Horrible experience with Q Acoustics 2020i

[GCE]

http://www.qacoustics.co.uk/2020i-stereo-speaker.htm?lang=it

89 dB woofer 10 cm

http://www.hifiengine.com/manual_library/pioneer/cs-535.shtmlhttp://www.qacoustics.co.uk/2020i-stereo-speaker.htm?lang=it

93 dB woofer 20 cm

I don't think those 3 or 4 dB of difference are a big problem for Nad.

I would point to difference in woofer and box dimensions :read:

 

[davedotco]

Take the 2 plus volts from a dac and play it through an input of that sensitivity and the music is going to get loud very quickly, and as we all know louder is, most definitely better. It is extremely hard to match levels by ear but if the levels were matched accurately, so that we were hearing nothing but the differences between the dacs, then it would be tiny. In fact I would put money on the difference not being consistently audible in a blind test.

We all knows this, and it is valid for any external DAC. Then, me and the other poster in the other thread you hijacked on here, clearly said the quality of the external DAC compared to the internal DAC was tested at the SAME VOLUME level.

Do you own a NAD D 3020, a DragoFly 1.2 USB DAC and a Arcam IrDAC and want to test it by yourself and listen the quality of the sound before blab about obvious conventions well reported by me and the other poster in the hijacked thread?

PS: everything you said about this correct thread about Q Acoustics was always said and BTW, I now own Monitor Audio BX2: they peacefully deliver the same output power compared to the vintage Pioneer with the same level of sound. We all said and knows 2020i needed more to do that considering they are 4.4 Ohm, then it still isn't a reason, IMHO, for failing so pityfull.

Perhaps with respect to the dac, perhaps you can explain how you matched the levels, I would be interested to know.

Regarding the speakers, the BX2 is larger, more sensitive and easier to drive than the 2020i, it is also balanced with a more forward sound.

It will therefore sound considerably louder, no surprises there.

By the way, I have not commented on the sound quality of any of the items mentioned, just attempting to explain how various aspects of performance are actually percieved by the listener, that is all.

 

[davedotco]

http://www.qacoustics.co.uk/2020i-stereo-speaker.htm?lang=it

89 dB woofer 10 cm

http://www.hifiengine.com/manual_library/pioneer/cs-535.shtmlhttp://www.qacoustics.co.uk/2020i-stereo-speaker.htm?lang=it

93 dB woofer 20 cm

I don't think those 3 or 4 dB of difference are a big problem for Nad.

I would point to difference in woofer and box dimensions :read:

My own experience suggests that the 2020i are not that sensitive in real world use, I do not think the 6dB difference I quoted is at all unreasonable.

Even if your figures are correct, to compensate for a 4dB difference in sensitivity, you would have to go from a 40 watt to 100 watt amplifier.

The bigger woofer and box is a reasonable point too, makes them easier to drive which of course makes the difference even greater even if only subjectively.

 

[ID.]

Perhaps with respect to the dac, perhaps you can explain how you matched the levels, I would be interested to know.

A more patient (or braver) man than myself. I decided not to pursue it rather than check whether "volume matching" just meant that he had the volume dial turned to the same point (which of course would not be volume matching at all and would have widely different volumes depending on the source voltage...)

 

[davedotco]

Perhaps with respect to the dac, perhaps you can explain how you matched the levels, I would be interested to know.

A more patient (or braver) man than myself. I decided not to pursue it rather than check whether "volume matching" just meant that he had the volume dial turned to the same point (which of course would not be volume matching at all and would have widely different volumes depending on the source voltage...)

I have a quiet day at home and thought I would investigate these threads further.

One big issue that comes up a lot (thanks Vlad) is the subjective effect of high gain early in the system. We have all experience amplifiers that 'seem' very powerful because, on a given input, they get loud very quickly on the volume dial.

This is impressive, even though you know the amplifier will run out of power by the time the volume gets to half way, it is hard to get past the impression that it actually sounds great like this.

Volume, both percieved and measured is pivotal to hi-fi, back in the day when speakers were demonstrated by direct switching on a comparitor, most people bought speakers that were clearer and had more 'presence', ie they were louder. Most of the better speakers of the day, the Spendors, Rodgers etc would barely get a look in when demonstrated in this fashion.

Whatever the reasons for their introduction, single speaker dem rooms changed all that and high sensitivity spreakers virtually disappeared from the mainstream. Interestingly some good modern designs are clawing back some of that sensitivity, look at PMC for example.

 

[Neptune_Twilight]

Castle Acoustics used to use fuses to protect the drivers then used Positec as they called it that some felt degraded the sound & was fitted to a pair of Durhams I had - Before then I had a pair of Clydes & the foam roll surround quickly deteriorated (before the days of re-foaming) & I took them up to Castle in Skipton & they fitted new drivers while I waited plus removed the fuses & fitted the Positec (thermistors) devices in their place & was able to have a look round, a most interesting day - As I remember they also replaced the spring clip terminals with banana plug sockets - Looks like Cerwin Vega use a similar system - I don't think they have a UK distributor & never heard any either, though probably ideal for rock apes?

http://www.cerwinvega.com/pro-audio/portable-sound-system/intense-portable-sound-speaker-series.html

 

[lindsayt]

My own experience suggests that the 2020i are not that sensitive in real world use, I do not think the 6dB difference I quoted is at all unreasonable.

