"For good reasons, horns often back-into sealed boxes."
Yes, it resonates the low-end at cut-off to boost the bass, but requires a bigger bulk for similar output to a TH.
If you have a straight-truck build FLH, if you own a van build TH.
Yes, it resonates the low-end at cut-off to boost the bass, but requires a bigger bulk for similar output to a TH.
If you have a straight-truck build FLH, if you own a van build TH.
Hold on a minute.
This interior discussion started with an assertion that some folks (me, for example) strongly prefer speakers with as few or as natural or as "meaningful" resonances as possible. Sealed boxes, IBs, and traditional horns (with sealed boxes behind) fall into that category while BR and TH and others that derive a quart of sound from a pint-sized box do not.
By "'meaningful' resonances" I mean that the motion of the cone bears a close/meaningful relationship to the output (which - just incidentally - is a criterion for being able to apply motional feedback of the cone to that kind of enclosure).
I think it is a reasonable assertion and a useful way to rank enclosures.
Ben
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Eric,
The tapped horns I have built and measured have 6 dB more SPL with the same voltage input as a bass reflex cabinet with the same low corner (Fb).
As I said, the effective use both sides of the speaker cone can result in an output around 6 dB more than the same speaker (of the proper parameters) used in a bass reflex cabinet.
The box volume was larger for the TH, but there is no misconception regarding the 6 dB difference in sensitivity I measured between the TH and BR.
As you say, a TH more effectively utilizes box volume.
Art
Ben,
Your assertions would carry more weight if you had actually ever heard properly designed BR and TH and compared them to IB and FLH.
Although a BR Wurlitzer jukebox is a "one note wonder", lumping all BR and TH designs in that category is as silly as dismissing all Ford product because the Edsel looked funny.
Having done listening and measurement comparisons between pretty much every LF design heard of, I find your opinions regarding LF enclosure design make little sense.
They are amusing to read though, I'll give you that 😀.
Art
"I mean that the motion of the cone bears a close/meaningful relationship to the output (which - just incidentally - is a criterion for being able to apply motional feedback of the cone to that kind of enclosure)"
Prove it.
A FLH in Hornresp does not have flat output vs cone motion.
Prove it.
A FLH in Hornresp does not have flat output vs cone motion.
I'll ignore that bit of patronizing arrogance about "amusing" except to say it brings the author and forum into disrepute. Perhaps if you revealed anything at all of yourself in your profile or signature, we would know just how much credence, or none, to place on your authoritative-themed pronouncement.
First, I am kind of sorry to have brought horns into this. I have run motional feedback with great success with my Klipschorn (want to call that "gildng the lily" of woofers?) and so I mentioned it.
All speakers - even my beloved ESLs - show disconnects between cone (or surface) motion and sound output across their sound compass. But for some, the relationship is orderly or coherent and for others less orderly.
When it is not orderly, you obviously can't use motional feedback to smooth the response. Pity.
For sure, both BR and TH depict major bumps and hollows in sound output relative to cone motion (as captured in impedance plots). Sometimes I use the term "traffic in resonances" to characterize those approaches. Sealed boxes and IB also have their bottom resonances but they aren't "trafficked" the same way.
Ben
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You might find this paper useful:
Hearing at low and infrasonic frequencies Moller H, Pedersen CS - Noise Health
Hi Art,
I am not disputing the 6dB of gain, in fact I have simulated in excess of 10dB gain when transitioning from reflex to TH on some drivers. I am disputing the origin of the gain. That 6dB, (which can be much more or less depending on many factors), comes from well utilised and greater box volume, not "both sides of the driver being utilised." A reflex alignment is already using "both sides of the driver." Just take a look at the output from the vent, that is a wave excited by the "rear" of the driver through the chamber and vent. A TH is a sophisticated way to sacrifice bandwidth and space for efficiency and SPL. Please understand I am not disputing the increase in output. In fact, I fully stand by it, I am comfortable stating that for the bottom couple octaves of sound reproduction, box design and size plays the largest role in SPL capability, accounting for as much as a 50dB range of efficiency and/or maximum output for any given driver.
Regards,
Eric
Impedance of complete Klipschorn.
Response of Klipschorn bass unit only.
Hmmm, I thought we were talking about low subs not full-range from 10 to 20kHz?
Dirty pool to show those curves and esp. to choose to include that misleading caption as well. "Scoring points" or helping the discussion?
Ben
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I didn't like the statement made about the servo and the horn.
"Perhaps if you revealed anything at all of yourself in your profile or signature, we would know just how much credence, or none, to place on your authoritative-themed pronouncement."
NEW MEXICO MUSIC DIRECTORY
"Perhaps if you revealed anything at all of yourself in your profile or signature, we would know just how much credence, or none, to place on your authoritative-themed pronouncement."
NEW MEXICO MUSIC DIRECTORY
Ben,
Dennis (djk) graciously answered Djim’s question placed to you, “Can you show us the 'orderly' impedance plot of your Klipsch” in post #29.
I’d say that’s helping the discussion.
The charts he posted show the frequency response response of the Klipschorn bass unit only, and the complete impedance graph clearly shows the impedance peak centered around the 5 dB 75 Hz dip followed by a series of peaks rising some 20 dB above the passband response the Klipshorn exhibits.
The TH designs of Djim, myself (and dozens of others), and the PPSL BR designs of djk all have a smoother response in the bass pass band ( around 125 Hz and below) than the Klipschorn bass unit.
Most of the respondents (you being the exception) have actual experience with TH and more or less of the design process that can eliminate bad sounding cabinets from being built.
We may disagree from time to time about some of the finer points, but we recognize and respect the DIY work done by the others in their areas.
If you spent as much time learning about the various design palette available as propagating your “anti-resonance” agenda that you interject at any chance, however inappropriate, you might find that in terms of the things that really count in LF reproduction:
Smooth phase and frequency response, LF extension, moderate group delay change, efficiency, low distortion, TH can be very good in comparison to other designs.
I invite you to read, listen and learn, the long history of TH goes back before I was born, a bit before your involvement with audio.
Cheers,
Art Welter
P.S.
I sold the drapes mentioned in the Welter Systems New Mexico Music Directory listing in post #34, used some of the money to buy the B&C18SW115-4 speakers used in the Keystone TH subs before the price of neodymium went through the roof.
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