Dave's testing for 1980's looking Infinity speaker <$300 USD

[DaveFred]

Ever since I first saw them in the 1980's I loved how Infinity speakers looked, the red oak vertical slats making a half round on the sides, the black felt baffle face, dome mids and ribbon tweeters.

For Midwest Audio Fest 2024, I have decided to try and make an Infinity look alike speaker for under $300.00 USD. Consider these more of a Fiero kit car rather than a full on honest attempt to recreate a vintage Infinity speaker (that will happen another time).

To this end I have acquired a number of drivers to test and play with,

Peerless Tweeters,

$19.91, D26NC56-06
$14.66, BC25TG15-04
$13.91, XT25SC90-04
$12.17, DX20BF00-04










Peerless Mids,

$16.08, GBS-85N25PR03-04 (x4)
$20.73, GBS-115N25AL01-04 (x4)
$18.19, GBS-135F25AL02-04







Peerless Woofers,

$33.87, GBS-200F35CP02-04
$78.04, GBS-250F38CP01-04





Newark/Farnell Multicomp Pro Woofer,

$39.99, 55-5670





I have a number of cheapo Aliexpress Planar type tweeters that should show up soon to add to this list.

[DaveFred]

Here is the style of Infinity speaker I am referring to,



I will stress that it is a look I am going for, not a reproduction, I know that cannot be done with the selected drivers and budget.

Like the Price is Right, the goal will be to select the best drivers for the best output (frequency response/distortion, efficiency will not be a consideration) for under $150.00 USD per unit without going over...

Here is a pic of most of the drivers out on a table,



-----

And several possible configurations,

$19.91, D26NC56-06
$16.08, GBS85N25PR03-04
$20.73, GBS-115N25AL01-04
$39.99, 55-5670

total $96.71



-----

$20.73, GBS-115N25AL01-04
$19.91, D26NC56-06
$20.73, GBS-115N25AL01-04
$78.04, GBS-250F38CP01-04

total $139.41




-----

$19.91, D26NC56-06
$16.08, GBS85N25PR03-04
$20.73, GBS-115N25AL01-04
$78.04, GBS-250F38CP01-04

total $134.76




-----

$19.91, D26NC56-06
$18.19, GBS-135F25AL02-04
$78.04, GBS-250F38CP01-04

total $116.14



You get the idea...

I think I will come up with a standard box width and make a number of stacking boxes with single drivers in each, like stacking building blocks, to measure different configurations, at least in horizontal axis anyway to determine potential.

(note, I think the Peerless 8" dome might suck, but time will tell...)

Thanks for watching at home...

David.

[JonMarsh]

Hey! I've got several of those more recent quasi-dome drivers! I did not get around to figuring out something interesting to do with them, so seeing what happened here is interesting...

[tktran]

DigikeyDesign- I like it!

The IL60 had excellent directivity matching. Check out the service manual if you haven’t already.

A relevant old post that may be of assistance:

https://www.htguide.com/forum/mission-possible-diy/design-studies-theory/43477-any-thoughts-on-side-mounted-woofer-css-sdx10-in-floorstander-designs?p=836416#post836416

and I data for the recently built GBS200. PM me if you need.
But In short, for constrained spaces only. No demodulation device - distortion rises quickly above 100Hz. Limited excursion- SPL limits apply: similar to a good (but not excellent) 6.5” woofer.

[DaveFred]

The first driver I have looked at is the Peerless 10" "dome" woofer, ran a DATS 3.0 sweep and did some modeling,



Ported 45 litre box,



Then I was wondering how it would look in a German GHP (geschlossen mit Hochpass/closed with high pass) sim'ed with AJ Horn 7,





Looks like a closed box of 30 litres with a series capacitor of 700µF yields an F3 of ~35Hz.

I think I need to build a box for this and test it!

[DaveFred]

Also had five maybe different Planer tweeters show up from Aliexpress and Taobao, very interested to see if these are useful or a waste of money. Prices range from ~$13.00 USD to ~$29.00 USD each, well within the cheapo budget of this build.