[jmciver]

Originally Posted by Billfitz

I've run the specs on the Audisons, for your purposes they're no better than the OEM. They have a bit better low frequency output capability, but that's moot when you've got a sub.

Do you happen to know any of the T/S specs and frequency response for the OEM H/K underseat woofers? As expected, they are not easily available based on my searches. Based on what I have learned from my research, specs like Fs, sensitivity, and even a frequency response plot, can help me better estimate what cutoff frequencies are optimal for me to band pass the stock woofers to maximize performance and prevent distortion.

[Billfitz]

I've only been able to measure my Hi-Fi woofers.
Fs 51 Hz
Qes 1.00
Qms 3.02
Qts 0.75
Vas 18.4L
Re 2.4 Ohms
Le 0.22 mH
Sd 200 sq cm
xMax 6 mm

Impedance aside I doubt that the H-K are significantly different. I doubt you'd have any distortion issues with even a 60Hz high pass on them. Mine don't reach 10% THD at full tilt and they're not high passed.

[jmciver]

Quick update on this project…

The 10DSP, MOST interface and H/K harness came in. Hard to believe this much power and capability comes in such a small package. While on the bench (aka my dinning room table ), I powered it up and connected my laptop to take a peek and load up my initial tune files. I actually purchased a demo model that was previously installed in a 630i w/H/K so it already had a tune file installed (EQ'ed with an RTA and everything) so I am curious to hear how that sounds once everything is hooked up.

After much searching and back and forth, I finally decided on set of underseat woofers I want to use. I chose the Audison APBMW S8-2. I looked at A LOT of different brands (and even considered using the stock ones), many (but not all) provided the full specs for me to look at. Of the ones that did provide the specs, I liked these the best because of their 2 ohm impedance (allows for max power from the amp, even if I don't use it all), had a higher frequency range of 45-500 Hz (they will be band passed higher than stock woofers since I am using a trunk sub), and they had a high sensitivity spec of 91 dB. Not the cheapest underseat option (nor most expensive), but I am confident they will work well with my setup.

Still gathering a few other parts/components before I start the install. But more importantly, I am waiting for the temps to come up a bit. Plastic clips and trim pieces (and my hands) don't do too well working in a very cold garage when it is still sub freezing outside )

[anielsen71]

Hi there

Forgive my ignorance, but how much plug-and-play is this?
You just unplug the OEM amp and plugs in this kit?
To MOST connection and to speaker connections?
And then tune the setup with your laptop?

I have done conversions before with Mosconi Gladden components in my old E91, so im not new to this. That was kinda done like that.
Is it done the same kinda way?

[jmciver]

Originally Posted by anielsen71

Hi there

Forgive my ignorance, but how much plug-and-play is this?
You just unplug the OEM amp and plugs in this kit?
To MOST connection and to speaker connections?
And then tune the setup with your laptop?

I have done conversions before with Mosconi Gladden components in my old E91, so im not new to this. That was kinda done like that.
Is it done the same kinda way?

Actually, it is very plug-n-play with the H/K specific harness that you can get (and what I have). This is very similar to how the UP7BMW connects to the factory harness for BMWs with the HiFi (option code 676) system.

The big plug you see plugs into the factory harness to connect the 10DSP to the speakers in the car via the factory wiring. Disconnect the factory MOST plug from the factory amp and then plug it into the SDMI25 MOST adapter (then connect the MOST adapter to the 10DSP with an optical cable). You will need to run power/ground for the amp to the battery since larger gauge wire is needed to power the amp.

Search for the Bavsound Revanent Pro amp install video (they install it in a H/K equipped F80 M3). That is essentially the same install process you would do for the UP10DSP. Also, if you want to make your own H/K harness, Technicpnp.com sells a BMW harness kit to create your own H/K plug-n-play harness using the supplied harness that comes with the UP10DSP.

[anielsen71]

Originally Posted by jmciver

Actually, it is very plug-n-play with the H/K specific harness that you can get (and what I have). This is very similar to how the UP7BMW connects to the factory harness for BMWs with the HiFi (option code 676) system.

The big plug you see plugs into the factory harness to connect the 10DSP to the speakers in the car via the factory wiring. Disconnect the factory MOST plug from the factory amp and then plug it into the SDMI25 MOST adapter (then connect the MOST adapter to the 10DSP with an optical cable). You will need to run power/ground for the amp to the battery since larger gauge wire is needed to power the amp.

Search for the Bavsound Revanent Pro amp install video (they install it in a H/K equipped F80 M3). That is essentially the same install process you would do for the UP10DSP. Also, if you want to make your own H/K harness, Technicpnp.com sells a BMW harness kit to create your own H/K plug-n-play harness using the supplied harness that comes with the UP10DSP.

Nice. Thnx for clarification.
Could be one of the next upgrades in my F36 😊

[jmciver]

Another quick update…

The Audison underseat woofers came in. Best price I could find for the pair, including shipping, was from an overseas company. Not unexpectedly, they definitely look “beefier” than the stock H/K woofers (but I am no audio/speaker engineer either ). The pics below are the Audison’s compared to the stock woofers previously removed from my H/K equipped X7 following a Bavsound speaker upgrade I did approx 8 months ago. However, based on my research, the H/K woofers in the F-series cars appear to be essentially the same as those found in the G-series cars.

