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Old 22nd April 2012, 10:43 AM   #4621
tvrgeek is offline tvrgeek  United States
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Quote:
Originally Posted by a.wayne View Post
Tvr ,

My spenglish must be bad ....

IM NOT IN FAVOR OF SMALL DRIVERS, small systems or small amplifiers and don't get me started on FR single driver systems ...

Small "wide" range drivers have a very good use in a PA system as part of a line array. I plan on building a pair sometime for that use. They are not at all what I want in my living room. We would agree on that. A 5W amp has a very good use: Headphones.

I am beginning to think that matching the amp to the speaker should take a jump back in time to the old monkey coffin style, crossovers at 500 & 5K, three way. I think we are pushing the 6 inch mid-bass too low ( 80 Hz typically) causing muddy bass, and expecting way too much from our tweeters. With the approximate numbers stated, we have a chance of filtering out the higher harmonics of the 2K range and they won't upset the tweeter. I have never liked the idea of the crossover right in the highest sensitivity and most full midrange, but that is how drivers are made as it is the monitor class speakers that sell. Get it down to 1K, or up to 5.

Unfortunately the WAF for this configuration is very low.
My old Pereless 12's can make it to 500 just fine. Well maybe 400. A good "full range" 500 to 5K, and that lets use even a smaller tweeter with higher breakup frequency. This matches what the amp does better than our sub-satellite system now. If it is the high harmonics causing some of the problems, then the older concept of a "super tweeter" may have some merit. This would let you roll the tweeter off at a low enough frequency, 14K maybe, to have some effect on the harmonics to a tweeter that won't get upset until the dogs are barking. Just a thought.

My plan is to try steep LP filter on the tweeter first to verify this is actually the problem if it is related to how fast the higher harmonics fall off being one measurable difference between the Hafler and Rotel. ( at lower levels, 10W or so, they behave the same) Distortion at less than a watt has been suggested. I need to order some crossover parts.

Could I be chasing the totally wrong end of the problem? Could the problem be a otherwise very fine amp is passing some ultrasonics from the DAC that the Rotels, being slower, do not pass? IM problem maybe? Not the fault of the amp or tweeter, fault of the source? If I know the source impedance of the preamp, I can fiddle with the input RF filter. It should change the sound. I have wondered if the magic CD tube buffers were not anything but a LP filter.

Enough early morning over-thinking. Transistors came in to fix the Kenwood. I need to spend the time and find a source of enameled wire cheaper than pre-made coils from P-E. I can't believe they sell complete coils cheaper than I can find bulk wire. It used to be decent caps were the expensive part. Now it is the copper.
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Old 22nd April 2012, 11:28 AM   #4622
dvv is offline dvv  Serbia
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@tvrgeek

I have said this many times, and I repeat now - 3 way is the minimum you must have to be able to truly optimize your driver reproduction range.

4 way and more can work, but all too rarely does it work truly well. The problems you face rise exponentially with the rise in the number of drivers. And the cost sky rockets.

When you look back, MOST legendary speakers were 3 way - AR3a and later variants, JBL Century and later variants, most of JBL's 43xx professional monitor series, Yamaha NS1000, B&W DM6 ("The Fat Man"), etc. Too many for this to be just a coincidence.

Find me a company which is a strong advocate of 2 way speakers (as witnessed by their portfolio) which does not have its flagship model as at least a 3 way.

Acoustically, and in terms of audio "purists" (most of whom couldn't find their **** on a sunny day), the greatest stupidity of all time must be the current craze with single drivers.

There is no way in Heaven or Hell for just one driver to do it all no matter how you make it. Yes, their midrange is seductive, no crossovers, no phase shifts, but also iffy treble and awful bass, if any. That's really a pseudo bass, not even real bass. Just noise.

They are fine for public address arrays and playing loud country music on large country fairs - after all, that's what they were made for.

