Amiga Build

[djg]

SB Acoustics is a manufacturer of quality speakers. There are many DIY designs using them. You could not build an Amiga speaker with SBA components.

[Basshead]

djg SB Acoustics in Indonesia - I checked their website and it appears they have different driver brands; are they copies or replaceable with Dayton RS180's?

Geoff Millar "The vent is 2" diameter and is 3.5" inches long" somehow I managed to completely overlook that sentence!


Chris Roemer So it's safe to assume the "-s" suffix denotes the "shielded" version of the driver and it will have little impact overall. I already know the difference in voice coil resistance affects the selection of XO components.

[Geoff Millar]

:From Paul's website:

https://sites.google.com/site/undefi...speakers/amiga

"The cabinet is about 30 Liters internally, and is tuned to 39 Hz. This gives an F3 of 34 Hz (ooh, yeah!). The vent is 2" diameter and is 3.5" inches long."

When I bought our RS180P-8s (same price as the al version) they were A$64 each, shows you what's happened to our $ since then. At the time, something like the Peerless 830883 was about $90, now it's $109 so they haven't gone up as much in comparison, nor have SB drivers.

Money aside however, the RS180P is a great sounding, great looking woofer and the $$ are forgotten once we play some music.

Geoff

[djg]

Have you investigated sourcing your components from SB Acoustics in Indonesia? Top quality, maybe different supply chain. Going from China to US to AU is just crazy.

[Chris Roemer]

In the beginning ...

the 1st batch of RS (Al-coned) drivers were ALL shielded (remember CRTs?). Later (after the demise of CRTs) the shielding was dropped (co$t $avings - I presume?) without really changing the drivers names. (There WAS/is? a "shielded" woofer still made to drop into the most popular designs - could be the 180? - 180S now.)

Many designers tried dropping the NEW RS (unshielded) drivers into designs that started out w/the "original" (shielded) drivers, and almost all of them decided that the new versions could drop in w/out any crossover changes (and MOST box sizes/tunings were adequately "close" as well).
8ohm vs 4ohm designs require major XO changes.

[Basshead]

Thanks Wolf.

After further reading of the forum and PM’s with Geoff Millar, it’s likely the freight costs (to Australia) combined with the exchange rate will bump up the price of the knock-down kits (even with just the baffle) substantially.

I’ve been unable to locate any threads with specific details or plans showing the port dimensions for the Amiga (nor can I find them on Paul’s pages) - does anyone have the details?

Also, as I’ll likely be sourcing the drivers locally, is the RS180-S (as shown in the crossover diagram) the same as the RS-180-8? (Perhaps that just a typo or the model number has changed slightly in the past decade?). I’m assuming I need the 8ohm version?

The RS180-8 is presently AU$119ea locally (compared to <US$50 on PE) and the tweeters are approx AU$60ea locally (compared to US$20ea on PE). As a rough guide, US$20 (with straight exchange rate only) is approx AU$30 so we’re paying double the US prices for the same gear here in Australia. And that’s before freight and possible GST.

[Wolf]

1 cab/purchase, they do not come in pairs.
Wolf

[Basshead]

Sorry to hijack your thread… I was drawn to these speakers from their name and having used the computer with the same name since the late 80’s. I’m considering these speakers as a replacement for the front mains (L and R) for Paul Carmody’s Swope HT. Apart from the different drivers, would anyone know if this would be an issue?

Also, do the Amiga flat-pack (knock-down) kits come as a pair, or single (ie. would I need to buy 2 kits to build 2 speakers, or just one kit)? From the photos on the item description it implies there are parts for just one speaker, meaning I’d need 2 kits

[davidB]

If the EQ works, try a shallow notch in that area(as you weaken it with parallel resistance you will widen it, so you can pull the whole area back into line with the general power response slope you have going).

Don't give up on a good tweeter at the first problem.

[joshshetter]

You can see the hump here in my dirac measurements. Makes the speaker quite annoying to listen to.

[joshshetter]

I'm unsure of whether to finish these guys. I'm finding that I don't care for the tweeter too much. The initial honeymoon phase is over and there's some hump around the 5300hz region that doesn't gel with me at all. I have Dirac running on them and it really cleans them up a lot. I frankly find them quite shouty without the EQ. I don't know if I want to invest the money and time into a finish for a speaker that has such an issue.

So I've got xsim out and playing with the design and some other tweeters, and some xover mods. Might try something else, noticed that a lot of the soft dome peerless tweeters have a little bump at 5300hz on the tymphany sites measurements, wonder if that's a test rig thing or something inherent to many of their soft domes.

[djg]

It's Matt Grant associated with DIYSG. I used a pair in the S2000 MTMs I built. They are very nicely made.

[Operandi]

Oh, ok I thought they were doing custom PCBs specific to audio PCBs. Not sure as I haven't tried them but I think Madisound does but they do the entire crossover with components.

[joshshetter]

Just google "Amiga Crossover PCB" and it's the first result, ebay seller. They have PCB's for a few kits, not sure what one would do if they needed a custom PCB.

[Operandi]

Crossovers are put together, annoyed by one of the inductors but as the leg didn't want to play how I wanted so it sticks out a bit. Boy I don't know what I'd do without these pcb's you can order on ebay.

Those corssovers boards look really nice. I didn't know this was something you could do. Would you mind sharing which seller you used, searching on eBay is kind of a nigthmare.

Speakers look great btw!