So I’ve made a fundamental mistake with the a pillars… the passenger side infact, I can work around it
so a big issue, if I play 2-2.5khz from the left tweeter only I can hear it coming from more or less directly in front of me… how is that you ask… andy wehmeyer says you fit speakers wide and the stage will sound wider… not always…
so it’s physics… inadvertantly I have placed the tweeter an equal distance from the side window first reflection and the screen first reflection… which then effectively cancels the direct sound coming at my ears
effectively both reflections come towards my ears and combine 180 degrees out of phase at my listening position… but at the drivers side window there is no cancellation, so when that bounces back I hear it… this then makes my brain think that the 2-2.5k band of sound is coming from somewhere infront of me as it can only work by what it hears in both ears and it picks up more in my right ear so the sound pulls towards the right, clever huh…
the solution in my case is move the tweeter a little closer to the screen (or adjust the crossover to 2.6khz as I have done currently) and make the pillars a symmetrical or use a reflector on the outside of the left tweeter pod to artificially move the first reflection closer to the tweeter and therefore that particular comb filter higher… mathematically you would want the driver double the distance from one reflection to the other, this way constructive and destructive freqs will cancel each other out a treat!
it’s why you can listen to a speaker and have the sound smear across the dash
hopefully this will help someone reading in future who wonders why a driver doesn’t sound like it is where it is at certain frequencys
you wont see this comb filter on an rta unless you put the mic in the spot your ear occupies, and even then you can’t eq it or do anything about it (install IS everything!), a moving average will make it disappear… but an rta is stupid and measures what it hears, the human brain is a very clever evolution!
So I’ve made a fundamental mistake with the a pillars… the passenger side infact, I can work around it
so a big issue, if I play 2-2.5khz from the left tweeter only I can hear it coming from more or less directly in front of me… how is that you ask… certain guides says you fit speakers wide and the stage will sound wider… not always…
so it’s physics… inadvertantly I have placed the tweeter an equal distance from the side window first reflection and the screen first reflection… which then effectively cancels the direct sound coming at my ears
effectively both reflections come towards my ears and combine 180 degrees out of phase at my listening position… but at the drivers side window there is no cancellation, so when that bounces back I hear it… this then makes my brain think that the 2-2.5k band of sound is coming from somewhere infront of me as it can only work by what it hears in both ears and it picks up more in my right ear so the sound pulls towards the right, clever huh…
the solution in my case is move the tweeter a little closer to the screen (or adjust the crossover to 2.6khz as I have done currently) and make the pillars a symmetrical or use a reflector on the outside of the left tweeter pod to artificially move the first reflection closer to the tweeter and therefore that particular comb filter higher… mathematically you would want the driver double the distance from one reflection to the other, this way constructive and destructive freqs will cancel each other out a treat!
it’s why you can listen to a speaker and have the sound smear across the dash
hopefully this will help someone reading in future who wonders why a driver doesn’t sound like it is where it is at certain frequencys
you wont see this comb filter on an rta unless you put the mic in the spot your ear occupies, and even then you can’t eq it or do anything about it (install IS everything!), a moving average will make it disappear… but an rta is stupid and measures what it hears, the human brain is a very clever evolution!
So onto competition… the euros this year is in Salzburg in a few months… issue I’ve just bought a new house, not ideal timing, it’s also my last chance to go in skilled as per the rules once you’ve done a few years in skilled you must then move up to master, I’m fine with master, but I am also being robbed of my last chance at a European title in skilled 4k and the system is able to be done for skilled 4k instead of master 5k with a dsp swap to a dsp.3 and dropping a single sub (make a bolt on blank for the drivers side and drop all the levels by 6db to maintain the tonality, It gets hideously loud currently for an sq car and is very much good fun!… so decisions to be made heart says get it over there… brain says not and make the most of the money for bricks and mortar… who knows, I have until the end of next month to decide
Last edited by dumdum; 02-22-2022 at 04:37 AM.
It should be a great event to attend as the first euro finals since covid, and you will have contenders that qualified for the euros back in 2019, but also from 2020 and 2021 - depending on how the different countries did with events and qualifying locally in the past two years.
But then again, the cost of the trip will probably amount to half of what the price of the components in the €4k class :/
So in the meantime I’ve been busy moving into a new house
of course the stereo has to be on point!
rears have cables ran into the walls and up into the loft, then one run of conduit down the front left corner behind the subs makes cabling disappear more or less, a bit of cable protection with tesa tape where it runs through the stands and labels at the front behind the amp, also techflexed front left, right and centre speaker cables from my stocks all good fun
setup is Denon 3700 avr, Apple TV source, dali spektor series speakers, 6 floorstanders, vokal and spektor 2 sides, I also ran a couple of cables to the loft for height speakers eventually and may also Chuck some more up for rear heights as the sofa is maybe a touch tall for ear level rears
Who’s ready for more updates?? Stay tuned in the next week… first U.K. competition of the year has been announced, start of July… I’m off work next week so it will be rapid advancement of the install as it is currently… then midbass in kicks will be added later to see what they bring
im also considering a new car… Vw polo 2011-2014 ish… lhd if I can find one