What really causes boomy, slow and ill-defined bass?

Sorry I can't be more constructive at this time - (feeling a bit too pished!)

Steve B

Time another drink!

Steve B

enjoy

ken

2. Thank you Richard and Simon.

3. Stallion: I've always had standmounts: Mission 700s, Kans, AE1s, B&W N805s. I'm not certain I prefer them but I'm going to stick with them.

4. The room and speaker placement and rigidity:

It was partly to contain the thread and partly for sellfish reasons that I did not want to discuss these influences here. I've done all I feasibly and financially can.

I have 2 layers of RPG acoustic foam behind the speakers and 2 layers covering side reflection areas. Behind my listening position I have 6 RPG 'Skyline' diffusers. The rear room corners contain rolls of foam or a mountain of cardboard boxes.

The speakers are at least 2 metres from any wall and are on rigid and excellent granite stands, no wobble. Concrete floor.

5. The equipment and interconnects - additional to profile.

Chord Cobra 2 CD interconnect. Better than Naim's own. I'm very soon to experiment with Linn Silver. Speaker cable - Cabletalk 4.1 - works better in my system than Naca5, honest.

Other equipment comments: I was biamping using 2 250s but the gains were minimal so I'm now back to one. The 32.5 I now use is no worse at reproducing bass than the 82 I had; rather, although it may be a touch worse, it produces less which negates any ill-effects. I have heard the N805s with a 52 at Grahams and they sounded dreadful.

N805s
Laughed at by all flat earthers but they image superbly and have an excellent midrange, an adequate but disappointing treble given the amount of R&D in the Nautilus tweeter, and a bass which I am trying to determine here.

I think it perhaps over-simplistic to just blame the speakers.

NAP 250
Outside this forum there are many who think this is the problem.

6. What to do - my options given budget and inclinations.

Instinct tells me not to invest in a big sub but I may be wrong.

I don't want to go back to Kans or my AE1s - I want fast and tuneful bass, not tiny, fast and tuneful bass. Also, I want to keep the excellent midrange.

Change the power amp? If so to what?

Change the speakers to something like Dynaudio Contour 1.1s (auditioning Thursday) or, for more money try new Wilson Benesch Arcs (Thursday).

Next I will audition the Dynaudio Crafft and the Sonus Faber Electa Amator 2 hoping that one of these will work if nothing cheaper has.

£2500 is the upper limit of what I want to spend (including money from flogging 805s or 250).

Thanks in advance for any further help.

Alex

My sources are listed on the profile. I am fearful of any bragathonic complaints, but in case you can't be bothered to press the profile button they are: CDS2/CDPS and LP12/Ittok/Troika/Lingo/Linto

Regards,

Alex.

Steve (ex Sara owner)

quote:

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Originally posted by Alex S.:
Chord Cobra 2 CD interconnect. Better than Naim's own.

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I vaguely remember this being mentioned previously, but I suspect this might have had something to do with you dumping the 82.

I strayed from the fold for CD interconnect with my CD2, a Cable Talk was a lot better. Warmer, less harsh, more open.

With CDX & CDS-II the newer Naim offering is dramatically better. The bass was one of the biggest benefits. Even playing test tones through a REL subwoofer were dramatically tighter! (We were investigating room problems, BTW).

I have heard a Chord i/c in a mid-level SBL based system and, IIRC, it made the bass both thinner and much less controlled / well defined.

The tonal differences can be so large that you may have setup your system to compensate, thus the Naim would not immediately strike you as better.

JV sometimes commented that Naim was a 'system'. If you preferred replacing one component with Brand 'X' this was a sign of a problem elsewhere.

As for your original question - I have struggled with this problem with my Isobariks (and Kans!) for a few years now.

What helped (in no particular order)?

Source first on CD. Better defined but still tonal problems.

Latest service of LP12 has helped, including fittment of Cirkus. Much tighter all round.

