I think one of the reason it is not taken care of is the bounce frequency is dependent of position: position of drivers in loudspeaker layout, position of listening spot ( distance AND height hence the reason i linked to SBIR calculator in previous post),...
Most of this are out of touch for the designer once the product hit the market. And even if it was ( or is) specified in manual or recommendation about positioning who take care of that in audiophile world?
When i see some audiophile's room pictures i sometime wonder if the point is not only to show off money rather than sound.
Like Plasnu i do think the room is 50% at least ( i'm more 75% to be honest: 50% is located below schroeder frequency, 25% come from early reflection) of final sound but i came to same conclusion as him. It doesn't interest people ( it doesn't show off as much as technical items).
And more it make the 'magic/ voodoo' disapear and goes hard technical reality instead.
Nothing that comes inline with the esoteric words used to describe 'the sensation' and 'the metaphysical experience' of audiophile market target.
That said many point stated by Kimosto seems true to me. We adapt to signal and may compensate it. That said once you are used to the effect it can be localised and pointed easily on known records.
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10/10
I think this thread is a good illustration of how a little knowledge is dangerous.
To answer the original question, it's because a narrow 2.5 db dip is not that noticeable with most commercial speakers in most rooms, and an enduring business is usually built on selling more than a few pieces at competitive price points.
Most customers will notice a sin of comission before they will notice a sin of omission, so a spike will be dealt with before a dip.
I doubt that all the measurement methods of the last several decades are part of a deep conspiracy.
Most customers will notice a sin of comission before they will notice a sin of omission, so a spike will be dealt with before a dip.
I doubt that all the measurement methods of the last several decades are part of a deep conspiracy.
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Thank you for such an excellent and informative response
This was what I really wanted to know, and kind of confirmed my suspicions that there had to be something I was missing as to why we have a design pattern that seemingly offers some advantages, but is not widely used.
Speaker positioning is primary tool for floor dip compensation. For example 50...55 cm from inner front edge of the speaker to front wall produces about double delay compared to floor reflection which partly compensates in steady state response and overall balance. Other walls and ceiling affect too and are available for this purpose (if front wall is not), but other sound features such as sound stage and overall balance could be more important than remaining floor dip.
Until we expend as much effort on our rooms as we do on the speaker boxes, I find it's hard to hear recording acoustics in terms of near field microphones or far field recording setups. Presumably, the room ratios affect sound as much as the speaker box dimensions, for instance. And damping might help.
I think it's generally agreed that a dip is far less offensive to the ear than a peak.
Nevertheless, the Allison effect ( A dip...) is one of those room-related problems that might be investigated.
Forum friend Joachim Gerhard built a speaker which bears a passing resemblance to an Allison IC20:
This is where he got to, with doubled mids and tweeters:
A listening test in what looks like a ghastly lively room:
The Quintessentially German Loudspeaker of the 70th. Modern Interpretation.
Joachim was quite pleased with his effort.
This is the old AR MST, another design with interesting ideas to get over the bafflestep issue and dispersion amongst other things. I'd say it's a wall mounter, though whether it sits on the floor or higher up is debateable..
I do truly think that we must just try stuff out. I like good ideas, and there are loads of them in these designs.
I think it's generally agreed that a dip is far less offensive to the ear than a peak.
Nevertheless, the Allison effect ( A dip...) is one of those room-related problems that might be investigated.
Forum friend Joachim Gerhard built a speaker which bears a passing resemblance to an Allison IC20:
This is where he got to, with doubled mids and tweeters:
A listening test in what looks like a ghastly lively room:
The Quintessentially German Loudspeaker of the 70th. Modern Interpretation.
Joachim was quite pleased with his effort.
This is the old AR MST, another design with interesting ideas to get over the bafflestep issue and dispersion amongst other things. I'd say it's a wall mounter, though whether it sits on the floor or higher up is debateable..
I do truly think that we must just try stuff out. I like good ideas, and there are loads of them in these designs.
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Gee Steve, I think it depends on the dip in question
When coupling is strong, consider that wall as a part of the speaker. Dispersion is half that of the mirrored pair, and always reference DI to full-space.
A listening test in what looks like a ghastly lively room:
Joachim was quite pleased with his effort.
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It must be difficult to find the best speaker for such a room and placement? Well I understand the personal interest, but the outcome cannot be generalized!
Causes problems if woofers are too close to floor because they couple with floor sideways. And if you position higher to avoid this, obviously you lose out on the floor gain a front firing woofer wd benefit from., so they need to be fairly sensitive and probably large, needing a big cab. Then you have to cross them under 300hz minimum, so your front midrange has to include baffle step compensation
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Sorry about the resurrection, but I can't let a Snell reference go without giving my 2 cents.
Peter Snell really addressed the issue with his Type A's. They've been my main loudspeaker since I found a pair on eBay 10-12 years ago.
