Hi there!
In short - I really like sound of a single driver, ie a full range, but usually they lack bass. Here horns come into play, and I happen to like their sound as well. My particular issue is that currently I'm limited in space where I can put the speakers. The biggest single box I can have is roughly 80(h)x30(w)x40(d) cm (approx 31x12x15 in). This cuts off any existing designs like BiB, Dallas 2, etc. Even BK16 doesn't quite fit, though may be I can scale it down a bit. Anyways, the box I could have would fit a speaker like Fostex NV166 (or similar) and approx 1.6M horn length (give or take) and front opening at biggest 30x30cm (12x12 in), but realistically only 30x20cm (12x7.5 in) i.e. 600cm^2.
Here Tannoy Westminster enters the scene. While looking at their construction I thought that I can make the horn narrow - just to fit the driver, turn horn's mouth to look back toward the wall and add one more horn fold on each side to turn the horn to front again. This additional fold will add approx 40cm (15 in) - the box's depth - to the total length of the horn and make the horn opening, combined from both sides, circa 80x15cm (31x12 in) i.e. 1200cm^2 - twice of the "regular" one.
The result would be able (I hope) to play lower bass and the shape of the resulting horn will be closer to exponential one.
While for me it seems the approach is quite straightforward, I don't see any such design beside the Tannoys. So I'm wondering - what am I missing? The build will be definitely more complicated than a regular one, but are there issues with such design beyond the build? Does it make any sense at all?
PS H and D dimensions are max, in W I can go a little bit wider. Speakers will be standing against a wall.
In short - I really like sound of a single driver, ie a full range, but usually they lack bass. Here horns come into play, and I happen to like their sound as well. My particular issue is that currently I'm limited in space where I can put the speakers. The biggest single box I can have is roughly 80(h)x30(w)x40(d) cm (approx 31x12x15 in). This cuts off any existing designs like BiB, Dallas 2, etc. Even BK16 doesn't quite fit, though may be I can scale it down a bit. Anyways, the box I could have would fit a speaker like Fostex NV166 (or similar) and approx 1.6M horn length (give or take) and front opening at biggest 30x30cm (12x12 in), but realistically only 30x20cm (12x7.5 in) i.e. 600cm^2.
Here Tannoy Westminster enters the scene. While looking at their construction I thought that I can make the horn narrow - just to fit the driver, turn horn's mouth to look back toward the wall and add one more horn fold on each side to turn the horn to front again. This additional fold will add approx 40cm (15 in) - the box's depth - to the total length of the horn and make the horn opening, combined from both sides, circa 80x15cm (31x12 in) i.e. 1200cm^2 - twice of the "regular" one.
The result would be able (I hope) to play lower bass and the shape of the resulting horn will be closer to exponential one.
While for me it seems the approach is quite straightforward, I don't see any such design beside the Tannoys. So I'm wondering - what am I missing? The build will be definitely more complicated than a regular one, but are there issues with such design beyond the build? Does it make any sense at all?
PS H and D dimensions are max, in W I can go a little bit wider. Speakers will be standing against a wall.
Westminster-like design you described sounds good to me. Extra 40cm lenght and doubling the mouth area will certainly improve bass.
But, with mouth around 1200 sq.cm and total lenght around 2 meters its still fairly small horn.
So, dont expect miracles.
But, with mouth around 1200 sq.cm and total lenght around 2 meters its still fairly small horn.
So, dont expect miracles.
Look at it this way. Your envelope is ~90L external, which even for just an empty box leaves maybe 80L internal...adding all the internal horn path boards would maybe leave you 70L into which to fit your horn (probably closer to 65). Now go do the sims and see what what sort of horn you can fit into that and what it does. You could get something maybe 65Hz and a bit rough. Is that enough?
Thanks guys!
I've measured BK12 with a non-Fostex driver that I currently use and their F3 at about 90-ish Hz, AFAIR. So 65Hz certainly will be an improvement 🙂
So I could assume that this kind of build is just an unpopular one, but logically there's nothing wrong with it, so I'll proceed with it.
I've measured BK12 with a non-Fostex driver that I currently use and their F3 at about 90-ish Hz, AFAIR. So 65Hz certainly will be an improvement 🙂
So I could assume that this kind of build is just an unpopular one, but logically there's nothing wrong with it, so I'll proceed with it.
Well it's past "pushing it", for the size, basically. I think you should try posting a sketch so we know what you're thinking for path and perhaps you can get better predictions before undergoing extensive construction work. For example, if you are including the compound (front-) horn, that volume will both further compromise your back-volume and roll-off the top of the front radiation as well. If you need the front-loaded horn, too, my estimate is closer to 80Hz on the bottom than 65 (and compound horns are touchy, too). Hey--if you really just want to build something, that's understandable, too, but it'll be a lot of work and you honestly can do wider-bandwidth, cleaner, and smoother other ways, IMO. Try one in foam/cardboard/etc to see if it even has potential to justify the expense and work.
Attachments
yup, I'll draw something in F360 over the weekend
So far I don't plan to. AFAIU the front horn part in TW addresses something in the driver they use, to deliver the "sound picture" they want. With my practically total lack of experience it's highly unlikely I'll be able to effectively use that. That's why I'm looking only at adding of side folds plainly to lengthen the horn and increase mouth area. Another reason is that I've looked at couple builds of TW replicas and it's too complicated. While I totally understand what's going on there, I don't want to go that deep yet 😉
interesting, like what?
oh, that's a really good one, I haven't though about it. thanks a lot!🙂
Small horns get rough/ripple-ey the more the size gets compromised while trying to stretch paths and constrain mouths. Things that don't aim to do that will be smoother. Either some other design entirely (besides horn loading) or a horn that targets a higher f3 corner in the same small space. For possible examples of alternatives & Brian's spreadsheets, visit that page and scroll down to the MLTLs or TLs and see what might fit your envelope. Er not--the last thing I want to do is impede a blossoming horn maniac in the midst of The Fever 🙂
Such a small horn will mainly work as a pipe anyhow so why not make it a pipe
https://www.faktiskt.io/phpBB3/viewtopic.php?t=32975
I built this horn with the drivers on the narrow sides then the box is 38x33x68 cm
https://www.faktiskt.io/phpBB3/viewtopic.php?t=32975
I built this horn with the drivers on the narrow sides then the box is 38x33x68 cm
I see. may be that's one of reason why this approach isn't widely used.
oh lol 🙂))
With the foam core being so cheap, comparing even to mdf, I'll definitely try and measure number of variants, this one included. The exploration attracts me very much as well🙂
I'm not quite sure I got the point. The post at the link shows some speaker, but the picture with internals is missing. Googling for Michelson horn brings nothing, and for Voigt horn brings some corner standing horns. Unfortunately, corners aren't available for me.
Are you sure the link is correct?
Why not? Well, it will be weak and resonate, it's a no brainer. But still I think it can give an idea what the result will look like. Also it will give an idea how to assemble the real one and get the dimensions right. It's much cheaper to experiment with foam. Here it's 3 times cheaper than mdf.
Sd?
For me, this design is a no brainer, meaning that no, I wouldn't embark in such a construction. Want to make it scaled? it doesn't work like this.
132 cm^2, for this https://www.fostexinternational.com/docs/speaker_components/pdf/FE166NV2.pdf
Or I can go smaller if this one won't work.
I think I got your point and may be you're right. But at the same time I don't have your experience to see that and such undertaking will give me some 😉
Yeah, I know. I meant to take the layout, proportions and scaled down dimensions as a starting point and try to tune it to the point when it starts to work. I might not work at the end, but I'll get better understanding.