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Speakers and speaker design for organ-friendly hifi

Started by David Pinnegar, May 04, 2011, 04:36:38 AM

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David Pinnegar

Hi!

Thanks so much for these suggestions. I found the Italian programme very complicated and after having paid ££s for another programme :-( discovered HolmImpulse already on my machine:
http://www.holmacoustics.com/holmimpulse.php
I found it really easy to use in practice doing some sweeps so I started testing some speakers. Unfortunately my computer or microphone seems to be severely limited at 7kHz and above :-( but here are some results. The sweep is on the fast side, which I'm sure doesn't lead to accuracy and is too fast to measure building acoustics . . . but it's a useful piece of software:

Systems:
Tannoy Lynx 12 inch unit (akin to Gold) in vintage cabinet

Tannoy Monitor Gold 10 inch

Tannoy DC100 8 inch gold unit with traditional horn tweeter

Tannoy Sixes 609 with waveguide tweeter horn

Manger Zerobox 103

Lowther PM6C in Acousta cabinet

Lowther DX4 in 150Hz tractrix horn

Lowther EX4 in 150Hz tractrix horn

Void Basys including subwoofer

VOTT - TOA Altec Voice Of The Theatre:

Cheap 10 watt full range unit in 150 Hz Tractrix horn


Single Units:
8 watt 8 inch cheap unit:

15 watt 8 inch unit:

Monacor 6 inch

Monacor 4 inch

Eagle 6 inch

Eagle 4 inch


Best wishes

David P

David Pinnegar

Hi!

I was involved in a recording session today for piano and needed to play back the recording and rediscovered why speakers with tweeters with a 2kHz crossover point are "against my religion" in terms of speaker design.

Frequency analsysis software is not the whole story in terms of choosing speakers good for any particular job.

Of various speakers, although Tannoy DC2000 and Sixes 611 speakers may sound excellent to varying extents on continuous tones, the DC2000 sounding clinically sterile and the 611 exciting on trumpets, the percussive sound of a piano gives transducers a hard time. With the 2k ish crossover point, the differential of mass between the woofer cone and the tweeter means that the acceleration of the tweeter is faster than the woofer. The result is a clear separation of tuned percussion such as piano sounds, the tweeter coming across with a faster click and sounding like a piano hammer loose on its shank . . .

Among the speakers above, there was one which would have a chance of passing a blind test between the live performer playing the piano and his recording and the others simply did not come close . . .

Best wishes

David P

revtonynewnham

Hi

Yes - 2kHz is in the most sensitive range of human hearing - that's one reason why 3-way speaker designs are often preferred.

The most accurate speakers that I've heard were the Quad electrostatics - but they have their limitations, not least needing a large room because of the figure-of-eight polar pattern.

Every Blessing

Tony

Contrabombarde

Quote from: David Pinnegar on November 03, 2011, 08:12:40 PM
Of various speakers, although Tannoy DC2000 and Sixes 611 speakers may sound excellent to varying extents on continuous tones, the DC2000 sounding clinically sterile and the 611 exciting on trumpets.....

Among the speakers above, there was one which would have a chance of passing a blind test between the live performer playing the piano and his recording and the others simply did not come close . . .

So having had the privilege of listening to both types, and in addition some Lowthers (which I have to say were vastly better than anything I've ever heard before in my life), and in addition having just come from buying a secondhand pair of Tannoys (on your personal advice), which speakers did you think stand a chance of being confused with a live piano performance David?

Ever paranoid  ;)

Contrabombarde

David Pinnegar

Quote from: Contrabombarde on November 04, 2011, 12:00:14 PMhaving just come from buying a secondhand pair of Tannoys (on your personal advice), which speakers did you think stand a chance of being confused with a live piano performance David?

Dear David

:-) Perversely and confusingly the pair of speakers that you said you wouldn't give a thank-you for! (For that reason we had better not mention which those might be on a public forum . . . )

There is a difference between continuous tone reproduction and transient percussive reproduction . . . and certainly the Tannoy DC2000 or 611 speakers are excellent value for £100-£150 per pair rather than £500-£1200 for speakers that make the recorded piano sound side by side with the original . . .

For anyone near Nottingham http://www.ebay.co.uk/itm/190593747023 are worth going for . . .

