Subwoofer - Passenger leg-room

[stfallet]

I found this install for a subwoofer while searching for a solution for my A124. Might be as well of interest for the W124.036

Mercedes W124 E500 / unsichtbares Hifi System - Car & Audio GmbH

Subwoofer für Mercedes W124 Fußraum | KIT-SUB-W124

Any thoughts?

 

[gsxr]

It looks like a single 8" sub, which will add a little bottom end, but not a lot.

I'd seriously consider the Jehnert doorboards as an alternative. The dual 6.5's will have similar output as one 8.0, but won't play as deep. Look at @Jlaa's thread from a few years ago with Jehnert doorboards, Focal drivers, and DSP to get it all time-aligned.

To add serious bass you generally need an enclosure in the trunk, or 1-2 small subs in the rear deck in place of the first aid box.

 

[stfallet]

@gsxr, no disagreement on the W124, C124 but for the S124 or particular the A124, the trunk does not work. And if you want to keep the car original, this would be a solution. Even under the rear seat is not an option as it is full with all types of CPUs and system components

 

[gsxr]

Yes, good point about S124/C124. Sorry, I missed that you specified A124 in you original question.

However, on the C124/A124 the Jehnert doorboards allow FOUR midbass drivers per door!

The S124 is more difficult though. I'd still recommend starting with the Jehnert setup (or equivalent) and see if you want/need more bass beyond that.

Mercedes E-Class W 124 Cabrio / Coupé - Doorboards

Quadruple bass sytem 4x 165 mm (6,5″) JEHNERT »POWER WOOFER« per side…

www.jehnert.de

 

[jnes]

A bit off topic but I realized that I have Jehnert doorboards but the speakers and rest of the kit is missing. When I removed doorcards I noticed that those doorpocket assemblies were very professionally made. I wondered those a quite a long time since the rest of the speaker installation wasn't so we'll made but doorpockets were.

Then some more investigation and couple of email exchange with Jehnert confirmed this that they are their product. I almost give those away like free of charge. Unfortunately the original mesh installation from Jehnert is not available and mine are lost. I've been thinking of rebuilt it. I managed to find the snap on fasteners what Jehnert used back into the days (they have changed the design of cover for the speakers)

 

[maw1124]

I'd still recommend starting with the Jehnert setup (or equivalent) and see if you want/need more bass beyond that.

Why, when this seems so much simpler? The Jehnert still fires into the seat cushion and this fires up from one corner of the car.

They seem equally viable to me, and this one perhaps more easily reversible.

I still think the rear deck is the only place that makes sense, but I don't know that anyone wants to hack up a 500E that way.

maw

 

[gsxr]

Why, when this seems so much simpler? The Jehnert still fires into the seat cushion and this fires up from one corner of the car.

They seem equally viable to me, and this one perhaps more easily reversible.

It's mostly a function of cone area. Eight total 6.5" drivers can move a lot more air than a single 8". Firing into the cushion doesn't matter, the lower frequencies are non-directional. The sub is more reversible though, if desired.

I still think the rear deck is the only place that makes sense, but I don't know that anyone wants to hack up a 500E that way.

Totally agree on a sedan or coupé. But, the OP is dealing with a cabrio, and there is no rear deck available.

 

[maw1124]

I think the non-directional bass that you're thinking about is lower than the door boards play. But I take your point about surface area. I'll trade surface area for lack of obstruction. Of course, this sub still leaves mid-bass firing into the seat cushion, which is the real problem (with factory and Jehnnert). But we have rear speakers for that "fill".

maw

 

[gsxr]

Below 200-500 Hz, sound is largely omnidirectional. It depends on the specific crossover frequencies, but in general, most of what the doorboard drivers will play won't affect the soundstage by firing into the seat cushion.

This is where DSP works magic. Along with time alignment, the EQ capabilities will compensate. Without DSP it would be a lot more difficult to make this sound "right". Just ask @Jlaa.

 

[duuder]

It's mostly a function of cone area. Eight total 6.5" drivers can move a lot more air than a single 8". Firing into the cushion doesn't matter, the lower frequencies are non-directional. The sub is more reversible though, if desired.



Totally agree on a sedan or coupé. But, the OP is dealing with a cabrio, and there is no rear deck available.

never been a fan of the footwell option, even for a 911 and i have 3 6.5" drivers and they hit!

 

[maw1124]

Below 200-500 Hz, sound is largely omnidirectional. It depends on the specific crossover frequencies, but in general, most of what the doorboard drivers will play won't affect the soundstage by firing into the seat cushion.

