Which woofer ?

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low xmax, Vas is low - so you won't get much upper-bass lower mid boost in a small cabinet.

-kind of weak. The 8" version is more viable IMO. :eek:

..but either depends on how you use them (and in conjunction with other drivers).
You are right in that, but I will remind you that I have a width limitation for this loudspeaker and hence a 7" is perfect since it fits within the assigned baffle width I can accept, which is roughly 200 mm.



This project turned out to be quit fun actually :)
 
Time for an update.

There are 3 woofers which pass the eye of the needle for my upcoming project and in no particular order:

Scan Speak 18W4434G00. (6.5”)
Wavecor WF182BD03 (7”) - paper
Audiotechnology 18 h 52 17 06 SD (6”)

The Sd is similar for all of these. The Flexunit is the most expensive out of the bunch but a wonderful driver.

Here is a review of the Wavecor: Wavecor WF182BD03 midwoofer | HiFiCompass

The choices for now are more or less between the SS and Wavecor. The SS has an Sd of 137 cm^2 and Wavecor has an Sd of 131 mm^2. The force factor is slightly larger than (6.57) than SS (6). The overall impression for this Wavecor compared to the aluminum version is much better and is easier to drive and will fit quit well with the SB Acoustics 5” 4 ohm midrange driver, the SS 10” alu subwoofer and as icing on the cake, the Viawave GRT-145.

The GRT-145 is not a cheap tweeter, but considering the multiple outstanding reviews and the listening impression I have of – sadly not IRL – this is a serious contender. But there are other tweeters of interest that is much cheaper and also pass the eye of the needle and they are both from SEAS, the 22TAF/G and 27TBC/G.

Oneminde.
 
Maybe you can hear the tweeter in some factoryspeaker near you?
Regarding the Viawave, that is not an option. I would need to order from Jantzen Audio which is my closest supplier. But I have listened to fairly decent recordings from Rainer Weber (Kaiser Acoustics) and other recordings on Youtube which is a nice indicator. It actually has some of the signature which Accuton Diamonds have which I have IRL experience with, that and the oh so many wonderful reviews many give it - including Troels Gravesen - so I am fairly certain it would be a nice choice.


But I have another tweeter combo which is also on par with top performers like the Viawave, and that is the SEAS 22TAF/G and 27TBC/G. The 27TBC/G is a tweeter which Joachim Gerhard (Audio Physic) use. They shine in different regions. The 27TBC/G is a good candidate from 1.5kHz which is more than one octave above its Fs, but it starts to be problematic beyond 10kHz. That is where the 22TAF/G truly shines. It is open and airy, clear with loads of brilliance and would act as the super tweeter since it is useful up to 30kHz.
 
You are right in that, but I will remind you that I have a width limitation for this loudspeaker..

-but the baffle-step compensation driver should be on the side of the cabinet.

In that context the baffle can be just a bit wider than the 5" midbass, while the side panel needs to be "deeper".

If you do it just right, you will only need one low-pass filter - where the 5" and the baffle-step compensation driver are connected in parallel and both use the same low-pass filter. ;)
 
-but the baffle-step compensation driver should be on the side of the cabinet.

In that context the baffle can be just a bit wider than the 5" midbass, while the side panel needs to be "deeper".

If you do it just right, you will only need one low-pass filter - where the 5" and the baffle-step compensation driver are connected in parallel and both use the same low-pass filter. ;)
Unless you are aware of it, my target is the Audio Physic Codex / Structure loudspeaker. It is not strictly a reproduction but rather inspiration. So the width is dictated by the SS 18W/4434G00 woofer - yes, I chose that this time around - and this driver is 179.6 mm (dia), so it fits inside my 200 mm window. :)


I figured that I can always upgrade further down the road with the Wavecor or Audio Technology Flex woofer and Viawave tweeter etc
 
-but the baffle-step compensation driver should be on the side of the cabinet.
If you do it just right, you will only need one low-pass filter - where the 5" and the baffle-step compensation driver are connected in parallel and both use the same low-pass filter. ;)
The 10" will be side firing per "normal". But since this is a 4-way loudspeaker, each driver will get its own filter - I like dedicated, making sure things operate as optimized as possible ;)
 
Reckhorn D165, is a very nice woofer, for a 3 way or a sub. 30 € each ... use as many as you need and vented or closed
This might be a weird question, but. Is there a difference between how the low end is experienced between a 6.5" and say 15" ? I am thinking that the 15" has a much larger surface are and so the energy is distributed over a larger area, and in so doing, the energy isn't as focused as with the 6.5" ?
 
Unless you are aware of it, my target is the Audio Physic Codex / Structure loudspeaker. It is not strictly a reproduction but rather inspiration. So the width is dictated by the SS 18W/4434G00 woofer - yes, I chose that this time around - and this driver is 179.6 mm (dia), so it fits inside my 200 mm window. :)

That's cool. :)

I did remember your mentioning it - but I didn't know what it was specifically (..though I did know that it was a "slant" design with a cone tweeter). :eek:
 
..well I knew there were differences, what I meant was that I didn't know they had an additional driver on the baffle for baffle-step compensation (..looking like a an MTM design).

I thought we were discussing a design where the baffle-step compensation driver was on the side of the loudspeaker. (..and potentially also one on the side for the subwoofer.)
 
