audio-talk

These are very intriguing speakers. Cube manufacture their own drivers ( which you can buy separately at considerable expense) and this speaker features their latest 10inch driver which is allegedly a true FULL range driver. The speakers are getting extremely enthusiastic reviews ( make your own mind up what that is worth]. Given they are a single driver, crossoverless full range speaker I’m certainly intrigued and would like to hear them. As it happens sometime soon they are going to be on demo for a weekend at a hi fi dealer in Nelson, Lancs of all places. If there is interest I can post dates and address once confirmed.

Speakers with whizzers just trade electrical crossovers for mechanical ones.
What makes them more of a full-range driver than, say, one of the Audio Nirvana 15"s? Or even the Seas 8"s?

Going from 8" to 10" is only 3dB more cone area.

Chris

Speakers with whizzers just trade electrical crossovers for mechanical ones.

But there will always be a mechanical xover, so what you are really doing is removing a electrical one. (just saying).

The wisdom I’ve received over the years leads me to conclude that passive electrical crossovers are a bad thing and I’d choose an analog active crossover in preference every day of the week. If though you could do without any electrical crossover without introducing other compromises then that clearly would be ideal. Unfortunately the caveat in that last sentence can’t currently be satisfied AFAIK and so the question becomes one of deciding which set of compromises you prefer. ( That’s true of ALL hi fi designs as far as I can see.). So I’m curious to hear these speakers and discover how their particular set of compromises has worked out.

Nick wrote: ↑Wed Dec 19, 2018 11:22 am

Speakers with whizzers just trade electrical crossovers for mechanical ones.

But there will always be a mechanical xover, so what you are really doing is removing a electrical one. (just saying).

Hi Nick,

Which mechanical crossover are you referring to?
A 3-way design I'm looking at currently has all drivers operating in their pistonic ranges, which means hard metal cones and lots of work to make sure the bell-mode cone breakup peaks aren't excited. I can't see any mechanical crossovers there, though, apart from perhaps the highpass filter that comes from the cabinet's LF rolloff..?

Chris

Its still there though, its just you are choosing to roll off before they reach that point by the use of a electrical xover. Which I assume will require higher order xovers or active ones?

ps. I would definitely like to hear these speakers.

Nick wrote: ↑Wed Dec 19, 2018 2:19 pm Its still there though, its just you are choosing to roll off before they reach that point by the use of a electrical xover. Which I assume will require higher order xovers or active ones?

Higher orders or notch filters, yeah. There are a few ways to skin that particular cat. Putting a "bottomless" (no resistor) notch filter across the driver is useful, because it shorts out the driver at the notch frequency - makes maximum use of coil braking.

So if the speakers are (electrically) 40dB down before they start getting weird, is the mechanical crossover still in play?
I suppose that becomes subjective. I'd say no. At 40dB down, the mechanical issues aren't affecting the phase alignment etc of the intended crossover, so we're all good.

Chris

Though 40dB is 1% if we were talking about distortion, so maybe yes, it does matter. And your filters have just made life a lot harder for whatever is driving them, you have just moved the problem elsewhere.

But we're talking about a frequency response anomaly that has been shunted down in level. Listening rooms etc produce frequency response anomalies of the order of 10dB (the room here has a 7dB peak at 45Hz), so one of the drivers having a wiggle 40dB down from the nominal level seems pretty insignificant IMO. Given that, I'd say that the mechanical crossover would no longer be in play.

It's entirely possible for a complex passive crossover to present a nice resistive load, although I'd rather just use an amp that's capable of driving complex loads comfortably.
It's all compromise at the end of the day, and I generally prefer the low-distortion flat-response sound you get from good multi-way systems, and I'm willing to put the time in with the crossover to get where I want to be. With linear phase processing, they can also have the coherence of a full-range driver, too - the gap is closing in that regard, and I'm looking forward to bringing some of that tech to the next Owston.

Chris

Thing is as you say, its all IMO, but all you describe there sounds like a recipe for a sound that I try and avoid, and the exact opposite that the Cube speakers are aiming at producing.

Nick wrote: ↑Thu Dec 20, 2018 11:06 am Thing is as you say, its all IMO, but all you describe there sounds like a recipe for a sound that I try and avoid, and the exact opposite that the Cube speakers are aiming at producing.

I quite agree Nick, these drivers are recreating the the 50's and 60's when nearly every manufacturer made a range of sizes of full rangers.. I have wharfedales and Philips in 10" and both sound very good to me.
94 db speakers.. done right.. are a good compromise between efficiency and flat response ( and in my view realism)
But after a recent quick listen to steve's 12" fanes, they are sounding much better to me.. much smoother at the top end .. they are a no brainer for the money. I bet they sound better than the cubes as they are now..?
But I still think the addition of the matching 12" bass driver and a good tweeter would make them into giant killers..

Nick wrote: ↑Thu Dec 20, 2018 11:06 am Thing is as you say, its all IMO, but all you describe there sounds like a recipe for a sound that I try and avoid, and the exact opposite that the Cube speakers are aiming at producing.

Fair enough, can't argue with that.
FWIW, I personally look for something like good studio monitors - play any material at any volume level, and have it sound as the engineer intended.
Complex multi-way systems often end up low-efficiency, and I can see that the amplifiers typically used around here would have trouble producing real dynamics with something that's 82dB@1w.
I suppose I'm lucky in that way - I have plenty of multi-kilowatt amplifiers to play with, and some of them even sound good (upgrades have happened since the last Owston, that's for sure).

Have you played with linear-phase stuff yet? I think there's some mileage there, although I've only recently started exploring that.

Chris

Have you played with linear-phase stuff yet?

Do you mean FIR or something else?

Been thinking about amplifiers having to work into problematic loads. What never seems to be said is that they do that by eating into the feedback margin and so as the feedback is used dealing with non resistive loads, its not available to reduce distortion at the same time. What would be interesting is to run a distortion against frequency plot of an amplifier when driving a few different speakers.

Nick wrote: ↑Thu Dec 20, 2018 1:37 pm

Have you played with linear-phase stuff yet?

Do you mean FIR or something else?

Been thinking about amplifiers having to work into problematic loads. What never seems to be said is that they do that by eating into the feedback margin and so as the feedback is used dealing with non resistive loads, its not available to reduce distortion at the same time. What would be interesting is to run a distortion against frequency plot of an amplifier when driving a few different speakers.

Yeah, FIR. I recently bought some Powersoft amps that have 2048 taps (per channel) to play with, and the option to import custom FIR files. When the weather's nice enough for some outdoor measurements, I'll be having a lot of fun with that.

Interesting note about the feedback. Fits into the general observation that amps will often have increased distortion at low impedances.
Some amps (and I'm talking about solid-state ones here) are known to work better than others into difficult loads - are they likely to be the ones with very large feedback margins..?
Perhaps it's also about how the current limiting is set up.

Chris