[navin]

Originally Posted by DerAlte

And, ALL signal processing problems are in 'time domain'. Frequency domain is only a tool / platform to help solve problems.

Originally Posted by santosh.s

Time domain and frequency domain are two sides of the same coin, I believe. Anything that can be described in time domain can be expressed in frequency domain and vice-versa.

Moreover, mult-eq applies unique filters to each speaker (like what TA does), whereas parametric EQ I guess applies a certain filter to all channels, right? This way I don't think it can ever achieve some of the things that mult-eq or just plain TA can. Does it sound meaningful/convincing?

Originally Posted by low_bass_makker

For the Imprint they must be using delays and EQ to equalize the sound

What you see is an oscilloscopes view of the waveform (amplitude vs. time) is really the vector sum of all of the sinusoidal components vs. time. A spectrum analyzer is what one would use in the frequency domain.

To convert a time domain function to frequency domain one needs to apply a transform such as a "Z-", Laplace or Fourier transform. To convert back one has to apply the inverse transform.

The problem is that a regualr frequency spectrum is complex hainv both magnitude and phase. Spectrum analysers simply this by discarding the phase data.

Mathematical representation of time/freq domain data (Bode and Nyqusit plots) looks something like the equations shown here
Characteristics in frequency and time domain

While data is often easier understood in the frequency domain I believe the human ear hears in only the time domain and that includes echos, delays, reverbration, reflection, and refraction (doppler etc..) . So while you might use FFT to measure and understand what is going on, all corrections (EQ, delay, etc..) need to work in the time domain. This is why often simple EQs tend to make the msuic sound worse.

As processing power increased and DSPs are now prevalent a lot more procesing is being be achieved using DSPs or DSP related/derived technologies. As long as the final results of all the corrections applied are work in the time domain this DSP stuff will enhance our ability to enjoy music.

I have not heard an Audessy/multEQ equipped reciever but I know that the processing they have includes some sophisticated low frequency correction (much more advanced that Audio Control's stuff, as well as complex crossover maangement, polarity correction and delays.

[santosh.s]

Originally Posted by DerAlte

Wow, terrific. Maybe you should try using one some day -

Yes, I have been dreaming for long to have a reasonably good audio system for myself, before knowing that my profession would be even remotely related to anything audio. Hopefully, it turns into reality soon, starting with ICE!

Originally Posted by low_bass_makker

While doing TA in car for the sub. If we set the TA using a sine wave of 70 hz all is good till we are + , - 5 hz...when we go further up and down we see the TA going apart. So what do you think what is used in the H701...

I didn't understand what exactly you meant by "H701"? I believe delay added by TA will be applied to whole spectrum on that particular channel, but improvements noticeable in actual sound are expected to be more in lower frequencies.

Leaving technical and marketing hype versus reality arguments, I would just say that mult-eq technology has been in use for some time in Denon, Integra, Onkyo, Marantz, NAD, Phase Technology's home/professional products, and it enters into car audio in the form of Alpine-imprint, so I believe it must be worth giving a try and finding out yourself how much it delivers againts claims. So many good brands wouldn't have adopted it if there was nothing special at all! It is well known fact that room correction is indeed very complex problem to solve and something we have to live with, but going by DerAlte's signature- may be Audyssey has figured out a better solution, how knows?

Navinji, just noticed your post before hitting "submit" button, I absolutely agree with what all you said.

[navin]

Originally Posted by santosh.s

Navinji, just noticed your post before hitting "submit" button, I absolutely agree with what all you said.

My wife has got herself a Alpine 650. It will be installed in her car sometime between the 26th of March and 1st of April. I'll ask her for her opinion on the changes she notices. Since she does not even know the 650 is going to be installed (she will be out of town) I guess we'll get an unbiased opinion.

[stefanm]

I have finally done the imprint tuning on my 9887, the results were awsome in respect to the time alignment, the eq adjustments are pretty decent, the test cd we played was simply stunning the detail was shockingly good for a system in a safari, vocals have an added sparkle, i would have liked to do 2 passes but because we had spent 3 hours trying to get the correct software and I had to leave as I needed to pack for my return to Goa the next morning.

Overall very impressive, if anyone is planning to use this system make sure you turn the gain down on your sub amp, as this robs a little sub bass during the process. Definatly worthwhile if you are running a 9887hu.

Cheers,

Stefan

[rohan_fonseca]

Originally Posted by stefanm

I have finally done the imprint tuning on my 9887, the results were awsome in respect to the time alignment, the eq adjustments are pretty decent, the test cd we played was simply stunning the detail was shockingly good for a system in a safari, vocals have an added sparkle, i would have liked to do 2 passes but because we had spent 3 hours trying to get the correct software and I had to leave as I needed to pack for my return to Goa the next morning.

Overall very impressive, if anyone is planning to use this system make sure you turn the gain down on your sub amp, as this robs a little sub bass during the process. Definatly worthwhile if you are running a 9887hu.

Cheers,

Stefan

Now i know whats going to be the agenda for the next meet

[DerAlte]

Originally Posted by stefanm

... make sure you turn the gain down on your sub amp, as this robs a little sub bass during the process ...