Elimination of ground loop from LP12/CD. Cleaner sound, really frees up the bass.

Service of all kit (2 years ago). Gains all round - good value.

Recent recap of 52PS & CDPS. Surprisingly large improvement (BFG). 52PS was serviced as above, but only item not recapped at that time (?)

Moving off Mana (CDS or LP12).

Use of Naim interconnects. Much tighter & more tuneful.

Re-terminate existing A5 speaker cable with Naim plugs. MUCH tighter - who could have guessed?

Well specified mains spur with additional earth rod. As large a jump as from bare CDX to CDS-II. Big!

Damping the room - covering end wall opposite the speakers with bookshelves (filled with books). Not as large a benefit in the bass as elsewhere.

Replacing tweeters in Isobariks - treble quality is surprisingly important in the reproduction of bass.

Ultimately, the prime factor in good bass is a good source and amps. Small speakers will give surprising good and deep bass with good driving. Big speakers with lesser electronics will usually dissapoint.

cheers, Martin

P.S. for anyone reading this and wondering at a whole list of superlatives - you would understand this if you'd heard just how bad my system had become five years ago. It's been a real struggle, and I've been disheartened many times. I even stopped buying music for a long time.

Someone recently described my system as 'in fine fettle' - I was chuffed. Just a few tonal issues to sort out, now.

quote:

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Originally posted by Alex S.:
...Lingo...

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Alex,

have you done the Weekes tweak to your Lingo?

I found that the Armageddon really tightened the sound up considerably, but it was pretty much my only source at the time, so can't say whether it had a huge negative impact on CD replay (an Arcam at the time).

I have heard dramatic differences in other systems, although at the most recent demo the difference was negligible.

cheers, Martin

I do understand that your chosen room is an entirely different environment to what most of us here probably have. Do you by any chanace have a concrete ceiling? These are usually reinforced, and ring like crazy, effectively becoming a massive ABR.

I'd be very surprised if anything other than the room or the speakers turned out to be the culprit, and in your place I would try to dem non-ported speakers. If these are successful at fixing the bass problem, albeit at the expense of a shortfall in other areas, at least you've pinned it down. Or you could just take a shot in the dark, and get Graham's to lend you some Allaes...

Best;

Mark

(an imperfect
forum environment is
better than none)

2. The Cobra is about to go and be replaced by Linn Silver? This has been reccommended by someone who has a high stake in Naim gear and every chance to compare various interconnect offerings. Diplomacy prevents me from saying who it is.

3. Concrete floor, brick wall except one (concrete), plasterboard ceiling then who knows what.

4. "have you done the Weekes tweak to your Lingo?" No. But Andy Weekes has!

5. The vexed question of Mana. I have done enough recent experiments to pursuade myself that 3 levels of Mana works a treat under my LP12 and does not work anywhere else in the system.

6. Allaes. I was impressed at the show. How much of this was CDS2/52/500? Wall placed speakers would be inconvenient but I'll do anything if it works.

7. CDM1s. If these are the small things like the N805s but half the price then they're not in the same league although I admit that they are in the same family.

8. B&W in general. Presuming for a moment that I can live with N805s, I am almost certain that I could not live with any other B&W speaker, for a variety of reasons.

9. Bored Yet?

Alex

quote:

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Originally posted by Alex S.:
1. I have an old Naim interconnect. The Cobra is better than that.

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Alex,

have you tried a new-style one (so-called Lavender)?

cheers, Martin

Unfortunately you can't rule-out room problems as they have as much influence (and maybe more) than the difference between competent speakers. Here is what to do to minimise bass re-enforcement from the room:

Measure the distance across the room (L-R) and place each speaker 1/3rd of the way in from the sidewalls. Assuming you are using speakers in free-space, measure the length of the room from front to back, place the speakers 1/3rd of the way into the room from the speaker wall. The speakers are now at the minimum points of bass re-enforcement. Just doing this is probably enough to cure your problem.

