New receiver or seperate amp

decto

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Hi all,

Following a room change I've finally been able to get a larger TV (42" to 65") and update my elderly 5.1 system.
Which was: Sony DA2400ES, QA 1030i floor stander x4, QA 2000c, BK XLS200 DF.

As this is a living room 6x4m, I'm looking to eliminate the floor standers while retaining reasonable performance.
The surround have been replaced with Dali Alteco C-1

Due to room layout I'm using 5.1 which still sounds pretty good to me.
Oddly the audio on Netflix seems way better from the new TV downmix (optical) than it did from a Roku stick+ direct into the AV receiver.
This could be as I stepped up a Netfix tier to get the 4k streams but has been very noticable, the sound seems more spacious and enveloping!
Maximum future speakers will be 5.2.2 so only using max 7 channels from the receiver.

I'm about to order Dali Opticon LCR x 2 + Opticon Vokal however spotted that these are 4 ohm so I expect the Sony will really struggle to drive them effectively.

A new receiver is on the cards, Denon AVC-3700/4700, Marantz S6015/7015 or equivalent so £1-1.5k
However given I'll likely keep the receiver for 8+ years it may be better to hold off to the next release cycle and pick up a newer model without the HDMI issues. Though perhaps I'm over concerned about this and really if it became an issue would just HMDI direct to the TV and use eARC for the audio. Have looked at the new Yamaha, but from what I read the Audessy XT32 is much better than what Yamaha offer.

So a couple of options.
Pickup a new/used integrated/power amp to support the Sony in the short term. Something like the Audiolab 6000A which has AV bypass.
From a Hifi perspective I can then get the best of the speakers with audio direct, likely need a new source, while retaining the improved power for the LR channels during movies etc. Though quite how I configure subwoofers between the receiver and amp could be an issue and the Opticon LCR may not be the best for music usage without support of a SW. This could also reduce the receiver spend as I looked at the higher spec recievers for a higher multichannel power reserve rather than features.

Pick up a recent used receiver, though prices seem pretty high. A 6 year old Denon 5200W sold for ~£600 on ebay so I'd rather just get a new one.

Buy a new receiver and trade it later if needs change.

Buy last years recivers at discount and forget the whole 8k / 4k 120hz for now.
I'm unlikely to buy a 8k TV until there is no choice.

Thanks
 
Get one of these, original rrp £2k, now reduced but with 5 year warranty:


they will likely accept £1100.

supports 4K up to 60Hz, HDR/HLG/Dolby Vision and Dolby Atmos/DTS x

doesnt have 4K/120hz or 8K but I would wait until that is stable. You will not get a better sound signature for both music and movies without paying a lot more, see review here, it’s the same internals as the Arcam 850 without the class G amps (and a lot less money):


don’t worry about bugs, software is super stable now.
 
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Thanks for the suggestion.

I'd looked at the AVR390, however the AudioScience Review AVR390 review found that while the analogue amp section was great, the digital side needs work.

The Denon 3700 and 4700 measure well, less so the Marantz equivalent.

This really is a minefield
 
Thanks for the suggestion.

I'd looked at the AVR390, however the AudioScience Review AVR390 review found that while the analogue amp section was great, the digital side needs work.

The Denon 3700 and 4700 measure well, less so the Marantz equivalent.

This really is a minefield
Tbh don’t read too much into ASR reviews, 99% of what he finds makes no audible difference. Trust me, Arcam will beat Denon sound any day of the week. You could always get one on home trial from Peter Tyson.
 
So the search continues.

Inspired by the excellent spreadsheet I see Mr Wolf sharing, (no idea how to tag users) I had an attempt at something similar, mirroring the very logical format.

I also added some correction for speaker impendance to switch the sensitivity from db 1W/m (speaker spec) to db @ 2.83V/m to match the 8 ohm amplifier spec in the sheet and then added in a sense check to convert back for total wattage since neither AV recievers of BasX amps are anything like perfect and my speakers are 4-6 ohm except for the to be purchased heights which are nominally 8ohm. My version may well have less than ideal descriptions on the blue bits I added.

