Night of The Living Bassheads

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Wait a minute there Master Anthony.

Drivers you may know about yes. There are no drivers.

But in times past. This idea of a very high Qtc was not that rare. Look up Acoustic Research. Henry Kloss was a pretty smart guy. And he used his smarts to capitalize good sound out of a smallish enclosure in exactly the manner described by Ben.

Not every thing is new and improved. Some things have in fact regressed over the years.

What was the max spl in those types of high qtc sealed boxes? And at what frequency was the bump centered? What's the old saying about loud low and small?

There's a reason this type of system does not exist anymore. If you want a bump at a low frequency it's easy to get it with modern drivers and enclosures. No need to cry about times gone by, things are better now. The first step is to give up the sealed box requirement and that alone makes this whole concept easy to achieve.
 
The first step is to give up the sealed box requirement and that alone makes this whole concept easy to achieve.

It's the LAST resort in my book. I HATE using sealed enclosures. I like the vented voicecoil poles to get fresh cool air. I blew up 2 sealed 15's in my F150 SuperCrew. I've blown a sealed 12 in my wife's ex-Dodge Neon. I have NEVER blown up speakers in vented or BP4 enclosures. I always design BP4 enclosures where the speaker basket is mounted in the vented part of the enclosure. My home theater T-TQWT is still going strong!
 
What was the max spl in those types of high qtc sealed boxes? And at what frequency was the bump centered? What's the old saying about loud low and small?

There's a reason this type of system does not exist anymore. If you want a bump at a low frequency it's easy to get it with modern drivers and enclosures. No need to cry about times gone by, things are better now. The first step is to give up the sealed box requirement and that alone makes this whole concept easy to achieve.

Maybe you have some learning to brush up on.

I think you might be very surprised.

I have two sets of measurements on two different AR products that are good even today.
 
Maybe you have some learning to brush up on.

I think you might be very surprised.

I have two sets of measurements on two different AR products that are good even today.
Mark,

The AR-2 variant I tested was not particularly good in terms of output, LF extension, sensitivity or output. The graph below is the woofer only, drops off steeply below 50 Hz with a little bump at 60 Hz.

Tests with 10.9 V sine wave yielded about 10% distortion at 45 Hz in the sealed AR-2? cabinet.

Peak to peak excursion for the AR-2? (5.5 ohm DCR) at 10.9 V was:
20 Hz 8, 25 Hz 8, 30 Hz 9, 35 Hz 10, 40 Hz 12, 45 Hz 12.5, 50 Hz 12, 60 Hz 9.
Seems the air cushion limits excursion (and frequency response) below 40 Hz.

Art
 

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Good example of a bad AR speaker Art!

See one play one.

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AR LST

And the PDF has a measurement for the AR1

A little digging will find you some interesting information about how flat some of their products were.
 

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Maybe you have some learning to brush up on.

I think you might be very surprised.

I have two sets of measurements on two different AR products that are good even today.

Good example of a bad AR speaker Art!

See one play one.

View attachment 508687

AR LST

And the PDF has a measurement for the AR1

A little digging will find you some interesting information about how flat some of their products were.

Are you trying to be serious? We are talking here about subwoofers to play modern music. Modern music typically has notes in the 20 - 30 hz range and THX spec is 115 db. And this is what you bring to the table?

Looks like LST sensitivity is 82 db below 100 hz and response drops like a rock at around 60 hz. If I'm reading the middle attachment right it looks like max spl at 80 hz is 100 db. (They measured 105 db at 300 hz but decided not to measure at that power level at 80 hz. I wonder why. Maybe because it would destroy the driver.)

They didn't bother to measure max spl below 80 hz, very likely because 80 hz was the lowest frequency they could publish a respectable number for before xmax was reached. BUT assuming it could handle 31.3 watts (power level used to measure 80 hz max spl) at 30 hz, it would only be 70 db max spl at 30 hz. And it's VERY UNLIKELY it could handle 31.3 watts at 30 hz. They were likely running near xmax at 31.3 watts at 80 hz. So max spl at 30 hz is very likely significantly less than 70 db.

The AR1 drops off at 40 hz and yet their marketing says it can "shake and rattle the windows with the tones of the lowest note of an organ". And the AR1 likely has even worse low frequency performance than the LST in the low bass (below 40 hz).

I could beat the low frequency performance of a pair of LST and a pair of AR1 all clustered together with a single $50 modern 6 inch driver in a couple of cubic feet. So maybe you want to take another look at the stuff you posted and maybe you might have some learning to brush up on yourself. These antique speakers might be ok if all you have are a few antique records to play but we are talking about subwoofer duty for modern music in this thread unless it's become completely derailed for a second time while I wasn't watching.

(I'm not even sure what was being measured in the first attachment, all 6 of those speakers are rolling off hard at around 70 or 80 db, and presumably EVERYTHING you posted has well under 4 mm xmax - they are barely woofers much less remotely capable of subwoofer duty.)
 