Congratulations, Stefan! Must be sounding out of this world. Enjoy!

Could you please explain the above? Sounds a bit contradictory the way it looks. Did you mean Imprint tends to soften the bass and hence we should start with higher gain at the sub amp?

[santosh.s]

Originally Posted by DerAlte

Must be sounding out of this world.

@stefanm, do any of the instruments/voices sound "out of car"?

Originally Posted by DerAlte

Congratulations, Stefan! Must be sounding out of this world. Enjoy!

Could you please explain the above? Sounds a bit contradictory the way it looks. Did you mean Imprint tends to soften the bass and hence we should start with higher gain at the sub amp?

hi DerAlte - what he says is indeed the case, you should actually start with a lower gain, because when you start with a high gain it will drop to proper SQ levels ie linear, so the sub will not be playing any boom whatsoever. It will give you a totally linear response ie if the midrange and treble are at around 95db then the bass will also be at around 95 db

if you started with the bass gains high then you will lose that volume level when the EQ procedure makes it drop to linear levels whereas if you started at low gain the EQ will adjust the bass to be linear but if you want more bass you can adjust the gain to now go higher. this will definitely give you back the bass you lost even though this would now mean you are setting to basshead levels and not pure SQ levels. Obviously the level that the imprint sets it at should be your actual SQ level even though most people will now claim that the sub isnt actually playing but thats how pure SQ is supposed to be

its not a technically correct method of setting gains for the sub amp but its what the whole world and their dogs do with the imprint to basically adjust for increased bass levels

[DerAlte]

Thanks, @naughty001, that's what I was expecting out of a closed-loop configuration system. But somehow Stefan's expression was not sounding right, or maybe senility is catching on with me.

Santosh, your expectation is right, at least the bassist and drummer should be near the headlamps (and Aretha Franklin should be on the steering wheel). Didn't we discuss this in another thread a while back with B&T, LBM etc.?

[Bass&Trouble]

Originally Posted by stefanm

I have finally done the imprint tuning on my 9887, the results were awsome in respect to the time alignment, the eq adjustments are pretty decent

I've never used the Imprint processor with 9887. After the automatic setup is done, are the settings (TA, EQ etc.) stored on the head unit? If yes, could you please tell me what the TA has been set to, i.e. FL/ FR/ RL .. etc in cms?

Originally Posted by DerAlte

Did you mean Imprint tends to soften the bass and hence we should start with higher gain at the sub amp?

Yes, in all the setups that I have used Imprint processors in, there has been substantial trimming in subwoofer channels. Since I have used the 650 mostly, its just a matter of getting back manually into the subwoofer crossover menu on the processor after the setup, and removing the -10/ -12dB etc. (whatever trim has been applied during setup) and bring it up back to 0dB rather than trimming amp gains and increasing it again.

[stefanm]

Originally Posted by Bass&Trouble

I've never used the Imprint processor with 9887. After the automatic setup is done, are the settings (TA, EQ etc.) stored on the head unit? If yes, could you please tell me what the TA has been set to, i.e. FL/ FR/ RL .. etc in cms?



Yes, in all the setups that I have used Imprint processors in, there has been substantial trimming in subwoofer channels. Since I have used the 650 mostly, its just a matter of getting back manually into the subwoofer crossover menu on the processor after the setup, and removing the -10/ -12dB etc. (whatever trim has been applied during setup) and bring it up back to 0dB rather than trimming amp gains and increasing it again.

The set up is stored in multi eq mode, you can't adjust or even look at the settings, if you want to go back to your own settings you can, I haven't had an opportunity to try and match the imprints ta settings as yet, the big advantage with the imprints ta settings is that measurements are taken from each side to the instrument pod for the deflection etc something that would be extremely difficult to calculate and impliment. Also I forgot to add the Bass and Treble controls are available in multi eq mode.

Cheers

HI B&T the imrpint on the 9887 works differently to all the other imprint mdules on the lower models and very very differently to the 650

when you set the KTX100EQ imprint you get a choice of response curves - one of which you store. you can revert back to manual settings or imprint settings but you are not given any information on what the imprint settings are since it changes the T/A as well as crossover points as well as EQ levels so it is impossible to actually check any settings

people have tried to decipher the stored database file but even from that you cannot figure out anything. the KTX100EQ setting is a take it or leave it setting and it will fluctuate according to microphone setup so it will never ever be constant each time that you do the setup so you need to experiment for the best results and you will never ever know what adjustments have been done besides for what alpine tells you ie 512 differing points have been adjusted. Many take this to be a complex EQ adjustment which cannot be done on the headunit but i rather suspect it is merely a total derived from potential setting combination's out of the time alignment as well crossover adjustments and EQ settings

when you run the setting and store it you cannot access any information on what was adjusted or done, the stored setting can be activated by depressing the multEQ switch, at which point all manual adjustments cease to exist, it will not allow you to access those at all. besides for volume and balance and fader as well as now allowing you a treble and bass adjustment

