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Producer discovers AR18s and has orgasm

ToTo Man said:
I've often wondered about this, as I'd assumed that the speaker drivers in consumer boomboxes, tranny radios, etc, had a high-pass filter to prevent over-excursion at lower frequencies...
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All you'll be hearing from most of these things are harmonics. They mostly won't be able to produce much actual bass at all. I doubt if they'll need a filter, the drivers just won't do it and the amplifier won't be powerful enough to make them die trying.
 
ToTo Man said:
I've often wondered about this, as I'd assumed that the speaker drivers in consumer boomboxes, tranny radios, etc, had a high-pass filter to prevent over-excursion at lower frequencies, which would largely negate an engineer's attempt to boost the low end of a mix. It's been a LONG time since I listened to music on a traditional boombox (I graduated to a midi-system for my 9th birthday and finally progressed to proper separates by my 11th), but from memory I don't think I saw the little 3" boombox woofers pumping in and out much, certainly not as much as a proper, standalone mini monitor like a JR149 or LS3/5A, hence my assumption of a high-pass filter being present. However, I suppose a similar effect could be achieved by using drivers with stiff surrounds and relying on the air spring from the tiny internal enclosure volume to curtail its movement?
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‘Boost’ was a rather lazy word to use, it is more about EQ. The way you “fix” a bassline which sounds absolutely amazing through the 15” Tannoys, JBLs or whatever the large full-range monitors are, but just vanishes entirely on the ARs and Aurotones is to increase the upper range, i.e. give it a ‘bump’ at about 70-150Hz and maybe notch up some upper harmonics to give it a bit of ‘twang’. This isn’t about just hoofing up a bass control, it is more shaping the contour of the bass instrument so it still cuts through in higher ranges. You will never get any actual bass out of Auratones or a little transistor radio, but you do need to hear the notes the bassist is playing.

Electronica/techno etc is interesting here as it tends to play by its own rules being an underground music that very seldom gets radio play. As such you’ll often find tracks with basslines you can only hear on very good full-range speakers. Reggae can be interesting too, often you can hear the bass has been very deliberately EQ’d to cut through on smaller speakers despite being a very bass-heavy musical form.
 
Loved my AR18s (Grahams modified) back when i had my first decent system, A&R A60 amp, Rega Planar 3 turntable and Rega R100 cartridge. Great little system that got replaced after 3 years with an LP12 Nait1 & Kans.
 
AR18s NAD 3020 Rega Planar 2 with R200 Acos/rega arm , bought from Russ Andrews Hifi Northumberland Street, Edinburgh.
Early 80s, my first "real" hifi.
Loved it....
 
ToTo Man said:
I've often wondered about this, as I'd assumed that the speaker drivers in consumer boomboxes, tranny radios, etc, had a high-pass filter to prevent over-excursion at lower frequencies, which would largely negate an engineer's attempt to boost the low end of a mix. It's been a LONG time since I listened to music on a traditional boombox (I graduated to a midi-system for my 9th birthday and finally progressed to proper separates by my 11th), but from memory I don't think I saw the little 3" boombox woofers pumping in and out much, certainly not as much as a proper, standalone mini monitor like a JR149 or LS3/5A, hence my assumption of a high-pass filter being present. However, I suppose a similar effect could be achieved by using drivers with stiff surrounds and relying on the air spring from the tiny internal enclosure volume to curtail its movement?
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Amps in cheap transistor radios has a single rail 'power' supply (battery), so they obviously must have a capacitor on the output to the speaker. The speakers also usually work in more or less open air (like most guitar combo amps) so they must be very stiff in the suspension. Very far from HiFi ;)

As we (me actually) have mentioned big AR's used at Motown in the good old days, Barry Gordy himself listened to every single before release on a cheap plastic gramophone/transistor radio. If he didn't like it, it was a rebuff for Holland/Dosier/Holland! LP's where less important and therefore done by younger staff as a an exercise.
 
Tony L said:
You need to do it as that is how a lot of people access music. Back in my day a typical studio had a proper big pair of Tannoys, these were your absolute reference, they told you what you’d actually recorded. Then you had a pair of NS10s or AR18s as nearfields to give an idea of what things will sound like at home, and finally a pair of Auratones, which were a little cube shaped box with a small single driver in it to give an idea what the mix would sound like over a transistor radio or in the car (back when cars just had simple radios). The art, and it really is an art, is to get a mix to sound good on all three. It is incredibly hard as you can get a stunningly good sound from the Tannoys, but not hear any bass at all when you switch to the smaller speakers, likewise if you boost the bottom so it is driving things along on the Auratones you often end up with an overpowering muddy mess from the full-range monitors.

