Why does my new KEF 205/2 is so difficult to "master"?

Novalux

New Member
Hello, it´s the first time I write here;I´m living in Germany and I hope my english is OK....
I´ve bought 2 weeks ago 2 Speakers KEF Reference 205/2 and I have them running with a Marantz PM-6 fully restored with Kimber Kable 8PR single wire.
The Speakers were expensive although I bought them used. The guy I bought them had them runnig with a Tube amp from Triode.

I don´t manage to get the sound that it´s supposed to have,I tried with "Tone in" (you can change the frequency of Bass and Treble) and also with "Straight DC" (from Phono directly fed to the main amp).
By the first variation it sound a little strained and by the second one it has a loss of dinamic....it´s difficult for me to explain....

I had the same chain with my old JBL LX800 speakers and I had a good sound.....or it´s perhaps that I am now too analytic with the music???

I hear mostly Vinyl, have two 1210 MKII,one with a Ortofon 2M Red and the other one with an Ortofon Arkiv Concorde for Mono rcrds or an AT440MLa.
I would appreciate some help!!

Greetings from Germany!!

Ronny
 
A better amp will definitely lift the weight off the speakers, for sure and open them up.

Sometimes too, combinations don't really make for a musical sound - I've found that switching out the source or amplifier can make a significant impact on the enjoyment of the sound, even if something isn't quite right (rolled off treble, maybe sloppy bass, etc). Musicality is definitely important and this is what sounds like is missing.
 
I can understand that,but I thought this speakers would be a good companion for my Marantz PM6.....
I´ve just looked in the website from KEF and I didn´t see that detail....3,2 Ohm min....mmmmm
Could I compensate this difference? How with a Marantz SM-6 or a SM-8?? so I would have (like I would suppose) twice or some more power extra by Bi Amping
 
I honestly don't think your Marantz amps have the oomph and power reserve needed. It is not the amount of watts - getting more watts won't fix your issue. You need an amp with reserve power. This is Overkill - but this is an example- http://balanced.com/p-vk-3000se

Notice in the amp specs, the 8ohm/4ohm power - the power doubles? Well when your speaker has a load that low the amp has to put out more power - 8 to 4 ohms should double in a good amp. The Marantz are fine amps but not for this speaker - plain and simple.


Since you are in Germany, there is some nice European integrateds that would do nicely an match well.


It does say what I said about the minimum ohms that in the KEF link you provided - I quoted below.


REFERENCE 205/2

Whether you’re into Strads or Strats, Model 205/2 is an assertively musical performer when it comes to conveying the nuances of recorded sound – full-bodied, vigorous and sublimely expansive without ever compromising the unerring fidelity with which it reproduces intricate detail, however complex.

Model Model 205/2
Design Bass reflex three-way floorstanding loudspeaker, magnetically shielded
Drive Units 2 x 200mm (8in.) LF, 1 x 165mm (6.5in.) Uni-Q MF including a 25mm (1in.) titanium HF
Crossover Frequencies 400Hz, 2.3kHz
Sensitivity (2.83V/1m) 90dB
Frequency Response (+/-3dB) 45Hz - 60kHz
Maximum Output 115dB
Amplifier Requirements 50 - 300W
Magnetic Shielding Yes
Impedance 8 Ohms (3.2 Ohms min)

Bass Extension 35Hz (-6dB)
Weight 33Kg (72.6lbs)
Dimensions (H x W x D) 1105 x 285 x 433 mm (43.5 x 11.2 x 17 in.)
Finishes Piano Black, High Gloss American Walnut, High Gloss Cherry, Satin Black, Satin American Walnut, Satin Cherry and Satin Sycamore real wood veneers

At what frequency the impedance dip occurs also matters......

Regards
Mister Pig
 
That was a very good explanation,thank you! It´s really not so bad because I wanted to build a second System....;)

Does the Volume influence the performance of the speakers? What I mean is if I hear with low volume and the Marantz has 140 WPC could he better manage the sound?



I would like a system like with the Marantz: 2 Phono connections for two TT

I think its possible to connect a TT through a "device" so you can use also a CD/AUX conection so you don´t really need two phono conections.