Even if your figures are correct, to compensate for a 4dB difference in sensitivity, you would have to go from a 40 watt to 100 watt amplifier.

The bigger woofer and box is a reasonable point too, makes them easier to drive which of course makes the difference even greater even if only subjectively.

No you don't have to go from a 40 watt amplifier to a 100 watt amplifier. Not if you're listening at volumes where the peak listening levels are hitting about 1 watt with the less efficient speakers, which is what MaxD has reported he is doing.

You'd only need a 100 watt amplifier for the 2020i's if you wanted to listen at volumes where the peaks were approaching 105dbs at the listening position.

 

[davedotco]

My own experience suggests that the 2020i are not that sensitive in real world use, I do not think the 6dB difference I quoted is at all unreasonable.

Even if your figures are correct, to compensate for a 4dB difference in sensitivity, you would have to go from a 40 watt to 100 watt amplifier.

The bigger woofer and box is a reasonable point too, makes them easier to drive which of course makes the difference even greater even if only subjectively.

No you don't have to go from a 40 watt amplifier to a 100 watt amplifier. Not if you're listening at volumes where the peak listening levels are hitting about 1 watt with the less efficient speakers, which is what MaxD has reported he is doing.

You'd only need a 100 watt amplifier for the 2020i's if you wanted to listen at volumes where the peaks were approaching 105dbs at the listening position.

We have no real idea of the volume levels being used here, some of the comments are contradictory.

The comparison is well, comparitive, a 40 watt amplifier needs to be replaced by one of 100 watts to counter the 4dB difference in speaker sensitivity if the capabilities in terms of dynamics and headroom are to be maintained. This is self evident.

What power is actually being delivered is beside the point, though in this instance, the fact that two bass drivers were destroyed, in a speaker not known to be 'fragile', suggests that rather more than 1 watt is being used.

 

[lindsayt]

We have no real idea of the volume levels being used here, some of the comments are contradictory.

The comparison is well, comparitive, a 40 watt amplifier needs to be replaced by one of 100 watts to counter the 4dB difference in speaker sensitivity if the capabilities in terms of dynamics and headroom are to be maintained. This is self evident.

What power is actually being delivered is beside the point, though in this instance, the fact that two bass drivers were destroyed, in a speaker not known to be 'fragile', suggests that rather more than 1 watt is being used.

Oh yes we do. MaxD measured his listening levels as peaking at 82dbs.

I don't think he's a liar or incompetent or that his phone is more than a few dbs inaccurate. Do you?

He already has 16 dbs headroom over and above what he needs with his 40 watt amp. What's the point in him having any more spare headroom on top of that?

You might think that more than 1 watt was being used. I don't. You might think that MaxD is a liar or incompetent or that his SPL app on his phone is completely useless. I don't.

I think that on the balance of probabilities he just had two sets of speakers with manufacturing defects. No big deal. It happens.

Your whole argument about needing a higher powered amp when moving to less efficient speakers does not apply if we still have enough power for the worst case scenario. For example, I've been using a 300 watt amplifer with my 8 ohm 102 db efficient speakers. When I go to my kitchen to listen to my 4 ohm 86 db efficient speakers does that mean that I need a 12000 watt amplifier to maintain the dynamics and headroom? Of course not. For my listening levels a 2 watt amp would be fine for both sets of speakers in terms of dynamics and headroom and avoiding clipping and avoiding damaging the speakers.

What power is being delivered is not beside the point. It's the whole point when deciding whether our amps have enough power for our needs or not.

 

[Broner]

I don't think he's a liar or incompetent or that his phone is more than a few dbs inaccurate. Do you?

I've used a phone app to measure dBs that turned out to be incredibly inaccurate (by more than 10 dBs), but more importantly, the OP didn't measure the volume with the QA speakers, but with his current setup. All in all, the current measurements tell us very little of his actual use of the QA speakers.

We, however, do know that the OP likes to turn the amp up quite a bit, until the point that he starts hearing unpleasant sounds (which were absent at lower volumes), and subsequently goes on using the speakers at a high volume level for another 150-200 hours (hoping that the sounds will disappear over time).

Ps chill.

 

[davedotco]

We have no real idea of the volume levels being used here, some of the comments are contradictory.

The comparison is well, comparitive, a 40 watt amplifier needs to be replaced by one of 100 watts to counter the 4dB difference in speaker sensitivity if the capabilities in terms of dynamics and headroom are to be maintained. This is self evident.