Your job as an engineer or producer is to serve the music/the artist, not a tiny minority of audiophiles. The result has to sound good on a mono transistor radio in a transit cafe or the little Roberts radio in my bathroom as well as your or my multi-£thousand stereo. That goes for classical too. FWIW it actually amazes me how good R3 sounds via my little Roberts radio. The really skilled engineers get their mixes to sound good on any speaker, but many fail. It is one reason why I like running both a top-end vintage studio rig and a nearfield mini-monitor perspective as if something sounds overblown on the Tannoys (i.e. is obviously a nearfield mix) it will sound great upstairs via either the 149s or LS3/5As, and vice versa.
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I'm not sure that recordings got any better when nearfield alt reference speakers became the norm. Before Auratones and NS10s, plenty of perfectly decent recordings were done with a single reference for tracking and mixing, and a single reference for mastering.
 
I remember once reading that Ultravox's later stuff was mixed to sound good on a transistor radio - probably using 'horror tones'.

I was reminded of this recently when listening to 'Rage in Eden', which I always felt had a slightly strange sonic signature. Putting 'Systems or Romance' on after it had much better sound quality. Both were original LPs, but SoR presumably being older had more conventional mixing.
 
Yank said:
I'm not sure that recordings got any better when nearfield alt reference speakers became the norm. Before Auratones and NS10s, plenty of perfectly decent recordings were done with a single reference for tracking and mixing, and a single reference for mastering.
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You may well be right. My knowledge is really limited, and limited to my era (a couple of years either side of the 80s). Certainly every studio I have been in has had some degree of cross-reference in the monitoring rig and a lot of engineers do most of their mixing and EQ work on the nearfields. Looking at old pictures of RVG’s studio, Abbey Rd, Decca etc and there is usually just one pair of large Tannoys or Altecs. IIRC Porky did everything through his Tannoys, so it extended to mastering houses too.

There looks to have been another shift now with so much music being mastered on fairly small and cheap active monitors in home/project studios. I’m inclined to blame this for the tendency towards bass heavy and compressed mixes we see so much these days. It often amazes me just how much more punchy, dynamic and alive 60s and 70s vinyl can be compared to current releases which often sound lumpen and heavy to my ears. Obviously you can argue I’m using a 60s/70s studio monitor rig as my hi-fi, exactly the sort of system much of that music was created on, but I think it is more than that. I don’t think small modern ported actives are telling the truth a lot of the time. By saying that neither did NS10s, but the people who used the NS10s tended to understand that as they could so easily cross-reference with proper large full range speakers that could do dynamic range.
 
Don't know if you remember, @Tony L , seeing a pic of my JR149s and JR150s on my computer desk? In the late 2000's I used the JR149s, in conjunction with HD600 'phones, to mix and master my electronica creations. They translated surprisingly well onto my big speakers, until I made a mix on my 149s after upgrading them to the Hartle Type24 crossover which had less baffle-step correction. I remember cuing up my mix on my huge IMF Professional Monitor MK3s and almost soiling myself when the kick drum and bass landed! :D
 
RJohan said:
Amps in cheap transistor radios has a single rail 'power' supply (battery), so they obviously must have a capacitor on the output to the speaker. The speakers also usually work in more or less open air (like most guitar combo amps) so they must be very stiff in the suspension. Very far from HiFi ;)

As we (me actually) have mentioned big AR's used at Motown in the good old days, Barry Gordy himself listened to every single before release on a cheap plastic gramophone/transistor radio. If he didn't like it, it was a rebuff for Holland/Dosier/Holland! LP's where less important and therefore done by younger staff as a an exercise.
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Get yourself an old Hacker Sovereign with FM or larger vintage Roberts (606, 707, 900).
Auntie through one of those can often be more satisfying than through a hi-fi because they open the quality window just wide enough, but not too wide.
 
