Monitor Audio RX2 - Harsh treble, any user R&D?

fwiw, do you incorporate your sub when listening to 2 ch. music. if not I would and see if your upper freq. clear up as crossovering with the sub will give your tweeters more juice. just an option before spending more money.
 
No I don't use the sub for 2 ch music. I find the subwoofer bass very un-natural compared to the MA's. Interesting idea though to use the AVR crossover to see if the lower power drain improves the HF quality.

I had another listen yesterday, but was unable to drive the speakers like I can when next door neighbour is out. Speakers did sound fantastic I must admit - so like others have said I am possibly asking too much of the AVR and by adding another amp may be my solution.

Another question then, can I add another amp which will turn on/off with my AVR? Do I need a certain type of amp that works alongside my AVR?
 
Most power amps, and some integrated do come with 12V triggers. The PAs usually have one supplied as well. That would be the route I would go down rather than stereo amp.

Your problem with the sub can be either bass management from the AVR or the nature of the sub itself. I think the Yams are quite good with rolling off the bass. but the BK, although has good volume and extension, lacks the precision of serious hifi grade speakers; which I believe the RX2s to be. That could be why they sound disjointed.

Yea, I know, the costs do stack up. But that's the problem when you start developing a taste for the good stuff. Its neverending.

You should have stuck to the blissful, ignorant world of Bose....
 
I blame all this on my school. My work experience was at a shop in Halifax which is now closed but still open in Huddersfield. For a whole two weeks I got to play with some serious kit - and hence my obsession for quality sound (on my limited budget).

Now my obsession can be unleashed due to recently moving onto the housing ladder - unfortunately I now live in the real world where food and heating becomes a priority over my recent feeling of 'money burning a hole'....

Can you give me any examples of amps that I should be aiming towards? I am not bothered about brand new equipment, but it would need to be black to match my other kit.

The BK is great for movies and that is what I use it for. I knew it wouldn't be great for music when I bought it but thought my RX-A1010 would feed the RX2's enough to put a grin on my face.
 
At the entry level, I would suggest Rotel. As I said there is an 1582 2channel power amp on the classifieds which will be ok for driving the front 2.

I would avoid the Class Ds as they don't agree with everyone, and may not be that good for music. Movies are ok.

I think MikeEvo's got a Parasound 5c as well. Consider that if the price is ok. Some other gems do popo up. But you'll be surprised what a PA can do, especially for an entry level AVR (for the range that is). A small 5x100wpc RMB1565 smoothened the sound sweetly of my Arcam AVR360. The only problems was it's a bit cold.

Don't worry about too much power. Its you speakers that determine how much is drawn. There's always the volume control to regulate how much goes in.

Check the transformer type and rating. That will give you an idea of how powerful the PA is. Don't just rely on reported ratings.

A cruder way is how heavy it is. Good PAs tip the scales from 30kg up.

Just remembered, there is a NAD 7c advertised recently too. You can biamp the fronts with extra channels (I think its 7c). Can't remember colour.
 
OK thanks. I will need a couple months to save and will then start the hunt for a PA.

Appreciate the help all! :)
 
fwiw,imho although the bk sub might not be the most musical sub, but when "correctly" positioned and eq'ed in a 2 ch. mode it should give way better bass and freq. response than the speakers without one.when crossed over with sub less power is going to speakers woofer, this gives more power for tweeter and less cabinet resonance due to the speakers woofer not vibrating crazily(distortion) at high volumes making the upper freq. sound harsh
 
OK thanks. I will need a couple months to save and will then start the hunt for a PA.

Appreciate the help all! :)
Let us know how you get on and if the amp helps cure the harsh treble issue, Ive a sneaky suspicion it wont though it will likely improve the speakers low end and mid range.
 
When you saved up enough dosh, go to a dealer for some comparisons to decide whether a PA will cure it, or its the tonal qualities of the speaker that is the problem.

I would like to believe the MAs are decent. I mean, they are so highly rated by WHF magazine...
 
While the problem seems to be gradually resolving itself, let me add a few comments.

First, though I apologies for asking, is the speaker actually Bright or harsh, or did you simply read somewhere that metal tweeter are harsh, then incorporated that into your belief system?

To say a speakers is "Bright" implies an imbalance that doesn't suit your ear. Bright is more treble relative to the amount of bass. A tweeter that is a bit bright without being harsh, might be called Crisp. To make the distinction, do you actually hear crisp detailed sizzle in the cymbals, or is it more of a generic hiss?

