I also like large drivers and still believe that You cant beat qubic inches.
But, i don´t like x-overs, especially if they´re used in the fundamental voice region, say 300-3kHz.
This means i have to use LF drivers that are very good in the voice area, 10-12" is, in my opinion, the best choice for this.
We still want the fantastic low level dynamics that large drivers deliver, what to do?
First try, turned out really ok, was this:
A tiny litle speaker that actually is allmost a 2-way design, the larger of the round parts is a Beyma 21L50, this ,unfortunately out of production, 21" driver is lowpassed at about 85Hz, the smaller round thing is a Beyma 10G40, only lowpassed at about 3k, firing backwards in what could be regarded as a TQWT but with exponential expansion.
The square thing is a Beyma TPL150, AMT driver, system sensitivity at around 100dB and fantastic low-level dynamics.
It moved furniture at pretty modest levels so the 21" was perhaps a bit too large for our livingroom.
What to do then?
Ingvar
But, i don´t like x-overs, especially if they´re used in the fundamental voice region, say 300-3kHz.
This means i have to use LF drivers that are very good in the voice area, 10-12" is, in my opinion, the best choice for this.
We still want the fantastic low level dynamics that large drivers deliver, what to do?
First try, turned out really ok, was this:
A tiny litle speaker that actually is allmost a 2-way design, the larger of the round parts is a Beyma 21L50, this ,unfortunately out of production, 21" driver is lowpassed at about 85Hz, the smaller round thing is a Beyma 10G40, only lowpassed at about 3k, firing backwards in what could be regarded as a TQWT but with exponential expansion.
The square thing is a Beyma TPL150, AMT driver, system sensitivity at around 100dB and fantastic low-level dynamics.
It moved furniture at pretty modest levels so the 21" was perhaps a bit too large for our livingroom.
What to do then?
Ingvar
So, working on a project for a local restaurant i found a very nice 8" driver, Faital 8PR200.
This tiny driver showed a dynamic behaviour that i´ve never found i this size so i thought, could we use this in a real speaker, reproducing music the way it, to my ears, sound?
We could, we put two of them in a rearloaded horn.
Even the production manager approved of this.
Ingvar
This tiny driver showed a dynamic behaviour that i´ve never found i this size so i thought, could we use this in a real speaker, reproducing music the way it, to my ears, sound?
We could, we put two of them in a rearloaded horn.
Even the production manager approved of this.
Ingvar
I believe J Gordon Holt once wrote, "A speaker needs to move four times farther with each decreasing octave, a fact with which Paul Klipsch liked to impress customers and scare small children."now I'm confusedCan you explain? - I'm learning all the time
When the cone size greatly exceeds the voice coil diameter there's an inevitable loss of control, i.e., distortion arises. The answer is make the cone thicker, which means heavier, which means less highs, hence large cones are used for woofers and subs. But in that range below 100Hz, the best way to reduce distortion is to reduce the cone motion, and that means using even more surface area (or a HUGE horn, ala Klipsch).
So, for deep bass, there is no substitute for diameter, as increasing excursion is fraught with problems. (I've only mentioned cone breakup; there are also doppler effects, Xmax limits, port chuffing, etc.)
The other thing to consider is two 12s are wider than one 15, so that lowers the effective cross-over point. JBL ran their woofers as high as possible for max SPL, the relatively huge mid drivers were big for the same reason. It worked, but the younger engineers these days are favouring using smaller monitors closer to the console, as they're tired of yelling at the older engineers who can't hear anymore.
For a reasonable compromise, I suggest a low end target of 40Hz, which is low enough for most music, given that we interpret lows by their overtones. For this, at volumes that don't require ear protection, two 12s will suffice, and will maintain the look of the big JBLs. Strictly speaking, one 15 or two vertical 12s would be better, but if we use a good (full-range?) mid, we can cross over low enough to negate the extra width.
The end result will be a box about the size of a Marshall 4x12, and those are a one-man-carry if you put handles on the side, and will fit in most cars. I think we've expressed the idea bigger is better, but lets address portability, as well.
Arguments against?