So currently I'm looking at X3700H / 4700H or Marantz equivalent for max 5.2.2 with Audessy XT32.
The AVR390 suggested above doesn't have eArc which my new TV does and we'll be using the TV apps quite a lot, also is a little dated now so not clear what support it will get and I have no real idea how much of an issue this is. Youtube seems to be mostly influencers rather than objective reviews. D+M seem to have most current features and decent room calibration at this tier. I did look at the Anthem MRX540 but it's expensive and only has 5 amps so I would need to add at least a basic amp when I want to add heights.

Part of the issue is >3m to LCR due to couch to wall room layout so the fronts need to play loud to compensate, additionally the surrounds are surprisingly low sensitivity @ 83dB, something I didn't consider.

Anyhow, what I think that I learn from this is that either receiver class should be fine up to a volume of ~ -8db with the instantanous demand @ peak SPL +3dB and corrected impedence requiring 385W. Typically with my current 5.1 amp calibrated to 75db pink noise at 0dB reference I mostly listen at @-20dB due to kids / wife in bed. Solo I may crank to -10dB for short periods.

I stopped at -8db as 105W x 70% 'guarantee' with 5 channels driven is ~368W vs an all channel peak +3dB of 385W impedance corrected all channel.

Given the 105W vs 125W two channel and 660W vs 710W total consumption, It seems I gain less than 1dB opting for the more powerful amp (placebo territory) with features (+2 channels) I won't need so the cash would be best saved for an amp in the future or other upgrades.

If anything the X3700H class with option to upgrade to BasX A3 for LCR later seems the best option in my brain. Though even the BasX doesn't really step up to 4 Ohm given the ~40% power increase is at the cost of significant distortion.
  • 140 watts RMS per channel; 20 Hz – 20 kHz; THD < 0.1%; into 8 Ohms.
  • 200 watts RMS per channel; 1 kHz; THD < 1%; into 4 Ohms.

Comments welcome, especially those that validate or correct my the logic in the table below as this is the foundation for MED home audio.... (Minimum effective dose)


TwGE543.png
 
To tag members you just type the "at" symbol (same as the one used in an email address) and as you then type the member name it completes it and you select.

@Mr Wolf
 
To tag members you just type the "at" symbol (same as the one used in an email address) and as you then type the member name it completes it and you select.

@Mr Wolf
Thanks, I did try that but nothing popped up. Seems to be working now though.


To continue this, I checked on the Dali site and they were actually quoting in W@ 2.83V/1M so removed my correction to speaker impedance at the front end. Now I just use the dB offset to correct for amp power later on.

This changes the position, at -11dB I'm hitting the LCR rather hard, though this is peak with 3dB headroom. I'm still of the view that a more 'powerful' reciever won't make a lot of difference, but I am now steered more towards independant LCR amplification.


aR9xP6i.png


Independant amp.
Will have a little more headroom as the BasX output is @8Ohm.

FQqRM21.png
 
Don't forget that another thing @Mr Wolf normally adds as a comment is that with crossovers a generous portion of power is coming from your subs' amps.
 
Hi guys, sorry been out all afternoon - back home now for dinner. Well done @decto for having a crack at building your own model. I haven't checked it but you can compare your outputs to mine for your assumptions.

Based on what you've said, this is my take on your best configuration (Basx A3 for LCRs and AVR the rest) and the model indicates that you should be good up to -6dB volume. When I say "good", I mean at least 3dB of dynamic headroom is maintained at all times.

1623862884545.png


I've used the 105W as both the AVR's lowest and highest power figures as (per Dolby mixing rules) the summed SPL output of the surround channels combined shouldn't exceed the SPL of one of the main LCR channels. As they have 17dB peaks (not 20dB) peaks this means it's the equivalent of two channels being fully driven at a time. Hopefully this makes sense to you.

I wouldn't worry too much about the whole 4 vs 6 vs 8 Ohm speaker thing - they're just nominal averages and unreliable ones at that. I model everything on an 8 Ohm basis for several reasons:

1. All manufacturer's are supposed to rate sensitivity at 2.83V (which is 1W into an 8-Ohm load) even the speaker doesn't have an 8 Ohm nominal rating.
2. Speaker impedance isn't fixed and varies massively throughout the frequency range - in that sense, there is no such thing as a "x Ohm speaker"
3. Manufacturers cheat and lie about impedance ratings e.g. my B&W DM603 S3s have been measured as dipping under 4-Ohms at times but they still somehow get an 8 Ohm rating!
4. Analysis becomes overly complicated when you mix your drinks with different impedances!
 