You can soften Bright treble by dialing it back a bit, but you can not do that with a single resistor. If you use a single resistor, you are changing the perceived impedance of the tweeter as seen by the crossover. That will cause the crossover point to shift and either leave a gap or cause a peak in the response at the crossover.

So do this right you need an impedance balance L-Pad, as seen in the diagram below -

termatten1-jpg.310712


The values for of R1 and R2, you can use an L-Pad calculator as seen at the bottom of the next link -

Crossover Design Chart and Inductance vs. Frequency Calculator(Low-pass)

There are indeed metal dome tweeters that can sound harsh, but equally there are cone and dome tweeter than can sound harsh, and further there are metal dome tweeter that can be sweet as silk. The Canton speakers use all metal drivers - bass, mid, tweeter - and I did not find them the least bit harsh.

One problem with any metal driver is that while they sound fine within their working range, they typically have a massive break-up region above the working range. This can be seen in the frequency response graph of this Dayton reference woofer.

http://www.parts-express.com/pedocs/specs/295-355-dayton-audio-rs180-8-specifications-47079.pdf

Notice everything is fine up to about 5khz, then the speaker goes a bit crazy. These are very good sounding drivers, you just have to make sure you select and design the crossover to suppress this breakup region.

I suspect the same thing happens with metal dome tweeters, but the breakup region is well outside the range of human hearing.

Lastly room acoustics. Someone said room acoustics don't effect mid/high frequencies, when in reality they effect the Mid/High range most. Most of us are used to a Slap-Back echo, where you shout into a canyon "Hello" and a fraction of a second later you hear the canyon shout back "helloooo". In a typical room, the time delays are far too short to hear a slap-back effect, but echo is there none the less. This can cause timing errors especially in the treble range.

At the following link you will find some information about room acoustic. Pay specific attention to the video in Post #8.

Primer: Acoustics - Absorption & Diffusion | AVForums

This is an Australian guy who does pod-casting, mostly of just him talking. He is in a small room, but at the end of the video, he does a before and after acoustic treatments. Though his professional mic does not pick it up well, you can clearly hear the echo in the room on the camera microphone. His needs were limited to voice, so relatively shallow acoustic panels did the job for him.

The simplest way to evaluate room acoustics is to simply look around the room. If it is all hard surfaces, no curtains, no carpets, no clutter, then it is probably an acoustic nightmare. On the other hand if it is an old fashioned soft furnished, carpeted, curtained, cluttered room, the acoustic are probably much better.

Because of the timing errors, indeed a highly reflective room can make treble harsh.

Lastly, AV Receivers. The problem with most AV Receivers is that the Power Supply can't keep up with the Amps. In a recent review, a common and popular, and seemingly powerful AV amp only put out 30w/ch when all SEVEN Channels were driven equally. Frequently, an 700w total AV amp will only have a 500w power supply, that means no combination of channels can ever exceed a total of 500w.

That's somewhat OK, because in an AV Surround System, the front three channels carry the bulk of the weight. The Side/Rear channels don't strain all that much. So, you virtually never have equal demand on all the amp channels.

But, a typicial 100w/ch Stereo amp will have a 300w power supply, given massive reserves of available power. Many of these Stereo amps will have huge banks of Capacitors on the power supply giving massive short term current capability; 40 amps to 60 amps short term would not be unheard of. Just to illustrate, if we push 40 amps through 8 ohms, the equivalent power is 12,800 watts. That's not realistic, it just illustrates what a 40 amp short term current reserve means. It simply serves as a point of perspective.

Again, the conversation seems to be winding down, but I though I would add these points.

Steve/bluewizard
 
Ahh, the wise one has spoken.

Agree totally with what you say Steve. Its hard to know what the OP means exactly by bightness/harshness. Is it shrillness or distortion, or excessive reflections or clipping?

Hence I think a listen at a dealer demo room is essential. they tend to be the soft furnished type rooms you mentioned, which eliminates echos.

As for the material thing, I didn't want to go into that too much. B&Ws have alu tweeters (so did my creative PC speakers which are Ti!). They are crisp and sweet, particularly driven by a power amp.

Another point about AVR power supplies, what about those that are rated 1800W? Are they reliable? I suppose there is capacitance to consider as well. There just simply isn't enough space to cramp all that in.
 
I am in two minds here as to my next move. Just as I thought I was 51% (haha) sure as to what is going on someone like Steve throws in a very valid point.

A chap who installed my TV noticed how 'lively' my room is - by doing the clapping test I could hear the acoustic feedback which he was describing. From my seating position the front room is much wider than it is in length. The photo I attached of my room is taken from me sitting on our 'L' shaped leather settee, the foot stool you can see is positioned so that my calf/feet rest on it. The settee is within a couple centimetres of been up against the back wall. So not a great distance between my seating position and speakers.