..well I knew there were differences, what I meant was that I didn't know they had an additional driver on the baffle for baffle-step compensation (..looking like a an MTM design).

I thought we were discussing a design where the baffle-step compensation driver was on the side of the loudspeaker. (..and potentially also one on the side for the subwoofer.)
An externally hosted image should be here but it was not working when we last tested it.


At least to me we are still talking about the same thing.

It started with the idea of using 3 pcs 6-6.5" woofers to get a more narrow baffle but maintain some of the low end 2 pcs 8" woofers would produce, and while it is a viable option, the dormant 4-way side firing style became more appealing since I can fit a 10" and get better low end and that is when I remembered the Audio Physic. And yes they do have a 2-3 way as well which is just a tweeter and midrange-woofer on the front.

Also what is nice about this is that I can work more on the acoustical property in terms of materials, cabinet construction etc and I was heading in the direction of what the Codex / Structure does anyway.. But in the end, they will sound very different :)
 
In this picture/design (the Codex picture you provided) - the driver near the top of the cabinet is presumably the baffle-step compensation woofer. (..the cone tweeter is 1st order connected to the mid-bass below it.) It's also quite likely that all of the drivers have minimalist filters, BUT obviously the baffle-step compensation driver and the sub on the side are not going to be minimum phase because of the time delay from the physical off-set of the midrange.


Now,

-picture/(envision) the same tweeter and mid-bass below the tweeter ..but moved-up slightly on the baffle with NO baffle-step compensation driver above it. In other words the baffle will have a traditional TM design of a two-way like the AP Avanti.

ADDITIONALLY:

Below the mid-bass driver on the front of the baffle, YET on the side of the loudspeaker (outward-facing) and very close to the the edge of the baffle - is your baffle-step compensation driver. And it can be larger than 7" diameter (..because it's not on the baffle). Aesthetically similar to the Pen Audio picture below (but a slant baffle and the side compensation driver even closer to the baffle's edge). (..Note that the loudspeaker in front is the left loudspeaker, and the one in the left-rear is the right speaker.)

Ideally this driver would be a higher Vas and higher efficiency driver (than the mid-bass driver) and be in a smaller sub-enclosure within the loudspeaker, resulting in some boost near 100 Hz.

With it firing to the side, the overall response from this driver will be attenuated as freq.s increase, providing an acoustic low-pass response (..which is why you could use it in parallel with the on-baffle mid-bass driver at such a high freq. low-pass filter - at those freq.s the driver doesn't factor-in anywhere near the average within a fairly wide horizontal "window").

Done correctly it's elegant (in the context of driver's working together with fewer cross-over parts). Far more so than what the Codex is doing. And at least from the front and the "interior"/(near listener) side would look similar to the AP Avanti.


Below that of course on the side of loudspeaker would be the subwoofer (using most of the loudspeaker's interior volume).
 

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To be honest, your description did go over my head for a while, one of the reasons is my perspective which is that as much of the sound as possible should come from the front to a certain limit. Utilizing a narrow baffle makes it impossible to have a large driver on the front, hence the compensation driver is the one on the side, it serves as low end fill to compensate for the losses on the front.
On the other hand, large waves is omnidirectional so not as sensitive, that is why a side firing woofer is not an issue, taking care of the 20-100 Hz or thereabout.
[FONT=Verdana, Helvetica, Arial, san-serif]5/ The addition of a 0.5 bass speaker -- Set up a low pass filter for the lower woofer to coincide with the spreading loss of the upper woofer, net result is constant power output through the bass to midrange frequencies. Simple to do, all you have to do is run the upper woofer all the way down, while the lower woofer gets a 1st order rolloff. But it's best to do this with measurements, as for any of these techniques.[/FONT]
Source: Baffle Diffraction Step

Maybe I am missing something, and I think I am. Much of the joy which 7-10 inch drivers provide is when the energy hits the body, like a nice punch in the gut :D. This energy is lost as soon as you move to the side of the loudspeaker, what is left is the rumble. Same effect happens when the driver size increase - long throw 12 inch can generate this punch-less rumble - and now we are in the domain of sound that is more felt than heard and felt sound is secondary to me while the punch is a primary target.. however, wit that being said. A good loudspeaker need to reproduce the whole acoustical spectrum of a recording, so the felt music is therefore important, just not as much as the other. Also, felt sound is the most energetic, so it very easily resonates with stuff in the room and the room itself and cause many issues... off topic here but you get my point.

So the issue I have with your example loudspeaker is the loss of the punch, which to me is a gap in musical reproduction. But hey, its just a personal preference.
 
"punch" works..

For that it's more about the driver/loading + amp combination (high current reserves) ..than orientation (relative to the listener).

High force (Bl) + High Eff. and the more Mms for a given Sd relative to efficiency.


For that kind of woofer you will need a low-pass filter (and a more complicated one if it's put on the baffle, as opposed to the cabinet's side).

In a smaller Sd, this is the driver you will want for that in an appropriate bass-reflex design:

https://www.parts-express.com/pedocs/specs/294-652--8pe21-spec-sheet.pdf
 
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..sure it would, it's all down to the design. ;)


One last piece of advise:

With your intended baffle width (around 8") your -3db point is around 275-300 Hz (..depending on how you load your mid-bass). Somewhere just below that would be a good "crossover" (acoustic transition) for your baffle compensation driver.


Anyway, good luck with your project! :)
 
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