Delay line for front channel

[jayadev]

I May sound bit vague.

but I am looking for a solution to add delay for my front speakers.

for some wierd reasons I cannot place my subwoofers in front along with the front Loud Speaker rather they are at rear.

It sounds good but doesnt gel very well with main speakers.there is a bit of delay from front as they stands bit far almost 2 meters away and subwoofer at rear is only a meter away from me.

I wish if I could find easy solution to add a delay to front speakers .

I realize delay lines may compromise audio quality but I wonder if we have some sort of win win circuits with so much of technology in hand?

I am very poor or a nerd at digital and programming world with Mc and binary codes.

I am looking for multileged ic's with schematics which are better than bucket brigdes or inbuilt pre-programmed digital delays which I can assemble on my own..

[chrispenycate]

Is this a full ITU 5.1 system, or bass managed (the subwoofer, in addition to taking the LFE channel also handles the low frequencies for the main satellite speakers) Assuming the latter (as the LFE information should be direction unimportant) are the power amps driving the LCR information independent (normally built into the small loudspeakers) or built into the subwoofer (frequently done, as it concentrates all the weight and heat, meaning that the HF units have a higher WAF {wife acceptance factor} and fewer trailing wires.

That last situation gives problems inserting a delay, as the crossover and power stages are often integrated and frequently digitally controlled; cheaper than multi layer pots.

I'm actually surprised that delay on the bass channel is disturbing. Oh, the other way around, typified by the 'sub under the sofa' setup, where the vibration of the kick drum reaches your buttocks before the "thwack" hits your ear, or structure-borne information reaches you faster than air-carried, yes. But normally a few milliseconds delay between the impact and the rumble are quite natural. Are you certain there isn't a polarity inversion somewhere in your system?

I very much doubt if a decent quality chain involving an analogue to digital converter, a programable delay and conversion back to analogue, plus power supplies and input/output circuitry, could be built much cheaper than a ready built, high quality multiple audio delay. At the very least, try and hire one of these delay lines for a few days (they are used by PA companies to time align remote towers, so should be easily available) so you can check it actually does what you want (separate channels, obviously, not one input and multiple delays). Not, perhaps, as much fun as setting up your own anti-aliassing filters, but is it really worth reinventing the wheel, unless you can make an appreciably better one?

[jayadev]

I'm actually surprised that delay on the bass channel is disturbing. Oh, the other way around, typified by the 'sub under the sofa' setup, where the vibration of the kick drum reaches your buttocks before the "thwack" hits your ear, or structure-borne information reaches you faster than air-carried, yes.

Thanks for the prompt response.

exactly ,as mentioned above. this is my case.

It is a dedicated cd palyer in my bedroom where i can watch movies laying on bed. there is no way to place the woofer along with front speakers as it will obstruct the passage(doors) and i hate to place woofers under the cot(bed) sounds boomy.

only option left with me is to place the woofer(12 incher) as a table near my bed,where i can put my alarm,mobile,a flower pot adding to aesthetics of the room.
On the other hand woofer is completely hidden as it looks like a small table but the delay is haunting. I am unable to enjoy good great music the lower end overtakes the front main speakers sounding too aggressive and odd at times even if woofer level is reduced to nothing.
I repeat sound stage with woofer placed in middle of front speker is "awesome" and I just cant miss those lower end notes.with my room improvisations.

I have no idea about i2c programming and do not want to break my bank balance with pro delays. I am sure there exist some kind of economical solution without compromising SQ.
I checked datasheet of delay line from mitsubishi but those thre control line viz.sck ,slk,data..gives nightmares to me. wish i had learnt i2c programing long ago.yet i havent given up hope.

[jayadev]

Again I have dedicated 6.1 channel home theatre setup,combined with hand made HD projector. I have posted the project details in "moving images section" . up there delays is no issue as i have full control over them with my sound processor.

[chrispenycate]

Ah, I've just reread it. It's the bass you need about three milliseconds of delay on, not the fronts. Much easier; nearly all the quality factor are reduced (clocking speed, distortion, S/N, everything) and there's only one channel to delay (unless the surrounds are too close to you, too. But most cinema mixes take account of the fact that some audience are sitting too close to the surrounds anyway, and add extra delay).


