e46 Touring - audio refresh

[Olaf 3353]

8 hours ago, Neal said:

See if you can find one with a qtc of around 0.5 which in a sealed box should be around 0.7 qts . Best combo of response and low end imho. Cabin gain will help bring up the sub bass region below 50hz can be anywhere between +6 - +10 db. Your plan for back  corner are ideal as usually will play +3db louder than other locations . Important when running an 8.

With QTS value if you haven’t already picked up on it a value of 0.5 is very tight bass but not so good on extension , 0.7 considered the best combo of rhythm and low end extension. 1.0 and above is considered boomy and flabby bass, but ok for hip hop genre where the overhang can work quite well.

with the Alpine R2-W8D2 as an example, the spec sheet seems pretty close to what you've indicated?  I'd be looking at running the two nominally 2 ohm coils in series to make a nominal 4 ohm load, so that'd be the left hand column? (1.8ohm+1.8ohm), Fs 42Hz, Qts 0.48, and in a 0.3 cu ft enclosure, Qtc of 0.73.... am I on the right track?  

I'll need to figure out if it's easy enough to make a 0.3 cu ft (8.5 litres) enclosure - I suspect it is, if these guys can make a 0.5 cu ft (14.6 litres) enclosure for a 10" sub with a little more load area intrusion.  

Other consideration is the Alpine - unlike the more expensive examples - requires at least 4.6 inches (116mm) from front of baffle to clear  the basket and magnet.   I guess I can always mount it a little higher in the baffle, with magnet tilted downward and the baffle accounting for the tilt.

I'll take a look at those links tonight, cheers.

Edited December 29, 2024 by Olaf
link to Crutchfield's manual pdf, depth, dimensions

[Neal 551]

That’s looking good. Good combo of specs and ideal sealed box sub. 11mm one way xmax spec good too. If you compare to the focal that one really wants to be in an infinite baffle set up rather than a sealed box.

With the dual voice coils you could go the other way with a 1 ohm parallel load depending on sub amplifier. More recently there seems to be a number of class D amps that are 1ohm stable. You just do the old I R / V ohms law and work out maximum current and then wire gauge that’s suited. But I suspect 2mm2 will be more than large enough at your target power levels.

With the depth also allow room for the rear vent. If the gap is too small the sub won’t preform as well as it could. Think of it as additional spring loading if it’s too close to the back wall.
One trick you can do with the enclosure is to stuff it. Has the effect of making the enclosure 20% larger to the sub  if you are tight on volume. 

If you can fit it looking like an excellent choice.

At the high end price wise ( JL audio ) I’d skip that and use a stereo integrity bm11 . Similar box size requirements and shallow depth. Bass wouldn’t be as tight as alpine but can go down to 20hz with 0.4 box and 3 inch depth.

[Olaf 3353]

thanks for the sanity check Neal!  

Tight and tuneful is my focus... some of the most fun hifi speakers I've listened to aren't super-acurate (flat)  on the f response graph, or even go way-deep... I'd much rather listen to Linn Kans on a pair of Naim 135's than LS3/5a's on any round-earth amp you'd care to mention;  Royd Minstrels don't go at all deep (I think about 38Hz is it?), though man can they play a tune and portray the sound of bass convincingly.

I think going to a 1 ohm stable amp will require double the amp budget to get something with an iron grip into higher current loads.  To my current thinking (hur hur), there's some balance in the equation of 8" driver, my space constraints, lower-budget focus, and preference for  higher quality/value for money (I can probably find a reasonable sub mono block at around $400). 

the counterpoint is trying to do more quantity at the expense of quality within the budget envelope... a 10" needs more space and better control (or a better, more expensive driver as well...), or running 2ohm with the 8" (or 10") will need a bigger (more powerful) amp so I spend less on speaker quality...

[Neal 551]

Your thinking and logic is good. I have my 8s doing most of the bass range as they do it well and articulate the bass lines nicely with a reasonable amount of authority. 

[rogan 8]

On 12/29/2024 at 11:23 PM, Olaf said:

 

I think going to a 1 ohm stable amp will require double the amp budget to get something with an iron grip into higher current loads.  To my current thinking (hur hur), there's some balance in the equation of 8" driver, my space constraints, lower-budget focus, and preference for  higher quality/value for money (I can probably find a reasonable sub mono block at around $400). 

ex demo

https://hifihq.co.nz/product/7379-DLS-Audio-CCi500-40

 

Edited December 30, 2024 by rogan

[Olaf 3353]

On 7/28/2024 at 3:42 PM, Neal said:

Door connectors

Caution as door wiring  airbag goes via them. The usual disconnect battery before working around them goes without saying. Also stops the airbag light on dash coming on and needed a reset via usual BMW programing tools.

• Straight forward to take out, easy to take out kick pannels
• Connector parts by pulling connect tab
• The audio / speaker connector clips out on one side of the connector , was able to leave it inside door wire garter on my install rather than chopping it off
• Other side doesn't clip out , But the plastic is soft , used stanley knife to cut through the speaker section of the connector, Again didn't chop it
• With running speaker wire through the connectors / door wiring garter / door I used curtain wire as a pilot and taped the speaker wire to it 

 

Pictures

Brief question @Neal - speaker cable guage you used that passes through the connector, please?  16g?

[Neal 551]

Your thinking and logic is good. I have my 8s doing most of the bass range as they do it well and articulate the bass lines nicely with a reasonable amount of authority. 

[Neal 551]

13 hours ago, Olaf said:

Brief question @Neal - speaker cable guage you used that passes through the connector, please?  16g?

I think so , was a Jaycar speaker wire. 79x 0.2 strand.

 

 

Edited January 2 by Neal

[Neal 551]

Other way round do it is to get something like  an AVSS type thin walled high temp insulated wire and twist it together. It won’t take up as much room in the door connector garter. It was a tight fit from what I remembered .

 

eg. Automotive Wires AVSS 24 22 20 18 16 14 13AWG Speaker Audio Cable OFC Oxygen-free Copper Thin PVC Insulation Car Wire
https://a.aliexpress.com/_m0jAYWX

Edited January 2 by Neal