If you want to place the speakers at the points of maximum re-enforcement (in free space), do the same thing again but put the speakers at 1/4 points (ie 1/4 way in from the side walls and a 1/4 way in from the speaker wall).

The difference between minimum and maximum is LARGE, probably larger than changing to different speakers placed identically to where you have your speakers now.

One other thing, the difference between 1/3 and a 1/4 for a typical 16ft dimension is only about 1ft so positioning is CRITICAL. For rooms with non-parallel walls or an irregular shape, minimum points will have to be derived by experimentation around the theoretical values.

Allan

One word of advise, where they have been turned (Presumable ona lathe) the bottom of the bass bit can have a very slight point dead in the middle, on glass these can cause rattling and should be filed off.

quote:

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Peter Chappell:
I think the electronics/stand/floor & airborne vibes/speaker/room are all one "interacting system".

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I think that's one of the most sensible and logical statements ever to appear on this subject; a point which we are often far too engrossed in the details to remember.

As a given system is upgraded, the level of information retrieval is increased, so more data is fed into the "interaction". This gives the "interactive system" more raw material to work with, and consequently more to bugger up by the time it reaches one's brain.

To me, the one intractable piece of wisdom to come out of this, and other threads is:

Money spent upgrading a source component is never wasted, even though you may not get all the potential benefits straight away.

Best;

Mark

(an imperfect
forum environment is
better than none)

Are the bass issues common to both sources? I recently upgraded my Ittok to Ekos which certainly made the bass tighter and more controlled. Secondly, I am surprised that bi-amping with two 250's made little difference but I do not know the 805 - they may relatively easy to drive. I drive a couple of 804's with two 250's with spectacular results. I experienced issues with the bass (bass light and spongey) and the second amp brought all this back into line. There are some on this forum that are not fans of the 804. Doesn't have enough speed, too light in the bass, etc. I find them very exciting and have the attack that I need. Maybe a new pair of speakers is what you need - try the 804's.

Regards,

Nigel

I ended up with Dynaudio Contour 1.8s, which I think are a great compromise, but they need a lot of space behind them to perform at their best.

If you otherwise like the N805s, I also liked the N804s, which sounded to me just like an N805 but with more bass power and definition, but I didn't think they were 700 quid better than the Dynaudios.

Trevor

Stallion: Do the Nordost Pulsar thingies bugger up the base plate of the speakers. I've been blue tacked up to now and it seems a shame to damage the speakers if I'm just about to try and sell them. Anyway, wanna swap some for my CD3 transit bolt - that's about all that's left unless you're into photography.

Interconnect and cable advice: I will ensure that Naim's is compared to Linn's at the appropriate time. I have tried to re-introduce Naca5 three times and each time its failed to deliver in my system compared to CT4.1 (which is remarkably similar in any case).

Speaker stands: I use hne Cableway granite stands (empty, I've tried various degrees of filling). These are superb stands and work particularly well with the 805s which were apparently developed on granite stands. (B&W's own 805 stand is over-priced rubbish by comparison).

Everything is level and tight.

The CD is worse than the TT but I think this more of a software problem.

Biamping: Nigel, I don't want to sound a troll but I needed 2 250s to keep the 82 under control but one sounds better with the 32.5 (a little disjointed with 2). I have heard 135s at a dealers but not here; certainly a possible avenue.
One problem is the 805s are so obviously designed for bi-amping or bi-wiring whilst Naim isn't.

Thanks to all your advice and the little adjustments I have made things do sound better, certainly liveable with, but I guess I'm striving for perfection. I listen or half-listen to this stuff about 10 hours a day.

Cheers

Alex

Bringing the room question into the argument, I've just started using Elac's CARA speaker placement software. You can get it here :

Cara's webpage

It was well apreciated by Kalman Rubinson from stereophile, and whilst I can't yet vouch for it, it's offereing speaker and listening positions that I wouldn't have thought of. I'm using it to determine where to start placement in my new room.