The back wall is plain and painted - we were told to wait before decorating as our house is brand new and can expect it to shrink so pointless decorating before it has had time to dry out etc. I want to wallpaper the back wall and have it as a feature wall which I think also may help the room become less 'lively'.

The room is concrete floor with medium thick underlay and medium deep pile carpet. We have fabric Roman blinds on the windows which are usually down most of the way when I am listening to music. We have a coffee table in one corner and a ikea style bookshelf in the other corner both up against the back wall.

-----

As for my description of 'harsh treble' as per thread title. I am trying my best to remember the stereos I listened to while doing my work experience and while I will never reproduce that sound on my budget I just think the HF is out of proportion with the rest of the sound. I would say the treble doesn't distort but possibly my ears can't cope with the HF as well as the LF. I need to sit and listen to some music which will give me better detail of HF sounds - any recommendations for this?

My AVR is rated @ Output Power (20Hz-20kHz, 2ch driven) 110W (8ohms, 0.06% THD). I'm not sure how good the power supply is on this unit though.

The power amps I am looking at are rated @ 2 x 200 watts (20Hz-20kHz, <0.03% THD, 8 Ohms)

Realistically is my AVR rated well enough to get the best out of the RX2's. I know any Power Amp still has to go through the AVR DAC so not sure if I would be just using clean solid amplification (PA) on an already dirty signal (AVR DAC).

What I am thinking is try the PA route and if it doesn't have any effect (which surely it can't not help somehow) then I have a PA and RX2's to sell and put that towards different speakers.

All this is fun if nothing else.........
 
I live in Rawtenstall, and I pass Rochdale everyday. If you like Ill pop in one day when it suits and have a listen? Then I can give you my thoughts from actually listening etc.
 
Many good suggestions in this thread (and a few flakey ones just to balance it out!)

Have you tried noiseboy72 and BlueWizards resistor suggestions yet? In my experience of building and modifying a few passive and active speaker systems, this has a good chance of a favourable outcome and is dirt-cheap and easy to implement.

Even if it doesn't provide a 100% solution (and I think it won't), you'll likely learn something in the process.

I have a theory why the resistor suggestion won't provide a 100% solution and it's this: Metal dome tweeters (MDT) are better suited to active speakers rather than passives because, I suspect, most MDT's don't have the inherent self-damping of soft dome types so rely more on the connected amplifiers' electrical damping - and in a passive crossover, that electrical damping is variable and frequency dependant.

In a passive crossover, the amplifiers' damping influence (on all connected drive units) reduces around the crossover frequency region due to the action of the crossovers. The way I understand it (and I may be wrong here) is that the crossover is designed to gradually introduce resistance and thus reduce power fed to the drive units outside their allocated frequency bands. At the actual crossover point, in a two-way system, it's typical for each driver to be receiving approx. half power (-3dB) which means that the crossover has introduced a resistance approximately equal to the impedance of each drive unit at that frequency. And that means amplifier damping of each drive unit has halved. The crossover network gradually increases the resistance between the amplifier and the tweeter (i.e. decouples) as frequency decreases and therefore amplifier electrical damping continues to decrease for the treble drive unit. Obviously, at some low frequency, there will barely be any output from the tweeter so it can't affect sound quality, but up until that point, it can and possibly does.

I doubt this reduction in amplifier damping benefits any drive units but, I suspect, particularly adversely effects less well damped drivers. All drive units in active systems are directly connected to the amplifier so don't suffer this variable electrical damping effect.
 
...

...

Another point about AVR power supplies, what about those that are rated 1800W? Are they reliable? I suppose there is capacitance to consider as well. There just simply isn't enough space to cramp all that in.

Here is a review of a Denon AVR-E400 AV Receiver -

Denon AVR-E400 AV Receiver Test Bench | Sound & Vision

Notice the power ratings -

- 2 Channels driven to 8 ohms = 103w/ch at 0.1% THD
- 7 Channels driven to 8 ohms = 62.3w/ch at 0.1% THD

If you look in the Owner's Manual, you will see this -

General:
Power supply: AC 120 V, 60 Hz
Power consumption: 460 W


The maximum power supply output is 460w. The amps can never exceed that. If we multiply 62.3watt times seven channels, we get 436 watts.

Now some amps like Arcam and Rotel will rate their amps with 5 or 7 channels driven, so those will be very strong power ratings.

So when you look at power rating, you need to see how many channels were driven, what the distortion rating is, and what the load impedance was for that power rating. Frequently they will rate the power to 6 ohms as a means of inflating the numbers. The 8 ohms rating will be about 0.75x of the 6 ohm rating.

