P3ESR and a small amp - bass capable?

[kraiker]

Fellow Audiophiles,

Would like to know on your impressions, finding and tweaks that you might have made to make this a golden combo!

I recently applied Bass Boost to 3dB and noticed that the Bass capabilities of the P3's were vastly improved. I for one have the P3ESR SE and the Leben CS300X.
Also feel free to post some pictures for us to drool over

{Moderator's comment: You mean, the bass output of the P3ESR (or indeed any speaker) has been increased. But the bass capabilities of the 5" 110mm woofer logically cannot have been have been increased, otherwise you would have broken the Laws of physics and generated free energy. Be careful: a 5" woofer cannot be expected to handle or reproduce a huge bass signal input.}

[GregD]

Fellow Audiophiles,

Would like to know on your impressions, finding and tweaks that you might have made to make this a golden combo!

I recently applied Bass Boost to 3dB and noticed that the Bass capabilities of the P3's were vastly improved. I for one have the P3ESR SE and the Leben CS300X.
Also feel free to post some pictures for us to drool over

{Moderator's comment: You mean, the bass output of the P3ESR (or indeed any speaker) has been increased. But the bass capabilities of the 5" 110mm woofer logically cannot have been have been increased, otherwise you would have broken the Laws of physics and generated free energy. Be careful: a 5" woofer cannot be expected to handle or reproduce a huge bass signal input.}

In addition to the Mod's comment and speaking as a past owner of the CS300xs, I would add that the Leben CS300x is only about 12Wpc. With the P3ESR's small woofer and lowish sensitivity and the Leben's low power output, I would question whether using a bass-boost control is really a good idea. But you're obviously enjoying the results so who are we to disagree!

[kraiker]

In addition to the Mod's comment and speaking as a past owner of the CS300xs, I would add that the Leben CS300x is only about 12Wpc. With the P3ESR's small woofer and lowish sensitivity and the Leben's low power output, I would question whether using a bass-boost control is really a good idea. But you're obviously enjoying the results so who are we to disagree!

The CS300X is 15wpc and not 12. You are scarring me now with the bad idea thing, can you please explain ?

[kraiker]

Fellow Audiophiles,

Would like to know on your impressions, finding and tweaks that you might have made to make this a golden combo!

I recently applied Bass Boost to 3dB and noticed that the Bass capabilities of the P3's were vastly improved. I for one have the P3ESR SE and the Leben CS300X.
Also feel free to post some pictures for us to drool over

{Moderator's comment: You mean, the bass output of the P3ESR (or indeed any speaker) has been increased. But the bass capabilities of the 5" 110mm woofer logically cannot have been have been increased, otherwise you would have broken the Laws of physics and generated free energy. Be careful: a 5" woofer cannot be expected to handle or reproduce a huge bass signal input.}

You reckon I have damaged the cone ?
How can I tell, also didn't know the P3ESR would be that sensitive to a little bump in bass.

Thought it would be a little more durable ?

Anyway the volume was on 10 0'clock

[A.S.]

The CS300X is 15wpc and not 12. You are scarring me now with the bad idea thing, can you please explain ?

OK, let's step back and look at this logically.

Have a look at the picture (attached) of a full orchestra. Imagine for a moment that the conductor allowed us to walk onto the platform and set-up a pair of mini-monitors (like the P3ESR) on stands and connect them to an audio system and then to play back a recording of the performance that we'd just made - and (hopefully) impress the musicians with the fidelity of our audio system. What would be the outcome?

Logically, we can expect this:

... that the reproduced sound would be tiny compared to the live sound. So tiny that the musicians seated around our speakers would be straining (and chortling) at our efforts to reproduce their huge dynamic range. Our sound would seem very small indeed compared to the live sound. There are several reasons for this -

• The amplifier has far too little power (12-15W) when we would need perhaps 1000W (guess)
• The speakers are inefficient (as all speakers are)
• There are only two speakers trying to reproduce the entire orchestra of 60+ sound sources
• The orchestra produces sound across the whole stage (10m x 5m?) - the speakers produce sound from two tiny boxes

So how can the listener be fooled into believing that, sitting at home, his tiny speakers and amplifier in a small room can faithfully recreate the hall sound when self-evidently it's impossible to generate enough acoustic power in the listening room? Obviously there is some mental trickery going on here - willing self-delusion - in the same way that we look at a widescreen TV and allow ourselves to believe that we are actually in the jungle or up a mountain.