The really scary thing is that this shows that almost any idiot idea, once planted and plugged, can become the truth - until another such like idea comes along.
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Old 22nd April 2012, 12:56 PM   #4623
tvrgeek is offline tvrgeek  United States
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dvv,
We almost agree. The only reason I would say 4 way is to get the really low bass at really low distortion. So an array of 12's below 60, then go to a 8, 3 & 3/4 with the approximate crossovers I mention and it could stand a chance. Inches, sorry, we are beyond hope to ever move to metric in the US. The problem as I mentioned is the majority of drivers are made for the 6" & 1" with sub as that is what the market expects. Really good mids seem to be very scarce and I can't remember last time I saw a half-inch tweeter. Even the current B&W 800 series is using a huge mid-base and low crossover to the tweeter. They fail the wife test. Look at the old 2Ce: 8" three way, crossover at 5K. (still needs a sub) This is the ONLY conventional speaker that passes my wife's hearing she has auditioned. If a speaker costs more than a car, it might as well not exist for me so no references to $50K speakers is needed.

So the amp study has changed my direction for my next speakers. I should target one of those wide range drivers for a mid. That frees up the requirements on the tweeter. Guess I'll have to bother the single driver forum to find the best midrange, just not tell them what it is for. Fostex, Fountec, Mark, SB? What ever happened to Jordan?

The real trick is to be first to market the next really idiot idea that has just enough ring of truth to get all the magazine writers to jump on it. Let's see, terminal jumpers, bricks, foil triangles, amp stands, cable risers; all taken just like the customers. There are a lot of really bright folks in this thread, lets come up with an idea and get rich. It needs to actually do something, even if bad, and needs at least one flashing light when it is "working"
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Old 22nd April 2012, 01:28 PM   #4624
dvv is offline dvv  Serbia
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Quote:
Originally Posted by tvrgeek View Post
dvv,
We almost agree. The only reason I would say 4 way is to get the really low bass at really low distortion. So an array of 12's below 60, then go to a 8, 3 & 3/4 with the approximate crossovers I mention and it could stand a chance. Inches, sorry, we are beyond hope to ever move to metric in the US. The problem as I mentioned is the majority of drivers are made for the 6" & 1" with sub as that is what the market expects. Really good mids seem to be very scarce and I can't remember last time I saw a half-inch tweeter. Even the current B&W 800 series is using a huge mid-base and low crossover to the tweeter. They fail the wife test. Look at the old 2Ce: 8" three way, crossover at 5K. (still needs a sub) This is the ONLY conventional speaker that passes my wife's hearing she has auditioned. If a speaker costs more than a car, it might as well not exist for me so no references to $50K speakers is needed.

So the amp study has changed my direction for my next speakers. I should target one of those wide range drivers for a mid. That frees up the requirements on the tweeter. Guess I'll have to bother the single driver forum to find the best midrange, just not tell them what it is for. Fostex, Fountec, Mark, SB? What ever happened to Jordan?

The real trick is to be first to market the next really idiot idea that has just enough ring of truth to get all the magazine writers to jump on it. Let's see, terminal jumpers, bricks, foil triangles, amp stands, cable risers; all taken just like the customers. There are a lot of really bright folks in this thread, lets come up with an idea and get rich. It needs to actually do something, even if bad, and needs at least one flashing light when it is "working"
Good buddy, I'd love to be able to send you the complete blueprint for my own speakers, as without any false modesty, I have yet to hear a loudspeaker better than it is costing less than 3 times its price. And in its day, 9 years ago, it cost me 1,200 (that would be something like US$ 2,100 today, taking world inflation as 3% per annum).

Makes your jaw drop at what a 10 inch bass driver, operating to 800 Hz, can do in a room, not so much as depth (33 Hz at -3 dB), but as CLEAN AND ARTICULATE.

Unfortunately, there's not much point, since Son Audax, one of world's two oldest loudspeaker manufacturers (together with Britain's Celestion) is no more. Harman International appearently axed it a couple of years ago.

Both the bass and the 4" midrange driver use their take on the aerogel technology, and trust me, they knew a thing ot two about it.

But, enough of that, let's be practical.