Without the quality restraints, you could even use a bucket brigade; I put noise reduction round one for just the same purpose, for PA, where the big (4X18") cabinets had to go under the bleachers, as there was no space for them on stage (and I didn't particularly want to vibro-massage the instruments or the mics). Or there is a thread:- Low-Cost Audio Delay Line Uses 1-Bit ADC
Not that professional delay lines have to break the bank; the Behringer Shark DSP 110 comes in at less than $100, with comples eq algorithms and mic preamp; surely there must be something simpler as cheap (perhaps a multiFX unit designed for musicians? the quality should be more than adequate up to 120 Hz).

[Frank Berry]

IMHO, your ears cannot detect a 3 millisecond delay at low frequencies.
3 milliseconds is a very small percentage of a 30Hz sine wave.
If the audio from your Sub is creating a problem when it mixes with your front channel speakers, I suspect that the Sub is delivering audio above the normal subwoofer range.
Have you tried to correct your problem by adjusting your Subwoofer's high frequency cutoff?

[sreten]

Originally Posted by jayadev

I May sound bit vague.

but I am looking for a solution to add delay for my front speakers.

for some wierd reasons I cannot place my subwoofers in front along with the front Loud Speaker rather they are at rear.

It sounds good but doesnt gel very well with main speakers.there is a bit of delay from front as they stands bit far almost 2 meters away and subwoofer at rear is only a meter away from me.

I wish if I could find easy solution to add a delay to front speakers .

I realize delay lines may compromise audio quality but I wonder if we have some sort of win win circuits with so much of technology in hand?

I am very poor or a nerd at digital and programming world with Mc and binary codes.

I am looking for multileged ic's with schematics which are better than bucket brigdes or inbuilt pre-programmed digital delays which I can assemble on my own..

Hi,

The "solution" to your alleged "problem" is adding delay to the subs not
the fronts. 1m is about 3ms and pretty meaningless for subwoofer ouput.

Phase manipulation of the subs would make a far bigger difference, and
it could be lots of other reasons, too much overlap, too much sub ouput,
poor integration etc, I suspect a combination of all three.

rgds, sreten.

[jayadev]

Ah, I've just reread it. It's the bass you need about three milliseconds of delay on, not the fronts. Much easier; nearly all the quality factor are reduced (clocking speed, distortion, S/N, everything) and there's only one channel to delay (unless the surrounds are too close to you, too. But most cinema mixes take account of the fact that some audience are sitting too close to the surrounds anyway, and add extra delay).

thanks @ chrispenycate.

Hope I doesnt look acting funny here.

Actually I need it for front . as I have something else in my mind.I just posted one of the present case.

I have planned to shift the arrangement in a different way.where in front speakers and listener would be in equilateral triangle (as right now it is bit far and sounds as if from distant.) again the woofer would be moving to somewhere around 2.5 meter backwards that is what my wife suggest as present arrangement has made our life miserable.

I have tested with this new arrangement and found it much pleasing compared to that near bed arrangement where the bed used to vibrate annoyingly.again this is where sound staging gets totally compromised. My bad... I should have posted this at first place but I believe my requirement is understood here.

[jayadev]

Here is the plan of new arrangement .

Even though I got very nice sounding setup in my home theatre room but I cannot miss listening some good things while in bedroom so I am trying my level best to sort it out.

presently woofer is adjacent to bed but it keeps knocking hurting legs/knees, when somebody pass .

and subwoofer placement is too critical i cannot find anything better sounding than where it is shown in the below diagram but for the dreaded delay..

hope you get me.

[chrispenycate]

Do something. Try it like that without delay before going overboard. Remember, 3mS is 330 Hz, and having the highs attack first gives a crisp sound (so much so that Barcus Berry made a 'plug it into anything and it will sound better' box that delayed bass frequencies for exactly that effect).

And you never said where the crossovers and power amps for the satellite speakers are mounted. However, I hadn't realised it was only a two channel (+ sub) system.

Incidentally, you don't sound vague, and though I suspect some of the problems are due to room acoustics – bass is horrible to get right – I've met the "early bass=lack of clarity" syndrome, albeit with considerably greater distances involved.