amp which compensates the EQ bass-drop

hi there,

iam about to install a subwoofer and i found an amp that can boost bass frequencies in the 30-80hz range.

The EXTENDED BASS CONTROL controllers allow a extensive adjustment of the bass frequencies. The SUB BOOST controller defines the bass bosst from 0 to 18dB. With the FREQ RANGE controller you are able to adjust, on which frequency the bass boost (SUB BOOST) is effictive. The range goes from 20 to 80 Hz. With the Q CONTROL controller defines the Q-Factor of the crossover continuously, so that the playback quality of the cut-off frequency can be adjusted. Thereby you are able to adjust perfect transitions between the loudspeakers. • WIDE equates a Q-Factor of Q 0,3 (position very left below) = very wide frequency range. • NARROW equates a Q-Factor of Q 1,0 (position very right below) = very narrow frequency range. • Q 0,5 / LINKWITZ-REILLY is the standard-setting at the center position (12 o’clock position). • Q 0,7 / BUTTERWORTH is located the position right (3 o’clock position)

Click to expand...

also check the manual, which gives more in-depth explanation:
https://www.esxaudio.de/english/signum-se2000d-amplifier.html



sounds about fine and exactly what we need for our HU? right?

So far as I can see; that amp requires a line level input. I'm under the impression that our factory HU's don't have a line out.

Also... if the factory HU is filtering out everything below a certain cutoff frequency (and I'm not even sure if that's so or where it is); then I don't see how the amp is going to 'restore' that material.

Not trying to spoil the fun. Just asking questions and looking for the answers if someone has them.

i think ill try to tap one of the speakers by using a high-low adapter. which gives me the line-out for the amp.
but iam not sure if i should try that with the rear or front speaker. (?)
i surely need the signal _after_ the amp, from one of the speakers

regarding the cutoff:
its rather a linear drop in bass.
i tested with an app via my phone and i hear every frequency between 38-60hz, its just more quiet compared to the 70-90hz range.

Understood. I hope that it works for ya'.

Just keep in mind that as you amplify signal; you also amplify noise. A class D amp taking its input from a speaker-level transformer and then boosting a faint signal may be more noise than is acceptable. Just keep your receipts, I suppose.

Please post the results. And good luck with it.

The only reason that I comment at all is that I went through this about 20 years ago with my Del Sol. My experience when it was all said and done was not a good one.

MrWaYne said:

regarding the cutoff:
its rather a linear drop in bass.
i tested with an app via my phone and i hear every frequency between 38-60hz, its just more quiet compared to the 70-90hz range.

Click to expand...

Do you have the eight-speaker 180-watt output system, or high-power audio with 11 speakers ...?

How was the audio getting from your Phone to the Car's Head unit ?
Bluetooth or USB.
How do you know that the audio from the phone was not dropping off at the lower frequencies.? or what effect the Bluetooth or USB connection had on the frequency response before it hit the Head Units AMP.

"i hear every frequency between 38-60hz, its just more quiet compared to the 70-90hz range"

But even if they were at the same physical level, how do you know that the quietness of the 38-60Hz band is not due to your hearing -- or effects of the sound bouncing around inside the car, and cancelling out at those frequencies.

I suppose really, in the end, what matters is what YOU Personally hear, and how you perceive what you hear as being what you want to hear,

If you are going to fit a sub amp, and get a bigger/louder Sub speaker, you might want to consider getting a system with a fair reserve of extra power, because the more you listen to it with that extra loud bass, the more you will need to turn it up over the coming months (not years), as your low frequency hearing gets destroyed.

Sorry .. you can 100% rely on it going to happen, just a you can rely on the sun coming up tomorrow

I installed my amp and two 12s using a line out converter in my 19 si. I am a bass head, but being that this is my first new vehicle I'm being conservative with my volume levels.

In my previous civics, I pretty much rattled everything loose. This one, I'm just not going to let happen. Hopefully. I haven't noticed any extra noise in any of those vehicles with my install. And I haven't seen a drop in my hearing. I only say this because I'm tested annually for hear loss from working in a refinary.

So, with the setup, I unplugged my factory sub and spliced into those wires and ran all the other necessary ones like normal. A change in headunit would be ideal. But for those who would like to keep as factory as possible and add some more kick this is a great option...

Triple_peaz said:

I am a bass head, but being that this is my first new vehicle I'm being conservative with my volume levels.

. Hopefully. I haven't noticed any extra noise in any of those vehicles with my install. And I haven't seen a drop in my hearing. I only say this because I'm tested annually for hear loss from working in a refinery.

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That's very good to hear (excuse the pun)

Lmao, I know right?