Have you even considered getting your hands on some original AR speakers, such as, most notably, the AR 11? That's their latest version of the AR3a theme, a 12 inch bass, a 1.5 inch midrange dome and a 1 inch dome. If you can lay your hands on a well preserved sample (locally 450, or about US$ 600), having the bass suspension changed, and installing new quality capacitors and internal wiring WILL make you smile, and I suspect, your good wife will like it as well. It's a very unpretentious speaker, doesn't even try what it can't do, but what it does, it does better tnen 95% of all its contemporary competitors and off hand, say 70% of all modern speakers. It's an acoustic suspension type (BIG surprise, given that AR invented the principle), and therefore has a bass as clean as VERY few reflex types can boast.

But be warned - once you get hooked to AR acoustic suspension by AR, your will be hooked for life.

Look at me - objectively, my current speakers are better than the ARs, yet I still have a refurbished pair of AR 94s in the other room, and they ain't goin' nowhere. It uses two 8 inch bass/mid drivers, similar but not same, however, the lower one is cut off by means of an inductior at around 150 Hz. Thus, it serves to boost the full range bass/mid where it needs it. That was the world's first 2.5 way speaker, way back in the mid-80ies.

Ditto for older JBL 4312 Monitors (those which used the world's first titanium dome tweeter), ditto for Yamaha NS-1000, but beware, that is used as a text book example of a difficult load to drive. But the sound is truly heavely, if your amp is beefy enough. Beryllium mid and twwter domes, 12" bass, it's got it all - in spades.
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Old 22nd April 2012, 01:33 PM   #4625
dvv is offline dvv  Serbia
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As for leaving the irrational inches and feet masurement system, fear not, you will, eventually.

Your army is already using it, and armies the world around are the most conservative segments of society.

Most of your technical data is given in both inches and millimeters by default, you no longer have to ask for it, it's standard.

So, inch by inch, you'll get there.
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Old 22nd April 2012, 02:57 PM   #4626
tvrgeek is offline tvrgeek  United States
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You'd think missing Mars would have been a hint!

I grew up with an AR-2. My first speakers were AR-4's. I have always preferred sealed cabinets at about .6 QTS so you could say I was hooked 40 years ago.
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Old 22nd April 2012, 03:02 PM   #4627
dvv is offline dvv  Serbia
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Quote:
Originally Posted by tvrgeek View Post
You'd think missing Mars would have been a hint!

I grew up with an AR-2. My first speakers were AR-4's. I have always preferred sealed cabinets at about .6 QTS so you could say I was hooked 40 years ago.
All the better, then. Have you considered AR as a current option, assuming you refurbish and possibly upgrade it?
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Old 22nd April 2012, 03:06 PM   #4628
dvv is offline dvv  Serbia
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And missing Mars is a technical boo-boo, it could happen to anybody. :-)))))))

Too much diet Coke and decaf coffe can do that. :-))))))
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Old 22nd April 2012, 03:07 PM   #4629
Previously: Kuei Yang Wang
 
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Hi,

Quote:
Originally Posted by tvrgeek View Post
Small "wide" range drivers have a very good use in a PA system as part of a line array.
In the 80's there was an interesting genre of Speaker. A Semi-coax with a Slot Radiator Treble with a 4 Driver Line array of 5" Midranges (MMTMM) and a 15"Woofer frontloaded with a short horn to give similar H/V dispersion than the Mids. These where vertically stackable and did very well, but soon went out of fashion...

Ciao T
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Old 22nd April 2012, 03:14 PM   #4630
Previously: Kuei Yang Wang
 
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Hi,

Quote:
Originally Posted by dvv View Post
I have said this many times, and I repeat now - 3 way is the minimum you must have to be able to truly optimize your driver reproduction range.
No, 2 Ways will do fine. Example - Meyer X-10...

I may soon publish a System using a 15" active woofer and a hornloaded Magnetostat on top, 600Hz crossover, 102dB/2.83V/1m for the passive part.

Ciao T
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