Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: Divano Veloce on May 23, 2015, 12:12:50 AM

Title: alfa 75 audio options
Post by: Divano Veloce on May 23, 2015, 12:12:50 AM
Hello  75 fans

my new daily has an awful stereo. I would like to improve the audio system by simple upgrades, ie, head unit and speakers, rather than amps and sub boxes.... any advice on brands and size of components? Ie, what size speakers will fit in the doors and parcel shelf? Are there any other places for speakers? Is the factory speaker wiring any good?

cheers!
Title: Re: alfa 75 audio options
Post by: jazig.k on May 23, 2015, 10:12:59 AM
The front door speakers are 4x6" by memory. Terrible mounting onto the weak door card.

If you want really quick and simple, 5 1/4" speakers fit the door cars, but only 2 screw holes line up.
Bigger diameter magnet speakers will foul on the door steel and too deep will foul on the window guide. The magnet will also pull a weak mounted speaker towards these [ever seen warped speaker areas on 75 door trims?].
If you don't pay attention like my previous owner, the speaker terminals will rub the door steel and short that speaker out. Make sure they're rotated the right direction to avoid it. Previous owner scored 2 out of 2...

Get hold of some 6mm MDF and make a panel that fits the door cavity hole, screw that in securely. Then you can mount anything to the MDF, just cutting the hole to suit. If you need clearance from the window rail, you can space the speaker out by cutting rings. You can offset the speaker to avoid the the door steel too.

Having a solidly mounted speaker will improve efficiency too, with less energy flapping or moving the speaker around and more energy driving the cone itself. 

Picture for example.
(http://home.comcast.net/~n.a.anderson/pwpimages/DSC00021(1).JPG)

Or you can cut the hole through the door trim like many people do  :(. Still doesn't sort out the weak mounting surface.

Just buy coaxial speakers for the front and wire the stock tweeter in with the speaker. Unless you want to fiddle with mounting a tweeter. Without the stock tweeter the front sounds awful [speaker behind the door trim firing into the seat bolster...]. The tweeter is the saving grace for the terrible positioning.

The rears were 5 1/4" in my TS. Not sure if they changes sizes in any models.

I'm not up to date with brands or current models.
Buy from a store so you have access to warranty. Try to stick with a brand name. Most stores will only cover the headunit if fitted by themselves or a "professional".
Title: Re: alfa 75 audio options
Post by: lombardi on May 24, 2015, 01:36:07 PM
i updated my  75 with pioneer cd ipod radio unit fits perfectly and i play mi ipod through it, changed front and rear speakers but found rear speakers pioneer could not handle the base very good as the factory size given for speakers is quite small,i listen to a lot of heavy metal,since no one sits in the back i put 2x speaker boxes on back seats,not pretty but sound is improved out of sight, a bit unconventional but at least ill speead up my deafness
Title: Re: alfa 75 audio options
Post by: shiny_car on May 25, 2015, 10:06:05 AM
The factory wiring is adequate if you're only powering them from the headunit. Only need to upgrade if adding a powerful amplifier and if the speakers can handle high power.

The front speakers will also never generate any decent bass unless the open service holes are sealed over (this principle applies to any door-fitted speakers in any car).

(http://pic20.picturetrail.com/VOL166/13567593/24576632/409990455.jpg)

If you want to improve the sound, add some self-adhesive sound deadener (eg: Dynamat). Applied over the holes, it will seal the doors (of course, won't be 100% but still a vast improvement). It will result in better bass, clarity, dynamics, and power handling. Expect to spend another $100 or so for the deadener, then you can apply it yourself. Without it, a $200 set of speakers won't sound a lot better than $50 speakers. But sure, if you're only going for a cheap upgrade, you might skip this step.

I know you want it 'simple', but I plan some heavy modification for the stereo. I will fit 8" woofers in the doors, mounted over the hole in the bottom front corner (bottom left of the photo). There will be mdf wood spacers/baffle, to hold the speaker, the door trim will be modified, the doors will be extensively sound deadened. Still, it wouldn't be hard to cut a basic spacer/baffle to fit a 5.25" or even 6.5" speaker into the bottom front corner.