What power is actually being delivered is beside the point, though in this instance, the fact that two bass drivers were destroyed, in a speaker not known to be 'fragile', suggests that rather more than 1 watt is being used.

Oh yes we do. MaxD measured his listening levels as peaking at 82dbs.

I don't think he's a liar or incompetent or that his phone is more than a few dbs inaccurate. Do you?

He already has 16 dbs headroom over and above what he needs with his 40 watt amp. What's the point in him having any more spare headroom on top of that?

You might think that more than 1 watt was being used. I don't. You might think that MaxD is a liar or incompetent or that his SPL app on his phone is completely useless. I don't.

I think that on the balance of probabilities he just had two sets of speakers with manufacturing defects. No big deal. It happens.

Your whole argument about needing a higher powered amp when moving to less efficient speakers does not apply if we still have enough power for the worst case scenario. For example, I've been using a 300 watt amplifer with my 8 ohm 102 db efficient speakers. When I go to my kitchen to listen to my 4 ohm 86 db efficient speakers does that mean that I need a 12000 watt amplifier to maintain the dynamics and headroom? Of course not. For my listening levels a 2 watt amp would be fine for both sets of speakers in terms of dynamics and headroom and avoiding clipping and avoiding damaging the speakers.

What power is being delivered is not beside the point. It's the whole point when deciding whether our amps have enough power for our needs or not.

He also said that he turned the amplifier 'up to 100', ie full output. I said the comments were contradictory, which they were.

The OP also described the system producing 'cracking' noises, most likely overdriven bass notes, not likely to happen if only one or two watts are being used. The bass drivers were destroyed in this process, given the modest power of the amplifier I would suggest that even at maximum undistorted output, about 60 watts peak, or about 10-15 watts continuous, this should not have occurred.

Either the drivers are pretty fragile, which is not born out by the product's reputation or they were blown by an overdriven amplifier. I know which option I find more likely.

I also used the word comparative, all that means is that a 40 watt amplifier into one set of speakers is directly comparable to a 160 watt amplifier into speakers 6dB less sensitive in terms of dynamics and headroom. This is self evident whether you use the power or not.

What level you or anyone else uses is your/their choice and is not relevent to this discussion.

 

[steve_1979]

I can crank my NAD D 3020 volume up to 100 x 100

This says it all. Your amplifier was clipping and burned out the voice coils on the cheap Q Acoustics drivers. Simple as that really.

 

[matthewpiano]

Playing any amplifier into any speakers at max volume is likely to cause damage. Most amplifiers clip well before 'max'.

This is mis-use, which is why the internet isn't flooded with lots of other complaints about drive unit failure on Q Acoustics speakers.

 

[unsleepable]

While I agree that the speakers were probably fried by the amplifier clipping, and that it would have broken many speakers of other brands the same way, I am just not entirely sure that "mis-use" is a fair term here. After all, the OP used the amplifier and the speakers within the published specs.

From my point of view, the amp should stop short of breaking speakers. I guess it would be difficult to calculate the maximum volume that the amp should really play, as it also depends on the input voltage and the audio—but not impossible. From a commercial point of view, this would mean that many amps would play much lower than people have them usually playing—e.g., the OP—so I don't see this happening. In any case, in my opinion it should be NAD paying for the broken speakers here, not Q Acoustics or the user.

 

[MrReaper182]

As for What Hi-fi giving the Q Acoustics lots of stars. The answer to that is that we can all have our own individual star rating system.

You can get dizzy from the number of products awarded 5 stars from What Hi-fi?

That many products simply can't be that good.

I give just over three stars to my own system and I know that five stars would be so 'bonkers good' that I couldn't possibly afford it. What hi-fi are even giving five stars to sub £100 Bluetooth speakers!

They probably assign stars not in abolute value, they assign stars more on category-product-quality-price value. Then, IMHO, when something new is coming out, they tend to revise stars for older products. And this - especially for some kind of products like spakers - makes no sense. It should be curious to know for how long they listen the products when they review them. Reading the review they say, I'm listen this Kate Bush track, then this drumming from this OST and, ok, five stars, it is all done. What about the build of a product, how is it made, the component quality, the assembly, even the support? This makes a valid product exactly like the sound; my experience with Q Acoustics 2020i proved that sound is not enough if the product is cheapy made: like someone correctly said here, maybe you, you can't have margins for all the retail chain and still sell a five stars product at 150 £.

When What hi-fi give top stars to a product it does not mean that you should go and buy it (like so many people seem to think) they give top stars to products that should be on your listening list when your next demoing hi-fi. When a new product replaces a old one, the old one goes down a star because the new product is normally much more worth your time over the old one (I know that's not always the case but mostly it is) when demoing hi-fi. What hi-fi do talk about the build of the products they review but if you want to know more you can always talk about how the product your demoing is made with your hi-fi dealer, after all that's what they are their for. What hi-fi never tell you what to buy only what's worth demoing, they leave what product to take home up to you. If more people realised this then we would not get lots of people coming on this forum to complain that the 5 star product they just brought (without a getting a demo first.) is not the sound they were looking for or what ever else their unhappy with. Always demo before buying your hi-fi equipment people, that way you will not be coming on this forum to say how unhappy you are with the piece of hi-fi you just brought. Its not brain science.

