System improvement-guidance required

[Shashi Kumar]

I am a novice and at entry level, but I have been surfing and reading often for about an year now. My system consists of Marantz SR 5600 (90 watts per channel rms, 8 ohms) and definitive Procinema 80 speaker system having specs as per details below

Main speaker Promonitor 80: Single 4-1/2" long-throw upper bass/midrange driver and 1" Ferro-fluid-dampened Pure Aluminium Dome Tweeter
Linkwitz-Riley Crossover
Frequency Response: 60Hz – 30 kHz
Efficiency: 89db

Sub-woofer Prosub 80 Specs: Stiff, mineral-filled 8" Polypropylene cone with durable, long-excursion surround for fast action.
Huge magnet structure.
Frequency Response: 21-150 Hz.
250 Watt built in high power amplifier.
Low Pass Crossover: 24 dB/octave continuously variable (40 —100 Hz), plus Unfiltered setting option
Speaker Level High Pass Crossover: 6 dB/octave at 80 Hz.

Centre : Similar to the mains except that it has two of those 4-1/2 inches drivers and one tweeter

Surrounds are the same as the mains

I am interested more in music and would like to improve the system with minimum investment and maximum gains.

I am planning to replace the main speakers with a pair of Wharfedale 9.6. The ex mains can become the RL & RR for the 7.1 system.
The Wharfedale specs are:
Bass 8" 200mm Bass
Midrange 8" 200mm B/M, 2" 50mm tex midrange
Tweeter 25mm tex
Power 40-200W
Nominal Impedance 6ohm
Sensitivity 90dB
Frequency 28-24k @ -6dB
Crossover 150Hz, 1.0kHz, 6.0kHz
Frequency Fb 30Hz

My doubts are:
1. The impedance do not match. If you multiply the amp power(90) with the impedance ratio(8/6) you get 120 watts. The question is –is 120watts sufficient? The most common advice given is that amp power should be double of speaker rated power, which means the power is woefully inadequate.
2. Would the system become a serious mismatched speaker set, especially for movies and 5.1 musical video DVD’s?

My apologies for the long post. Please help.

 

[AVRat]

Not to worry about the impedance issue, Marantz can handle it w/o problem and supply enough power for the Wharfes. Hopefully, your ugrade path is directed toward an all Wharfe system for timber matching in HT use.

 

[Shashi Kumar]

Thank you AVRat for the immediate response. Because of computer trouble, I could log in only today.
My upgrade stops at 9.6 Wharfe. Dollar trouble at the moment. It is just that the Promonitors and the Prosub do not combine well enough for two channel (stereo)music. If you start from below, frequency wise, I think the promonitors do not pick up from where the Prosub drops off. So there is a huge gap after the 80-100 Hz upper limit of the prosub. You cant expect much from a 4-1/2 driver I suppose. You may counter you cant buy the moon in 100 dollars.
Imagine a percussion artist playing the Conga drums. He strikes the drum with his hands, and immediately removes it from the drum face in one smooth, fast and continous move. The drum would go "dhummmmmmm". But what if he strikes the drum and leaves his hand on the drum face. Now it would go "dhup". My present system "dhup's" all the "dhummmmmm's".This is the best way I can put it, as I am not yet proefficient with terms like "tinny" forward, etc. I think some of the frequencies above 100 hz are not reproduced powerfully enough by the present combination.

I expect that the Wharfe with its tweeter, two mid ranges, and the 8" woofer, would have drivers covering right across the audible range, relieving me from the agony I have been living with and solving the mystery of the missing frequencies.

No no, dont acuse me of poor placement or bad bass management. I have been reading on these two issues.

I think this is the bane of small speakers. You have the sub covering the lows, the tweeter covering the highs, and one (Poor Me) mid range covering the huge in between. You cant expect one driver to cover this wide range, can you? So, with your selection of small speaker, you gain some or loose some. or enhance some and smother some (if you prefer) of the frequencies. Its a trade off, and depending upon your preferences, minor or major.

What do you say?

Regards,