why does a large fullrange speaker sound special?

[Tristen]

A (rough) analogy using cars would be to compare a bare-bones hatchback with a normally-aspirated 1.5 liter four cylinder engine and narrow wheels to a Camaro with the 6.2 liter V-8 option and 20" steamroller wheels: sure, both cars can cruise easily and stably at 60mph, but - and of course I'm talking about the Autobahn in this next example - when cruising at 100mph, which car will be more stable & drivable at THAT speed?

As a random point of interest: I very regularly drove a 1.6L I4 NA car with narrow wheels that would spank a Camaro with the 6.2L V8... On the other hand, though, my car had a super high compression and high-reving build. It was also mid-engined, and quite stable at 100mph (and very stable at high speed on windy back-roads too). Similarly, I also drove a 250cc shifter-cart that would hit a top speed of 120 and pull 3g's in the courners. Camaros can basically go fast in a straight line where something nimble will not only beat it in a straight line, but also on a track that has turns.

As far as bare bones hatchbacks with.... subaru wrx and mitsubishi lancer evo's both have 4 cylinder engines. (though they're turbo'd and the evo is 2L I4 and the wrx is a boxer (4F) ... i digress) :zoom:

 

[BadassBob]

^ Yep looks like someone may have been inspired by the RCA....but hey, if it sounds good, doesn't matter when it was designed! That must be destined for a laptop, one of the popular methods of listening to music for many people nowadays.....

BTW this idea kind of partly defeats the purpose of using an FR driver i.e. no crossover, but if an FR sounds too "shouty" a contour network could help with that by depressing the midrange just enough to create a more balanced-sounding listening experience. Such a network was described in the Weems RS design book (which I bought in '83) for that 40-1197 driver. The classic BBC LS3/5a mobile broadcast monitor used something similar to increase that speaker's perceived bass output by severely depressing everything above a certain point (I want to say 100Hz but can't remember for sure). Trade-off? Sucked up a lot of power to do this, but since size was the critical parameter for this model, that was deemed acceptable.

What youre speaking of sounds like a Baffle Step Correction circuit. I employ one with my FE207s. It attenuates everything above 500Hz by -3dB so the perceived bass is louder. A BSC circuit is generally nothing more than a resistor and inductor wired in parallel, then wired in series with the driver. My speakers suck up that much more power, they still play quite loud with my 3W SET. They went from 95dB 1W/m to 92dB. I wouldnt necessarily say it defeats the purpose of a full range driver, youre just tailoring the driver to suit your needs. The BSC circuit doesnt hammer down the rising response of the speaker, there are notch filters for that. A notch filter only addresses the peak in the midrange, while a BSC attenuates everything past a certain frequency.

 

[RadShak1251]

Tristen: I wanted to use a specific car model in my analogy but didn't want to piss off anyone. The "barebones hatchback" to me means an entry-level model with vinyl seats, an AM/FM radio-only deck, no anti-roll bar for the rear suspension, mushy bushings/shocks/springs, etc. And the Camaro is the new one based on GM's new "global" rear-wheel drive platform (though IIRC it was designed in Australia), with 4-wheel independent suspension rather than the solid rear axle of all previous versions and the other modern features a global platfrom must have these days to keep a car company from being ridiculed. Not that I believe a Camaro will embarrass a TOTL Porsche but it certainly has come a long way since the days of leaf springs and fussy 4-barrels.

 

[RadShak1251]

I wouldnt necessarily say it defeats the purpose of a full range driver, youre just tailoring the driver to suit your needs.

Oh I agree. But I was mostly referring to FR purists who want to see only a couple of wires between the driver's leads & the binding posts on the rear panel.

 

[BadassBob]

Oh I agree. But I was mostly referring to FR purists who want to see only a couple of wires between the driver's leads & the binding posts on the rear panel.

Ahh yeah...those types lol. Those are usually the folks you see with the elaborate cabinetry.

 

[TerryO]

Oh I agree. But I was mostly referring to FR purists who want to see only a couple of wires between the driver's leads & the binding posts on the rear panel.

Hey, I'm one of those luddites myself!

Well, not exactly, as I'm certainly open to filters........"IF" they increase the overall quality of the sound.

Passive crossovers or filters are subtractive and do affect the signal to some degree. I'm willing to employ any means to get better sound, as long as I'm not limiting something else that I find even more desirable. It may be that in one instance I need effeciency due to an amplifier with limited output and I would be losing some clarity of sound by imposing a notch filter that perhaps isn't that critical by comparison.

I think that the least amount of filtering needed is best, but it's a choice that each "designer" must make for themselves.
Let's not forget that a lot of the single driver crowd tend to approach these situations from a mechanical standpoint. This would mean actually modifying the driver, or even redesigning the cabinet/enclosure, to correct or mitigate the shortcomings of a driver. Often this can overcome most of the perceived faults to an acceptable degree.

Best Regards,
TerryO

 

[RadShak1251]

Hey, I'm one of those luddites myself!

Sorry, I am still learning about this field of audio and wasn't implying an FR purist was a luddite. But you can imagine my surprise when I first began to check out the world of fullrange systems and saw FRs paired with a tweeter, albeit crossed over at a very high frequency so it was really a supertweeter. So obviously there's some "wiggle room" in the FR universe.

This would mean actually modifying the driver........

I gotta admit this scares me a little, especially if it involves an Xacto knife!

 

[BadassBob]

Sorry, I am still learning about this field of audio and wasn't implying an FR purist was a luddite. But you can imagine my surprise when I first began to check out the world of fullrange systems and saw FRs paired with a tweeter, albeit crossed over at a very high frequency so it was really a supertweeter. So obviously there's some "wiggle room" in the FR universe.
I gotta admit this scares me a little, especially if it involves an Xacto knife!

Ive taken an Xacto to my FE207s...the hardest part is building up the nerve to cut into em lol. I had to do it to install my phase plugs. While it was nerve racking at first, the end result made it worth it :thmbsp:

 

[mhardy6647]

I had the same experience with 40-1354 drivers I waited until I had three pairs on hand before I tried the dustcapectomy to add Dave Dlugos' phase plugs. That result, also, was worth the effort/risk (FWIW).

 

[BadassBob]

I had the same experience with 40-1354 drivers I waited until I had three pairs on hand before I tried the dustcapectomy to add Dave Dlugos' phase plugs. That result, also, was worth the effort/risk (FWIW).

I was going to order another pair of FE207s when Madisound had the fire sale on them....just in the event I slipped the Xacto the wrong way. In all honestly, the job wasnt as difficult as I anticipated. After I removed the bulk of the dust caps, I stuck a wad of masking tape on the pole piece, to catch any debris that might fall as I was removing the excess material.

 

[TerryO]

Sorry, I am still learning about this field of audio and wasn't implying an FR purist was a luddite. But you can imagine my surprise when I first began to check out the world of fullrange systems and saw FRs paired with a tweeter, albeit crossed over at a very high frequency so it was really a supertweeter. So obviously there's some "wiggle room" in the FR universe.
I gotta admit this scares me a little, especially if it involves an Xacto knife!

No need to apologize, "The Way of the Fullrange" is a difficult journey for those of us brought up in the traditional Multiway Gestalt.

Ok, I'm certainly overdramatising it a bit, but it does entail a different approach. Truthfully, in the FR Universe it's all about "wiggle room!"

I remember on the old "Bass List" that one of the members, Magnus Idland (sp?), went about with an Exacto knife cutting up cones. We all knew he was nuts, but when he finally finished doing his thing, he then released the Scan-Speak slit cone drivers which, it was admitted, sounded very nice indeed.

It's all Good!

Best Regards,
TerryO