I really prefer vintage Hifi with two Phono conections...I really don´t know if vintage Amps this particularity have....What for a minimum watt pro channel into 4Ohm are we talking?
Could you name some brands?? Is the example also a recommendation?
 
Would be possible to keep my Marantz like a Preamplifier and buy a Amplifier??
For example this one have I found on Ebay,a Marantz SM-80....I would be interested on buying a used Amp ´cause I don´t have so much money left at the time....

http://www.ebay.de/itm/Marantz-Endstufe-SM-80-Champanger-Guss-Seiten-/221609136539?

This are the Specs from Marantz SM-80:

Power output: 100 watts per channel into 8Ω (stereo), 300W into 8Ω (mono)
Frequency response: 20Hz to 20kHz
Total harmonic distortion: 0.02%
Damping factor: 200
Input sensitivity: 1V
Signal to noise ratio: 121dB
Dimensions: 420 x 132 x 334mm
Weight: 13kg
Year: 1990

or perhaps this one:

The Luxman M-02
utilizes discrete output transistors and maintains high dynamic power even into low-impedance loads.
Specifications

Power output: 140 watts per channel into 8Ω (stereo), 300W into 8Ω (mono)

Frequency response: 10Hz to 100kHz

Total harmonic distortion: 0.025%

Input sensitivity: 1.2V

Signal to noise ratio: 120dB

Dimensions: 453 x 141 x 336mm

Weight: 14.5kg

It could be that my thougt are not correct and It would be better to buy another Amp,but I would like to keep the marantz with the two Phono conexions and I would´t have to change so much in my Hifi......
I won´t be able to answer so fast because I must work......
 
Last edited:
Hi,
Yes, it should be possible to use the Marantz as a preamp and use a different amp...I am doing the same thing in my basement system with a Pioneer SX-525.

Just thought I'd mention Emotiva as a potential "cheaper" amp that would be high-current and should handle your speakers with no problems. They have several models to choose from...I am using one of their cheaper ones, UPA-200. It is rated at 125W into 8 ohms and 200W into 4 ohms. The power doesn't quite double, but it is pretty close.

https://emotiva.com/

Yes, you could buy something more higher end and probably do "better" but if you're looking for a low-cost solution, I think this would fit the bill.

Here are the specs on it:

Topology: Fully discrete, dual differential, high current, short signal path Class A/B.
Number of Channels: 2
Power Output
(rated power; THD < 0.05%):
125 watts / channel (8 ohms; all channels driven).
200 watts / channel (4 ohms; all channels driven).
Rated Power Bandwidth (at rated power; 8 Ohm load): 10 Hz to 20 kHz + / - 0.1 dB.
Minimum Recommended Load Impedance: 4 ohms (which equals one 4 ohm load or two paralleled 8 ohm loads per channel).
Frequency Response: 5 Hz to 80 kHz + 0 / - 2 dB.
THD + N: < 0.03%
Signal to Noise Ratio (8 Ohm load):
> 92 dB at 1 watt (A-weighted).
> 106 dB at rated power (A-weighted).
Damping Factor (8 Ohm load): > 500
Speaker Output Connections:
Full-sized 5-way binding posts; one pair per channel x 2.
Power Supply:
350 VA high current ultra-low noise toroidal power transformer.
40,000 uF of storage capacitance.
Input sensitivity (for rated power; 8 Ohm load): 1.1 V (for full output; 8 ohms).
Gain: 29 dB
Input Connections: Unbalanced (RCA); one per channel.
Input Impedance: 47 kOhms
Trigger:
Trigger Input: 5 - 20 V (AC or DC); < 10 mA input current required.
Trigger Output: 12 VDC; can drive any load up to 50 mA.
Power Requirements: 115 VAC or 230 VAC +/- 10% @ 50 / 60 Hz (automatically detected and switched).
Front Panel Controls and Indicators:
Standby; push button (changes color to indicate Standby or On).
Status LEDs (one per channel); illuminate blue for normal operation or red to indicate a fault (may be disabled by rear panel Status LED switch).
Rear Panel Controls:
AC Power switch; rocker switch (switches AC mains power).
Status LEDs switch; small slide switch on left rear (disables front panel Status LEDs).
Protection: The UPA-200 is protected against excessive operating temperature, shorted speaker connections, ground faults, and other common fault conditions. If a fault occurs, the UPA-200 will return to Standby mode, the Standby push button will light amber, and the Status LEDs will flash red.
Size:
unboxed: 17" wide x 3.375" high x 16.5" deep
Weight: 24 lbs (net); 32 lbs (boxed)
 