 

[davedotco]

While I agree that the speakers were probably fried by the amplifier clipping, and that it would have broken many speakers of other brands the same way, I am just not entirely sure that "mis-use" is a fair term here. After all, the OP used the amplifier and the speakers within the published specs.

From my point of view, the amp should stop short of breaking speakers. I guess it would be difficult to calculate the maximum volume that the amp should really play, as it also depends on the input voltage and the audio—but not impossible. From a commercial point of view, this would mean that many amps would play much lower than people have them usually playing—e.g., the OP—so I don't see this happening. In any case, in my opinion it should be NAD paying for the broken speakers here, not Q Acoustics or the user.

In this particular case it would appear that a high output external dac was used to drive the D3020 via it's analogue inputs.

Normally, the internal dac does not output (internally) an analogue signal at a particularly high level, so used in this way the amplifier can be driven close to, or even at maximum (depending on the recording) on the volume control without massive overload. This would probably come close to your unbreakable criterea above.

However, feeding some 2 volts or more from an external dac, into the line input appears to 'drive' the amplifier much harder than the internal dac, this would make it much easier to overdrive the amplifier, hence the damage.

We were not there so can not say with any certainty what actually happened so we rely on experience, it is concievable that the speakers were faulty or that something else unusual happened to cause the failure that was not remotely the fault of the user, however I think Occam's Razor applies here.

 

[lindsayt]

I don't think he's a liar or incompetent or that his phone is more than a few dbs inaccurate. Do you?

I've used a phone app to measure dBs that turned out to be incredibly inaccurate (by more than 10 dBs), but more importantly, the OP didn't measure the volume with the QA speakers, but with his current setup. All in all, the current measurements tell us very little of his actual use of the QA speakers.

We, however, do know that the OP likes to turn the amp up quite a bit, until the point that he starts hearing unpleasant sounds (which were absent at lower volumes), and subsequently goes on using the speakers at a high volume level for another 150-200 hours (hoping that the sounds will disappear over time).

Ps chill.

Even if his phone app is measuring the SPL 13 dbs on the low side, that still leaves us with peak listening levels of 95dbs, which would be less than 10 watts with the 2020i's. That's still below the clipping level of his amp.

I once refoamed a bass cone. Not very well because the voice coil wasn't centred in the gap. At volumes of 50 dbs it sounded fine. Turn the volumes up to 80 dbs and you'd get horrible scraping, cracking noises on certain bass notes. 80 dbs on those speakers was about 0.1 watts. My solution was to re-refoam the bass cone surround, making sure I centred it properly this time. It has sounded fine ever since.

80 dbs does represent turning the volume up quite a bit to many people. It's loud enough to drown out normal speech. Loud enough to annoy the neighbours. Loud enough to get physical impact from the music. Loud enough to sound unrealistically loud for vocalists. But in terms of what the amp and speakers can take, it's well within their comfort levels - if they don't have a pre-existing manufacturing fault.

English doesn't seem to be MaxD's native language. When I read about his 82db measurements, followed by confirmation that that was as loud as he listened to his 2020i's I tokk the following statement from his opening post to be a figure of speech:

It is like three weeks they now work with a lot of fun and satisfaction from my side on my system, I can crank my NAD D 3020 volume up to 100 x 100 and they still sound great with pretty much no distortion and especially they do not fail.

(my bold).

I took his statement of 100 x 100 volume to mean peaks of 82 dbs (+/- accuaracy of his phone app). And not to mean he turned his volume until it hit its endstop. Think about it. If he were doing this with his BX2 speakers it would sound horrible, with a lot of clipping, instead of sounding "great with pretty much no distortion".

When you look at speaker drivers it's amazing they can take as much power as they do because the voice coil wires are so thin, you'd think they'd burn out like a filament lightbulb. Most likely explanation for the failure of MaxD's 2nd set of 2020i's is that 1 watt to 10 watts was sufficient to burn the voicecoil wires out.

Who is prepared to take me on for a bet? I will buy a new pair of 2020i's. We will feed it with 1 watt then 10 watts then 50 then 75 watts continuosly over a period of a few days - with my 300 watt amplifier. If the speaker fails you pay me £200. If it doesn't I give you the 2020i's plus £50.

 

[davedotco]

I don't think he's a liar or incompetent or that his phone is more than a few dbs inaccurate. Do you?

I've used a phone app to measure dBs that turned out to be incredibly inaccurate (by more than 10 dBs), but more importantly, the OP didn't measure the volume with the QA speakers, but with his current setup. All in all, the current measurements tell us very little of his actual use of the QA speakers.