Best wishes

David P

David Pinnegar

Dear David

On your mentioning that KEF do dual concentrics I bought a unit for a KEF Q35. The tweeter is a simple tweeter within the voice coil assembly, so its vibration is in phase with the larger cone. The larger cone is plastic (against my religion) and has a discernable treble cutoff. Using a Tannoy 603 crossover, which is straight through for the bass and a simple capacitor and resistor for the treble, the KEF unit makes a very natural sound. It's good because the tweeter provides simple natural augmentation of the lower unit, working in harness with it. It would be nice to get an 8 inch unit.

In contrast the Tannoy Dual Concentric units have a very sharp cutoff from one to another. The 611 is brighter but the DC2000 is more natural, although male voices have perhaps a more disembodied bass. The KEF units may be more natural. However, the Tannoy 611 may be quite exciting for organ Trumpets. I use an arrangement of DC2000s for the Tuba on my instrument . . .

I wonder if there is a difference between the 611, 611MkII and DC2000 crossovers . . .

Best wishes

David P

David Pinnegar

Quote from: David Pinnegar on November 05, 2011, 03:28:15 PM
In contrast the Tannoy Dual Concentric units have a very sharp cutoff from one to another. The 611 is brighter but the DC2000 is more natural, although male voices have perhaps a more disembodied bass. The KEF units may be more natural. However, the Tannoy 611 may be quite exciting for organ Trumpets. I use an arrangement of DC2000s for the Tuba on my instrument . . .

I wonder if there is a difference between the 611, 611MkII and DC2000 crossovers . . .

Hi!

There is no difference between the 611 and 611MkII crossovers but they are simpler crossovers than the DC2000:
http://www.diyaudio.com/forums/attachments/multi-way/114749d1219912536-tannoy-dc2000-3000-dc2000.pdf

I suspect that the 611 is more exciting on trumpets on account of the tweeter and the DC2000 appears to have an extra coil capacitor bridging the unit which probably takes out a resonant peak. So if you want your DC2000 to do well on trumpets, disconnect the 4.7uF capicitor from the coil.

Listening to the radio, although better speakers exist, the DC2000 units are as accurate as good value speakers come . . .

Best wishes

David P

David Pinnegar

Hi!

This thread has been subverted into realms of speakers . . . so we'll have to split the thread at some stage. Apologies.

On ebay at the moment are a pair of speakers that no-one will regret buying:
http://www.ebay.co.uk/itm/330648463547

The units are deteriorating but being hand built can be rebuilt and I replace foam speaker surrounds and spiders for people. Years ago I was lucky to find the jig to ensure proper centring of the coil upon remounting.

It looks as though they will go for a song, and whilst I don't use them regularly it was a pair of such speakers which side by side with a piano one had difficulty in identifying the live instrument or the recording.

Of other speakers, the Kef dual cone speakers are effective but the number of units one sees with defective tweeters tells a story. It is the efficiency of the horn of Tannoy units that makes a concentric unit able to cope with the stresses of real life sound reproduction.

Best wishes

David P

David Pinnegar

Hi!

A forum member has just reported to me:
Quotethe DC2000s are on mounts to speak near the top of the case (which sound maybe a bit distant from the console but quite realistic, and absolutely awesome from the centre of the room).

. . . .

So a really big thanks for the Tannoy recommendation - they are absolutely superb even if in your library the XXX blows them away.

I am using a modified pair of DC2000 units combined with another make for the Tuba stop of my instrument and it is remarkably superb. If anyone is interested in the modification I will be happy to share the tip and provide plans for private use.

Best wishes

David P

David Pinnegar

Hi!

If anyone has the space, although I have not heard the Hedlund design, http://www.ebay.co.uk/itm/Hedlund-Horns-Lowther-DX2s-/190614588322 looks as though their organ-sized dimensions . . .

http://www.vt52.com/diy/diypage/hedlund/hedlund.html


Best wishes

David P

David Pinnegar

Hi!

The Hedlund horns fitted with good units http://www.ebay.co.uk/itm/190620278642 are still available and reduced to £1000. They are very much organ sized speakers . . . :-) so should reproduce very well. It looks as though they are based in Southampton.

Best wishes

David P

David Pinnegar

Hi!

In repairing a number of speakers recently and looking at issues of crossovers http://www.bcae1.com/passxovr.htm is incredibly useful (but make adjustments for 8 ohm rather than 4 ohm speakers) and http://www.maniac-sound.com/index.php?tld=en&page=product_table&category=accessories&product=01_01_Flexpower is the most amazingly useful variable crossover for experimentation or implementation http://www.ebay.de/itm/39830-Variable-Frequenzweiche-2-Wege-8-ohm-Crossover-/320728078753

In England I can get them at a remarkably better price if anyone is interested . . .