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Thanks @Mr Wolf , definitely no need to apologise, I appreciate you stopping by to advise when you get the chance. Looks like I'm good on the main calculated figures vs your original, just my impedence 'adjustments' complicating the picture somewhat.

I also now understand how you calclulated the max surround channel power as the highest 2 surround speakers. That did have me stumped so thanks for the explaination.

As I understood, when power @ 2.83V is quoted, it gives a sensitivity advantage of +3db to 4 Ohm speakers as they will draw 2W vs the 1W of an 8 ohm speaker so power required for final SPL is doubled when comparing an ideal 4 Ohm speaker to an ideal 8 Ohm speaker.

Looking at the Dali speakers, Stereo Magazine has analysis of a couple of different models incuding a different Opticon and the impendance seems quite conistant with the 4 Ohm rating through a good part of the frequency range, definitely nearer an average 4 than an average 8.

I take your point on the wide impedance vs frequency variation in speakers, I've seen a few articles on variance, specs and marketing games. Also agree that the complexity of correcting nominal impedence is less useful now I've tried it. I think the simplest answer may be that I allow a little more headroom when speakers are labelled as 4 Ohm and paired with amps such as the BasX which don't derate linearly with impedance. Once the 4 Ohm is corrected to 20-20Khz 0.1% likely it is more like 160W vs the 140W @ 8 Ohm so seems the amp is rather current limited. Still enough power to push the speakers to the top of their power rating and beyond where I'd be using them.

Given the surround sound requirement is actually pretty low vs the LCR, I'm now back to wondering if the BasX really that significant upgrade over a mid range D/M receiver with 70% 5 channel so 5x 75 @ 8 Ohm / 5 x 88W @ 8 Ohm.

I did ask in the Emotiva chat if they had any full range 4 Ohm data, they just said the A3 it's 4 Ohm stable!

Dobbyisfree mentioned that power requirement is actually quite a bit less due to cross over to sub at 80Hz. Any thoughts on that, I haven't yet found a good article on power vs frequency.

So back round the loop, receiver or reciever + amp.
 
Dobbyisfree mentioned that power requirement is actually quite a bit less due to cross over to sub at 80Hz. Any thoughts on that, I haven't yet found a good article on power vs frequency.

In order to maintain the same SPL output a speaker's cone has to move twice as far every time the playback frequency halves i.e. 80Hz requires the movement of twice volume of air that 160Hz does. For various reasons that doesn't translate to being eaxactly twice the power requirement but naturally it will be substantially more given that air resistance is a chief opposing force to the movement. This is why it is often said that subs do the heavy lifting in a system. James Larson (sub/speaker tester at Audioholics) has often said how using multiple active subs that are capable of playing high (for a sub) can when used in conjunction with a higher crossover setting to cost effectively increase a system's dynamic headroom.

Something else for you. A key difference between amplifiers you may not have considered is their level of capacitance and its role in delivering power to speakers. It would be useful to know the size of the Emotiva's power reservoir capacitors - I'm pretty sure your Denon has 24,000uF.

About 6 months ago I got involved in a lengthy debate about the relative importance of capacitance and ACD amplifier test results which you may find interesting/useful.

Question - Yamaha 3080/2080 or Marantz SR7015

It's a fairly long thread but to save you reading it all I'll quote myself from it:

"Real world peak power handling has far more to do with capacitance than maximum continuous current flow from the PSU. Research has shown that over 99% of the loudest peaks in movies only last milliseconds and, if you do the maths, you'll find that these peaks can usually be handled by the sizeable power smoothing capacitors and not spike a current demand on the PSU at all. This is probably why, in practice, power amps can sound so awesome when on paper (or in an ACD test) they don't look much better than some high end receivers. IMO, capacitance is the great unmeasured and often unpublished "secret sauce" of a good amp."