The factory positions are terrible. For better stereo imaging, the left and right speakers need to be as equidistant from your ears as possible. The factory location has the right speaker much closer than the left, and 'down there' instead of 'up front'. The soundstage is 'dragged, down there', which sounds terrible.

But most people are not too fussy, and fair enough.

:)
Title: Re: alfa 75 audio options
Post by: GTVeloce on May 25, 2015, 11:05:12 AM
Agree with all said so far. As I have a great system in the GTV I didn't want to spend big bucks on the 75. So I got the best 4x6's (didn't want to mess with the original finish of the door cards) that have minimal depth and swapped them over. Kept the original tweeters. Some new 5 1/4in speakers for the rear and a good head unit. I also put some dynamat under the rear speakers. Still no mid range or bass to speak of.

I then blocked the holes in the front doors as Shiny suggested. Some improvement but still not enough bass to make quality sound. Managed to get an old subwoofer and cheap amp - make a quick box and shoved it in the boot. Big improvement. Great sound? No. No longer painful, thin music? Yes.

Currently I am a fan of the JVC KR90BT head unit. It works well with bluetooth (both music and phone calls), has two USB ports, a CD as well as an auxiliary and has great adjustability including being able to adjust imaging properly. It is a single Din unit so will slot in perfectly into the existing space. The major negative is no preset radio buttons so its not great for swapping radio stations. We used it on Perth to Paris and loved being able to connect a tablet to it so the passenger could watch movies or Top Gear will we were driving and have good sound.
Title: Re: alfa 75 audio options
Post by: Divano Veloce on May 25, 2015, 03:52:28 PM
THanks guys,

i found this resource.. seems like lots of work but worth the effort!

http://www.sounddeadenershowdown.com/
Title: Re: alfa 75 audio options
Post by: Divano Veloce on May 31, 2015, 06:57:11 PM
I auditioned the existing stereos in both 75s today (I found an old tape of the trainspotting soundtrack). Both had the same issue which is distortion at even low levels of bass, mainly the door speakers vibrating and rattling.... Soundstage is pretty good though. As such, I think that I'll first replace the head unit with one from the Berlina and add 5.25" component speakers in the doors and 5.25 coaxial in the parcel shelf. If I'm not happy with this combo I'll add an amp and some woofers in the parcel shelf. I'll be driving this car a fair bit so want some reasonable sound...!

Any suggestions for 5.25 speakers?

Just to complicate things, would a 6" speaker fit in the place of the 4x6?
Title: Re: alfa 75 audio options
Post by: jazig.k on June 01, 2015, 05:58:33 PM
A 6.5" won't fit, the magnet and frame are too large in the woofers I tried directly behind the speaker holes. A small frame and magnet combo 6" might fit?
If you make up the mdf panels, you can move the woofer backwards, not ideal but you can gain more room. Sound only has the holes in the door to come through, it might sound awful...

Making fibreglass pods can get you into all sorts of combos, and ideas go wild. More work. More time. More money. Not too hard though. I'd be happy to help if need be.

There is a white 75 wrecking in eBay with pods in the pictures. Look awful! But they should be cheap. No idea what size speaker they are made for.
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 02, 2015, 10:59:49 AM
You're right, they do look awful! I think i could do something a bit more subtle....
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 08, 2015, 05:13:36 PM
New (old) head unit is in! Sound is roughly the same of course.

I was thinking of installing alpine spr-50c 5.25" speakers in the doors and the same or coaxial version in the parcel shelf, all run off the head unit using the factory wiring. Also add dynamat as suggested. Any alternate suggestions for speakers? These are not cheap but are efficient so I should get away without a 4 channel amp and associated wiring. For bass I may add a sub and single channel amp at a later date...
Title: Re: alfa 75 audio options
Post by: jazig.k on June 08, 2015, 08:25:53 PM
The rear end of the spr series looks pretty small. How are you going to mount them? If not just to the door card as original, you could mock up a cardboard dummy to see if the spr60 will fit the front doors in your position idea.
Cut 2 cardboard circles the same diameters as the mounting diameter and magnet, spaced/joined by a toilet roll cut to mounting depth. Hot glue gun from a cheap shop and you knock up dummy bits quick and easily. I can't find the magnet diameter though.


