A Tapped Horn Experiment

[Triticum Agricolam]

From the looks of that design I would say it's the ported chamber that's handling the low end and the horn does the higher frequencies. The horn path is much too short for it to be tuned very low.

That's an interesting design, I just wonder if the ported section would be able to keep up with the output from the horn.

[Patrick Bateman]

In any loudspeaker, you can have output from the front of the cone, or the front *and* the back of the cone.

In the picture above, we have output from the front *and* the back of the cone.

The reason why you don't see a lot of boxes like this is because the output from the back of the cone is going to be severely limited by that port. Big ports = big bass, and that's a small port.

Tapped horns are kinda clever because the entire enclosure is basically one big port.

[Mike Gann]

That seems like a 6th order to me.

Yes definitely is. Would that help in the way that I mentioned?

[Mike Gann]

From the looks of that design I would say it's the ported chamber that's handling the low end and the horn does the higher frequencies. The horn path is much too short for it to be tuned very low.

That's an interesting design, I just wonder if the ported section would be able to keep up with the output from the horn.

Yes this was just the first and few picture I can find of it, It's a bad design actually the website it's from people are saying his horn needs to be at least 7ft to hit 40hz. Says it's too much like a Cerwin Vega ha.

[Mike Gann]

In any loudspeaker, you can have output from the front of the cone, or the front *and* the back of the cone.

In the picture above, we have output from the front *and* the back of the cone.

The reason why you don't see a lot of boxes like this is because the output from the back of the cone is going to be severely limited by that port. Big ports = big bass, and that's a small port.

I know all this, I'm making an observation that adding a port to the horn might lift some of the lower frequencies and filter out the useless highs (useless because the response graph is all over the place) OR could this be a fix for drivers that have too much motorforce and smooth out the response a bit? I can't find any response tests or data on these kind of horns.

In case one I'm thinking tuning high (small port) might do this if it acts in any way like a bandpass might, and in case two maybe a long low tuned port may or may not help a peeky woofer.

[Broke_Audio_Addict]

That seems like a 6th order to me.

Yes definitely is. Would that help in the way that I mentioned?

I'm the wrong guy to ask, this discussion is way over my head.

[Triticum Agricolam]

Tuning lower will help smooth out a peaky sub, so will will shrinking box size. Both strategies will reduce peak output, so you have to be sure that's a sacrifice you are willing to make. Another problem with shrinking box size and tuning lower is they both require the port to get longer and you can quickly run into a situation where the port needs to be unreasonably long.

Another way to deal with this would be to use a t-line. It's easy to tune a t-line low without running into the problem that small low-tuned ported boxes have. Also with a T-line you can stuff the line to further reduce the output peak at tuning.

[Mike Gann]

Another way to deal with this would be to use a t-line. It's easy to tune a t-line low without running into the problem that small low-tuned ported boxes have. Also with a T-line you can stuff the line to further reduce the output peak at tuning.

The thought of stuffing a horn came to mind

[Patrick Bateman]

Another way to deal with this would be to use a t-line. It's easy to tune a t-line low without running into the problem that small low-tuned ported boxes have. Also with a T-line you can stuff the line to further reduce the output peak at tuning.

The thought of stuffing a horn came to mind

I'm a big fan of copying what works. Basically all of my best results have come from copying designs from pros, Danley in particular.

If you look at the Danley designs, he doesn't use stuffing. The only exception that I'm aware of is the DTS-10 and the TH-SPUD, which are aimed at the home theater market, where listeners might prioritize smoothness over sheer output.

Stuffing can reduce output in a hurry; it's pretty easy to lose 2-3dB from stuffing. That's like going from a 15" woofer to a 12" woofer, maybe even a 10" woofer.

Back in the 90s, Bose used this hideously complex triple chamber bandpass subwoofer. It's a complex design, but it basically extracts every last ounce of SPL from a set of relatively cheap woofers. (I was the first person to publish an Akabak script for it here : http://www.diyaudio.com/forums/subwoofers/186855-post-your-triple-reflex-bandpass-designs.html )

Nowadays, the Bose Acoustimass is much MUCH simpler. There's no stuffing. There's only a single path. There's no ports. Besides being simpler to construct, the new design is less sensitive to driver variances, which means it will sound better as it ages. (Woofer parameters drift as they age.)

[Loud_Low_SuperSlowed]

BFM designed horn?