Anyone run drivers full range (no crossovers) in their DIY speakers and prefer it? Li

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#21
Jim85IROC said:
like everything else, it's a compromise. I think loudspeakers are where compromises are still the most prevalent, because they're the only part of your signal chain that's still got a mechanical element. Less filters may improve upon some aspects that are considered desirable, but in turn will negatively impact others. Allowing 2 speakers to have a wide overlap in frequencies introduces a whole host of potential problems, especially when their phase alignment isn't perfect. Vertical off axis response usually suffers. Imaging can suffer because you've got 2 separate point sources playing the same thing. Overall sound quality can suffer because woofer breakup nodes aren't well controlled. Baffle step compensation becomes difficult to implement, so these simpler designs often have a weak midbass output, which colors the sound. I generally find these compromises to be too much for whatever perceived benefit that you can get from minimal filtering, but other folks see it differently.
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Yes all speakers are compromises as you say and some people like different compromises which appeal to their ears.

Ive often wondered about the overlap thing also. There are many line array designs out there which do exactly this yet its still popular and has been for some time in the hifi world. And if you go to any sort of professional live event line array set ups are one of the most popular used. It for whatever reasons is used a lot so there must be quite a bit of method and science behind the madness and it must be effective.
 
#22
oon_the_kid said:
I notice the top and bottom speaker drivers look slightly different, with the top having slightly smaller dustcap. Maybe the top is for mid and bass, bottom for bass only. It would create a baffle step like freq response, a 2.5 way I think that's how it is called.

Oon
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Hmm not sure about 2.5 way, but you might be right as these do not have dedicated crossovers to split 3 ways. The bass driver is slightly different from the mid bass above. I wouldnt say there's much midrange coming from the lower driver its more towards the lower registers, they are sold as a 3 way and can be triwired but they are slightly different from a conventional 3 way crossover design, although they achieve a similar overall result I'm sure.
 
#23
Galu said:
The Audax tweeter was high passed at 5,000Hz using a second order filter, but these particular units were actually designed to handle a first order filter as large as 4.7uF.

However, the Audax tweeters eventually stopped tweeting and I 'upgraded' them.

Heresy alert! I run the replacement tweeters via a 2.2uF cap in sympathy with the MS100's minimalist vibe!

I encountered a similar, airy minimilism when renovating my friend's Bose 301 Series 2 speakers.

P.S. I think Jim has just summed up the design philosophy of the MS100. It doesn't have a poly woofer, but it does have a real wood veneered cabinet which helped justify its price! 😉
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Really liked those old bose. I think they were the number one selling speaker ever at one point. Nothing fancy paper cones and paper tweeter cones. Different type of design to conventional again but still just something about them that worked. Interesting you've minimalised them.
 
#25
Galu said:
I have a pair of Mordaunt-Short MS100 speakers from the late 80s.
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I had Royd 7, a smallish British 2-way, claim to fame, no dustcaps, single cap XO (to an audax 10mm dome*). Sounded quite decent.

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*(i still have a handfullof these little tweeters on my give-away pile, i’m keepin ghte special ones with the vapor deposited metal player on the dome.)

dave
 

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#35
The real world problems are that cones break up and sound harsh. Plastic cones have less breakup than paper, and metal is usually off the scale with breakup.

5" breaks up around 7kHz. 6" around 5kHz, 8" around 3kHz. This should be notched IMO.

Tweeters usually have an impedance peak at Fs resonance around 750-1500 Hz. Again this should be dealt with if using a single capacitor.

Mike Chua does a thorough job here with a tidy 6" woofer and horn-loaded Morel CAT 378, though I can think of other woofers like the Peerless 830874 which might do the same things:

Finch (Morel CAT378 + Vifa PL18W0-09-08) – AmpsLab

email him for the circuit. You will learn a trick or two! The best coil and cap design I have seen. But it's not 6dB/octave in practise. And it is not quite as simple as you might expect.
 
#36
midrange said:
The hugely popular RadioShack Minimus 7 had the main driver full range, and a 2nd order hp filter on the tweeter. Sounded very good within its size limitations and still saleable on Fleabay.
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Remember these speakers well, they were very decent actually for what they were. Metal cabinets and surprisingly good sound for these size and price. I had a pretty tasty system once in the 90s and I put these on the end of it just for fun, they sounded phenomenal with it almost as good as my floorstanders at the time, but obviously without the scale.



system7 said:
The real world problems are that cones break up and sound harsh. Plastic cones have less breakup than paper, and metal is usually off the scale with breakup.

5" breaks up around 7kHz. 6" around 5kHz, 8" around 3kHz. This should be notched IMO.

Tweeters usually have an impedance peak at Fs resonance around 750-1500 Hz. Again this should be dealt with if using a single capacitor.

Mike Chua does a thorough job here with a tidy 6" woofer and horn-loaded Morel CAT 378, though I can think of other woofers like the Peerless 830874 which might do the same things:

Finch (Morel CAT378 + Vifa PL18W0-09-08) – AmpsLab

email him for the circuit. You will learn a trick or two! The best coil and cap design I have seen. But it's not 6dB/octave in practise. And it is not quite as simple as you might expect.
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Didnt know that about plastic cones, good to know.
 
#37
Fond memories of the Minimus 7's

I too owned two pairs, from about 1986 to 2004. Ironically, I bought them because I was fascinated by the then-current Polk SDA speakers that provided crosstalk cancellation. I'd never actually auditioned the Polks, but from the articles in the magazines, their "secret" was easily understood. Since one of the requirements was for the "cancel" signal to be within head's diameter (about 6") I ended up with the first narrow enough speakers locally available -- the Minimus 7 at the local Radio Schlock 🙄 . Some reasonably careful set-up, with a ruler and tape measure, and no beers, allowed for a passably "3-D" sound field, especially after additional beers, even better IMO than the Carver Sonic Holography method, which I also had at the time.

After sitting idle for many years, I sold them on Ebay. This was before I realized what a "classic" they were! 😱
 
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