pressing the mulEQ switch again will now deactivate the imprint setting and you fully revert back to the manual settings you had prior to imprint settings - so you are allowed to store a preferred setting, and when you rerun the procedure it will flash a new setting in and all you know about the setting will look like this on the laptop screen



note not my picture - ive found this in google but i can get some screen shots of what we have done, but it will waste time so i've borrowed this picture to convey the idea

this is about it, after following the setup procedure this is all you see on the screen with no further information given regarding any settings and you cannot adjust the imprint settings at all in any form or way. once you double click that "send filter" button on the left hand side of the screen the resultant curve is stored and each time you use the mulEQ button you will alternate between fully manual and absolutely no adjustment of imprint settings

its just the way that the 9887 works with the KTX100EQ. if you find a setting you like then you will not lose it even if you unplug the power from the headunit. The only way to lose the setting is to store a new one

Santosh, your expectation is right, at least the bassist and drummer should be near the headlamps (and Aretha Franklin should be on the steering wheel)

the drummer near the headlamps is a great expectation, ive yet to hear that much depth though whilst in terms of width world championship winning cars get basically more or less from just past the rear view mirror on the drivers side to just past the rear view mirror on the passenger side, you will not get it much better than that in a car

also in terms of vocalist and centre stage, it should not be centred at the steering wheel since this means that one side would be constricted. according to IASCA competiton rules as well as USACI or EMMA the centre is always in the centre of the dash, and in fact in the past IASCA use to have "two seater" categories where two judges sit in a vehicle and both need to hear the vocalists centred in the middle of the dash. This ideal is absolutely difficult to achieve and even the imprint struggles until you get your mic placement absolutely spot on in each seat

the absolute best soundstage depth i've ever heard in a car that won the best of show at the South African Finals was the drummer just around 20 centimetres past the windshield and this was considered world class by an american judge who is constantly judging at world finals. he actually even stated that if that car entered world finals it was sure to place

its easy to get a centre stage to where the steering wheel is since 9 times out of 10 it is automatically there because the driver side speakers are louder than the passenger side speakers but to get it properly centred to where the vocalist sounds just under the internal rear view mirror is hectically difficult and its why time alignment etc exist ie you want to delay the arrival time of the sound thats closer to you so it arrives to your listening position at the same time as the other side - this simulates the equilateral triangle that you use in home hi-fi for the perfect "sweet spot"

[santosh.s]

Originally Posted by DerAlte

Santosh, your expectation is right, at least the bassist and drummer should be near the headlamps (and Aretha Franklin should be on the steering wheel). Didn't we discuss this in another thread a while back with B&T, LBM etc.?

I don't remember anything clearly, but we surely talked about imaging/localization etc. Even if Imprint does theoretically a perfect job, it is not possible to get original imaging, unless you are using a headphone and a binaural recording (which is NOT common). However, I do expect that it may make sound come out of widow panes or something like that. BTW, listen to this recording, in case you haven't earlier (by now it might have become popular!). It will amaze anybody for sure. Must be heard using headphones, Sennheiser will give special effects, but it is not a must. Just a cheapo "Frontech" is all you need!
http://media.noob.us/virtualbarbershop.mp3

[Bass&Trouble]

Thanks for the detailed explanation, naughty, but I meant to ask something else. I understand that the response curve parameters will not be available to the user to study or modify. But settings like Time Alignment, Crossover Frequency, Channel Level etc are stored on the 650. After saving the desired response, one can manually access these settings in the processor menu. So I thought these must probably be stored in the 9887 in stefan's case. If not, then what does the TA menu in the 9887 show after the Imprint settings are saved? Does it continue to show 0cm-0cm..?

If not, then what does the TA menu in the 9887 show after the Imprint settings are saved? Does it continue to show 0cm-0cm..?

you cant access it, if you try to it will just tell you that multEQ is switched on, much in the same way as you cannot select any of those settings if you have the "defeat" selected. It works in a manner like a source "direct" like on home theatre and hi-fi amplifiers

you wont be able to get to T/A parameters or EQ or crossover if you have the MultEQ selected. Note that multEQ can only be selected if you have a setting stored, the only way to access any manual settings is to deactivate multEQ but at that point you are reverting totally back to manual setup, you absolutely cannot see any of the settings that the imprint has done, it seems like the audyssey settings are stored in the audyssey chip and there is absolutely no way to access these at all like in the 650 and the C701

I understand that the response curve parameters will not be available to the user to study or modify

BTW look at the picture again, the imprint doesnt only adjust frequency curves. It also does adjustments in the time domain ie the curves on the right are the time response graphs, this is how it corrects for the imaging and staging to become centred properly and it also works on the crossover ie any manual crossover settings you have are adjusted totally besides for subwoofer phase. the crossover adjustments is a thing i dont really like since i reckon it wont be long before the imprint adjusts a driver to levels it cant really work at but it does adjust the crossover settings too so if you want to use the imprint on the 9887 then you have to live with this which is why i think that getting a more basic headunit with a C701 (or audison bit one) works out much better than a 9887 with imprint