@botrytis - definitely...just giving him some more options! I think Emotiva ships overseas, although I don't know what shipping would cost. Definitely lots of options, just look for a good price and a good power supply (power doubles from 8 to 4 ohms) from a reputable brand and you should be golden. Would love to hear some Kef 205/2's! I have the older 107's and would love to hear the newer ones, especially the 207's.
 
Very interesting information!! I thank you both Hawkweye83 and boytritys!!
Now I mostly know what I need....

I have three more questions:
1.Would be OK an amp like the Emotiva UPA 200? Or I need more power....(my idea is to buy first an amp to try the KEF....afterwards I look perhaps for another....

Power Output
(rated power; THD < 0.05%):
125 watts / channel (8 ohms; all channels driven).
200 watts / channel (4 ohms; all channels driven).

of course the bigger the better.....Emotiva SA 250
Power output (both channels driven): 

400 watts RMS per channel @ 4 ohm (0.1% THD)

250 watts RMS per channel @ 8 ohm (0.08% THD)

The price category I could handle it without argue with my wife....;)

2.The amp requirements from KEF are they per speaker or both channels??
(Amplifier Requirements 50 - 300W
Magnetic Shielding Yes
Impedance 8 Ohms (3.2 Ohms min)
That means 150WPC x2 = 300 ?

3.What for a minimum watt pro channel for the Amp into 4 Ohm are we talking?

I think the guy I bought the KEF he had it also running in a too small Amp...Tube amp from Triode....and it was in a 16 m2 room;he sold it because they were too big....lucky for me :)

Last but not least: If I buy an Amp and run it with my Marantz,would be a good recommendation for afterwards to buy a complete other Amp and not any more to use the Marantz with the KEF??
 
Last edited:
I think the UPA-200 would be fine. I am using it on my Kef 107's and they are rated at 4 ohms. Of course, more wouldn't hurt...but the UPA-200 is certainly cheap enough to give it a try, unless you can find something better with more power.
 
I have issues with the speaker to start out with. having two 8" drivers separated as they are operating up to that high of frequency can cause some sever midrange anomalies down to 120 hz. I know two drivers can handle a lot more power, but having them both ported is what is causing the impedance to swing all over the place. Personally I would have picked a more amp friendly speaker. You will also notice they are not capable of producing the bottom octave of the frequency spectrum even though the amp is trying to. This can cause all sorts of distortion issues for the amp as it will not have the proper loading and the speaker woofers will just be flopping around in an uncontrolled fashion. You can tell I love speakers with ports, tuned labyrinths, and reflex openings. You'd be much better off with speakers with sealed enclosures. They won't be quite as efficient, but the bass well roll-off more smoothly, the speakers will be less difficult to drive, the bass distortion will be a lot lower, too. That being said you need an amp that stable and able to drive 2 ohms. And there are very few receivers or integrated s that can do that. Some say they can, but aren't successful. Mcintosh makes a MA 7900 at 200 watts and a 300 watt beast MA8000. They use autoformers to match the load to the amps outputs. Separates, pre-amps ands amps are the most common way of getting good sound with complex loads. But unless you are willing to pay some bucks your in for a challenge. Bryston, Crown, Threshold, Krell, B&W, Mcintosh, aren't cheap. Be ware of the Orient amps they don't always perform as we would wish. Unless you can pony up for Accuphase or you can find amps proven to operate at 2 ohms.

Now I hate to say this but KEF is no longer a totally English manufacturer, the speakers being made in China I understand. That doesn't mean they can't be just as good as the older home made speakers, but are they? Sounds like you are saying they are not.
 
twiiii,
yes, partly you are right, KEF doesn´t make MOST speakers in England but the Reference series are done completely in UK,the speakers come along with a frequency response chart specific for this pair cordially signed by the builder,by my pair from Graham Humphries.