Robert said:
The bass driver is designed specifically to work in a small closed box and still have bass. That's very, very rare today.
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For acoustic suspension, Total Qtc of the closed box must be at least twice the value of the woofer Qts. That means for a maximally flat amplitude response of Qtc=0.707, the woofer Qts value should be 0.35 or less. Qtc/Qts < 2 is infinite baffle.

Qtc/Qts is proportional to fc/fs, where fc is -3db cutoff response of the system and fs is the free-air resonant frequency of the woofer. That means the lowest value fc is at least twice fs.

Driver fs is mostly a product of mass and suspension compliance. Heavier cones with highly compliant suspension will exhibit lower fs. This is why Acoustic Research used foam surrounds that barely offer any resistance.

The perfect (mid)woofer for acoustic suspension enclosure that can play bass will have Qts of less than 0.4; fs of less than 25Hz and equivalent volume (Vas) of no more than three times the intended box. For something small like the AR18, Vas is likely 30L or less.

A modern driver with these parameters is a rare thing indeed. The closest I can find is the Scan-speak 18W-8535-01.
 
I would love to hear a pair of properly restored AR3s. Been shopping for a while. Heard an old beat up pair that had not been maintained for years. They sounded terrible. Next heard a restored pair, but not all original drivers. Sounded kind of boom-tish to me, but I had always read that midrange was the AR3’s strength. Oh well, maybe next time I’ll get lucky.

Shouldn’t the thread title have read ARgasm?
 
James said:
For acoustic suspension, Total Qtc of the closed box must be at least twice the value of the woofer Qts. That means for a maximally flat amplitude response of Qtc=0.707, the woofer Qts value should be 0.35 or less. Qtc/Qts < 2 is infinite baffle.

Qtc/Qts is proportional to fc/fs, where fc is -3db cutoff response of the system and fs is the free-air resonant frequency of the woofer. That means the lowest value fc is at least twice fs.

Driver fs is mostly a product of mass and suspension compliance. Heavier cones with highly compliant suspension will exhibit lower fs. This is why Acoustic Research used foam surrounds that barely offer any resistance.

The perfect (mid)woofer for acoustic suspension enclosure that can play bass will have Qts of less than 0.4; fs of less than 25Hz and equivalent volume (Vas) of no more than three times the intended box. For something small like the AR18, Vas is likely 30L or less.

A modern driver with these parameters is a rare thing indeed. The closest I can find is the Scan-speak 18W-8535-01.
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Just looked back at my tests for various AR bass units from my old refurb and build archive.

Sure enough fs of the AR 8 inch bass driver (any vintage) is 24-25Hz as you can see by the peak on the impedance plot. I found it consistent across several drivers manufactured from the early 70s into the late 80s:

 
Hook said:
I would love to hear a pair of properly restored AR3s. Been shopping for a while. Heard an old beat up pair that had not been maintained for years. They sounded terrible. Next heard a restored pair, but not all original drivers. Sounded kind of boom-tish to me, but I had always read that midrange was the AR3’s strength. Oh well, maybe next time I’ll get lucky.

Shouldn’t the thread title have read ARgasm?
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A lot of the vintage pre Teledyne era ARs had a shelved down treble response. Might be a little unsettling today as we are used to flatter response lines and more top end.
But then in those days, tone controls were on nearly every amp and receiver so you had some control.
 
Tony L said:
Electronica/techno etc is interesting here as it tends to play by its own rules being an underground music that very seldom gets radio play. As such you’ll often find tracks with basslines you can only hear on very good full-range speakers. Reggae can be interesting too, often you can hear the bass has been very deliberately EQ’d to cut through on smaller speakers despite being a very bass-heavy musical form.
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Yep, I've noticed this with a lot of electronica I play.
 
Robert said:
A lot of the vintage pre Teledyne era ARs had a shelved down treble response. Might be a little unsettling today as we are used to flatter response lines and more top end.
But then in those days, tone controls were on nearly every amp and receiver so you had some control.
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Dr. Bruce Edgar found that in the AR 3A, the mid was -3dB down from the woofer, and the tweeter was -3dB down from the mid.
 
Mr Pig said:
A friend of mine has a pair of big old Celestions and loves them. Big, punchy sound for not a lot of money.
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I ran celestion UL-6's for a while, partnered with a chi-fi valve amp. Surprisingly good. Can't find them easily any more, and regret selling them. But onwards and upwards...
 
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