[ctuna]

Usually in the absence of a way to bandpass the under seats you
just low pass them at the amp.

The underseats can only play so low so in away they are kind
of self bandpassing on the low end.

[jeffb335]

Originally Posted by sfarisbradistan

I'm aware of that. What I'm asking is most amplifiers that don't have a dsp built in have either a highpass or a lowpass filter built in, so you use one or the other. So I get the fact that the subwoofer has been low passed using the mono amp and that the door components have been high passed using channels 1 and 2, but how have the underseats been bandpassed. The only way I can think is that they have been highpassed on the radio and lowpassed on the amp to give the bandpass that is needed?

That particular MB Quart amp he was running has a bandpass function where you can use the LPF and HPF at the same time.

In your case I'm not sure I would high pass the underseats at 50hz if you are not going to run a trunk sub, since you are running a bit ten you should be able to dial them in pretty good down to 30, just roll them off gently to 30 and then steep below that. So long as you dont put a big boost on them real low they should work fine. I ran Jehnerts in my car for a while like that and it worked fine although I eventually went back to the trunk sub as the Jehnerts could not quite keep up down real low at higher volume.

[sfarisminhas]

Originally Posted by jeffb335

That particular MB Quart amp he was running has a bandpass function where you can use the LPF and HPF at the same time.

In your case I'm not sure I would high pass the underseats at 50hz if you are not going to run a trunk sub, since you are running a bit ten you should be able to dial them in pretty good down to 30, just roll them off gently to 30 and then steep below that. So long as you dont put a big boost on them real low they should work fine. I ran Jehnerts in my car for a while like that and it worked fine although I eventually went back to the trunk sub as the Jehnerts could not quite keep up down real low at higher volume.

I've changed direction a little. I've still got the Audison underseats. The Bit ten has gone and instead I'm going for the Pioneer 80prs. I was thinking of going fully active upfront but debating it because of the hassle of running new cable through the door boots. So will probably stick to front components, rear coax and the underseat subs. Saying that, I now have a professional headunit for sale that's got USB and hifi coded.

[Lockman_321]

Hi All,

Long time not posting on here.

I can see there have been a few updates since I last posted!

Returning as I am changing the headunit.

For the question around the bandpass for the underseats, I purposely bought that amp as it has a bandpass setting on it. You can achieve this by setting High Pass Filter 80hz and the Low Pass filter 150hz (so underseats play all frequencies between 80hz and 150hz (bandpass)

In terms of the headunit I have decided to change it. (Dynavin n6). Not to bash the product as it has served me well the last few years but the reason for getting rid of it is I want a CarPlay unit. I purchased the carlay dongle for the n6 but the audio and video quality was so bad that I never ended up using it. Very disappointed with the ilink . I just ended up going back to Bluetooth.

In fairness when I bought the n6 the ilink didn’t exist so it would have been a bonus.

I know CTuna won’t agree with this as the pre outs won’t be as good as on the dynavin (2v as oppose to 4v) I have decided to pick up the eonon ga9365 and the carlinkit wireless CarPlay dongle

The eonon was £250 compared to the £599 I spent on the dynavin. The resolution is better, il have wireless CarPlay and the I think I have much more options with it being an android based headunit (e.g torque app) Will post some pics and an (subjective) audio comparison once installed.

[sfarisminhas]

Hey Lockman. I recently completed an install. The headunit I have is the Pioneer 80prs which has a 5 v pre amp output. Initially I had it in standard mode but have since switched over to network mode which gives me a three way active stage. I got rid of the rears completely so the tweeters, mids and underseats are running directly from the amp and there are no crossovers. I have noticed one thing though since getting rid of crossover is that I've had to highpass the mids at 200hz on a 12 dB slope instead of the 125 I had them at when the passive crossovers were in place, so I think the crossovers were masking something because now at 125 they distort hence I have them running at a higher frequency and then they are lowpassed at 5000hz at which point the tweeters take over. The underseats are Audison APBMW s8-4 which are lowpassed at 125hz in a 12db slope. Still got some tuning etc to do in the car. I'll be stripping it down again tomorrow to run new cabling and RCA's as the crossovers seemed to have masked a static noise that was coming from the fronts.

[sfarisminhas]

I will be putting the crossovers back to reclaim two channels, onto which I'll add the two Audison underseats in a stereo configuration. That'll free up the 5th channel to which I can add a subwoofer in the boot to take care of the sub 80hz frequencies.

[sfarisminhas]

An update to my install. I recently switched the amplifier to a five channel Pioneer GM-D9705 from the JBL five channel I had. Two reasons. I needed more power to the sub which the Pioneer gave me, 600watts at 2ohms rather than the 350watts at 2ohms I was getting with the JBL. There was also the independent sub control. This amp was just better documented and seemed to work better with my headunit. The other thing I did was move the amp from the left corner where the original amp location was to the space under the boot carpet which helps when it comes to tuning etc as I don't have to keep removing the fender carpet.

[E92x7z]

I have the same mb quart underseat subs i would really say if i'm allowed to test it with gladen audio extreme I didn't mean to make a difference in quality........... by force alone