Peter

Apart from perhaps venturing into Isobarik territory, I've decided to limit myself to stand-mounters (for the time being anyway). Did you happen to listen to Dynaudio 1.1 or 1.3s during your tests?

Peter

Not sure I want to pay 70-odd DM. Also, my foam is now glued and very difficult to remove so I have to fiddle about within certain boundaries. Thanks anyway.

Alex

quote:

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I have heard 135s at a dealers but not here; certainly a possible avenue.
One problem is the 805s are so obviously designed for bi-amping or bi-wiring whilst Naim isn't.

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Having just made the jump from a 250 to 2*135, I can assure you that bass control and tunefulness is improved markedly. I was really surprised at the jump in performance.

I've still got my 250 here. Just for fun, maybe I'll try hooking up the 250 to the bass drivers with the 135s on the tweeters. We'll see what this bi-amping thing does in the context of my system.

Regarding those two sets of binding posts on the back of your speakers, my Albions have them as well. Just because you have them doesn't mean you need to use them.

-=> Mike Hanson <=-

quote:

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Originally posted by Alex S.:

Stallion: Do the Nordost Pulsar thingies bugger up the base plate of the speakers. I've been blue tacked up to now and it seems a shame to damage the speakers if I'm just about to try and sell them.

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Alex,

I would really suggest you try out spikes (or cones if necessary) under your speakers.

Does anyone really mind about spike marks underneath a speaker?

As an alternative, could you borrow some spiked stands from your dealer?

quote:

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Biamping: Nigel, I don't want to sound a troll but I needed 2 250s to keep the 82 under control but one sounds better with the 32.5 (a little disjointed with 2).

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I'm not quite sure what to make of this point.

I have heard the 82 sound disjointed/lumpy but this was due to setup issues.

I have also heard 4x135s sound disjointed with my 52.

I both cases, I suspect that the additional drive has extended the response of the system down to frequencies where either the source is exposed (32) or your room problems are exacerbated (82 example above).

In general, it would seem that firing speakers across the room excites the deep frequencies less badly.

I was also surprised how much effect the stand for the CDS-II has on it's bass balance. I really would be tempted to try placing your whole system on one particular brand of wooden racking. In my limited experience wood seems to avoid emphasising deep base problems, whilst the Sound Orgs are particularly bad for this.

They don't need to be anything fancy - see if you can try out some cheep-and-nasty wooden (chipboard?) shelving (maybe fom Argos - they have a 16 day money back guarantee). If necessary, the shelves can be widened by the use of ball-nutters and MDF boards. I've heard good results in a DBL system with this arrangement.

You would want to re-try all-Naim cabling at the same time, if possible.

cheers, Martin

quote:

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Originally posted by Alex S.:
Peter

Not sure I want to pay 70-odd DM. Also, my foam is now glued and very difficult to remove so I have to fiddle about within certain boundaries. Thanks anyway.

Alex

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The software is also labour intensive, you have to construct an acoustic model of your listening room including all the acoustically signficant elements. You wouldn't necessarily have to tear down your accoustic foam, you can model their effects. You have to consistently fine tune the listening position. For example, it you set up the model for your current position, the software will most likely move the speakers and the listening position, but it wont move your chair. So when you line the chair up with your ears, in the computer model, then you've changed the acoustic property of your room. 70Dm is about +/- 25GBp half the price of pulsar points and many other low price accessories

Peter

[This message was edited by Peter Stockwell on MONDAY 24 September 2001 at 14:35.]

The bit about 1/3 way into the room being minimum reinforming and 1/4 way into the room being maximum reinforcing is interesting. Do you have a reference or a link for this? I like this kinda stuff but don't want to add it to my bag of tricks without a reference.

Also...for those of us who place are speakers nearer the back wall, are there other ratios that accentuate or decentuate bass? A 1/3-way into my room, with my sideways setup, would put the speakers on the coffee table!

- GregB

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