteria was power supply. He suggested looking at amplifiers as ability to deliver constant voltage regardless of impedence as being important.

So, using Ohm's Law and your speakers/amp:
Your Parasound can deliver (based on ratings) 32volts into an 8 ohm load. 32v / 8 ohms = 5amps. 5amps x 32v = 128 watts.

At 4 ohm; your Parasound can deliver: a little of 28volts. 28v/4 ohm = 7 amps. 7 amps x 28v = 196 watts.

So, your amplifiers power supply decreases voltage slightly as the impedence is halved (perfect would remain at 32 volts; or 8 amps; or 250 watts).

Obviously, many amps aren't perfect, but the numbers on their spec sheets can lie (even under report the 8ohm values to that the 4ohm value doubles). But, it's a start.

So your amplifier works harder to maintain the same voltage as impedence decreases.

But the voltage sag isn't too bad, so the power supply is adequate for your speakers.

The actual amount needed was addressed by Flint.

Removing the lowest bass frequencies from your speakers will help your amplifier, but I'm not aware of a concrete calculation to determine (Parasound may help......great company). I wouldn't think it would change by more than 30 watts or so. The biggest effect would be on spikes (explosions)......where heavy demands on the amp are needed for short durations.
 
Thanks Jamhead!

The dynamic response is directly related to the power supply and these ratings:

Current Capacity: 45 amperes peak per channel
Slew Rate: >130 V/µsecond
 
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