Dimensions SPR60:
    Woofer Diameter (mm): 165mm
    Woofer Mounting Diameter (mm): 136mm
    Woofer Mounting Depth (mm): 59mm


Dimensions SPR50:
    Woofer Diameter (mm): 130mm
    Woofer Mounting Diameter (mm): 118mm
    Woofer Mounting Depth (mm): 57mm
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 09, 2015, 06:27:15 AM
Those dummies would probably make good replacement door speakers on their own... they couldn't sound much worse anyway!

I think putting 6.5 speakers might be a slippery slope....They're not that much more expensive but I may then want/need an amp to power the suckers....

Started driving the 75 today for the first time since RWC. At very low volumes and albeit with no mid or bass, the soundstage is really nice (or maybe I have low standards...)

Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 09, 2015, 06:39:19 AM
Another speaker option is this offering from Pioneer

TS-D1320C

Quite a bit cheaper at $170 a pair but the tweeters are a bit "look at me". I'd rather not....
Title: Re: alfa 75 audio options
Post by: jazig.k on June 09, 2015, 11:09:12 AM
You can mount the tweeters behind the original tweeter grill. You need to destroy the original tweeter though, by memory. A bit of hot glue to get it positioned there then something a bit more solid to hold it forever (arildite? Spelling?).

Sound stage is awful. But Im only aware of it because I've had the chance to listen to some competitive cars. Before those cars I had very little idea just how bad the 75 was, or even just any factory car for that matter. That's why I started playing with setups.
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 11, 2015, 08:49:56 AM
I'm thinking that whatever I do i will be cutting the door card (i have two sets to play with...) so i can mount the speaker to the door frame instead. I can mock everything up on the red car then do the install on champs.

(http://i90.photobucket.com/albums/k248/ohospaghettio/F98ED752-F139-43E3-B7A3-D598C1ED17CE-265-000000152E4808A0_zpsrndvwshh.jpg) (http://s90.photobucket.com/user/ohospaghettio/media/F98ED752-F139-43E3-B7A3-D598C1ED17CE-265-000000152E4808A0_zpsrndvwshh.jpg.html)
Title: Re: alfa 75 audio options
Post by: jazig.k on June 11, 2015, 09:08:19 AM
You could follow along with my idea? gets the speaker nice forward and at a better height! These Eclipses are 6.5" with huge rear ends. I built them sticking out so far so I didn't cut anything like the door trim [Edit: tiny enclosure issues for the woofer are less than ideal]. The smaller framed speakers would be much more suitable.

(http://i819.photobucket.com/albums/zz112/jazig_k/1988%2075%203lt/75%20sound%20system%20-%20custom%20pods%20and%203-way%20splits/P1010174.jpg)

(http://i819.photobucket.com/albums/zz112/jazig_k/1988%2075%203lt/75%20sound%20system%20-%20custom%20pods%20and%203-way%20splits/P1010308.jpg)

Link to more pictures.
http://s819.photobucket.com/user/jazig_k/library/1988%2075%203lt/75%20sound%20system%20-%20custom%20pods%20and%203-way%20splits?sort=3&page=1
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 12, 2015, 09:07:05 AM
I think what you've done is beautiful!

Unfortunately I don't think I have time for such a project.... :(



Title: Re: alfa 75 audio options
Post by: jazig.k on June 12, 2015, 10:31:26 AM
They didn't take very long at all! The door pods were probably a weekend job, one day measuring, cutting and glassing, the next a quick sand and cover. 1/2" foam before the vynal for a soft trim and it covers all the faults.
Title: Re: alfa 75 audio options
Post by: lombardi on June 12, 2015, 11:58:56 AM
Awesome work, very inventive and original
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 12, 2015, 12:41:57 PM
Alas I have committed to a path a bit more along what Julian has done with his 75.

I have purchased component 5.25" speakers for the doors (alpine spr-50c) and some cheaper coaxial 5.25 (polk DB510)  for the parcel shelf.... Boring I know... With the savings on rear speakers I have purchased a dynamat door kit and some extra for the parcel shelf. Total outlay of $410.