What brings the sonic illusion to an abrupt end? The reality check is that this illusion of an orchestra in all its glory in front of us only works at a low replay level within the capability of the speakers. Look at the surface area of all the instruments of the orchestra (it must be many m2) and then consider that the P3 woofer has a surface area of about 1/3 of a sheet of A4 paper and you'll appreciate that it must be working really hard, moving backwards and forwards pumping air, to even vaguely create the illusion of the big, full sound of the real instruments.

Adequate bass realism at a moderate loudness is allowed for in the design of the woofer. But what isn't is intentionally electrically boosting the contribution from the bass-heavy instruments (turning-up the bass control on the amp) so that the small drive unit is being asked to work excessively hard. That will run the risk of bottoming the voice coil deep in the magnet (destroys the woofer) and/or over cooking the voice coil and/or much increased low frequency distortion and muddy mid band.

Hope that helps.

[kraiker]

Alan,

I think I understand what you are implying with the orchestra example, but my question still stands.

All I did was applied the Bass Boost to increase the bass by 3 dB and played some music at enjoyable levels, I mean if this switch was so destructive Mr Hyodo would have put a big warning sign in their amp manual.

And to think of it, Leben actually recommended the P3ESR's to me, surely they would warn me of accidentally blowing my cone ?

[A.S.]

Alan,

I think I understand what you are implying with the orchestra example, but my question still stands.

All I did was applied the Bass Boost to increase the bass by 3 dB and played some music at enjoyable levels, I mean if this switch was so destructive Mr Hyodo would have put a big warning sign in their amp manual.

And to think of it, Leben actually recommended the P3ESR's to me, surely they would warn me of accidentally blowing my cone ?

The reason we have to become actively involved in posts like this is to prevent users following advice that is surely going to cause them expensive non-warranty incident.

To imply that +3dB low frequency boost is just 'a little bump in the bass' (your post #4) is a complete misunderstanding of the physics of trying to produce low frequency sound using a drive unit 1/3 of the size of a sheet of paper. In fact, +3dB makes a huge increase in demand on the forward/backward motion of the cone at low frequencies - any cone, any size. Yes, there will be (some) increase in bass as you have heard but what's the catch? There cannot be energy for free so yes, more bass output but what then? The catch is that if there is a bass note which is just a little too big when electrically given the +3dB treatment at just the wrong frequency (as far as the woofer is concerned) the voice coil will be thrown right out of the magnet. That's bad. But worse, because the woofer cone is on a spring suspension, the spring effect will yank it back and it will crash into the magnet. End of woofer. Can you reliably predict in advance which note on which musical track will do this at a certain volume setting? No. Even if you heard the oncoming note, you just couldn't leap from your chair fast enough to drop the volume.

As for an amplifier manufacturer adding any sort of equalisation or boost controls, caveat emptor. When the damage is done, please remember that neither we nor the amp maker (nor your dealer) forced you to turn up the volume or turn on the EQ (a dangerous combination).

The line between great fidelity and the realities of the Laws of physics are most carefully optimised in a small woofer. I'm reminded that the power handling spec. for the B110 5" unit as used in the similarly sized, similar concept LS3/5a is about 5W. Yes, five watts. It's a miracle that we can reproduce good bass from such small boxes with such minuscule power handling capabilities. We can, but only when the woofers are not driven beyond their linear range.

I stress: you have not as you said in post #4 'vastly improved the bass capabilities of the P3's'. That simply cannot be done. Conversely, the boost you have applied has actually decreased the driver's capabilities although it may well have subjectively increased bass loudness. Power handling will have been much degraded. If you like this boosted bass sound (and you may well do) then please turn the overall volume down by at least 3dB to compensate for the bass lift.

This bass boost idea used to be called the loudness correction or contour and was designed for late night, quiet listening which put no stress on the woofer. I wonder if, in the amplifier manual it says that is the intended use to which this +3dB boost control should be put?