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Wait a minute there Master Anthony.

Drivers you may know about yes. There are no drivers.

But in times past. This idea of a very high Qtc was not that rare. Look up Acoustic Research. Henry Kloss was a pretty smart guy. And he used his smarts to capitalize good sound out of a smallish enclosure in exactly the manner described by Ben.

Not every thing is new and improved. Some things have in fact regressed over the years.

Regarding this specifically in the context of you last post - neither the LST or the AR1 are high qtc speakers. I didn't look at the measured rolloff rate very carefully but I did find this almost immediately in a quick search for more LST info.

"The sealed box AR-3a and AR-LST have a Q of .707,"

From here - http://www.audioholics.com/loudspeaker-design/sealed-vs-ported/sealed-vs-ported-p2
 
To give credit where credit is due, I certainly realize the value of these speakers in their era. To make a small 1.7 cubic foot speaker play flat down to 40 hz at up to 105 db (only in the midrange, mind you, and there really was no recorded low bass in 1954 anyway) was something special. They did the best they could do with the technology and materials they had available, and the result was very good.

Don't confuse good results in 1954 with even remotely adequate results by today's standards. And just because all this happened 20 years before I was born don't assume I don't know about acoustic suspension and high compliance sealed box speakers that used the airspring as their main source of suspension.

Hoffman's law did not suddenly come into effect suddenly sometime in the recent past. You couldn't have loud, low and small in 1954 and you still can't have it today unless you can afford ultra high xmax drivers and massive pro amps.

Today's recorded music has demands that are completely unlike 1954 recorded media. You need to go a lot lower and those low notes need to be a lot louder. So don't show me 2 way sealed box speakers from 1954 and imply they are remotely adequate in the low bass by today's standards - at least not in a 15 hz 123 db tapped horn subwoofer thread called "Night of the living bassheads". Can you see the irony here or no?

I know Ben would be thrilled if we were stuck with this 60 year old technology and the world was full of nothing but acoustic suspension speakers, 1 meter square electrostat panels, klipschhorns (despite their horrid resonances and awful frequency response) and antique 2 mm xmax woofers used on OB baffles but there's a lot of good reasons why things have evolved and you don't see that kind of stuff anymore.
 
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Anthony do you have any recordings from the 1950's?

I do.

And many of the classical recordings that I have from that long ago far away era are very well done. And have both very high dynamic range and full and wide frequency response.

I'm not trying to say everything back then was stellar and the best of the best. But there were some seriously talented and well equipped recording engineers right around the time that the Ar products were coming out.

Look up Mercury Records.

Living Stereo

Decca.

Archiv.

Some of the recordings hold their own in every aspect up to today.

And I do believe that we have the ability to produce better driver today.

I just like to learn from those that did it before me.
 
Hi mark,

Those talented and well equipped recording engineers from the late fifties already were using 15 inch 50 watt Altec 604D's (in the famous green hammer tone) in large vented boxes or horn systems in order to reproduce the sounds down to 40ties. Just a couple of years later the Urei 813's with dual 15 inch (duplex) in vented systems became the new standard that delivered true low 30ties when flush mounted.

Perhaps that's the secret why those recordings sound so good... ; -)

Cheers,
Djim
 
They didn't bother to measure max spl below 80 hz, very likely because 80 hz was the lowest frequency they could publish a respectable number for before xmax was reached. BUT assuming it could handle 31.3 watts (power level used to measure 80 hz max spl) at 30 hz, it would only be 70 db max spl at 30 hz. And it's VERY UNLIKELY it could handle 31.3 watts at 30 hz. They were likely running near xmax at 31.3 watts at 80 hz. So max spl at 30 hz is very likely significantly less than 70 db.

Oops, that should read 88 db, not 70 Max spl at 80 hz was 100 db, 30 hz is 12 db lower than 80 hz, so 88 db (although it's unlikely it could actually do 88 db at 30 hz within xmax).

Here it is corrected.

They didn't bother to measure max spl below 80 hz, very likely because 80 hz was the lowest frequency they could publish a respectable number for before xmax was reached. BUT assuming it could handle 31.3 watts (power level used to measure 80 hz max spl) at 30 hz, it would only be 88 db max spl at 30 hz. And it's VERY UNLIKELY it could handle 31.3 watts at 30 hz. They were likely running near xmax at 31.3 watts at 80 hz. So max spl at 30 hz is very likely significantly less than 88 db.
 
Hi mark,

Those talented and well equipped recording engineers from the late fifties already were using 15 inch 50 watt Altec 604D's (in the famous green hammer tone) in large vented boxes or horn systems in order to reproduce the sounds down to 40ties. Just a couple of years later the Urei 813's with dual 15 inch (duplex) in vented systems became the new standard that delivered true low 30ties when flush mounted.

