Technical Deep Dive on Speaker No.1786 --- 15" 2-way

[@indopleaser]

this video is why i enjoy audio equipment. great example of a mad scientist

[@csj9619]

Awesome looking speakers! If I was gonna build some speakers, it would be something similar. Pro audio midbass/woofer and HLCD is right up my alley. The "Econowave" design is what first got me interested. Congrats on acheiving your desired results this time.

[@rhalfik]

Came to remind you how fantastic channel you made and what a pleasure it is to see you every time you post a video. I like where you're going with your products. They develop into original and practical furniture.

[@locmanw1583]

I really like your two way designs!👏😃👍

[@BIGSMONITORS]

Congrats on a great design for a system. you might mention that if you have a driver with a low Qts that would produce an overdamped condition, you can increase the Qts by inserting an appropriate resistor in series with the driver, This may allow you to use some excellent drivers in sealed enclosures.

[@DannerPlace]

Excellent information.

[@paulgyro]

How do the 1786 compare to Sabourin sonically? From a build standpoint I assume the 1786 to be much easier to build as one doesn't have to build the horn?

[@EduardBroekman]

That's a generous sharing on this design and some interest quotes from that book- thank you. I had been looking at both these drivers some time ago.. SB has interesting options. From what SPL level do you find this speaker sounding as intended?

[@plcamp1]

If I sent you the data sheet for my 15” OB woofers, could you advise whether this bass cabinet would allow drop-in ? My woofers have a qts of 0.7 and Fs of 40 hz, neodymium motor, similar sensitivity and made by Eminence. I am guessing they would match well here. I actually have four of them, wondering how two 15” per side might use a cabinet design similar to this?

[@garyvitrano8362]

Have you compared the SB Audience Bianco 120B150- 12" to the 15”?

[@ZvoolabAcoustics]

Thank you for your video

[@gerhardwestphalen]

Step response is based on the frequency and phase responses. Steeper roll off of the ported speaker will cause an apparently uglier step response. If you EQ the sealed speaker to match the rolloff of the ported then the step response will also match. Similarly the high frequency extension will make the step response look "faster" so a low passed woofer will look much worse than the same woofer with a low pass on it. IMO step response is only useful for checking time alignment and looking for excess phase behavior

[@CorradoVR6z]

You should watch some of Bennett Prescott's videos to understand B&C's design philosophy. Basically they tend to design their drivers to have a motor as strong as possible (low Q) and assume the user will use DSP to correct the response since volts are cheap nowadays.

[@jenniferwhitewolf3784]

Yuk! I prefer to not need complex EQ to just get basic performance from a driver. Requiring DSP is bad design criteria

[@JosephCrowesDIYSpeakerBuilding]

That’s certainly the case for the pro sound market. Home hifi still requires drivers that have reasonable parameters.

[@CorradoVR6z]

@@jenniferwhitewolf3784 As I suggested, watch some of Bennett's videos to fully understand the concept behind it. Scott Hinson has also posted some interesting tests comparing pro audio drivers and hi-fi.

[@paulgyro]

@@CorradoVR6z what KZbin channel are these on?

[@CorradoVR6z]

@@paulgyro youtube.com/@bennettprescott

[@mikevincent6332]

Sealed cabinets have nice tight / clean bass

[@JosephCrowesDIYSpeakerBuilding]

Yes they do

[@Clobercow1]

So the entire premise of this is to get that "fast bass" sound? My thinking here is that the group delay of a ported enclosure, especially in the lower octaves, like 30hz or so, is inaudible, so why not ported to begin with? You'll still get the same performance in the upper bass as you would sealed anyhow and you get the benefit of the improved efficiency of the ported design with no audible downside.

[@JosephCrowesDIYSpeakerBuilding]

From ‘Recording Studio Design’, 4th Edition “The audibility of these time shifts is not well understood, but the consensus is that the sound is more natural if the group delays (the phase shifts) are kept to a minimum. The late Michael Gerzon, one of the most respected audio investigators of the twentieth century (co-inventor of the Soundfield microphone, Ambisonics, the Meridian Lossless Packing data compression system, and the first proponent of dither noise shaping), was of the opinion that for natural sound reproduction, the minimisation of phase shifts down to 15 Hz was more important than the maintenance of a flat amplitude response down to much higher frequencies. Figure 19.5 illustrates the idea diagrammatically, with the low order roll-off of the (a) curve tending to sound more natural, despite rolling-off from a higher starting point than the (b) curve. In general, the subjective audibility of the low-frequency roll-off characteristics in small loudspeakers still needs much further investigation.”

[@anandshah71]

Anyone made the speaker would like to hear their opinion

[@ahnenpost5237]

first you cite a text, saying a total Q of 0.5 is the goal, but then realize a enclosure with a Q of about 1. Contradiction obviously. Step rresponse: is not text-book, it's typical, meaning that there are two steps, the first one arriving first from the mid/high horn und then later the one from the woofer - to me, it's a bad performance, because the time delay can be fixed, especially by using a DSP. Lot of room for improvement. By the way, the two differing step-responses can be heard. Siegfried Linkwitz was adressing this issue always in his designs und he urges every designer to not skip this.