[STHLS5]

I think if you are implying that P3ES2 is bass shy and need an artificial boost then you may not have placed them correctly. For such a little speaker the bass is more than adequate.*

However, if you play your system moderately and you need an additional 3 dB bass I think it is still safe. Most amplifiers with tone and bass control give you a plus minus 6dB. Surely, that is within the safe workings of speakers played at moderate level. Unless you are already driving the speakers at breaking point. Otherwise, I have to rethink of replacing my vintage Classe Model 25 with a tone and bass control equipped Marantz amplifier.

Alan, I understand your message but what damage can a maximum peak of 75db when increased to 78dB cause?*

ST

{Moderator's comment: the woofer will have to move twice as far in and out. Reasonable?}

[EricW]

I'm reminded of the (intentionally) awkward acronym coined by science fiction writer Robert A. Heinlein: TANSTAAFL, or "there ain't no such thing as a free lunch". Everything costs something.

In this case, you increase relative bass output at the cost of either (1) decreased overall loudness capability, or (2) risk of damage. You pays your money, you takes your choice. Or you buys a bigger speaker.

{Moderator's comment: (3) more distortion.}

[STHLS5]

From previous posting
==================

c)...... One of the greatest mysteries and acts of insanity in the audio business was the deletion of tone controls from hifi amplifiers from about the 1980s with some utterly discreditable mumbo jumbo that 'tone controls are no part of a hifi system'. I can categorically assure you that a properly designed and executed tone control circuit does not degrade the signal quality and never has done; this is extremely easy to prove under blind listening conditions*. Tone controls were deleted from hifi amps as a marketing gimmick to attract a new 'minimalist' consumer away from amps laden with buttons and controls.

Perhaps the greatest intellect in amplifier design was the late Peter Walker of QUAD. Key point: he was an expert on both amplifiers and loudspeakers, and designed for real rooms. He knew from measurement and listening how real rooms corrupted even the most carefully designed speaker response at low frequencies and obviously, putting high fidelity first, made sure that his amplifiers always gave the user the ability to tune the speaker to the room - via the tone or tilt control. How many amplifier designers know anything about speakers? How many actually measure speakers in real domestic rooms? How many are obsessed with chasing ludicrously (and needlessly) low noise and distortion figures to 0.0000% when the room corrupts the low frequencies by 50-500%?*

As I live in the real world and know only too well from measurement how all rooms disturb my designed nice smooth low frequency response, I can say that personally, the only amplifier I would myself be really happy to use in my untreated room at home would be fitted with a bypassable tone (or better, tilt) control. Those controls would, in practice, give me a sporting chance that I could make any speaker work in just about any room. They'd save me the inconvenience and cost of treating the room. They are 100% wife friendly. However, handicapped by the fact that 'audiophiles' consider tone control to be anathema, I have to listen during the design stage with bypassed tone controls to represent what most users experience.

*....... In short: if your amp has a tone control you are more likely to get the best overall fidelity because you can tune the speaker/room interface to suit you. Tone controls empower you not some marketeer who has decided on your behalf that tone controls are evil.

Attached two adverts from 1956 for amplifiers featuring tone controls. The physics of real speakers in real rooms have not changed in fifty years so why have tone controls been deleted from all but a few domestic hifi amplifiers? What is the engineering logic behind that? This has always seemed to me the act of the greatest illogicality in our industry.

>

This is a very difficult post because I just couldn't put across my message without triggering the mod censorship but I just can't ignore the obvious oversight.

OK, now we have two contradicting posts here. Unless, you meant the use of tone control is to reduce bass and increase treble I am alarmed with your caution about the bass boost of 3 dB of Leben. I am just beginning to shed the audiophile minimalist thinking and move to one box solution, i.e. an integrated Amp equipped with tone control until this post appeared.

Interestingly, the Leak and RCA in the advertisements give you an overall bass boast of 12 dB at 40Hz and 50Hz respectively which in my opinion may cause more damage than the modern amp where the bass boost is usually around 80Hz which is within most speakers flat FR.

ST

[kraiker]

Agree with more distortion, did notice that!

Hopefully nothing is damaged, fingers crossed.

[A.S.]

