Do you have any thoughs of where I could model this (maybe visualize it) and find out for myself prior to building it?
I understand that a WTW configuration has some drawbacks, but my understanding is that at x-over the symmetrical woofers help reduce floor and ceiling reflections from the tweeter
I've read that the drawbacks are potentially the "revealing" nature of these types of speakers, but never that the lobes and nulls are a problem... Is it because I'm turning the horn vertical? Would that be the case even if the distance between woofer and tweeter will be less than 1/4 wavelength at X-over, which will be about 5.2" at 650 hz?
Thanks! - Six.
I'd like to keep the price of each woofer closer to $100 than to $200, but if a $200 driver fits the bill perfectly, that would not be a deal breaker.
I do expect this will take me some time... to research, build, test, repeat...
10" are a possibility, but there are already so many choices in the 12" size, that I don't see the need to expand the search just yet, when I'm basically starting to look. So far, the 10" i've seen don't seem to provide a better SQ up to 1000 hz but they also don't go as low as the 12"...
Thanks again! - Six.
It was my standard woofer back in the '90s, great bang/buck! Last paid $63 @ Madisound, so an even better bargain today once inflation is factored in, though makes me wonder if actual specs are as close to published as back then.
GM
"mass is the enemy" is a quote from one of the pro speaker designers I meet years ago. He told me all else being equal; stick with the smallest diameter driver that will do the job for you for a better defined upper range but mostly for a quicker and more precise transient response. All else being equal is part of the clue. If you have a 10 inch that will do everything a 12 inch will do; the 10 inch "should" be able to follow the signal more accurately than a 12 inch. This isn't always the case obviously but some 12 inch woofers that reach down REALLY LOW have trouble once you get above a few hundred hertz. My SB 29 (should really be considered 11 inch) for example isn't giving me the mid and upper bass I was looking for but it does go very low in a small, closed box. I just ordered a new Crown pro amp to drive it because my Dayton APA 150 just is way under-powered here. I think the SB29 sensitivity is way lower than spec. or the Dayton power is way over stated. If I were to do it over again; I would go with the new SB Satori 9 1/2 inch woofers; not THAT much more expensive. They wouldn't go as deep (in my closed box) as the SB29 but the mid and upper bass would be WAY more precise. They have gotten really high praise in the few pieces I have seen written about them. I had also considered the ETON 11 inch, the newer Symphony II model. The specs show it usable up to about 1000 Hz where as the original was recommended for only up to 100 Hz. HUGE improvement! Anyway; once I get the new amp and finally get all the bugs worked out with my REW and M Audio measurements; I may STILL decide to sell the SB 29's and go for the Satoris!???
Long response I realize but it helps better explain my thought process.
Long live deep, powerful and "ACCURATE" bass!
Moving the speakers around it becomes immediately clear it's a bit bigger than most of my other 3-way classics. Heavy! So is the bass response from the 9½" bass driver. It goes deep.
What took the most time was the point of crossover between bass and mid. 400 Hz, 500 Hz, 600 Hz, etc. Starting at 400 Hz made the middle midrange a bit weak on vocals, lacking the fullness and warmth I wanted. Thus, gradually the point of crossover was moved upwards and ended at 580 Hz making the best blend of lower-mid and middle-mid. Lower-mid does take some membrane area to give the fullness of vocals and instruments. The distance to the floor becomes a factor here too in making the best bass-mid integration. I found 50 cm stands ideal, but try it out. It can have a significant impact on sound how high your midrange are above floor level.
What thrilled me the most was the seamless integration of upper-mid and treble from its 1. order crossover and the smooth - and utterly dynamic - presentation of e.g. cymbals and other instruments with high-frequency content. This speaker surely rivals the AT-3WC and also the PRELUDE speakers - and at a much lower price. Not since the PRELUDE had I done a 1st order crossover, but I remember what it did. And this all thanks to the MR13 midrange drivers, which is not necessarily flat, but smooth all the way to 14 kHz without any excessive dips or peaks. It takes equalisation, but only from an RC circuit across the series coil.
I sometimes have mails asking for a construction giving "dynamic deep bass, smooth and transparent midrange and silky treble". Well, we all want that. Only way to find out if we can have it is building loudspeakers. Enjoy!
ABOVE>>>An excerpt from "Troels" on a vented box 3-way he did with the new Satori 9 1/2 in.
Full discussion here:
SBA-941
He is using the 8 Ohm version...
If you did a vented box using two of the W024P-8 in parallel (per side obviously); you "might"??? get everything you are looking for...deep bass but also accurate mid and upper bass. WAY smaller than 12 inch I realize but this makes for a good argument re smaller vs bigger "all else being equal"... I don't have enough space in my listening room for large, stereo vented boxes which is another reason I chose the SB 29's. For the money and size; 37 Hz closed box is quite impressive; nothing "FAKE" or wimpy about the lower bass I'm getting now for sure. I do have separate subs for the 16 Hz to 32 Hz octave and they are also in a small, closed box but tucked away behind the TV cabinet in the corner so that was "wasted" floor space and doesn't intrude on the usable and visible small space I have to work with. I wanted stronger stereo bass from about 40 Hz and up. I was previously using a stereo pair of the Satori 6 inch woofer in small, vented boxes. Very good bass from 40 Hz to well past 800 Hz if wanted BUT; I felt I needed to move way more air and I already had the Satori 6 inch mids plus the Pluvia FR for anything above 300 Hz...(again, my logic and thought processes that got me to where I am currently)...