@SCOPESYS

i've the 450w sound system in my honda (more than 8 speakers) and i tested those frequencies with an app via android/bluetooth and additionally with a soundfile. i will try via USB aswell, but i doubt i hear any difference.

iam using that procedure on my home-cinema speakers aswell and it was always accurate (my hearing is also very sensitive and fully ok ).

not sure when i find the time for installing the amp&sub, but it will be the next 1-2 months. will keep you guys updated!

maybe one more info: i've a euro civic (10th gen, hatchback) which comes without a factory sub. maybe there is really no massive cut-off in bass?
i was testing with the following app:
https://play.google.com/store/apps/details?id=com.luxdelux.frequencygenerator&hl=en_US

I would recommend a volume sensitive option (like the LC2i) over a straight EQ option. The Civic really turns the bass down as you turn the volume up, and it became very noticeable to me when configuring my sub. Set it to sound perfect when the volume is at 30, now it's boomy and overdone when the volume is at 20. Set it perfect at 20, now it's weak and boring at 30.

MrWaYne said:

@SCOPESYS

i've the 450w sound system in my honda (more than 8 speakers) and i tested those frequencies with an app via android/bluetooth and additionally with a soundfile. i will try via USB aswell, but i doubt i hear any difference.

iam using that procedure on my home-cinema speakers aswell and it was always accurate (my hearing is also very sensitive and fully ok ).

not sure when i find the time for installing the amp&sub, but it will be the next 1-2 months. will keep you guys updated!

maybe one more info: i've a euro civic (10th gen, hatchback) which comes without a factory sub. maybe there is really no massive cut-off in bass?
i was testing with the following app:
https://play.google.com/store/apps/details?id=com.luxdelux.frequencygenerator&hl=en_US

Click to expand...

This weekend I just Honda hacked the HU, and installed a Frequency Generator (that I like )

https://play.google.com/store/apps/details?id=com.keuwl.functiongenerator
https://play.google.com/store/apps/details?id=com.keuwl.functiongenerator
I can run that without any fear of USB or Bluetooth affecting the results.

Did some quick & dirty test with the Generator & a scope. Should be possible to get some nice Gain/Freq plots for all the channels, and at different volume levels.
Not found an easy way yet to automate the Plotting, so might have to do it by hand, which will be very tedious.

I did look at the SUB channel (which at the moment I have loaded with 4 ohms).
I need to change that to 2 ohms. (Power amp chips in unit are rated for both 4ohm & 2 ohm loads !!)

The Sub Channel has a 3db BW from about 5 Hz to 45Hz, and looks reasonably flat.
The issue is, even at 45W (peak), and full output (Rail to rail( without clipping, a sine wave sounds not very loud !!!. You can FEEL it, but it does not blow your ears off, like a 1Khz tone @ 45W

From my initial examination of the amp, it looks like the HU is just feeding it Left & Right channel data (possibly Flat), and it is the AMP that has pre-filter audio Low power chips, that are defining the channel bandwidths.

Once I get some plots, it will be more obvious what may need to be attempted to be changed !! (Nothing on the AMP's Power Amp that cannot be repaired if I blow it up !!!
The Lower PSU board with the Digital AUdio to analogue IC, may not be so easy to fix if I mess that up !!

MrWaYne said:

i think ill try to tap one of the speakers by using a high-low adapter. which gives me the line-out for the amp.
but iam not sure if i should try that with the rear or front speaker. (?)
i surely need the signal _after_ the amp, from one of the speakers

regarding the cutoff:
its rather a linear drop in bass.
i tested with an app via my phone and i hear every frequency between 38-60hz, its just more quiet compared to the 70-90hz range.

Click to expand...

The Sub's top end -3db (1/2 Voltage) point is about 45 Hz, so do not expect to hear anything much in the 70-90hz range

The low cut of point (-3db) is about 5 Hz, so you should be able to hear/feel 5Hz to 38Hz quite well.... probably FEEL more than hear !!

Note: Testing with your Phone app, via Bluetooth or USB, could well introduce gain/freq variations, due to the Bluetooth or USB codecs .

Just asking... not trying to be a wise-ass or anything...

Are these frequency counter apps taking their input from the phone's onboard mic?

shoegazer said:

Just asking... not trying to be a wise-ass or anything...

Are these frequency counter apps taking their input from the phone's onboard mic?

Click to expand...

Frequency counter apps ???

The app I am using is a Frequency GENERATOR app... does not use the Phone's Mic.

Using the Phone's Mic to capture the sounds for analysis, is not really going to work well, the Phone Mic's Frequency response is a total unknown.
To get an accurate reading from a Mic, you would need a Calibrated Mic, like a Calibrated USB mic.

I am not even taking the speaker's characteristics into the AMP's Frequency response measurements I am doing. I am having the amp fed 4 Ohm load resistors, and measuring the output voltage with a Oscilloscope. Using the scope, I can also see any limiting.

Yeah. I was a little lost re: analyzing the signal. Carry on.