Realistic Minimus 11 mid- woofer upgrade

[Quad Knobs]

I am interested in replacing lower driver in Minimus 11with something more dynamic. Original driver does not seem to play very low or match well with replacement tweeter ( AMT mini-8 folded in original paper tweeters wave guide ). Any ideas for this metal cabinet? Adapter could be made, but would be nice to find drop in driver. Original crossover is in place. Cabinet has been damped.

[Geoff Millar]

Generally speaking, swapping drivers without changing the crossover won't work very well; in this case, the tweeters are already different to what was there originally.

Here's a thread which might be interesting, but the builder worked up a new crossover:

https://www.diyaudio.com/forums/multi-way/293176-rs-minimus-11-look.html

The replacement drivers were the SB Acoustics SB13PFC-8, which have the same odd-shaped frame as the originals.

HTH

Geoff

[Quad Knobs]

Thanks for information.

[AEIOU]

I am interested in replacing lower driver in Minimus 11with something more dynamic. Original driver does not seem to play very low or match well with replacement tweeter ( AMT mini-8 folded in original paper tweeters wave guide ). Any ideas for this metal cabinet? Adapter could be made, but would be nice to find drop in driver. Original crossover is in place. Cabinet has been damped.

Well, there isn't really a lot of room for improvement since many factors come into play. I would say if the original woofers are 8 Ohms, replace them with 4 Ohms, if you can find 4 Ohm woofers that will fit. That of course will necessitate a reworking of the crossover.

[Quad Knobs]

Crossover upgrade likely. Why 4 Ohm woofers?

[AEIOU]

Crossover upgrade likely. Why 4 Ohm woofers?

More voltage sensitivity, up to +3dB more than 8 Ohms woofers. Plus if you decide to implement some BSC, you'll end up losing a few dB. My thinking is that louder woofers will sound more dynamic. One other thing too, whatever woofers you choose to use make sure that the tweeters are at the same level, same SPL. Muted tweeters will make the music sound less lively and even affect your bass perception.

[Stash]

I never liked the 11's. The 7's had a really good overall sound for such a small cabinet. They were fairly well balanced (although treble seemed a bit bright). Bass seemed incredible thanks to psycho accoustic illusion hahaha. Midrange was very accurate. They were breaking-the-rules of speaker building, back in the day. The 11's bass extension was always disappointing. If I remember correctly, RS even tried to include a so-called 'bass port' in the 11's. A tiny ported hole, which accomplished nothing, IMO.

I cannot recall if the 11's used an actual 5 inch driver or a more common 5.25 inch driver.

PE sells a low priced woofer, DC130A-8, which may mate well for your needs. But it is 5.25 inches. Will it fit? It is the proper "pin-cushion" style. Rubber surround. 50Hz fs, which should be comparable or better than the OEM woofer. A response of 50Hz-5Khz, which will match pretty well with your tweeter, without any expensive alterations to the OEM crossover.

I would limit the amount of acoustic fiber fill to just a loose handful. Any more, and you will essentially choke the woofer and kill the bass extension, lose the fullness of music and reduce SPL. These small cabs need to offer as much free air as possible to generate a full warm sound. The cabs are solid die-cast aluminum. You shouldn't have to worry much about cab resonance.

If there is a ducted port, you can try playing with port sealed and open. You may hear a slight difference.

Another riskier option, slightly 'dope' the cone, if you are willing to experiment. But, in such case, you have to add a tiny amount of weight at a time. Expect to do very thin layers. And, worst of all, expect the possibility of ruining the driver.

Good luck!

[Quad Knobs]

Minimus 11 has 5" woofer, no port. I have several sets of Minimus 7, stock and upgraded. They work well with a subwoofer but with larger cabinet of the 11s I'm looking for a fuller range sound. They might still serve best as satellites. The metal cabinets are really impressive, even if harder to modify. I also have Canton Plus S which are like high end M7s, and Bang and Olufsen C40, C50 andCX100. Just replaced surround on woofers and damped cabinets on those. Anyone played around with these? Super strong cabinets but rear panels are vented plastic. Aperiodic maybe?

[Quad Knobs]

I have decided to use my modded Minimus 11's as sats. So I don't really need a "mid-woofer", just a nice mid-range driver to match the Dayton Audio mini 8 AMT tweeter I have already installed. Does anyone have a suggestion for a nice match? I have several subwoofers to try with them.