"I'm not saying nobody needs a power amp in their home set-ups but the reason they might want one is for better sound quality, not more SPL. This is due their ability to better handle very loud dynamic peaks, especially if they have hard to drive speakers or are crossing them below the standard 80Hz. Their benefit is mostly due to their design, of which continuous wattage output capability (i.e. ACD testing) is only one part. Take the AVC-8500, probably the most powerful AVR currently being made. It has 44000uF of total capacitance which for an AVR is very good (Z7 only has 36000uF, also good for an AVR). These don't look so impressive when compared to IOTA's 7CH AVPX1 power amp which has 90,000uF. Or Monoprice's 11CH power amp which has a whopping 246,400uF (22,400uF per channel!). This extra capacitance means reduced peak current demands on the PSU which means fewer and smaller voltage drops which means less compression which means better sound quality. It's also why they run very cool as the PSU is much less stressed."

"The point I've been trying (but maybe failing) to get across though is that the ACD test results won't be hurt by a lack of capacitance as it's effectively a maximum PSU continuous output test. The performance boost you get from caps is short-lived and gone as soon as they dump their charge into the current flow. It's the main reason I hate the over-focus on the ACD test. In the real world only very small amounts of power are required on anything resembling a continuous basis. You still need a decent PSU though to help with the peaks and replenish the caps quickly in time for the next peak."
 
That's interesting. I don't know what's inside my Denon but, going along with the point made above about external power amps, my 5 channel Rotel power amp has eight 12,000microfarad caps. So, that's quite generous across 5 channels. And the 2-channel Rotel I have is four at 8,200.
 
I suspect your Denon has 24,000uF (2 x 12,000uF) caps as that's what the X4xxx series has.

Having multiple smaller caps is apparently better than having fewer larger ones as it allows energy to get in and out quicker (a bit like PC RAM where 2 x 8GB sticks is better than 1 x 16GB stick).

Arcam AVRs typically have strong capacitance and probably explains why some while ago Steve Withers, having reviewed/tested both, said that the AVR390 seemed more powerful than a Denon X6500 despite having a lower rated power output per channel.
 
I suspect your Denon has 24,000uF (2 x 12,000uF) caps as that's what the X4xxx series has.

Having multiple smaller caps is apparently better than having fewer larger ones as it allows energy to get in and out quicker (a bit like PC RAM where 2 x 8GB sticks is better than 1 x 16GB stick).

Arcam AVRs typically have strong capacitance and probably explains why some while ago Steve Withers, having reviewed/tested both, said that the AVR390 seemed more powerful than a Denon X6500 despite having a lower rated power output per channel.

Ah, so I realise there are lots of variables here but initial pointers are (if/when the Rotel gets up and running again on the DB25 connector) I'm better putting the main five channels out to the 96,000µF Rotel instead of the 24,000µF Denon!

Although just edited as the Rotel's caps are a lot older than the Denons - try factoring that one in!

For any fellow geeks µ is ALT 230 🤣
 
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Ah, so I realise there are lots of variables here but initial pointers are (if/when the Rotel gets up and running again on the DB25 connector) I'm better putting the main five channels out to the 96,000µF Rotel instead of the 24,000µF Denon!

Although just edited as the Rotel's caps are a lot older than the Denons - try factoring that one in!

For any fellow geeks µ is ALT 230 🤣
Just had an idea for a test you could do when you get your Rotel up and running. Playback the same (loud and dynamic) movie scene with all your amps connected to the same 4-gang extension lead which in turn is connected to the wall socket via a energy plug/meter. The configuration which plays back the scene with the lowest maximum peak power consumption is probably making best use of capacitance to handle the peaks.

I ran my Yamaha RX-V3900 AVR for several months connected to an energy plug and (listening up to -10dB volume) the maximum peak wattage power draw I ever measured it pulling from the wall socket was 260W. Considering it draws 88W without any signal playing and Class A/B is only 50-70% energy efficient at best it shows just how little power AVR amplifiers use in practice, even to cover the peaks. My AVR has 36,000µF (2 x 18,000µF) capacitance - loving that ALT 230 tip! :smashin:
 
Just had an idea for a test you could do when you get your Rotel up and running. Playback the same (loud and dynamic) movie scene with all your amps connected to the same 4-gang extension lead which in turn is connected to the wall socket via a energy plug/meter. The configuration which plays back the scene with the lowest maximum peak power consumption is probably making best use of capacitance to handle the peaks.