The true test, of course, will be how they sound with the rest of the system in the car - and I am confident they will sound good (and better than the stock ones). Spring has not quite “sprung” yet here in the northeast, but average temps are starting to rise finally so hopefully it will be warm enough soon for me to get to work installing this stuff …..

[Billfitz]

The Audison woofers aren't any better than the H-K, although they will go louder with the same volume control setting due to their 2 ohm impedance versus the 8 ohm H-K. That's fine if you're using an aftermarket amp that has 2 ohm load capability. Used with the stock H-K amp it would probably overheat.

[jmciver]

Originally Posted by Billfitz

The Audison woofers aren't any better than the H-K, although they will go louder with the same volume control setting due to their 2 ohm impedance versus the 8 ohm H-K. That's fine if you're using an aftermarket amp that has 2 ohm load capability. Used with the stock H-K amp it would probably overheat.

That is exactly why I wanted to go with a non-stock underseat woofer with this amp as the UP10DSP will provide 160W at 2 ohms to the two underseat channels. The Audison’s have a good sensitivity spec at 91 dB as well (better than stock, but I am speculating, and better than almost all 8” woofers I could find). And finally, while the Audison’s can’t go as low as stock (or other aftermarket alternatives, like the Earthquakes), I have a trunk sub to take care of the low frequencies. The higher frequency response of the Audison’s (45-500 Hz) will allow me to use the underseat woofers to fill in more mid-bass, working with the rest of the mid-ranges in the car, since the lower subwoofer frequencies will be handled by the true subwoofer in the trunk….

At least, that is the method to my madness…

[Billfitz]

I doubt that the Audison go higher than stock, nothing in the specs indicate that, and you don't want to venture far into the directionally locatable frequencies with the woofers anyway. But you're right in not getting a woofers that go lower than stock, as that results in lowered broadband sensitivity, and when you've got a trunk sub anyway there's no upside to using underseats like the Earthquakes.

As for the claimed 91dB sensitivity of the Audisons, it's actually 85dB at 1 watt. It would be 91dB at 2.83 volts, but that's 1 watt into 8 ohms, not 2 ohms. In the business we call that a marketing department writing a check that the engineering department can't cash. Still, with the same applied voltage the Audisons will go audibly louder than stock.

[jmciver]

Originally Posted by Billfitz

I doubt that the Audison go higher than stock, nothing in the specs indicate that, and you don't want to venture far into the directionally locatable frequencies with the woofers anyway. But you're right in not getting a woofers that go lower than stock, as that results in lowered broadband sensitivity, and when you've got a trunk sub anyway there's no upside to using underseats like the Earthquakes.

As for the claimed 91dB sensitivity of the Audisons, it's actually 85dB at 1 watt. It would be 91dB at 2.83 volts, but that's 1 watt into 8 ohms, not 2 ohms. In the business we call that a marketing department writing a check that the engineering department can't cash. Still, with the same applied voltage the Audisons will go audibly louder than stock.

I definitely agree with you about not playing these at a frequency too high where directionality (or beaming) becomes an issue - especially since they are mounted in the underseat position (vice a door). While I could not find a graph for these specific woofers, I found graphs of similarly spec’ed 8” woofers where beaming began to occur around 300-350 Hz or so. Obviously an apples to orange comparison here, but what I learned is that I will not band pass them too high in order to prevent beaming while still trying to provide more mid-bass.

I am looking forward to playing with the tuning…

[Billfitz]

Beaming only occurs above where the cone diameter is a wavelength. Most eights have a cone diameter of around six inches, which is one wavelength at 2200Hz, and even there it's not really beaming, it just has no more than a 180 degree dispersion pattern. I run tens and twelves to 2kHz without a problem. You can have midrange response roll-off from an eight, but only those with very low Fs and a commensurate high Mms. You'd see that in some subs with Fs lower than 35Hz, like the Dayton Ultimax 8, but even that runs OK to 1kHz.

[J555]

Originally Posted by Billfitz

The Audison woofers aren't any better than the H-K...

Have you ever listened to them? Are you familiar with HK, finally?

The difference is night and day (as with any single crappy HK speaker compared to quality aftermarket ones).

[jmciver]

Ok, quick update so people don't think I abandoned this project . It is still pretty cold here in New England, as Spring can't come soon enough. But there have finally been some warm enough days I could work in the garage without seeing my breath while working… .

I added some sound deadening material to the trunk. Both to help with road noise a bit and also to help the trunk sub perform better and limit some vibration/resonance. I also specifically added sound deadening material to the driver side area of the trunk as that is where I will put the trunk sub now (previously I was going to put it on the other side).

As far as the Match UP10, I have made some progress getting the amp rack done, but still need to work on the cable routing/management a bit before final install as the space is tighter than I originally thought. That said, for anyone else installing this amp, what I am doing is not required - I just want to have a more "tidy" install . Also, one other feature of the UP10 that I am looking to incorporate is to have my V1 radar detector interface directly with the amp, that way any V1 alerts will come through the car's speakers instead of from a remote speaker I have installed behind my dash. With the DSP functions, I can even pick which speakers I want the V1 alerts to come from (like only the front driver speakers for example).