What took the most time was the point of crossover between bass and mid. 400 Hz, 500 Hz, 600 Hz, etc. Starting at 400 Hz made the middle midrange a bit weak on vocals, lacking the fullness and warmth I wanted. Thus, gradually the point of crossover was moved upwards and ended at 580 Hz making the best blend of lower-mid and middle-mid. Lower-mid does take some membrane area to give the fullness of vocals and instruments. The distance to the floor becomes a factor here too in making the best bass-mid integration. I found 50 cm stands ideal, but try it out. It can have a significant impact on sound how high your midrange are above floor level.
What thrilled me the most was the seamless integration of upper-mid and treble from its 1. order crossover and the smooth - and utterly dynamic - presentation of e.g. cymbals and other instruments with high-frequency content. This speaker surely rivals the AT-3WC and also the PRELUDE speakers - and at a much lower price. Not since the PRELUDE had I done a 1st order crossover, but I remember what it did. And this all thanks to the MR13 midrange drivers, which is not necessarily flat, but smooth all the way to 14 kHz without any excessive dips or peaks. It takes equalisation, but only from an RC circuit across the series coil.
I sometimes have mails asking for a construction giving "dynamic deep bass, smooth and transparent midrange and silky treble". Well, we all want that. Only way to find out if we can have it is building loudspeakers. Enjoy!
ABOVE>>>An excerpt from "Troels" on a vented box 3-way he did with the new Satori 9 1/2 in.
Full discussion here:
SBA-941
He is using the 8 Ohm version...
If you did a vented box using two of the W024P-8 in parallel (per side obviously); you "might"??? get everything you are looking for...deep bass but also accurate mid and upper bass. WAY smaller than 12 inch I realize but this makes for a good argument re smaller vs bigger "all else being equal"... I don't have enough space in my listening room for large, stereo vented boxes which is another reason I chose the SB 29's. For the money and size; 37 Hz closed box is quite impressive; nothing "FAKE" or wimpy about the lower bass I'm getting now for sure. I do have separate subs for the 16 Hz to 32 Hz octave and they are also in a small, closed box but tucked away behind the TV cabinet in the corner so that was "wasted" floor space and doesn't intrude on the usable and visible small space I have to work with. I wanted stronger stereo bass from about 40 Hz and up. I was previously using a stereo pair of the Satori 6 inch woofer in small, vented boxes. Very good bass from 40 Hz to well past 800 Hz if wanted BUT; I felt I needed to move way more air and I already had the Satori 6 inch mids plus the Pluvia FR for anything above 300 Hz...(again, my logic and thought processes that got me to where I am currently)...
It seems that the designer was into horns. Direct radiators are a different matter. Their mass remains dominant and I don't see transient response being a problem.
Actually, these were not horns; just standard bass reflex or vented. I agree there a lot of 12 inch woofers with very good mid and upper bass as well as quick and accurate transient response. My main points are that we sometimes get stuck on an idea of driver size and haven't considered other possible and viable options. I am just as guilty in this regard as anyone else. I had one of my best sounding designs ever with two 8 inch woofers in a large, vented box. These were in the category of "discrete alignments" that Dickason mentions in LDC. At one of my training seminars; we had a visiting Professor that said if you can achieve a bass reflex with a woofer Q of about 0.39; they sound REALLY good. I don't want to mention this person's name but he was a PHD and one of the world's leading experts on acoustics and speaker design. Long story again; sorry; anyway; these dual 8 inch in a very carefully designed vented box totally blew away any single 12 inch design I ever heard EXCEPT maximum SPL. NOTHING was missing; f3 in room of 27 Hz; in-room measured very flat from 40Hz to 400Hz (my X/O). Transients were FAR superior to any 12 inch I ever heard and the deep bass, mid bass and upper bass were all very well balanced, musical, natural and real. So, just sharing past experiences and knowledge handed down from true world experts that I personally spent a week with learning theory and hands on...FWIW...
[well; in my way of thinking, impulse response, step response, etc.] How quickly and accurately can any transducer respond to any given signal. A lot of the better speaker tests, reviews, evaluations, etc. include measurements and discussions on impulse response. This includes the rise and fall times both. I know motor strength plays a big role in transient ability and better cone motion control and cone mass or cone area are not in and of themselves the sole determining factor of accurate "response" of all kinds. Maybe I am not choosing the correct terminology. Again; we are back at all else being equal. Obviously there are dozens of variables that go into what makes an accurate "sounding" speaker that can faithfully reproduce the incoming signal. Here is an example; say there is a large, quick "burst" from a bass drum or tympani (kettle) drum "hit"; we would want the woofer to respond as accurately as possible to the entire signal (within the limits imposed by the crossover, etc.). So, not only the lowest bass content but the entire spectrum of that complex signal. This; as I am trying to explain it; depends in part on the ability of that woofer to track or duplicate fast transients. Am I making any sense here or just confusing the issue further?