We, however, do know that the OP likes to turn the amp up quite a bit, until the point that he starts hearing unpleasant sounds (which were absent at lower volumes), and subsequently goes on using the speakers at a high volume level for another 150-200 hours (hoping that the sounds will disappear over time).

Ps chill.

Even if his phone app is measuring the SPL 13 dbs on the low side, that still leaves us with peak listening levels of 95dbs, which would be less than 10 watts with the 2020i's. That's still below the clipping level of his amp.

I once refoamed a bass cone. Not very well because the voice coil wasn't centred in the gap. At volumes of 50 dbs it sounded fine. Turn the volumes up to 80 dbs and you'd get horrible scraping, cracking noises on certain bass notes. 80 dbs on those speakers was about 0.1 watts. My solution was to re-refoam the bass cone surround, making sure I centred it properly this time. It has sounded fine ever since.

80 dbs does represent turning the volume up quite a bit to many people. It's loud enough to drown out normal speech. Loud enough to annoy the neighbours. Loud enough to get physical impact from the music. Loud enough to sound unrealistically loud for vocalists. But in terms of what the amp and speakers can take, it's well within their comfort levels - if they don't have a pre-existing manufacturing fault.

English doesn't seem to be MaxD's native language. When I read about his 82db measurements, followed by confirmation that that was as loud as he listened to his 2020i's I tokk the following statement from his opening post to be a figure of speech:

It is like three weeks they now work with a lot of fun and satisfaction from my side on my system, I can crank my NAD D 3020 volume up to 100 x 100 and they still sound great with pretty much no distortion and especially they do not fail.

(my bold).

I took his statement of 100 x 100 volume to mean peaks of 82 dbs (+/- accuaracy of his phone app). And not to mean he turned his volume until it hit its endstop. Think about it. If he were doing this with his BX2 speakers it would sound horrible, with a lot of clipping, instead of sounding "great with pretty much no distortion".

When you look at speaker drivers it's amazing they can take as much power as they do because the voice coil wires are so thin, you'd think they'd burn out like a filament lightbulb. Most likely explanation for the failure of MaxD's 2nd set of 2020i's is that 1 watt to 10 watts was sufficient to burn the voicecoil wires out.

Who is prepared to take me on for a bet? I will buy a new pair of 2020i's. We will feed it with 1 watt then 10 watts then 50 then 75 watts continuosly over a period of a few days - with my 300 watt amplifier. If the speaker fails you pay me £200. If it doesn't I give you the 2020i's plus £50.

You are very selective in what parts of the thread you take as accurate and what parts you choose to take as a figure of speach, most posters, taking everything said into account, seem to think that the speakers were destroyed by an overdriven amplifier and I am with them.

Speaker specs, particularly power ratings are not clear cut. Sure speakers can be blown by the heating effect of quite modest RMS power if applied for a reasonably long period but that has no real relevance to a speakers capability on music, when even quite compressed recordings require modest RMS power.

The amplifier in question will have a peak power capability of about 60 watts. Driven up to, but not into clipping, the rms power being delivered will be in the range of 6-15 watts, depending on the dynamics of the recording

I would expect that even the inexpensive drivers in budget speakers would be able to handle that but I suspect that something else was happening to cause the drivers to fail, and given that distortion was audible, my bet is on an overdriven amplifier producing damaging waveforms, clipped bass notes for example.

FWIW. I have no idea what you speaker rebuilding anecdote is meant to prove and you proposed 'experiment' bears no relationship to reality. I have no idea what you are getting at with either comment......... :?

 

[MaxD]

I don't think he's a liar or incompetent or that his phone is more than a few dbs inaccurate. Do you?

I've used a phone app to measure dBs that turned out to be incredibly inaccurate (by more than 10 dBs), but more importantly, the OP didn't measure the volume with the QA speakers, but with his current setup. All in all, the current measurements tell us very little of his actual use of the QA speakers.

We, however, do know that the OP likes to turn the amp up quite a bit, until the point that he starts hearing unpleasant sounds (which were absent at lower volumes), and subsequently goes on using the speakers at a high volume level for another 150-200 hours (hoping that the sounds will disappear over time).

Ps chill.

Even if his phone app is measuring the SPL 13 dbs on the low side, that still leaves us with peak listening levels of 95dbs, which would be less than 10 watts with the 2020i's. That's still below the clipping level of his amp.

I once refoamed a bass cone. Not very well because the voice coil wasn't centred in the gap. At volumes of 50 dbs it sounded fine. Turn the volumes up to 80 dbs and you'd get horrible scraping, cracking noises on certain bass notes. 80 dbs on those speakers was about 0.1 watts. My solution was to re-refoam the bass cone surround, making sure I centred it properly this time. It has sounded fine ever since.

80 dbs does represent turning the volume up quite a bit to many people. It's loud enough to drown out normal speech. Loud enough to annoy the neighbours. Loud enough to get physical impact from the music. Loud enough to sound unrealistically loud for vocalists. But in terms of what the amp and speakers can take, it's well within their comfort levels - if they don't have a pre-existing manufacturing fault.