Perhaps that's the secret why those recordings sound so good... ; -)

Cheers,
Djim

I grew up listening to Altec 604's. My uncle had a set and he and my father built a set of Klipsch horn bass bins in 1980. My uncle had the Altecs set up on an infinite baffle and the horns loaded into the corners. We had great fun playing Pink Floyd Dark Side of the Moon and tons of other heavy hitters both classical and contemporary.

The Altecs have some good points and some not so good points.

I'm sure that like most good engineers headphones were also used as a reference for the midrange and top end.

The top end of the 604's always sounded an little strange to me even as a budding hi-end geek. And the transition between the horn and the cone is ever so ragged.
 
Lots of nonsense posted about old speakers. Here's a trace from this morning with my 1954 AR-1W and 1975 home-brew electrostatic panels. Nice to have speakers with distortion 50 dB down over the bulk of the spectrum. These traces were run at about 80 dBC at one meter and 78 dBC at my chair. But capable of loudness more than I can stand (about 100 dB).

As far as I can see, the improvements in cone driver theory and build over the last 50 years have been trivial. (But big gains in other parts of the reproduction chain and esp in our understanding of room acoustics from Toole.)

Anybody have nicer traces to post? Or do the sim adherents want to stick to theoretical performance?

Ben
PS. I was obliged to use EQ for the AR-1W to get that wonderfully flat bass. It has two CUTS around 50 and 90 Hz for eigentones. He, he.
 

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Today's recorded music has demands that are completely unlike 1954 recorded media. You need to go a lot lower and those low notes need to be a lot louder. So don't show me 2 way sealed box speakers from 1954 and imply they are remotely adequate in the low bass by today's standards - at least not in a 15 hz 123 db tapped horn subwoofer thread called "Night of the living bassheads". Can you see the irony here or no?.

Just for laughs, I calculated how many sealed twelves would be required to hit 110dB. It worked out to somewhere around three HUNDRED boxes :O
That would be an expensive project.

And hooray for room gain.
 
Lots of nonsense posted about old speakers. Here's a trace from this morning with my 1954 AR-1W and 1975 home-brew electrostatic panels. Nice to have speakers with distortion 50 dB down over the bulk of the spectrum. These traces were run at about 80 dBC at one meter and 78 dBC at my chair. But capable of loudness more than I can stand (about 100 dB).

As far as I can see, the improvements in cone driver theory and build over the last 50 years have been trivial. (But big gains in other parts of the reproduction chain and esp in our understanding of room acoustics from Toole.)

Anybody have nicer traces to post? Or do the sim adherents want to stick to theoretical performance?

Ben
PS. I was obliged to use EQ for the AR-1W to get that wonderfully flat bass. It has two CUTS around 50 and 90 Hz for eigentones. He, he.

Nobody cares about your in room measurements, Ben. You have 2 sets of speakers playing WITH EQ IN ROOM in that measurement and it's measured at low power. And there's 20 db between the lines. This measurement means absolutely nothing. We've already established in other threads that you eq the responses you post and that you have an extraordinary room gain profile that is not at all typical. And you also measure at very low spl so you can't see that your eq'ed speakers won't be able to play very loud before hitting xmax and terrible distortion.

If you want to show a measurement, take the speaker OUTSIDE, and play it WITH NO EQ. If you get really brave, take subsequent measurements at higher power levels until the speaker can't take it anymore.

If you really believe there's no improvement to driver tech and materials directly translating to vastly improved performance it's clear you don't understand very much about any of this.
 
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Let's get real about loudness.

Here is a clip of Hurricane Mama (Disney Hall organ) playing the well-known Saint-Saens organ symphony.

Wall of Sound - The New Yorker

I've been playing the clip at 100 dBC in my music room (both channels). Plays good. But that's way louder (about 12 dB) than I ever play stuff, way louder than for any kind of paying-attention to the music content, too loud for ear health, and not least important, far, far, far louder (like 12 dB and that includes gut-rumbling pedals) than any church organ concert or symphony I've ever attended (and that includes the Phantoms of the Organ, discussed on another forum.... this year, Oct 30 at 9 PM - I never miss it).

Ben
 
You have 4 speakers playing, it shouldn't be any trouble at all to read 100 db peaks in the midrange.

Let me see a 16 hz sinewave measured at 100 db please. Seems like you are saying this is no problem.

Even with your incredibly atypical gobs of room gain this test will destroy your speakers if you attempt it.
 
I was obliged to use EQ for the AR-1W to get that wonderfully flat bass. It has two CUTS around 50 and 90 Hz for eigentones. He, he.

No boosts. Not even at 20 Hz. Just cuts.

Gosh, it seems be pretty rare to see anybody else post what they listen to every day. No TH curves.... with distortion shown... from some of the more outspoken enthusiasts? Do none of those outspoken enthusiasts have working systems at home they are proud of? Talk is cheap, esp. anonymous talk.

I don't for a moment think my present set-up is so special (just sold off some great gear). But I really would like to see comparisons to other every day systems. Please.

Ben
 
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