Should be a fun one day project!

(current projects list extends beyond the grave...)
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 24, 2015, 03:16:37 PM
Speaker baffles made:

(http://i90.photobucket.com/albums/k248/ohospaghettio/828B9F15-5894-4AE7-BB43-5D0081ECD581-9218-00000530BCDB9458_zpsda9nshr3.jpg) (http://s90.photobucket.com/user/ohospaghettio/media/828B9F15-5894-4AE7-BB43-5D0081ECD581-9218-00000530BCDB9458_zpsda9nshr3.jpg.html)

trial fit. The wiring connectors can be flipped to the inside of the door to make way for the baffle. I have connected the speakers and they sound rubbish like this.... next job is to make some more sections to cover the smaller openings then glue/screw it all together with deadener. I think I have a plan for how to integrate a frame mounted speaker with the door trim... It will poke through.

(http://i90.photobucket.com/albums/k248/ohospaghettio/CF4D6812-442E-46B8-839A-FA53F81196F9-9218-00000530AF9EB89C_zpsxgzfrndn.jpg) (http://s90.photobucket.com/user/ohospaghettio/media/CF4D6812-442E-46B8-839A-FA53F81196F9-9218-00000530AF9EB89C_zpsxgzfrndn.jpg.html)
Title: Re: alfa 75 audio options
Post by: shiny_car on June 24, 2015, 04:59:11 PM
They look decent. Good work.

Also cover over the other service holes to improve the performance (eg: with self adhesive sound deadener like Dynamat).

:)
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 25, 2015, 08:07:21 AM
Thanks shiny,

I have heaps of dynamat and will seal up the whole door pretty well. I'm resisting the urge to go bananas with some of the cabin quieting techniques like decoupled MLV.... http://www.sounddeadenershowdown.com/products

The worst cabin noise in the 75 seems to come from the wind deflectors on both front doors.
Title: Re: alfa 75 audio options
Post by: jazig.k on June 25, 2015, 09:28:25 AM
The noise seems worse without them though, but I don't have the smooth deflectorless trim piece, just pulled the plastic out so it catches wind.


Looking good! Nice solid mounting.
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 25, 2015, 10:59:26 AM
It could be that mine are cracked....
Title: Re: alfa 75 audio options
Post by: GTVeloce on June 25, 2015, 02:34:48 PM
Mine aren't cracked and are still the primary source of noise while cruising at speed. Like the look of your mounts and the rest of your install plans. But love the look of Jazig's pods! The other good thing about them is you can return the original inserts at any stage if you want to return it to original.

I have often thought of removing the deflectors to see if it improves the wind noise. Has anyone actually had success doing so?
Title: Re: alfa 75 audio options
Post by: Divano Veloce on June 29, 2015, 08:59:22 AM
In between pulling sumps and bearings I fitted the door cards to the 75 which required cutting for the woofer. With just the main  speaker baffles installed with no sealer or deadener I auditioned the setup. I'm super pleased! With just the front speakers connected this is the second best sound I've experienced in a car, the best being Julians GTV... :P

I am really impressed with what can be achieved with a head unit amp and 5.25" speakers! I've mucked around with car stereos before but never put so much effort into speaker installation. Thanks to everyone for your advice and suggestions.
Title: Re: alfa 75 audio options
Post by: Divano Veloce on July 10, 2015, 07:51:13 PM
Sooo.... I did the seal the door trick with 'Dynamat' to the LHS first, then back filled the door card with foam. Compared left to right and there was a big difference in the lower frequency response.

Sealing the doors have improved the lower frequencies, but overall its the clarity in the midrange and highs that I'm really taken by. I very rarely feel the need to adjust the eq and if I do its only by a couple of dB. In comparison, my wifes Octavia has much more bass but midrange is missing and I'm always either adjusting the eq or volume to try to account for it....

Unfortunately the rear speakers sound terrible in comparison so I'm going to have to build them a nice home too...
Title: Re: alfa 75 audio options
Post by: shiny_car on July 10, 2015, 11:03:18 PM
Sounds like a good result. Nice.  8)