English doesn't seem to be MaxD's native language. When I read about his 82db measurements, followed by confirmation that that was as loud as he listened to his 2020i's I tokk the following statement from his opening post to be a figure of speech:

It is like three weeks they now work with a lot of fun and satisfaction from my side on my system, I can crank my NAD D 3020 volume up to 100 x 100 and they still sound great with pretty much no distortion and especially they do not fail.

(my bold).

I took his statement of 100 x 100 volume to mean peaks of 82 dbs (+/- accuaracy of his phone app). And not to mean he turned his volume until it hit its endstop. Think about it. If he were doing this with his BX2 speakers it would sound horrible, with a lot of clipping, instead of sounding "great with pretty much no distortion".

When you look at speaker drivers it's amazing they can take as much power as they do because the voice coil wires are so thin, you'd think they'd burn out like a filament lightbulb. Most likely explanation for the failure of MaxD's 2nd set of 2020i's is that 1 watt to 10 watts was sufficient to burn the voicecoil wires out.

Who is prepared to take me on for a bet? I will buy a new pair of 2020i's. We will feed it with 1 watt then 10 watts then 50 then 75 watts continuosly over a period of a few days - with my 300 watt amplifier. If the speaker fails you pay me £200. If it doesn't I give you the 2020i's plus £50.

This is pretty much exactly the scene. First of all, the NAD D 3020 doesn't have an end point for the volume knob. It is a new type of knob and it simply deliver the db scale (from -100db to 0db) and even if you still rotate the knob it will do nothing. IMHO this is a questionable design, the only glitch I can find to a fine amp.

So when I say I turn up the volume to 100 per 100 means that volume scale on the unit is 0 db. I never totally listen music to the scale at 0 db, usually I think it is was -5db with the 2020i, also becouse when you listen cranked sound, you tend to lower the volume (like with the 1st pair of 2020i), with MA BX2 I need less volume to drive them at the same level of sound pressure I like, usually they just get SPL 82 db on the app with a volume just lil up than -10db. With those hardening sounding 2020i I needed pretty much something less than -3 db.

Even if NAD technician said to me I could go all the way becouse class D amps have virtually no distortion (do you guys owned a class D amp? I'm impressed becouse it is very clear in the sound and it runs less hot compared to my old Rotel RA-560; even when 2020i were fried it wasn't all that hot), I NEVER did it, I always let the meter not completely at full scale even when those second pair woofer fails.

Related with the first pair of 2020i, they never properly failed like the second pair, even if they've been used like the second pair, the one fried.

First pair just had some unpleasent crank and bop when I pumped up the volume on bass frequencies. It happened not with all the recordings, like I always write, just wit SOME recordings. Swapped for the new one, they are on a new home - seller said - a new home where probably the owner is satisfy with just some background music, becouse those speakers were failing IMHO.

It is also true I didn't measured SPL with 2020i, then - as is said pretty much in many posts - is: I like to listen to the same level of pressure with all my gear and in every situation, it means my level of satisfaction to drive speakers is the same, it is the level of satisfaction I need to enjoy the music. So it is arguable I played the 2020i as loud as I now play the BX2.

As I said, it is true I needed more power to drive the 2020i at the same level I now run the BX2, then - as I said - the power request was within the specifications of my amp and my speakers, so if Q Acoustics failed for that we surely have to blame them for it, not surely NAD (like crazy someone wrote in one of this thread posts, or me, I simply used my gear within specifications).

Said that I bought the DragonFly 1.2 DAC AFTER the 2020i was always fried (and for other reasons, needed hi-fi from my laptop and iPad, considering sometimes iPad is my recording studio and I wanted something to play iPad files hi-fi without transfer them on a pc), then I wanted to try it on desktop pc in the studio room, so I used it - connected to a line input of D 3020 - just with Pioneer CS-535 and MA BX2,

I don't know if some of you guys active on this thread have phisically handled some 2020i, then this model of Q Acoustics seemed to me like a toy from the day one I had them in my hand. Wood seems ok, then the rest isn't: Woofers looked like made of some poor thick paper and bass reflex cone never really convinced me: the sound was hard from day one, then it was agreable. No, definitely not like MA BX2 and no, the dynamics of the sound was way under those of Pioneer vintate CS-535 and BX2.

From day one I blamed myself becouse I bought something on the paper, based on the Whathifi 5 stars more than my ears, my ears always said MA BX2 was my right choice way before I decided for 2020i. And from day one I asked myself how those guys at Whathifi rated the speakers becouse I never ever could give 5 stars to 2020i after holding them in my hand, with the poor feel of 2020i. MA BX2 have a much more professional look and feel when you handle it in your hands, you touch the woofers, you look at the bass reflex coin, you look at the tweeters, they seems solid, "professional".