I see the buy of the KEF like a way to better music listening, perhaps at this time I don´t have a good sound because of my Amp, but I´m not on the end of my way, I´ll buy another Amp and I will use my Marantz like an preamp; I need time to decide what Amp I should buy, thank to the information from the last 24 hours I have a target on my mind....

Because I live in Germany an idea could be to buy for example an NAD C272,they are not so expensive cause I´ll buy it used...I´m sure they are "made in China" and not in UK.....



C 272 Stereo Power Amplifier Features

2 x 150W Minimum Continuous Power into 4/8 ohms
220W, 340W, 460W IHF Dynamic Power into 8, 4 and 2 ohms, respectively
PowerDrive™
High Current Holmgren™ Toroidal Power Transformer
Bridgeable to 400W mono (8 ohms)
Both fixed and variable inputs, switch selectable
Double set of loudspeaker binding posts to facilitate bi-wiring
All Discrete Circuitry
Gold plated RCA Connectors
NAD Soft Clipping™
12V Trigger Input for remote Stand-by/On switching
IEC Detachable Power Cable
ATOLogic

Perhaps it was not the best idea to buy this speakers now,but I´m sure that in the future I´ll get a very good companion for them....
 
I think you did quite well on the speakers...I'm sure they're great! Kef makes great speakers, especially the Reference series. You'll find a higher-powered amp and will be enjoying them in no time. Please report back on the sound after you find a better amp :music: :yes:
 
Yes I´ll do it.....and if you´re on the "area" don´t forget to ring to have a little music session.....;)
 
A more cost effective purchase would be a pro amp. They are powerful, capable of driving low impedances and can have excellent sound qualities. For example Peavy has a line of DJ models
http://peavey.com/products/index.cfm/series/704/PV® Series that have a very musical sound.

Another option is class 'D' amplifiers. Modern class 'D' amplifiers are near cutting edge. Look at something like this https://wyred4sound.com/ or http://www.peachtreeaudio.com/ .

I know you are buying used the sites suggestions are simply informative.
 
Speaker quality...

Hook them in series and run them on only one side of your amp and see if there is a difference.
The setup will for sure change the sound of the speakers. I know my experiments with series hookups changed the "voice" of many speakers. Some speakers respond very much to this process.
Others don't respond at all.

Paul
 
Thanks another time for the many answers....
I´m thinking of buying something like the Parasound HCA 1000:

Circuitry designed by John Curl
THX Ultra-certified
Direct Coupled -- no capacitors or inductors in signal path
Input stage uses hand matched complementary JFETs
SPECIFICATIONS
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

Afterwards I could buy a second one,perhaps more powerful like the Parasound HCA 1500 and do Bi Amping:
SPECIFICATIONS HCA 1500
Continuous Power Output - Stereo:
205 Watts RMS x 2, 20 Hz-20 kHz, 8 Ω, both channels driven
315 watts RMS x 2, 20 Hz - 20 kHz, 4 Ω, both channels driven

An other Idea would be an NAD 208 THX like this one:
http://www.ebay.de/itm/261678787518?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Technische Daten NAD 208
Dauerleistung (bei Klirrfaktor)
8 Ohm: 250 W (0,03%)
Dynamikleistung
8 Ohm: 600 W
4 Ohm: 800 W
2 Ohm: 1000 W
Gesamtklirrfaktor: < 0,03%
Dämpfungsfaktor: >200 (8 Ohm, 50 Hz)
Frequenzgang: 20 Hz - 20 kHz (+0, -3 dBdB)
Signalrauschabstand: 96 dB / 120 dB (1W / rated Power)



or to buy first two Monoblocks from Marantz MA 500 and the two more for Bi Amping:
http://www.ebay.de/itm/351243832531?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

or first one,afterwards a second one from Rotel RB-980BX:
http://www.ebay.de/itm/Rotel-Endstu...deo_Elektronik_Verstärker&hash=item3399029600