Here is another example from the pro sound side of things. In fact; I got involved a bit on the topic of choices of speakers for "bass guitars". In the 1970's; it was common practice for a bass amplifier combo to employ two 15 inch speakers. Now days, it is more common to use multiple smaller speakers. Four 10 inch bass speakers with or without a "tweeter" is now more the norm. As long as we are talking 4 string bass so we need only be concerned with 40 Hz and above; the bass players today much prefer the "4X10" over the "2X15". Why? Not just mid and upper bass response but transient response as well.
Compared to the 4X10 arrangement; the 2X15 sound "sluggish"....again; all else being equal. I guess this is coming from my musician side; not just my technical side. Most bass players agree they MUCH prefer the 4X10 "sound".
Kind of apples and oranges here but the basic idea is valid.
When you need 30 Hz for keyboards and 5 or 6 string electric bass; then you normally supplement the 4X10 with maybe a 2X15 for just the "low end" ONLY. The 4X10 still does the majority of the spectrum.
Compared to the 4X10 arrangement; the 2X15 sound "sluggish"....again; all else being equal. I guess this is coming from my musician side; not just my technical side. Most bass players agree they MUCH prefer the 4X10 "sound".
Kind of apples and oranges here but the basic idea is valid.
When you need 30 Hz for keyboards and 5 or 6 string electric bass; then you normally supplement the 4X10 with maybe a 2X15 for just the "low end" ONLY. The 4X10 still does the majority of the spectrum.
Agree on the impulse; no need to split; I have said all I need to on the subject. It would interesting to have other's inputs on driver choices. I have NO PROBLEM with 12 inch; again, just adding to the knowledge base from what I have heard and learned over the MANY years from others; in person and in my studies and readings.
Ok, so I found a way to model the CTC spacing (15") and the various crossover frequencies, at 600 hz there is only one 60 degree lobe, at 635 it starts to develop small side lobes, and here is at 650 below...
Since the horn is 60x40, this appears to be in-line with my expectations of reducing floor and ceiling bounce.
Six - Minneapolis
Attachments
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5 Options Modeled, updated driver data...
Here are the 5 drivers modeled in a vented and sealed box, plus additional driver data I typically use for comparisons....I'm still studying the graphs, so I have not come to a conclusion yet... but before I saw the graph, the Peavey was a strong contender, I just don't see it performing well at 30Hz. The two that seem to have the best low end extension are the SB Acoustics and the Peerless but the vented box sizes are significant. I was surprised the Dayton did not go as low as those two, but the box size is much smaller...wonder why?
The Eclipse seems to be a nice compromise between low extension, reasonable box size, and price...
Would love to get opinions on this! - Thanks! - Six.
5 Driver Datasheet Comparison
SB Acoustics
Peerless
Peavey
Dayton
Eclipse
Here are the 5 drivers modeled in a vented and sealed box, plus additional driver data I typically use for comparisons....I'm still studying the graphs, so I have not come to a conclusion yet... but before I saw the graph, the Peavey was a strong contender, I just don't see it performing well at 30Hz. The two that seem to have the best low end extension are the SB Acoustics and the Peerless but the vented box sizes are significant. I was surprised the Dayton did not go as low as those two, but the box size is much smaller...wonder why?
The Eclipse seems to be a nice compromise between low extension, reasonable box size, and price...
Would love to get opinions on this! - Thanks! - Six.
5 Driver Datasheet Comparison
SB Acoustics
Peerless
Peavey
Dayton
Eclipse
Attachments
This is GREAT! Now; here is where we REALLY need a 3rd party test. Because; the OEM specs. are not always updated; they are not always accurate and we need a totally unbiased opinion based on both scientific methods and listening tests. Some things I trust; Zaph, Troels and Audio Xpress, also there are many others but I'm snacking right now waiting on my Crown amp. delivery so I'm not into a deep dive myself right just at the moment. I suggest doing a deep dive into 3rd party tests to confirm the OEM specs. You can model and speculate all day long; if the specs. are off by 20%, 50 % as some are; well...come to your own conclusions about accuracy and validity...
PLEASE SEE MY POST NUMBER 52..."3 1/2 way with sub...my upgrades" The SB29's are for sale now! The WAY smaller Satori MW16P-4 in a vented box absolutely DESTROYS the SB29's!
The SB29's have a place; they are just not for me though. So you see; everything I have been saying above here on THIS post has just once again come to light.
The SB29's have a place; they are just not for me though. So you see; everything I have been saying above here on THIS post has just once again come to light.
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