LAN speaker invasion into the dash impossible hole

deQuincey

deQuincey

Quousque tandem...?
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the dash hole is not enough hole

modern speakers find difficult to sit in that place, it is a 4x6, but modern speakers tend to be 4,01 x 6,01 enough to be not fitting the hole

moreover the depth is not compatible with the grille

so
1713190022719.png
 
the inner support, all cuttings have been strategically defined in order to allow assembly and sound flow, but keeping robustness and structural integrity


1713190206018.png
 
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jmackro said:
The Harmon box you photographed says "Nominal impedance: 3.0 ohms", so wouldn't connecting two speakers in series give 6 ohms? And if that's what you are doing, where did you mount the second speaker?
Click to expand...

apologies, yes, 6 Ohm
second speaker seats on top of rear transmission tunnel
insde an appropriate blaupunkt box, it is cute non obtrusive and works well
 
I had the same problem with my 635. The speakers stuck out too far. Solution was a spacer behind the grill of matching material the
that the grill was made of
 
deQuincey said:
is that possible in the e9 ?
Click to expand...
I think it would be tricky; if I understand tthe suggestion well, it would mean bringing the speaker grille further into the passenger compartment, and to (for example - sacrilege warning here:) use an old grille where you remove the slats, so to keep only the 4 edges.

Problem is that directly in front of the grille is one of the wooden pegs on the vinyl tray. The grille couldn't move more then a few mm's.
Erik.
 
eriknetherlands said:
I think it would be tricky; if I understand tthe suggestion well, it would mean bringing the speaker grille further into the passenger compartment, and to (for example - sacrilege warning here:) use an old grille where you remove the slats, so to keep only the 4 edges.

Problem is that directly in front of the grille is one of the wooden pegs on the vinyl tray. The grille couldn't move more then a few mm's.
Erik.
Click to expand...
You right
 
deQuincey said:
drilling holes no space, so hand engine

View attachment 180735
Click to expand...
Curious as to why you have those ports on the right and left. The dash is not sealed, so it acts like what is known as an "infinite baffle". The sound waves from the rear of the speaker are 180 degrees out of phase with those from the front, so if you let the two combine, you will be substantially reducing the speaker's acoustic output.

In addition, all speakers exhibit what is known as "free air resonance" This is the point where the mechanical and electrical characteristics of the speaker combine to create a resonant point. If you take a speaker sitting free, with no enclosure and sweep across the frequency band, you will find a spot where the cone starts moving a LOT. That os the resonant frequency opf the speaker. At that point this input impedance also goes way up, and this causes all aorts of havoc witl the frequency response and, depending onyour amplifier, is hard to drive.

Ported cabinets(AKA bass reflex) use an enclosed box with a port, or hole. The port is designed to compensate for the speaker resonance, but that requires a specific port area and placement which depends on the speaker and the size of the enclosure. Sealed box enclosures manage this resonance by simply damping the mechanical behavior by compressing the air inthe sealed box (sometimes known as "acoustic suspension".

If it were me, I would make that front speaker baffle the same as the rear one (i.e. no side ports).

Also, seems like there should be a lot of low profile oval speakers available. https://www.parts-express.com/speaker-components/hi-fi-woofers-subwoofers-midranges-tweeters

Anyway, I guess the proof is in the result. How does it sound?
 
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ScottAndrews said:
Curious as to why you have those ports on the right and left. The dash is not sealed, so it acts like what is known as an "infinite baffle". The sound waves from the rear of the speaker are 180 degrees out of phase with those from the front, so if you let the two combine, you will be substantially reducing the speaker's acoustic output.

In addition, all speakers exhibit what is known as "free air resonance" This is the point where the mechanical and electrical characteristics of the speaker combine to create a resonant point. If you take a speaker sitting free, with no enclosure and sweep across the frequency band, you will find a spot where the cone starts moving a LOT. That os the resonant frequency opf the speaker. At that point this input impedance also goes way up, and this causes all aorts of havoc witl the frequency response and, depending onyour amplifier, is hard to drive.

Ported cabinets(AKA bass reflex) use an enclosed box with a port, or hole. The port is designed to compensate for the speaker resonance, but that requires a specific port area and placement which depends on the speaker and the size of the enclosure. Sealed box enclosures manage this resonance by simply damping the mechanical behavior by compressing the air inthe sealed box (sometimes known as "acoustic suspension".

If it were me, I would make that front speaker baffle the same as the rear one (i.e. no side ports).

Also, seems like there should be a lot of low profile oval speakers available. https://www.parts-express.com/speaker-components/hi-fi-woofers-subwoofers-midranges-tweeters

Anyway, I guess the proof is in the result. How does it sound?
Click to expand...

Of course everything you mention is very interesting, and I would love to do something to limit the effects you have pointed out.

My problem is mechanical in nature, I have had to solve the mounting of a speaker behind a grille that does not leave enough space

The two openings that, according to you, spoil the sound are essential to be able to insert a tool that holds a nut from the inside

see here:
1717097142806.png




In relation to your question, I can say that it sounds good, but this is not saying much, because in essence I should compare it with a well-placed speaker without the openings; thing I can't do

I wonder if you think that introducing absorbent material through the two openings and thus blocking the bottom of the speaker would be an improvement, well, I can do this

thank you so much
 
Interesting problem!! And a very clever solution? A U-turn socket!...

Yes, blocking the holes should produce more and better sound. You might try some absorbent material, but simply adhering a thin piece of wood (that doesn't interfere with the grille) over the holes will work better. Use an adhesive that can be pried loose later if you need to go back in. I'd patch that gap at the bottom as well. You might also consider paintng the wood black, so it doesn't show through the grille.

Stereo wasn't exactly a super common thing in cars back then. I am an electrical engineer with a serious audio hobby. I have been building speakers ever since the late 60's (Yikes, how did I get that old?!). I have been pondering how to get good sound in my E9 without going too far off the original setup.

I see you are in Bilbao. Always wanted to go there. In October, we will be traveling from California to Barcelona and along the coast to Lisbon (my closest friend moved there from California last summer). I have been many places in Europe, but never to Espania. I live about 60 km north of San Francisco, in the California wine country.
 
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Also, are you familiar with these? They are specifically designed for your situation. Used extensively for blind-bolting speakers to baffles.

TNut.jpg
 
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