Dauerleistung (bei Klirrfaktor)
8 Ohm: 2 x 100 Watt RMS (20-20.000Hz, 0,03%)
4 Ohm: 2 x 180 Watt (1kHz, 1%)
Spitzenstrom: 80 A (0,1 Ohm, 10µs, 1 Impuls)
Gesamtklirrfaktor: 0,03%
Dämpfungsfaktor: 1000 (20 bis 20.000Hz, 8Ohm)
Frequenzgang: 4 - 100.000 Hz (+0,5/-3 dB)
Signalrauschabstand: 120 dB (IHF, A-Netzwerk)

It´s a good idea to buy a THX certified Amp? or better something like the Rotel?? :music:
Would they run good the speakers with this extra power? :banana:

....i would have thought that is a good idea to put an xtra Amp for one Channel to see the difference like it was the idea from pdm4606

By the Rotel I could have it to try it for some days....
 
Last edited:
Hi,
Yes, it should be possible to use the Marantz as a preamp and use a different amp...I am doing the same thing in my basement system with a Pioneer SX-525.

Just thought I'd mention Emotiva as a potential "cheaper" amp that would be high-current and should handle your speakers with no problems. They have several models to choose from...I am using one of their cheaper ones, UPA-200. It is rated at 125W into 8 ohms and 200W into 4 ohms. The power doesn't quite double, but it is pretty close.

https://emotiva.com/

Yes, you could buy something more higher end and probably do "better" but if you're looking for a low-cost solution, I think this would fit the bill.

Here are the specs on it:

Topology: Fully discrete, dual differential, high current, short signal path Class A/B.
Number of Channels: 2
Power Output
(rated power; THD < 0.05%):
125 watts / channel (8 ohms; all channels driven).
200 watts / channel (4 ohms; all channels driven).
Rated Power Bandwidth (at rated power; 8 Ohm load): 10 Hz to 20 kHz + / - 0.1 dB.
Minimum Recommended Load Impedance: 4 ohms (which equals one 4 ohm load or two paralleled 8 ohm loads per channel).
Frequency Response: 5 Hz to 80 kHz + 0 / - 2 dB.
THD + N: < 0.03%
Signal to Noise Ratio (8 Ohm load):
> 92 dB at 1 watt (A-weighted).
> 106 dB at rated power (A-weighted).
Damping Factor (8 Ohm load): > 500
Speaker Output Connections:
Full-sized 5-way binding posts; one pair per channel x 2.
Power Supply:
350 VA high current ultra-low noise toroidal power transformer.
40,000 uF of storage capacitance.
Input sensitivity (for rated power; 8 Ohm load): 1.1 V (for full output; 8 ohms).
Gain: 29 dB
Input Connections: Unbalanced (RCA); one per channel.
Input Impedance: 47 kOhms
Trigger:
Trigger Input: 5 - 20 V (AC or DC); < 10 mA input current required.
Trigger Output: 12 VDC; can drive any load up to 50 mA.
Power Requirements: 115 VAC or 230 VAC +/- 10% @ 50 / 60 Hz (automatically detected and switched).
Front Panel Controls and Indicators:
Standby; push button (changes color to indicate Standby or On).
Status LEDs (one per channel); illuminate blue for normal operation or red to indicate a fault (may be disabled by rear panel Status LED switch).
Rear Panel Controls:
AC Power switch; rocker switch (switches AC mains power).
Status LEDs switch; small slide switch on left rear (disables front panel Status LEDs).
Protection: The UPA-200 is protected against excessive operating temperature, shorted speaker connections, ground faults, and other common fault conditions. If a fault occurs, the UPA-200 will return to Standby mode, the Standby push button will light amber, and the Status LEDs will flash red.
Size:
unboxed: 17" wide x 3.375" high x 16.5" deep
Weight: 24 lbs (net); 32 lbs (boxed)

Hi,
I have just now a Rotel rb 990 BX,here the specs:
http://www.rotel.com/content/manuals/rb990bx_eng.pdf
It has 200 WPC an 8 Ohm and 300 WPC an 4 Ohm....

it has very much power but I don´t like the sound because is very analitic, that´s like I would describe it.....
Could you say that your UPA-200 is a "Warm" amp?
I´m thinking about to buy the XPA-200 from USA and getting it to Germany....
 
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