Best wishes

David P

Holditch

Hi David

That does look quite an interesting device (saves soldering lots of different crossover boards up!)

However the common problem with trying to design basic crossovers is that people tend to forget that the impedance of a driver is not constant across its frequency response, hence entering 8 or 4 ohms at a specified crossover frequency will not necessarily give the correct component values as the impedance of the driver may be wildly different at that frequency

Having said that I would still be interested to know how much you can get them for?

Marc
Dubois is driving me mad! must practice practice practice

David Pinnegar

Dear Marc

Yes - non-linear speaker impedance is a theoretical problem but looking at Kef and Tannoy crossovers, they don't seem to do much about it. However the Lynx Tannoys put the tweeter into a voltage divider with the tweeter shunted by a resistor, which must somewhat stabilise the impedance being fed by the capacitor to even out impedance changing effects.

What I don't understand is the Tannoy's use of 2.2uF capacitors for tweeters, at an 8 ohnm impedance giving a crossover point of 9kHz, whilst stating around 1.5-1.8kHz as the crossover points for most of their units.

The variable crossover from Maniac Sounds has tweeter capacitors from 2.2uF to 6.8uF shunted by a coil if not in the OFF position of between 0.22mH and 0.47mH with the bass section using an inductor of between 0.5mH and 2mH, if not in the off position, shunted by capacitors of 6.8uF to 22uF.

What I do not understand is that those values, with 8 ohm units, give a lowest tweeter frequency of around 3kHz using the 6.8uF on the tweeter and a highest woofer frequency of around 2.5kHz using the  0.5mH coil. All other settings seem to leave rather a gap between woofer and twetter . . .

Best wishes

David P

KB7DQH

I am guessing the "gap" in frequency response in these designs accounts for mutual energy conversion (in the respective speakers) and the slope of the filter... the "cutoff" is essentially where the frequency response of the circuit begins to change, gradually, then rolls off and "slopes", in the case of the crossover under discussion at somewhere around 6dB per octave...  At some point in a frequency sweep the woofer and tweeter are both producing sound together and will thus add... so the woofer output only gets attenuated 6dB at 5khz, the tweeter similarly at 1.5khz...  Now with wider "gaps" in frequency coverage one could stick a third driver in there, a midrange with NO filtering components and adjust the woofer and tweeter frequencies away from the passband of the midrange and  thus use this 2 network crossover in a three speaker system... Sounds like a fun toy to play with... but as I have literally tons of scrap electronics here lying about I could comfortably "roll my own" without much difficulty, hence the value of the links posted earlier in this topic 8) 8) 8)

That being said... My most successful homebrew speaker and enclosure system involved using three surplus automotive speakers (two of them the factory supplied units removed from a decade-old Honda Civic ;) wired in series and in phase, and mounted into a triangular-shaped enclosure of a dimension to suit the scrap wood on my pile at the time and sufficient to accommodate the speakers...
Twelve ohms, NO CROSSOVER WHATSOEVER, and no acoustic damping insulation inside.  These serve to reproduce the frequencies above the range of my infinite-baffle subwoofer...  After constructing the pair I was pleasantly surprised upon evaluation that they worked as well as they did as the design process involved none of the math normally used for such projects :o  If I recall correctly I didn't even use a tape measure although I did use templates and marked the  the board I mounted the speakers into prior to cutting the holes :o ;)

Eric
KB7DQH


The objective is to reach human immortality—that is, to create things which are necessary to mankind, necessary to the purpose of the existence of mankind, and which have become the fruit that drives the creation of a higher state of mankind than ever existed before."

Contrabombarde

This is a most interesting thread. However, the audio buff websites tell me that you should budget around half or less of your budget on the speakers, as much again on the amplifiers and anything that's left over goes on the speaker cable (some of which I saw recently for a mere £5000 a metre....) So in addition to what hifi speakers are good for organ music (on the face of it, I'd say dual concentrics plus a decent subwoofer if your space or budget doesn't extend to full range Lowthers...) - what sort of amplifiers come particularly recommended for listening tio the organ through hifi speakers?

David Pinnegar

/Hi!

My personal experience is that the best sensitive speakers will sound great on the output of a transistor radio . . or even on a mid-fi setup and are far and away the most important things.