I ran my Yamaha RX-V3900 AVR for several months connected to an energy plug and (listening up to -10dB volume) the maximum peak wattage power draw I ever measured it pulling from the wall socket was 260W. Considering it draws 88W without any signal playing and Class A/B is only 50-70% energy efficient at best it shows just how little power AVR amplifiers use in practice, even to cover the peaks. My AVR has 36,000µF (2 x 18,000µF) capacitance - loving that ALT 230 tip! :smashin:

Good plan. I can extend on that too, re: how much power based on crossovers!

I have these "2NICE" wifi switchable 13A sockets (pack of 4) that we use on lamps in the lounge. Amazingly, the Gosund app they use (seems OTT to me), reports the instantaneous Voltage and Power, then records Power against time and you can look up kW/h etc.

So, when it's all set up (target August by the way), if I put them on the sub powers and then one on the AVR and power amp, I can see real time how they're sharing it. I realise there's the .1 channel as well but hey, if you had no sub then the speakers would be doing that too.

Of course, the subs have caps too!
Quakes: two times 4700:
1623924896051.png

And Storms: two times 10000:
1623925183929.png


This can't be definite as, I know that the Storms have been serviced, but they're still old and maybe they won't be happy plugged into one of them, we'll see. No buzzing allowed :)

Before service they were sensitive to even being close to one of them! But the Quakes (newer Q series) didn't care.

OMG, think we may have just made another interesting point by accident.

Denon mid range AVR 24000µF then 27 year old REL Storm (in each sub) 20000µF - think this shows that subs have a lot of peak power to cope with!

Wonder what all the "big boy" subs on AVF have in them? CAPS are probably bigger than the ultracapacitors you get on hybrid vehicles!
 

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Thanks again @Mr Wolf

Good point that the seperate amp will significantly increase the headroom for responding to peaks in the audio as I'll have a separate capacitance pool for LCR and surround.

From what I can find, the previous gen BasX amps had 40,000µF and the new models look to be a similar design with 4 smoothing caps so for the 3 channel version that should be reasonable to supply the LCR.

For the receiver, I think I'm going to hold off and see what launches over the next few months as we seem to be fast approaching the refresh window, in the interim pick up an amp. BasX A3 the favourite for now.

Now to read the thread you linked....
 
@Mr Wolf thought you'd come back to my post above knowing some subs with massive cap whoppers o_O
I actually have no idea as the specs aren’t published.

Due to the greater duration and loudness of deep-bass transient peaks I suspect that subs, compared to AVRs/amps, have to rely far more on their power supplies to meet the power demand than capacitors. Capacitors would surely have to be enormous to make an appreciable difference given that 10db louder peaks requires 10x the power!
 
@Mr Wolf when you say for example 100w is required based on a speakers efficiency (8ohms) is this calculated from a theoretical amplifier.

Ie. A speaker with a min. Of 4ohms on an amp with 100w@8ohms 150w@4ohms not work.

Or the same speaker min 4ohms on an amp 150w@8ohms 200w@4ohms work.
 
I'm sorry but I'm not really sure I understand the question but will try and address what I think is your concern.

My calculations assume speaker sensitivity ratings have been measured in accordance with industry norms which is the SPL generated at 1 metre when fed 2.83V which would produce 1 watt of power when fed into an 8-Ohm load. While in practice speaker impedance and sensitivity varies across the frequency range we use averages because it's simple and gives a general representation of what's going on.

If you wanted to, for a 4-Ohm rated speaker, you could perform all of these calculations on 2V / 4-Ohm basis, 1 Watt being produced when 2 volts are fed into a 4-Ohm load. In doing this you would of course need to de-rate the 2.83V speaker sensitivity rating by 3dB to ensure you're comparing apples with apples.