This is where DSP works magic. Along with time alignment, the EQ capabilities will compensate. Without DSP it would be a lot more difficult to make this sound "right". Just ask @Jlaa.

I have DSP and time alignment and all that... omni-directional is subwoofer bass (80Hz and down), not 6.5" bass. Slim mount under seat and other 10" subwoofer designs didn't evolve for nothing is my view. But reasonable minds can differ I suppose.

maw

 

[stfallet]

I have DSP and time alignment and all that... omni-directional is subwoofer bass (80Hz and down), not 6.5" bass. Slim mount under seat and other 10" subwoofer designs didn't evolve for nothing is my view. But reasonable minds can differ I suppose.

maw

Do you know something that fits under the seat in a W124 with electric seats?

 

[maw1124]

Do you know something that fits under the seat in a W124 with electric seats?

Nope... I suppose you could try to make one of the BMW specific units fit

Bavsound Ghost Underseat Subwoofer Upgrade

GET DOUBLE THE BASS IN YOUR BMW OR MINI IN ABOUT AN HOUR.Simply swap your factory underseat woofers with our plug & play upgrade kit and, get incredibly ...

www.bavsound.com

But that's a science project that I'm not interested in. I feel like I've read about some for the newer Benzes, but again, a science project. I went with a sub in the trunk which has its limitations, as do the door mounted units, it's all puts and takes. In this car I'm more interested in keeping it stock-ish and easily reversible. The exhaust is a more interesting note.

maw

 

[stfallet]

Trunk is on the A124's sadly not an option. I did find a spot between the headrests, just not sure how healthy that would be for the kids besides needing some metal work.

 

[Jlaa]

Below 200-500 Hz, sound is largely omnidirectional. It depends on the specific crossover frequencies, but in general, most of what the doorboard drivers will play won't affect the soundstage by firing into the seat cushion.

This is where DSP works magic. Along with time alignment, the EQ capabilities will compensate. Without DSP it would be a lot more difficult to make this sound "right". Just ask @Jlaa.

Yeah, I have my Jehnerts (with twin 6-3/4" woofers from Focal in each doorboard) crossed over at 250 Hz. I use the door speakers largely as bass modules. The soundstage all comes from the dash. You can see my dash midranges go from 250 Hz - 4500 Hz and my dash tweeters go from 4500 Hz to 20 KHz.

I remember using the All-Pass filter in the DSP with a center frequency of 85 Hz to really ensure that bass output between L/R was additive and didn't get all messed up, firing into the seat bottoms.



I feel like the biggest reason I was able to get this whole thing to work was because of active amplification --- each driver (tweeter / mid / woofer) could be independently levelled and time aligned and crossed over. If I remember correctly, my biggest lessons, after fussing with the DSP for several years, was that:

a) Adjusting output (volume levels) does a lot more than one would think for steering soundstage at the midrange and up.​

b) Adjusting time alignment and phase (all pass filter) does a lot for finding optimum bass output. Many people think time alignment == DSP but actually its a tiny part of what you can do with DSP settings. Adjusting phase on a per-driver basis is huge for bass. You can't do that unless you are actively amplified & using a DSP.​

c) Cranking up max delay for the rear speakers AND using the DSP to ensure the rear speakers are Left MINUS Right (the difference between L and R channels) made a big difference in adding a nice concert hall feel to the car.​

 

[Jlaa]

never been a fan of the footwell option, even for a 911 and i have 3 6.5" drivers and they hit!

Good observation. I have an old 911 as well and have two 6.5" woofers in the front door panels firing into footwell. That totally hits! I figure it hits because:

1) Footwells act as some kind of resonance chamber.
2) Small cabin = high degree of cabin gain.

My 4x 6.5" woofers in my 500E's Jehnerts firing into the front seat bottoms totally DID NOT HIT to the degree my 911 did, and I was chagrined for a few years. Playing with time alignment / EQ curves / crossovers frequencies didn't help much.

Only after a few years when I stumbled into using All Pass Filters (in the DSP) to adjust phase to the woofers did I get the 4 x 6.5" woofers in the 500E's Jehnerts to really really hit. Now the 500E hits harder than the 911, and it's great.

By the way, you can see how if you have a single bass driver (like a small subwoofer playing in mono in the trunk) then an All Pass Filter won't do anything because its playing bass with only one driver --- no need to ensure multiple drivers are in phase.

However, if you have multiple bass units playing (like 4x 6-3/4" woofers) then All Pass Filtering could do a lot to ensure proper phasing.