Pairing Amps with Speakers

[CharlyD]

Yes, you can use the formulas I gave previously at least to get an approximation on what loudness gain you'll get with increasing power. As I described in my last posting, sensitivity is based on a standard voltage input, not power. But the formulas should get you close. There are many variables that impact the maximum volume level a particular speaker will achieve with a particular amplifier. We haven't talked at all about dispersion patterns or room effects. For the JBL's, make sure that the amplifier/receiver you choose is spec'd for driving 4 ohms on all speakers. An amp or receiver rated for that load should give you good service up to the clipping point. Don't crank it to the point where it's obviously distorting.

[anm]

Specific question
Will this amp be able to support speakers like JBL Studio L series L890 for fronts, LC2 for center and L810 for surrounds?

Rated Output Power
North American (FTC):
(FL, FR, C, SL, SR)100 watts minimum continuous power
per channel, 8 ohm loads, at 1 kHz, with
a maximum total harmonic distortion
of 1%
(Subwoofer) 105 watts minimum continuous power
per channel, 8 ohm loads, at 80 Hz, with
a maximum total harmonic distortion
of 1%
(FL, FR, C, SL, SR)115 watts minimum continuous power
per channel, 6 ohm loads, at 1 kHz, with
a maximum total harmonic distortion
of 1%
(Subwoofer) 125 watts minimum continuous power
per channel, 6 ohm loads, 1 channel
driven at 80 Hz, with a maximum total
harmonic distortion of 1%
European (IEC): 6 ch × 110 W at 6 ohms, 1 kHz, 1ch driven
Maximum Output Power
Asian (JEITA): 6 ch × 120 W at 6 ohms, 1 kHz, 1ch driven
Dynamic Power 180 W + 180 W (3Ω, Front)
140 W + 140 W (4Ω, Front)
95 W + 95 W (8Ω, Front)
THD (Total Harmonic
Distortion) 0.9% (Power Rated)
Damping Factor 60 (Front, 1kHz, 8Ω)
Input Sensitivity and
Impedance 200 mV/ 47 kΩ (LINE)
Output Level and
Impedance 200 mV/ 470 Ω (REC OUT)
Frequency Response 10 Hz–50 kHz/ +1 dB-3 dB (Direct mode)
Tone Control ±10 dB, 80 Hz (BASS)
±10 dB, 20 kHz (TREBLE)
Signal to Noise Ratio 100 dB (LINE, IHF-A)
Speaker Impedance 6Ω– 16Ω

[anm]

Another set of specs (please also look at the post just before this one )- can this drive L890 along with LC2 center and L810 surrounds?
Audio Section
Stereo Mode
Continuous Average Power (FTC)
40 Watts per channel, 20Hz–20kHz,
@ < 0.07% THD, both channels driven into 8 ohms
Five-Channel Surround Modes
Power Per Individual Channel
Front L&R channels:
30 Watts per channel,
@ < 0.07% THD, 20Hz–20kHz into 8 ohms
Center channel:
30 Watts, @ < 0.07% THD, 20Hz–20kHz into 8 ohms
Surround channels:
30 Watts per channel,
@ < 0.07% THD, 20Hz–20kHz into 8 ohms
Input Sensitivity/Impedance
Linear (High Level) 200mV/47kohms
Signal-to-Noise Ratio (IHF-A) 95dB
Surround System Adjacent Channel Separation
Analog Decoding 40dB
(Pro Logic, etc.)
Dolby Digital (AC-3) 55dB
DTS 55dB
Frequency Response
@ 1W (+0dB, –3dB) 10Hz–100kHz
High Instantaneous
Current Capability (HCC) ±25 Amps
Transient Intermodulation
Distortion (TIM) Unmeasurable
Rise Time 16 μsec
Slew Rate 40V/μsec

[CharlyD]

I checked some measurements on the JBL's and, indeed, the impedance does hover at less than 5 ohms over much of the audio band. I also found that it's quite difficult to find A/V receivers that are spec'd at 4 ohms. One of the spec sets you gave is from the low-end Harmon-Kardon. That line touts their high current drive and would likely be the best bet to drive the JBLs. If you can afford it though, step up to more power than 30 WPC. Everything I"ve seen about the audio performance of HK receivers is quite positive

[anm]

Originally Posted by CharlyD

One of the spec sets you gave is from the low-end Harmon-Kardon.

Wow Charly - you are very correct. It is indeed HK AVR 132!

What do you think about the other one? This one is an Onkyo HTR 340 - pdf can be found here - http://63.148.251.135/redirect_servi...S3100_En_A.pdf

I can afford either of these right away - and plan to get better speakers as my first upgrade, as and when money flows in.

regards

[CharlyD]

It sounds as though you are purchasing this system to get decent quality now but with intent to replace everything as your economics improve. With that model, you can expect to be making some compromises. The Onkyo has quite a bit more power, but is rated with a minimum speaker impedance of 6 ohms. It will probably play louder than the HK, but you may encounter problems such as overheating. The HK will likely sound better at low levels but probably does not have sufficient power to get you close to realistic levels for movie soundtracks. If I were in your situation, I'd wait until my situation was better or buy something cheap to get me by. On the other hand, I noticed some very good NAD receivers (T-744, T-754) for sale (half price!) here in the states. I'm guessing the price is so low because HDMI and the new surround codecs are not supported. Either of these receivers would drive your JLB's quite well and could be used with an external processor in the future.