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Discussion Starter #1
Sold my Alpine and bought Kenwood BT61U (Kenwood X995 in US) and to be honest i prefer the sound from Kenwood than Alpine even though i haven't set it up properly.

I was looking doing time alignment first and when i checked on this HU it says in cm so basically i just input the distance difference?

Sub: 190cm
FR: 95cm
FL: 135cm

Basically, 190-95 = 95cm for FR, 190-135 = 55cm for FL?

Thanks
 

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Generally, time alignment computed by taking the distance from the furthermost speaker from the driver's position and the other speakers. Again generally, this is so that the audio signal from the various locations will arrive at the driver's position at the same time.

Now, I use the term generally because not all manufacturers implement time alignment the same way. Also, while time alignment is nice, any music that has phasing or tons of spatial enhancement just sounds flat out weird in the car with time alignment when compared to the home with equidistant placement of the drivers. Been there, done that, and humbled the "my car sounds better than your home" crowd many times over.
 

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best way to set T/A is with your ears. you will get marginal results at best by just sticking distances in there.

http://www.diymobileaudio.com/forum/how-articles-provided-our-members/96196-precision-time-alignment-using-only-noise-tracks-your-ears.html
So true... I always start with measurements as a base line then finish it with pink noise and my ears. As soon as my lazy self gets around to it, I'll have a closed loop setup to run Smaart in my car to check the relative phase from the driver's seat.
 

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Discussion Starter #5
Yeah was thinking about doing it by ear for the final adjustment.

So do i need to divide them by 34 or just the distance in cm as the HU only asking in cm.

Where should i aim the position, is it on the windscreen/dash right in front of me or centre of the dash?

Also was playing about with EQ last night and i have no idea what i was doing lol. For this HU got 5 Bands; 62.5hz, 250hz, 1khz, 4khz and 16khz and each -9db - +9db.

At the moment i'm doing the crossover through the HU and set to off on JL JX360.2 and set it at 80hz -12db slope but for my sub, JL JX500.1 there's no HP,LP or OFF switch and i set it at on amp 80hz and on HU 60HZ -12db? How could i set it just use the one on HU?

I've done gain set with DMM and what is the next step, TA then Crossover and then EQ last?

Sorry for all the questions but i think only people in this forum can point me to the right direction.

Many thanks
 

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I usually do crossover, gain, time alignment, gain, then EQ. Then again, I'm full active and the thought of sending the full audio signal to a full-range driver or a tweeter is NOT a good idea in my particular case.

Also, when EQing, I prefer to cut than to boost any particular frequency. Boosting by 1 dB isn't bad, but boosting by more than 3 dB, depending on frequency, can lead to excessive clipping and drivers going up in smoke.
 

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Discussion Starter #7
Only running passive at the moment but might run active at some point as only remember that i still have MTX 3 Way Crossover from when i did first install in my car back in 1998 at my mum's house, lol.

So what the actual crossover at when i set 80hz on the amp and 60hz -12db slope on the HU?

Trying to get the crossover and TA right after work and maybe EQ tomorrow. What kind of output should i expect when i EQ-ing? I mean what kind of sound and how do i know which band should i EQ and how much as i have no idea EQ-ing at all.

I also have SPL meterjust wondering if any use for TA, EQ and also crossover?

Thanks
 

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nope an SPL meter will really not be of much use. you might be able to use it to set crossovers, but even that will be sketchy.

if you dont have an RTA, then setting your EQ will just be by ear. not alot of science, just set it until it sounds good and remember to use cut where you can, not boost.

if you have the HU set on 60 hz 12dB/oct and the amp at 80hz, then the amp will have some small effect for any sound that makes it to the 80hz area.
 

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Forget using a yard-stick to determine your time correction values; you'll sound terrible. The reason for this is all the reflections that go on in a car. In addition, your passive crossovers will have a bit of 'time correction' in them (phase shift) and will screw things up even more.

It's been mentioned already, and is a great point, but some program material has some weird spacial **** going on too. What that means is that you'll set up your time correction, by ear, to sound great on one song/CD and it'll sound like ass on another. The 'fix' for this is to keep things as simple as possible.

Only time correct the driver's side speaker. Start delaying and you'll hear the soundstage move up and up. Once it starts to move over to the driver's side, even a little bit, go back. Bam, you're done. This is a quick & dirty method to setting up your T/A so that it'll sound good no matter what's in your CDP and it's something I've always done as a reference. Tweak & tune to your heart's content after that...it's just kinda nice to have something to go back to if you're unsure you've made a difference for the better.

Rear speakers? I've always run them in a Hafler circuit or they've been of the IB subwoofer variety. So I can't really help ya there.

EQing; there's a neat sticky on the SMD forum on how to set up your EQ with an IASCA test disk. If you'd like to use a Rat Shack analog SPL meter, that should work too if you have an Autosound disk.
 

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Discussion Starter #10 (Edited)
So wot should I set it at to get it at 60hz as I can hear that the sub comin out from behind me.

Yeah I tried to play with TA after work and set the driver to 4cm and the sound felt like coming out from in front of me and I tried 6cm and shifting a bit to near centre of the dash and at 8cm shifting to middle of the dash. I haven't even set left sPeaker yet. But the sound of the sub still coming out from the rear. How to shift sub sound to the dash?

Weird thing happen as well when I set the gain tonight. I'm getting alternator whining noise!!! How is that cos I only unplugged speakers wires from the amp. Is it because when I was testing I didn't run the engine for probably around 20-30 min and it charging the battery so that's where the whining noise comes from?

Thanks a lot guys for helping me :)
 

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So wot should I set it at to get it at 60hz as I can hear that the sub comin out from behind me.
set it at 60hz, either on the HU or the amp. the way you said you had it, would actually give you a faster slope past 80hz. if you dont want to worry about a strange slope, then turn one or the other off.
 

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these are both low pass correct? turn one of them off! doesnt matter which one. having 2 crossovers at the same freq is not gaining you anything.
 

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Discussion Starter #14
Yeah both for sub. The amp is no defeatable. No switch cos mono amp? It's jl jx500.1. The reason I want to set it on the hu so I can use the dsp on hu as the option either bypass or through on the hu. Also to use TA, slope and also EQ
 

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ok, then set the lowpass on the amp to the highest setting. most amps will set to 150+hz or so. then it will have little to no effect and you can use the one on the HU
 

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Yeah both for sub. The amp is no defeatable. No switch cos mono amp? It's jl jx500.1. The reason I want to set it on the hu so I can use the dsp on hu as the option either bypass or through on the hu. Also to use TA, slope and also EQ
Effectively turn it "off" by setting it
To the highest frequency.

I have the same hu, I have only had marginal results with the ta. The x995 has all sorts of goofy useless adjustments. I only cut on that eq.
 

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Discussion Starter #17
The amp from 50 to 200. So if I set the amp to 200hz and the hu to 60hz so basically the output is roughly 60hz?
 

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The amp from 50 to 200. So if I set the amp to 200hz and the hu to 60hz so basically the output is roughly 60hz?
yes, it will be crossed 60hz that way.
 

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Discussion Starter #19
Ok thanks will try that. Wot about slope etc? Tried shifting it to 18db or 24db bt didn't notice any difference? Is it jut me or do I need to play test tone aka pink noise etc?
 

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you should hear a mild difference between 18 and 24. between 12 and 24, alot. if you want to hear it, then play a test sweep from 20-200hz. you should be able to easily tell the difference in the slopes

personally I like 24dB/oct slopes for subs, you can set the freq a little higher and have it roll off faster.
 
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