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The driver is Faital HF104, an annular ring driver, memebrane manufactured in in Ketone, Faitals propriety polymer, reputedly made out of equal parts green cryptonite, catshair and turkish yoghurt, flare is also Faital, their smallest tractrix, STH 100.
Measurements are somewhere around here, i´ll look and post.
Aim, thou, was to walk a bit further, 2x8" is about the same area as one 12" which i originally designed the RLK horn for, driver in designprocess was Beyma 12P80Nd but has since changed to Beyma Liberty8, the magical recreation of JBL L120, just better in all respects but one, higher build quality, lower Fs, lower Qts, lower sensitivity thou, only102dB.
This driver in the RLK horn is the speaker most true to music i´ve ever heard, dynamics, low or high level is utterly stupefying, mind You, i´m partial here, i designed it, but it´s not a comercial design, drawings are free for anyone who wants them.
Ingvar
Measurements are somewhere around here, i´ll look and post.
Aim, thou, was to walk a bit further, 2x8" is about the same area as one 12" which i originally designed the RLK horn for, driver in designprocess was Beyma 12P80Nd but has since changed to Beyma Liberty8, the magical recreation of JBL L120, just better in all respects but one, higher build quality, lower Fs, lower Qts, lower sensitivity thou, only102dB.
This driver in the RLK horn is the speaker most true to music i´ve ever heard, dynamics, low or high level is utterly stupefying, mind You, i´m partial here, i designed it, but it´s not a comercial design, drawings are free for anyone who wants them.
Ingvar
Isn't thermal compression another issue, driving less efficient speakers with more and more power to achieve the same as an efficient driver can with 100W?
Thanks for you input and getting us back on track Keriwena!!
So how do the Eminence Beta 12's look? Would the 4351 be a better arrangement?
I wound not be averse to a single 15 if it better suits the end result
Attachments
Building the foundation - BASS FIRST
Thanks for chiming in guys. I'm aiming for 'the best we can do for reasonable outlay' multiway speaker in the vein of JBL and Altec for immediacy, delicacy, visceral, tangible, iron fist in the velvet glove sound
I dont mind going with horns (multicellular or CD) or staying with standard drivers to achieve the goal.
Right now I'm concentrating on the bass section.
Dual 12's have been tabled, also a single 15 per side. Any input on the drivers noted above or others you think are suitable (within sensible $ range) along with alignment options? Will a Klipsch horn/Bass bin (Altec side of the design brief being satisfied here!!) give impact along with depth & control or would a vented/IB design be better?
Thanks for chiming in guys. I'm aiming for 'the best we can do for reasonable outlay' multiway speaker in the vein of JBL and Altec for immediacy, delicacy, visceral, tangible, iron fist in the velvet glove sound
I dont mind going with horns (multicellular or CD) or staying with standard drivers to achieve the goal.
Right now I'm concentrating on the bass section.
Dual 12's have been tabled, also a single 15 per side. Any input on the drivers noted above or others you think are suitable (within sensible $ range) along with alignment options? Will a Klipsch horn/Bass bin (Altec side of the design brief being satisfied here!!) give impact along with depth & control or would a vented/IB design be better?
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basicly, for the bass, stay away from cheap woofers with light cone(mms) and high output
also usually have highish Qts above 0.4, despite a relatively big heavy magnet
it indicates a large magnet gap to ease production
but leads to poor control and distortion
but if suggested to look at Fs no higher than 30-35hz, all those woofers would be closed out automaticly
and be prepared to go fully actice, or forget about it
also usually have highish Qts above 0.4, despite a relatively big heavy magnet
it indicates a large magnet gap to ease production
but leads to poor control and distortion
but if suggested to look at Fs no higher than 30-35hz, all those woofers would be closed out automaticly
and be prepared to go fully actice, or forget about it
I agree. The JBL based (2225, 2123, DE250+Ewaves) 3 way I threw together a couple of years back was a ripper, much better than the KEF 104/2 I also had at the time. It was a fun project before I bought a new apartment and ran out of money. I'm now using Acoustic Elegance drivers in the same format for my surrounds, which I hope to have finished by the end of October.
Some waveguides worth looking at are the SEOS from Autotech or diysoundgroup in the US. I'll be using these (SEOS12) in the surrounds.
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