First horn woofer - ideas please

[GM]

Greets!

You're welcome!

Some things are counter-intuitive, using multiple drivers actually allows for a smaller horn since you can make it shorter. The mouth area is a function of the desired Fc (horn equivalent of a BR's Fb) after any boundary and/or room gain is factored in, and since the area of a WL exponentially increases with decreasing frequency, a basshorn without lots of room help either has a huge mouth or doesn't work very well by your stated standard.

Anyway, if you cut it in half and separate them some distance, they will perform much worse than if left as one set in between the mains and the designer has already told you what performance to expect if not closely coupled to a corner.

GM

[Eva]

SoundNERD:

You can't use a single driver and you can't make it smaller without ruining it. Horns are complex and some times counter-intuitive devices. Actually, using two drivers is likely to allow the horn to be smaller and to have a lower cut-off due to increased throat and radiation areas. The expansion profile won't be the same for a single driver. Also, you can't cut the horn in two halves because the surface to length ratios of the cavities are what determine horn response, and you would be changing these ratios dramatically.

If you really want to know how bass horns sonund, you will have to build an exact copy of something known to produce good performance. Alternatively, you may learn about horns and build your own custom ones, but that would involve spending money in tools, wood and drivers for prototypes and understanding a lot of new concepts.

Finally, you have to understand that 40Hz waves are nearly 9 meters long, and that horn size is determined by the longest wave you want them to play efficiently, so you can't have a 40Hz horn of the size of a bookself speaker. Actually, the dual 10" horn shown in the link that you posted is nearly the smallest than you can go, and it's only valid for corner placement (wall or floor placement would either require a much bigger horn or to stack several smaller ones).

[cowanaudio]

G'day again Mike

I figure you're getting the idea by now. The 40Hz horn I designed is pushing a 40Hz horn about as small as it can go. It will not perform well unless it is corner loaded and in a "normal" sized room. Given this however, it works very well. You could design a single 10" horn with the same performance, but as GM pointed out, it would actually be bigger, because of the longer horn path required. You could do much worse than to build one of these horns, and put it in a corner to see what you think. It requires little time or timber and will give you an excellent idea of what a horn can and can't do. I use the horn pictured on my website in my HE workshop system and it gets dragged out to the occasional party, and I tell you, it thumps, and never breaks a sweat.

Cheers

[noodle_snacks]

Originally posted by cowanaudio
G'day Mike

Having designed and then built a few of these horns, I have a fair idea of what they will and won't do. Firstly, DON'T split the horn in half. That gives you a mouth that is way too small to be useful for anything. My suggestion would be to build a pair of these horns with a 15" driver in each. If you corner load these two horns behind the main speakers, you will get lots of high effeiciency bass to below 40Hz, in a typical room. In small rooms, I've seen this horn measure flat to below 30Hz, due to room gain. One horn outdoors has trouble getting to 50Hz, and has a lot of ripple in the response. Not sure where you live, but the Eminence Delta 15 and Jaycar Venom 15" available here in Australia are excellent performers for the $$$.

Cheers

I built two of these subwoofers with the Jaycar Venom 15in drivers, i have yet to get the photos of my camera (built them months ago), but considering the total cost etc of the drivers i used they work amazingly well (Part of my party system)

[soundNERD]

For now, the 10" horn sun has been put aside. I've got two decent 10" woofers (old pyle drivers, before they became trash).

Now, I've got a 4" subwoofer driver from a Boston Acoustics subwoofer. It's a heavy little driver, looks really nice. It's magnetically shielded, thick paper cone with rubber surround.

I'd like to build a little set of computer speakers, with a horn-loaded subwoofer using this driver.

Is there any way I could bulid one of these but adopt it to a 4" driver? I can live with slightly higher frequency responce.

Thanks!

[xstephanx]

i tried to use horn resp but hornresp>me, so i cant figure out which 15" drivers are suitable for this horn, and which arent. im planning on building a pair fo them, both would be corner loaded, worst comes to worse theyd be stacked and in one corner at a partay.

but yeah i cant get hornresp to work, and i need to find out whcih drivers are suitable, so ill link you to a couple i have acess to, and hopefully someone here will feel nice enough to help out a pooooor 15 year old.

here are some options, theyre all from partsexpress.
http://www.partsexpress.com/pe/showd...number=290-384
http://www.partsexpress.com/pe/showd...number=290-394
http://www.partsexpress.com/pe/showd...number=292-218
and if i stretched the budget
http://www.partsexpress.com/pe/showd...number=290-407

so id REALLY appreciate if someone would help me out!

im not going for the higest of quality bass here, but i recently saw a sigur ros concert, and thought wow im building party speakers, but if i could get this kind of bass at a party, i would be so happy(im sure the people at the party would be too!). i dont really need much below 40hz

[cowanaudio]

G'day xstephanx

All the drivers you linked to are not really suitable for horn loading. They all have very weak motors and the Qes is way too high. Look for a driver with a Qes a bit below 0.5 and an FS between 30 and 40Hz. That would be a good start for you to feed numbers into Hornresponse. It's unlikely you'll be able to obtain a good reponse with the proposed drivers. You'd be better off making one horn with a better driver, and adding a second when you can afford it.

With the right drivers, however, you should easily be able to outgun the bass you heard at that concert in a domestic environment with two of these subs. One of these subs will do 125dB when corner loaded and measured in the middle of my 10 by 5 meter room.

Cheers

William Cowan

[xstephanx]

well the bass was VERY hot at that concert, and the venue isnt huge, so i was impressed. and thanks for the tips!

could i use a 12" driver for that horn and still achieve good results?

[xstephanx]

sorry to double post, but looking at the prices of woofers, the cheapest was around 80$ us for a 15"(eminence gamma15a), looking at the price of 10" woofers it may be more economical to go with dual 10s.

heres one i found
http://www.partsexpress.com/pe/showd...number=290-083

although the power handling is low, i doubt these will need much power to get the volume i need. also xmax is less than 3mm one way, which also scares me.

[cowanaudio]

G'day again

The horn will work best with dual 10"s or a 15" The 10" drivers I use are FS 32Hz, Qts 0.39, X-max 6mm and 200W thermal power handling. Others have used the Eminence Delta 15LF with success.

Cheers