So still more to come but hopefully I will have music coming from the amp this weekend and possibly even start playing around with tuning a bit….

[johnung]

Originally Posted by Billfitz

I've only been able to measure my Hi-Fi woofers.
Fs 51 Hz
Qes 1.00
Qms 3.02
Qts 0.75
Vas 18.4L
Re 2.4 Ohms
Le 0.22 mH
Sd 200 sq cm
xMax 6 mm

Impedance aside I doubt that the H-K are significantly different. I doubt you'd have any distortion issues with even a 60Hz high pass on them. Mine don't reach 10% THD at full tilt and they're not high passed.

Hey Bill,
If you would like to gather information on the HK subs I could easily ship you mine to test. I'll pay the return shipping too to contribute to the knowledge base. I can probably send you an HK midrange and a tweeter at the same time too. Please let me know.
John

[Billfitz]

I thought I already agreed to that in a PM, like a year ago. I'd post the measured specs and frequency response charts so anyone can compare them to aftermarkets, although finding them for most aftermarkets is like playing 'Where's Waldo'.

[blau3er]

Interesting!

[Neil07]

Originally Posted by jmciver

Ok, quick update so people don't think I abandoned this project . It is still pretty cold here in New England, as Spring can't come soon enough. But there have finally been some warm enough days I could work in the garage without seeing my breath while working… .

I added some sound deadening material to the trunk. Both to help with road noise a bit and also to help the trunk sub perform better and limit some vibration/resonance. I also specifically added sound deadening material to the driver side area of the trunk as that is where I will put the trunk sub now (previously I was going to put it on the other side).

As far as the Match UP10, I have made some progress getting the amp rack done, but still need to work on the cable routing/management a bit before final install as the space is tighter than I originally thought. That said, for anyone else installing this amp, what I am doing is not required - I just want to have a more "tidy" install . Also, one other feature of the UP10 that I am looking to incorporate is to have my V1 radar detector interface directly with the amp, that way any V1 alerts will come through the car's speakers instead of from a remote speaker I have installed behind my dash. With the DSP functions, I can even pick which speakers I want the V1 alerts to come from (like only the front driver speakers for example).

So still more to come but hopefully I will have music coming from the amp this weekend and possibly even start playing around with tuning a bit….

Did you get your system up and running yet? I'm curious about how the mids sound? I took the path of installing the Bavsound Revenant Pro Amplifier. To be honest it sounds like a better version of the stock HK system but it is still lacking mids. I'm thinking about changing over to what you are doing.

[jmciver]

Originally Posted by Neil07

Did you get your system up and running yet? I'm curious about how the mids sound? I took the path of installing the Bavsound Revenant Pro Amplifier. To be honest it sounds like a better version of the stock HK system but it is still lacking mids. I'm thinking about changing over to what you are doing.

Unfortunately, "life" (i.e. family, work, etc.) has slowed me down more than I would have liked. But I made some decent progress this past weekend and should have some sound out of the system this coming weekend. The only component I don't have yet is the trunk sub, but I don't need it to get the system initially up and running. Below is a pic of my amp rack on my workbench, which is finally installed in the car (but not powered up yet)…..

[dkroks]

If you don't mind me asking, where did you purchase your Match / Helix gear online? There does not seem to be a whole host of retailers with an online presence. Looking to pick up the same set-up and have been struggling to find a source.

thx

[jmciver]

Originally Posted by dkroks

If you don't mind me asking, where did you purchase your Match / Helix gear online? There does not seem to be a whole host of retailers with an online presence. Looking to pick up the same set-up and have been struggling to find a source.

thx

I had similar issues as well and after several negative search results, including using the "find dealer" feature on the Audiotec site, I found a vendor in the UK, via eBay. Search "allwoodsaudio" and they even offer remote tech support as well (which I have not needed to use yet, but may in the near future).

[jmciver]

So for those of you wondering about the amp rack part of this project, I chose this route (as opposed to using Velcro and/or double sided tape) because I wanted some additional install flexibility. After watching a lot of YouTube videos by car stereo shops/influencers, I decided to give it a shot. This is my first time with this type of project.

Unlike the UP7BMW amp by Audiotec, the UP10 does not have the OEM mounting bracket on the back of the amp that mounts to the factory amp bracket. I purchased a cheap, used BMW HiFi amp off eBay from a F25 X3 to serve as a donor for the mounting bracket. I attached the slightly cut/modified bracket to the back of a cellular PVC board purchased from Home Depot (pic below).

I mounted the amp, MOST interface, and power distribution blocks to the cellular PVC board using screws and screw inserts to make removal of components easier if necessary - and I needed to remove/install components on the PVC board several times as I figured things out.

The power distribution blocks, one for power and the other for ground, were used so that I could easily get power to the separate amp for the subwoofer that is coming. While moving slower than I would like, it has been a fun DIY project so far .