Rew and car Hi-Fi. Is there a target curve?

[Bow_Wazoo]

As part of my car hi-fi upgrade, I wonder if a target curve for cars exists.
I would like to do an FR measurement with Rew and optimize the FR.

And what is the best way to time delay alignment?

​

 

[Sokel]

Do you mean a preference curve?
I cannot imagine a research with people going in and out of a car listening so to establish a solid percentage about it

 

[Bow_Wazoo]

Yes, exactly.
I wonder if you can transfer the "classic" Harman Target?!

 

[Sokel]

Yes, exactly.
I wonder if you can transfer the "classic" Harman Target?!

How can you do that?
Harman curve is a result,not a target.
Is the result of decent speakers in a fairly decent room,before EQ (above the transition),etc.

If the same result can be obtained naturally in a car (depends on the placement and directivity of the speakers I suppose) who knows,maybe the same preference can apply to it.

 

[Denon545]

Here's some good information on using REW in car audio-

https://testgear.audiofrog.com/wp-content/uploads/2018/03/A-Straightforward-Stereo-Tuning-Process-and-Some-Notes-About-Why-it-Works.pdf

 

[Bow_Wazoo]

How can I use REW to measure whether the sound comes from the left side and the right side at the same time?

 

[Bow_Wazoo]

Apparently Audiotec Fischer has a software that, among other things, corrects the FR.
Btw. the target curve looks familiar.

I'm just wondering why they don't use a 20-20khz sine sweep for the FR measurement?!

 

[GXAlan]

Apparently Audiotec Fischer has a software that, among other things, corrects the FR.
Btw. the target curve looks familiar.

I'm just wondering why they don't use a 20-20khz sine sweep for the FR measurement?!

The Audiotec Fisher requires you to generate the test tone, which means there is no ability to sync the log chirp.

It works well and my BMW with an Audiotec Fisher amp beat out the JBL 708P when measured as a mono recording on a calibrated mic.

 

[JSmith]

... from Floyd Toole's book and this PDF;

4.2 Car AudioConsumers spend considerable time listening to music intheir cars through audio systems that nowadays can be quitegood. These systems can only be measured after installation in the acoustically complex automobile cabin. Fig. 15shows results from U.S. subjective evaluations by Olive andWelti [51] and Clark [52], an Italian study by Binelli andFarina [53], and measurements in five multi-national luxurycars. All boost the bass to compete with the substantial road,aerodynamic, and mechanical noise at low frequencies (insome vehicles this can vary with speed and/or backgroundnoise). There is substantial agreement through the middlefrequencies, including the predicted small-room curve fromFig. 13(a). Apparently, designers wanted cars to sound likegood home systems. Differences in how the in-cabin automotive data are gathered lead to some disagreements incurve shape at very high frequencies. The perceived soundsare likely to be more similar than these measurements indicate

https://www.linkwitzlab.com/Toole-Room%20calibration.pdf

JSmith

 

[Bow_Wazoo]

The Audiotec Fisher requires you to generate the test tone, which means there is no ability to sync the log chirp.

I dont understand that

 

[GXAlan]

I dont understand that

Audiotec Fisher makes aftermarket car audio amplifiers. They are DSP amplifiers with USB ports.

Car amp USB to laptop
UMIK-1 to laptop
You cannot hook up the UMIK-1 to the USB port on the Audiotec Fisher amp (at least the ones I know of)


You can do an RTA measured by the UMIK-1 and apply a PEQ/GEQ. The software for controlled the Audiotec Fisher amp cannot take your laptop control via USB to generate test tones. You have to do it through your head unit or the line in/spdif in.

Therefore, for the Audiotec Fisher auto Eq, you need to manually supply your pink noise.

With an Audiotec Fisher DSP amp, you play your noise, you adjust the level of the target curve so you aren’t boosting or cutting too much and then you press one button and it tries to match the target curve.

 

[Bow_Wazoo]

Oh, that's what you mean. Yes, I understand that. I want to go a different way anyway. I want to use a amp "stand alone" by connecting a Bluetooth receiver and stream audio via my Android phone.
I want to measure with REW, and create a profile for Wavelet.

I just don't know, how to solve the problem with the time delay. It's a shame that Wavelet doesn't have this function.

Although I have most of my music stored on my smartphone anyway, and ican use Neutron Player.

 

[ZolaIII]

I don't think time delay will be a problem in near field or close to it it's a car not a bus. However what will be a problem is aiming tweeters at ears level. Wavelet uses many fixed points EQ in psy manner in plane txt format but I don't know any FIR to Wavelet converter. Doing first 300~350 enteries by hand is a bit too much for most folks and that's only about up to 1 KHz. A common problem is making good quality crossovers and preferably digital. To minimise time domain and related delay issues use up to 10" subwoofer's in open or closed enclosure just not ported ones. Effect is similar tho you gain on space using a trunk as a box and cuple dB more on SPL but it's not ideal as it remains exposed and fragile (when you need to use trunk for transporting something).

 

[Bow_Wazoo]

In my last car, I had a headunit with built-in DSP. There it was possible to set the time delay.
I felt the advantage this brought was huge.
My car has 2 subwoofers under the seats.
the tweeters are located here:

 

[ZolaIII]

I told you the physics of it and under the seats and smaller than 10" meaning lass than 1m delay shouldn't be a problem. Even with ported sub's. You can buy a CS43131 based BT clip alike dongles with LDAC suport for about 50$ and they will give 1.75 to 2 V unbalanced output. For example Hiby W3 II (1.75 V or - 1.5 dB to 2 V) and you can plug them to USB power input while using (not to rely on built in battery). That's not a bad spot for tweeters in car try to rework it so it aims at ear highs ± 5° if you can.

 

[Bow_Wazoo]

I ordered an Ldac BT receiver. This is powered via USB. That's not a problem.

The only thing I'm still concerned about is correcting the time delay. I might buy an amp with built-in DSP. There are some from Axton that are in my price range. Plus, the settings are done via an app. I like that.

 

[GXAlan]

In my last car, I had a headunit with built-in DSP. There it was possible to set the time delay.
I felt the advantage this brought was huge.
My car has 2 subwoofers under the seats.
the tweeters are located here:

View attachment 381757

If yours is HiFi model, getting this can be a fast and easy way

MATCH UP 7BMW

7-channel Plug & Play upgrade amplifier with integrated 8-channel 64 Bit DSP for BMW HiFi sound systems

www.audiotec-fischer.de

 

[Bow_Wazoo]

Thanks.
But it's too expensive for me.
I've decided on the Spectron sp-n4207.
An BT receiver is connected to it I stream from my smartphone and use the Neutron player as a DSP.
If Wavelet also had time delay correction, I would be completely happy...

 

[Bow_Wazoo]

@dmitrykos

Can you please program a DSP app that works like Wavelet, on a higher level?

(I am convinced, that you would earn a lot of money, with such an app.)

 

[Vacceo]

The first task in a car should be adding butil, aluminum and matt beneath the panels.

That is expensive and adds the weight of almost a passenger, but at least that gives you a more inert and controlable interior. It will also reduce the noise transfer.

From there, EQ to get the curve you want, or the closest you can get.