OK, now we have two contradicting posts here. Unless, you meant the use of tone control is to reduce bass and increase treble I am alarmed with your caution about the bass boast of 3 dB of Leben. I am just beginning to shed the audiophile minimalist thinking and move to one box solution, i.e. an integrated Amp equipped with tone control until this post appeared....ST

It never crossed my tiny mind that my comments above would be imply a need for and tool to boost bass in the listening room. Quite the opposite. What's universally needed for normal daytime use is bass cut in many environments.

We all know that *all* normal domestic rooms boost loudspeaker bass output by many decibels, and boost low frequencies in a sometimes very irritatingly uneven way such that individual notes, when exciting the rooms natural acoustics, cause the LF note to 'hang-on' or boom. That's true in every normal, lightly damped domestic room I've listened in. The use of tone controls - and in particular the QUAD-like tilt control - is designed primarily to compensate for the room characteristics by the use of gradual shelf filters. Conversely the Baxendall-type conventional tone controls do not apply a shelf-eq: they have fixed peak frequencies, with a variable amount of boost/cut at those frequencies. If there is a coincidence between the tone control bass peaking frequency and the maximum excursion capability of a speaker - and there will be - just a little bass boost and as I mentioned, the poor speaker is working extremely hard at that frequency.

You mention the boost of 12dB etc. from the 1956 advert. Have you considered the physical size of speakers at that time, long before the mini-speaker was invented? Not only were they huge cabinets, they had typically 12-15" woofers and tight, low compliance suspensions (no rubber surrounds then, only corrugated paper) that could more easily tolerate some bass boost. Today's mini-monitor with a soft, highly compliant surround is a totally different animal.

If you want to have a look at the design of bass tone controls consider this:

As typically implemented, (unlike the QUAD tilt control) the conventional hifi bass boost (or cut) never flattens out but continues to increase (or decrease) as frequency falls as shown in the last coloured graphs here where you can see that as implemented the bass boost red-curve is providing more and more bass signal to the speakers right down to sub-audio frequencies. Sensible for a small speaker? Absolutely not. Small speakers cannot be expected to produce 16 foot organ notes as this amount of boost implies.

Contrast the conventional tone control with the ingenious QUAD tilt control here where the boost positively shelves and does not continue to low frequencies straining the speaker.

Excellent article on the flexible QUAD 34 tone controls here from which I attach a picture of the measurement of the tilt control which shows the broad band bass tilt action which unlike the conventional tone control does not continue to increase/decrease down to ridiculously low frequencies. As I've said before, what Peter Walker didn't know about the speaker/room interface isn't worth knowing.

>

[STHLS5]

Thank you for the explanation.

Now, I understand why some users' speakers always suffer from burnt voice coil every few years.

In view of the danger of bass boost, what's your view on room correction softwares? Could there be hidden dangers of bass boost when we use such system? My understanding of electronic EQ is to use it to attenuate and never to boost any frequency. But a DSP may not work similarly.

ST

[A.S.]

In view of the danger of bass boast, what's your view on room correction softwares? Could there be hidden dangers of bass boost when we use such system? My understanding of electronic EQ is to use it to attenuate and never to boost any frequency. But a DSP may not work similarly.ST

Interesting question.

The point that I hope is now firmly accepted is that it is completely and utterly impossible for two 110, 200 or 300mm bass units to generate the sound of an orchestra at home. The only reason that home hi-fi works as well as it does is because it deceives the listener much of the time with an illusion that is just convincing enough that we're carried along with the experience. It's the same as being in the cinema: for the first few minutes we notice how soft and grainy the picture is, how colored the sound, how uncomfortable the seat .... but once our mind is absorbed with the whole experience, we lose the ability to be critical. We accept unquestioningly the nasty reality of the soft-focus grainy picture with its tiny optical dynamic range as faithful to life and are carried along with it. Also, how many audiophiles actually experience live musical sound to have a valid means of comparion? And as we observed with one recent A/B musical comparison here, only 10% of contributors recognised the original sound. 90% preferred a compressed 'soft-grained' defocussed, analogue version of digital reality.

As far as I know, no attempt is made (or should be made) by a room correction system to boost weak notes in the bass. The fact that there are some or a series of musical notes which are a little or a lot less audible than adjacent notes when the loudspeaker is producing them as soundwaves of equal pressure indicates one thing: some sort of cancellation is occurring in the room. If you play the musical scale and certain notes are completely inaudible, this has something to do with the dimensions of the room, not the speakers. And the key point is this: if the notes are inadible because of the cancellation of soundwaves opposing each other, no matter how much sound power the speakers generate there will always be cancellation. So if bass notes are missing due to cancellation, EQ cannot ever fill them in, but it can tame those frequencies where there is an excess of bass by applying less power. That's my understanding.