I think confusion arises when we think about speaker impedance and its relationship with power. The estimating tool shows that, all things being equal, there are three key variables in play that impact the power required - listening level, speaker distance and speaker sensitivity. Any change in these will impact voltage output required from an amplifier. A change in speaker impedance does not change the voltage output required from an amplifier but it does change the current (i.e. amps) required to maintain that voltage (Ohm's Law, V=IR) . Depending on its design (including PSU output, power reservoir capacitance) an amp may struggle to deliver the additional current required which is why we consider 4-Ohm speakers as being harder to drive than 8-Ohm ones.

This is explained really well in this recent Audioholics video when it is suggested that, due to this confusion, we should stop rating an amplifier's SPL output capability in Watts but instead use sustainable voltage at varying loads.




If there's a mismatch/inconsistency with my calculations, it's probably that I'm assessing SPL output capability by using a continuous (i.e. not a peak) power output rating to cover a peak power demand, a demand that in most cases lasts a tiny fraction of a second. This is very conservative, particularly when it also makes no allowance for amplifier power capacitance either.
 
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My question is which amplifier do I choose if you state I need 100w@8ohms?

If my speaker drops to 4 ohms min. Does this imply I need an amp that is 200w@4ohms or is 100w@8ohms enough?
 
Enough for what?

The amplifier you choose depends on your power requirement which in turn depends on the three variables I referred to above that form the basis of my calculator. Speaker impedance is not one of these and only becomes a factor at high SPL levels close your an amp's limits where it may struggle to deliver the current required to support a low impedance.

If your speakers have low impedance dips, you need to make a judgement as to whether you need to scale back the watts available in the calculator. For example, this is the (measured by Stereophile Magazine) impedance to frequency plot of my main speakers.

1624182362303.png

These speakers are 8-Ohm rated by B&W due to their average impedance but you'll see that their impedance level dips as low as 3.1 Ohms at about 15Khz and sits only just above 4 Ohms around two other points - 40Hz and 200Hz.

The only area of concern is the 200Hz one as 40Hz is handed off to a powered subwoofer and there's very little content/energy at 15Khz. Despite the impedance dips, I still use 8-Ohms for my power requirement calculations as my AVR has plenty of headroom at my listening levels so I'm not concerned about extra current required for the dip at 200Hz plus it's been independently tested as having a strong (245W) output into a 4-Ohm load (vs 150W into 8-Ohms).

Another manufacturer may have nominally rated these speakers at 4 or 6 Ohms but it wouldn't change the calculations at all.

Another reason not to be too concerned about low impedance dips is the difference in practice that it makes to system headroom. You'll see that my AVR is about 22% [ (2 x150W)/245W ] more energy efficient when driving 8-Ohm loads compared to 4-Ohm loads. This is due to reduced heat loss from a lower current flow. In practice, 22% more power only equates to about 0.9dB more headroom which is an almost imperceptible level. And as the model already factors in a 3dB headroom requirement across the board I really can't get excited about that 4-Ohm dip.

At the end of the day, if you want to be ultra-conservative calculate everything on a 4-Ohm basis using 2V sensitivity and 4-Ohm power output ratings, just don't expect the result to be appreciably different.
 
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While all these graph and number are interesting it's really like Van Gogh using using a painting by numbers set.

Fact of life are Denon make really good value for money AVs and I have purchased a few in the past and been perfectly happy with them for Movies. It's a different story with music and they why you will see the AV forum litter with question from Denon owner want to either get an all-one AV or get a separate Stereo amp for the job.

Now in a Denon you get something like one of these,
1624200896514.png


Note the need for a big label, While in say an Arcam you get one of these

1624201154916.png


And see there no need for a sticker on this bad boy. You can go all the way though and see better quality components used.

The bottom line is that the money has been spent on the hardware and it has to be said sometimes the software is lacking.

While Denon have made a good solid all round product that meets the needs of AV. It's not going sounds as good as a NAD or Arcam partially with Stereo, but that's the decision you have to make.
 
Very interesting pictures of "robots in disguise". However, surely this thread has been mostly about the need for external power amplification. So, I don't really see the link? Are you saying that the power supply quality has an effect on the pre-amplification quality? And we should all use Arcam for this?

Many of the power amplifiers people are using have nice big toroidal power supplies. My 5 channel power amp is considered weedy by many on here but it has a 1.5kVA one here:

1624258774609.png
 

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