Now I want it is clear, here I discussI about Q Acoustics 2020i model: I hope new models, I read they weight more, like Concept 20 or Concept 40 are less poorly made. They cost pretty much roughly a double figure compared to 2020i, I owned and handled in the past also a pair of Magnat Supreme Monitor 200 (in another room connected to a Denon PMA520) and believe me, they are made of material apparently ten thousand stronger and better than 2020i. And even the sound, too harsh, is not that bad, and again they doesn't fail.

For me Q Acoustics, also - maybe expecially! - for them pre and post sales attitude (they are virtually not existant, they do not interact with customers and seller also said they do interact a little even with sellers, considering he said they are now sending him the woofer for the 2020i repairing, and it is him that have to do the work of replacing them, his own lab, they are not interested in see what happened and fix the problem) are a close chapter.

Yes, it will be curious to see if they didn't failed if the amp was a more powerfull amp, I think they always fail, they are poorly made, then whats the point to have a 100 + 100 amp driving a 150 £ speakers? It simply makes no sense to match a 1,500 £ amp with a ten rimes less expensive pair of speakers.

Q Acoustics has to rethink his model businness, to revise his entry level speakers 2020i and Whathifi should be a lot more carefull in rating is products, that is my opinion, firm and strong.

 

[steve_1979]

Who is prepared to take me on for a bet? I will buy a new pair of 2020i's. We will feed it with 1 watt then 10 watts then 50 then 75 watts continuosly over a period of a few days - with my 300 watt amplifier. If the speaker fails you pay me £200. If it doesn't I give you the 2020i's plus £50.

Your 300 watt amp won't be clipping so it's much less likely to damage speakers than a 30 watt amp that is clipping.

 

[steve_1979]

In this particular case it would appear that a high output external dac was used to drive the D3020 via it's analogue inputs.

Normally, the internal dac does not output (internally) an analogue signal at a particularly high level, so used in this way the amplifier can be driven close to, or even at maximum (depending on the recording) on the volume control without massive overload. This would probably come close to your unbreakable criterea above.

However, feeding some 2 volts or more from an external dac, into the line input appears to 'drive' the amplifier much harder than the internal dac, this would make it much easier to overdrive the amplifier, hence the damage.

We were not there so can not say with any certainty what actually happened so we rely on experience, it is concievable that the speakers were faulty or that something else unusual happened to cause the failure that was not remotely the fault of the user, however I think Occam's Razor applies here.

+1

There are three factors at play here.

Louder than usual DAC output

+ an underpowered amp turned up to full volume

+ difficult(ish) to drive budget speakers

= excessive clipping and burned out voice coils

 

[MaxD]

In this particular case it would appear that a high output external dac was used to drive the D3020 via it's analogue inputs.

Normally, the internal dac does not output (internally) an analogue signal at a particularly high level, so used in this way the amplifier can be driven close to, or even at maximum (depending on the recording) on the volume control without massive overload. This would probably come close to your unbreakable criterea above.

However, feeding some 2 volts or more from an external dac, into the line input appears to 'drive' the amplifier much harder than the internal dac, this would make it much easier to overdrive the amplifier, hence the damage.

We were not there so can not say with any certainty what actually happened so we rely on experience, it is concievable that the speakers were faulty or that something else unusual happened to cause the failure that was not remotely the fault of the user, however I think Occam's Razor applies here.

+1

There are three factors at play here.

Louder than usual DAC + underpowered amp at full volume + difficult(ish) to drive budget speakers = excessive clipping and burned out voice coils.

Read my previous post: 2020i were fried using D 3020 INTERNAL DAC, DragonFly was bought AFTER for the laptop and then used also with the NAD D 3020 becouse I found out it sound quietly better compared to internal DAC, then I played it only with Pionner vintage and MA BX2.

About the clipping: as a recording technician too, for me clipping means when I turn out too much some mic on the board, voice clips. I correct this in the studio, like I think every engineer in this world do! I never heard the same clip noise on a cd or LP becouse they are corrected before, usually the clip I say can destroy tweeters not woofers and BTW I never heard such a sound on my stereos, I mean my hi-fi. Never ever with the 2020i, they just cranked the bass (1st pair, exchanged and now working in a new home, like seller said to me); the failing pair simply stopped to play and woofer were gone.

 

[davedotco]

This is pretty much exactly the scene. First of all, the NAD D 3020 doesn't have an end point for the volume knob. It is a new type of knob and it simply deliver the db scale (from -100db to 0db) and even if you still rotate the knob it will do nothing. IMHO this is a questionable design, the only glitch I can find to a fine amp.

So when I say I turn up the volume to 100 per 100 means that volume scale on the unit is 0 db. I never totally listen music to the scale at 0 db, usually I think it is was -5db with the 2020i, also becouse when you listen cranked sound, you tend to lower the volume (like with the 1st pair of 2020i), with MA BX2 I need less volume to drive them at the same level of sound pressure I like, usually they just get SPL 82 db on the app with a volume just lil up than -10db. With those hardening sounding 2020i I needed pretty much something less than -3 db.