[Takis]

Interesting question.

... The only reason that home hi-fi works as well as it does is because it deceives the listener much of the time with an illusion that is just convincing enough that we're carried along with the experience. It's the same as being in the cinema: for the first few minutes we notice how soft and grainy the picture is, how colored the sound, how uncomfortable the seat .... but once our mind is absorbed with the whole experience, we lose the ability to be critical. We accept unquestioningly the nasty reality of the soft-focus grainy picture with its tiny optical dynamic range as faithful to life and are carried along with it....

Excellent!
This is the "break-in period" for every hi-fi component, that so many audiophiles believe...

Brain adjustment...

[A.S.]

Excellent! This is the "break-in period" for every hi-fi component, that so many audiophiles believe...

Brain adjustment...

100% correct. There is no real physical or electrical 'burn-in' (aside from a few hours of softening of the speakers suspension). What's called 'burn-in' in audiophile circles is entirely a mental issue of becoming acclimatised to a new experience. Of that I am absolutely and utterly certain.

Failure to accept this as fact demonstrates a basic lack of awareness of how the human mind works in all areas of observational experience, from engineering to love.

[STHLS5]

.... but once our mind is absorbed with the whole experience, we lose the ability to be critical. ...

Yes, you said it well. Once we are absorbed with the music we are not only non-critical but also shouldn't be critical. It defeats the purpose of listening to music.*

*Also, how many audiophiles actually experience live musical sound to have a valid means of comparion?*

That's what I have been telling. We (some of us like myself) just do not know what a live unamplified sounds like in a proper venue. We do not know how a real high quality violin, piano or a woodwind is suppose to sound. If I am a musician and my sound reaches 90% of the listeners would I want change my music to be technically correct so that I meet the standard which is only recognizable by 10% of the listeners?

Some used to say the guitar sound in my room is like coming from nylon strings. i know they are referring to reverbs so I covered about 30 percent of the absorber in my room with aluminum sheets. The results was a "real" guitar sound even though it is colored with reverbs and I do not like the vocals due to the high reverbs but to others it was perfect.

Honestly, despite being pointed out to me about the *reduced reverbs in the clips I still cannot hear the difference. Is it because the music played in a venue that I have no prior reference. *Can a westerner tell if a veenai or a sarod or a gamelan's sound is correct or you could readily hear the trailing reverbs? But we live in a world where Louis Armstrong's voice is gift from god despite normal humans never sound like that.

Just my random thoughts .

ST

p.s. I have no idea why the asterisk appears in my posts. Must be something to do with my IPad.

[A.S.]

I suggest that we move this topic to another separate thread as we are some way from the original theme of this one.

I've duplicated the last few posts so we can pick-up again with ease.

Discussion continues here ....

[DSRANCE]

I'm wondering if the Leben amp isn't "soft clipping" the bass signal in the manner of old valve compressors such as the Fairchild (I think it was).

Use of this latter when mastering old singles was to give music more "punch" but without sounding obviously "squashed." I've used re-built Quad II power amps with P3ESR's and although the sound was lovely, it's not as purposeful or "strong" as it is with a more powerful amp of high quality.

The "clipping performance" of many low powered valve amps is what makes them usable at all these days I think.

[kraiker]

I'm wondering if the Leben amp isn't "soft clipping" the bass signal in the manner of old valve compressors such as the Fairchild (I think it was).

Use of this latter when mastering old singles was to give music more "punch" but without sounding obviously "squashed." I've used re-built Quad II power amps with P3ESR's and although the sound was lovely, it's not as purposeful or "strong" as it is with a more powerful amp of high quality.

The "clipping performance" of many low powered valve amps is what makes them usable at all these days I think.

Don't know mate on the soft clipping issue, but listened to the same Cold Play tracks yesterday without the Bass Boost but the music did sound distorted, I'm thinking its the recording because my usual audiophile stuff sounded just fine!

Anyway bass or no bass , I will stay away from the Bass switch for now !