The only difference in amplifiers is whether they are Class A or Class B, class A giving excellent results with sensitive speakers at low volumes and class B, having a crossover point between one output device turning on and the other turning off, each doing half the cycle, being not so good at low outputs and great when beefing out disco stuff. . .

My approach is that if one is trying to get a Hauptwerk or other electronic source to sound like a pipe rather than a recording of a pipe, it has to behave as a pipe with all its nuances. As a result I go for as sensitive speakers as I can afford and some brands of Class AB or "New Class A" amplifiers are really cheap on eBay.

Speaker cables - what a load of sliver plated spider's web that is (see the humorous post on this forum about the NoSound HiFi Company that makes that stuff). I've always used bog-standard mains cable. Preferably 2.5mm twin and earth, putting the earth with the intended neutral or using it as neutral with the two main conductors and stereo live pair. For long runs I use 4mm or 6mm. NoSound voice coil wire was probably invented by the brilliant Roger Russell who entirely busted the myth of silly speaker cable . . . http://www.roger-russell.com/wire/wire.htm. A the sort of prices you speak one could find pipe organ building in merely buying a few metres of wire!

However for the Hammerwood beast, operating around 30 channels, I use simple 0.5mm cheap bell wire for lengths of only a few metres and driving low power speakers of 8 ohms.

Best wishes

David P

KB7DQH

OH boy... more noise about speaker cable :o ;)  David and I agree here... anything with reasonable conductivity that can be obtained should do just fine... A good scrounge should pay NOTHING for speaker cable!  If appearance is important and you are not in an environment saturated with radio frequency energy, and you likewise have not visited the correct dumpsters in the dead of night will do just fine with
"household mains cable"...  Failing that there is always appliance power cord material.  In the event the system may be susceptible to strong RF fields (which get rectified and detected in the amplifier circuits and appear in the speakers as nasty noises!) then one can use old coaxial RF transmission line such as RG-8...  This provides a sturdy center conductor good for at least a thousand Watts and even more meat in the braided outer conductor ;)  This material is often scrapped after water migration makes this useless for passing radio frequencies but as long as the ohmmeter shows no conductivity between shield and center conductor it should perform marvelously in the domestic home environment.
Another alternative is the 8 conductor "CAT-5" ethernet cable... Use all 8 conductors wired together at both ends and a pair for each speaker... There is an outfit here locally which sells this with the fancy gold-plated pins made onto both ends of custom-cut lengths for way too much money :o ;) ;D
Similarly I have taken salvaged multiconductor cabling left over from commercial Trimble GPS receiver installations and have had excellent results. 

One expenditure which should be considered for best performance of mains supplied high-power audio amplifiers is to install an individual branch circuit from the distribution panel to where the Hi-Fi system is to be installed as this  ensures the amplifiers receive enough "juice" and tends to keep noise from other appliances from sneaking in to the amplifiers via the mains...

And speaking of amplifiers... As long as one has no interest in long, medium, or shortwave listening, that automotive "brick" type solid-state amplifiers are relatively inexpensive compared to "plug-in-the-wall" varieties and are generally extremely quiet, linear, and for the most part, durable, and available in virtually any imaginable power level :o 8)  provided a suitable power supply to convert the mains to 13.8VDC at the required current is available...

I am sure there are "naysayers" who would claim my concepts are "ghetto" but the results are convincing...

Eric
KB7DQH
The objective is to reach human immortality—that is, to create things which are necessary to mankind, necessary to the purpose of the existence of mankind, and which have become the fruit that drives the creation of a higher state of mankind than ever existed before."

KB7DQH

A friend of mine took a 5 transistor battery powered AM radio and connected its output to one of the early Klipsch horns and filled a theater with sound ;) ;) ;) 

Eric
KB7DQH
The objective is to reach human immortality—that is, to create things which are necessary to mankind, necessary to the purpose of the existence of mankind, and which have become the fruit that drives the creation of a higher state of mankind than ever existed before."

David Pinnegar

Quote from: KB7DQH on January 03, 2012, 06:48:05 PMautomotive "brick" type solid-state amplifiers are relatively inexpensive compared to "plug-in-the-wall" varieties and are generally extremely quiet, linear, and for the most part, durable, and available in virtually any imaginable power level :o 8)  provided a suitable power supply to convert the mains to 13.8VDC at the required current is available...

Hi!

http://www.ebay.co.uk/itm/280534435407 look great and http://www.ebay.co.uk/sch/zhzy5500/m.html always has them in stock. This ebay seller is a primary source of repair materials for speakers.

Best wishes

David P