For what it is worth.

Steve/bluewizard
 
@dogfonos

No I didn't get time to try the resistor suggestion yet. Monitor Audio kindly sent me some binding posts FOC to replace my lost ones and they turned up yesterday so removed the bi-amp and re-wired mono-wired. I must say the speakers do sound different, as subtle as it is from what I listened to last night and again this morning my ears do seem more acceptable to the HF now. I don't know if I have lost some clarity through doing it this way (it's so hard to remember every last detail between using bi-amp and non bi-amped).

I guess what I need to do now is chose one particular track and listen to it until I am completely fed up with it so at least I can half try remember how it sounds before and after bi-amping.

I have also purchased a Rotel RB-1582 from on here - I am a sucker for 'upgrading' and the Rotel ticked all the right boxes so it was hard to ignore a punt at it. I am lucking forward to it - and realise that once this PA is in place I will be limited to non bi-amped anyhow.

Now the wait begins for my Monitor Audio RX Centre to arrive and now also my Rotel RB-1582.
 
It will be surprising if monoamping sounds worse than biamping. Suggesting either the amplification is inadequate, or balance of sound is off in the speaker design.

Congrats on getting the Rotel!
 
I would say 100% the amplification is not quite there with my current setup. Based on the information Steve gave above my amp is pushing around 87w/channel @ 6ohm (0.06%THD) which I believe is ~20% lower than where I need to be.
 
Its more nuanced than that. You would need to measure speaker impedence across the frequency spectrum. Then measure the output from the receiver across these frequencies and look at the THD, clipping and other parameters.

Or you can use your ears.
 
(it's so hard to remember every last detail between using bi-amp and non bi-amped).
I guess what I need to do now is chose one particular track and listen to it until I am completely fed up with it so at least I can half try remember how it sounds before and after bi-amping.

Yes, I agree. The intervening time period between carrying out the two tests makes comparison tricky due to memory bias:
List of memory biases - Wikipedia, the free encyclopedia

Also, we humans are prone to other psychological effects that can alter our perception of what we hear, e.g. we become sub-consciously influenced by our own expectations and prejudices so tend to hear what we expect (or have been told to expect).

Best to carry out these audio comparative experiments as 'blind' tests, i.e. get someone else to change things from one state to the next so you don't know what setup you're listening to. Aim for a speedy changeover to minimise memory bias.

I'm working on convincing myself that the very cheap recorded music playback setup I use is the dog's b******s. That way, I won't hanker after upgrades. Happy days!
 
A power amp may well help, but the room is the single biggest factor... I (and many others) have found this out the hard way. My current room is somewhat similar, and based on hearing speakers in a variety of rooms, I'd wager this is probably why it sounds as it does. From my point of view, as bass is far less directional, it will spread a lot more than treble, which for a few reflections, will just bounce between the two walls that are closest... That's a really bad explanation really, but I hope you get the idea.
 
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Blind test are fine if you happen to be a larger research institution with substantial funding. But the opportunities for the average user to test equipment in this manner is virtually NIL.

Go have a listen; you like what you like. If possible, see if the dealer will allow you to take the speaker on approval. Though be fair about this. The dealer is extending a courtesy, not an invitation to abuse his generosity by trying speaker after speaker and not buying anything. Don't take a speaker home unless you are really and truly intending to buy.

Next, on the issue of Class-D Digital amps. For music, I absolute favor Class-A/B analog amps. But Class-D digital amps can sound amazingly good, assuming they are amps made for Music. Tiny very low powered T-Amp can sound extremely impressive when used with in their limited power range. I think the new NAD Master Series are Class-D amps. For Home Cinema, you get very high power without the bulk and heat of traditional amps and without the bulk of massive power supplies. They certainly do have an advantage in Home Cinema setup.

However, personally, just me, if I were building a serious Home Cinema Room, it would have serious Class-A/B Stereo amps rather than a single 5 or 7 channels Class-D amp. But then, that's just me.

Just a few thoughts.

Steve/bluewizard
 
Class-Ds aren't necessarily bad. Just not a mature technology. the biggest culprit are the B&O ICE module based amps. They made Class-D work, but at an expense of expressiveness.

The Class Ts are pretty promising. They would be the Bel Canto range I believe. Not cheap.

Primare is another company that made a decent stab at Classs D. But the 30.7 doesn't come cheap.

And so far as I know, the cream of the crop is Anthem M1 monoblocs. Looks like a stereo pre amp but is a complete rethink of Class D technology.

I know, stick to traditional Class A/B...
 

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