Even if NAD technician said to me I could go all the way becouse class D amps have virtually no distortion (do you guys owned a class D amp? I'm impressed becouse it is very clear in the sound and it runs less hot compared to my old Rotel RA-560; even when 2020i were fried it wasn't all that hot), I NEVER did it, I always let the meter not completely at full scale even when those second pair woofer fails.

Related with the first pair of 2020i, they never properly failed like the second pair, even if they've been used like the second pair, the one fried.

First pair just had some unpleasent crank and bop when I pumped up the volume on bass frequencies. It happened not with all the recordings, like I always write, just wit SOME recordings. Swapped for the new one, they are on a new home - seller said - a new home where probably the owner is satisfy with just some background music, becouse those speakers were failing IMHO.

It is also true I didn't measured SPL with 2020i, then - as is said pretty much in many posts - is: I like to listen to the same level of pressure with all my gear and in every situation, it means my level of satisfaction to drive speakers is the same, it is the level of satisfaction I need to enjoy the music. So it is arguable I played the 2020i as loud as I now play the BX2.

As I said, it is true I needed more power to drive the 2020i at the same level I now run the BX2, then - as I said - the power request was within the specifications of my amp and my speakers, so if Q Acoustics failed for that we surely have to blame them for it, not surely NAD (like crazy someone wrote in one of this thread posts, or me, I simply used my gear within specifications).

Said that I bought the DragonFly 1.2 DAC AFTER the 2020i was always fried (and for other reasons, needed hi-fi from my laptop and iPad, considering sometimes iPad is my recording studio and I wanted something to play iPad files hi-fi without transfer them on a pc), then I wanted to try it on desktop pc in the studio room, so I used it - connected to a line input of D 3020 - just with Pioneer CS-535 and MA BX2,

I don't know if some of you guys active on this thread have phisically handled some 2020i, then this model of Q Acoustics seemed to me like a toy from the day one I had them in my hand. Wood seems ok, then the rest isn't: Woofers looked like made of some poor thick paper and bass reflex cone never really convinced me: the sound was hard from day one, then it was agreable. No, definitely not like MA BX2 and no, the dynamics of the sound was way under those of Pioneer vintate CS-535 and BX2.

From day one I blamed myself becouse I bought something on the paper, based on the Whathifi 5 stars more than my ears, my ears always said MA BX2 was my right choice way before I decided for 2020i. And from day one I asked myself how those guys at Whathifi rated the speakers becouse I never ever could give 5 stars to 2020i after holding them in my hand, with the poor feel of 2020i. MA BX2 have a much more professional look and feel when you handle it in your hands, you touch the woofers, you look at the bass reflex coin, you look at the tweeters, they seems solid, "professional".

Now I want it is clear, here I discussI about Q Acoustics 2020i model: I hope new models, I read they weight more, like Concept 20 or Concept 40 are less poorly made. They cost pretty much roughly a double figure compared to 2020i, I owned and handled in the past also a pair of Magnat Supreme Monitor 200 (in another room connected to a Denon PMA520) and believe me, they are made of material apparently ten thousand stronger and better than 2020i. And even the sound, too harsh, is not that bad, and again they doesn't fail.

For me Q Acoustics, also - maybe expecially! - for them pre and post sales attitude (they are virtually not existant, they do not interact with customers and seller also said they do interact a little even with sellers, considering he said they are now sending him the woofer for the 2020i repairing, and it is him that have to do the work of replacing them, his own lab, they are not interested in see what happened and fix the problem) are a close chapter.

Yes, it will be curious to see if they didn't failed if the amp was a more powerfull amp, I think they always fail, they are poorly made, then whats the point to have a 100 + 100 amp driving a 150 £ speakers? It simply makes no sense to match a 1,500 £ amp with a ten rimes less expensive pair of speakers.

Q Acoustics has to rethink his model businness, to revise his entry level speakers 2020i and Whathifi should be a lot more carefull in rating is products, that is my opinion, firm and strong.

Thank you for that.

That is a very clear account of your experiences and your views.

It all makes perfect sense and I think I now have a pretty good appreciation of what has happened here.

 

[Cypher]

Playing any amplifier into any speakers at max volume is likely to cause damage. Most amplifiers clip well before 'max'.

This is mis-use, which is why the internet isn't flooded with lots of other complaints about drive unit failure on Q Acoustics speakers.

I told him that (and many other people here) many times but MaxD simply won't listen. He should treat his speakers and amp with care and not point the finger at Q Acoustics because the speakers are not to blame here. The user is.

 

[Riksta73]

Don't worry, I had a pair of 2020i for a tear and the were fine, I've got 2 pairs of 2050i in my surround setup over 18 months no problem at all, great sound with my Onkyo 818 and I haven't got a sub! For the money QA make very good speakers.