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Building Horn Speakers...

JTC

JTC

PFM Villager...
Has anyone tried this? I'm thinking of a single full range driver, Lowther DX3 or DX4 say, and as compact a cabinet as I can get, corner placement.

I originally thought about making speakers based around a good bass driver and HF unit, but the black art of crossover design and the fact I've moved to a flea powered amp make me want to look into high efficiency horn speakers.

Any tips for folded horn designs & construction would be gratefully received. I'm aiming for an efficiency of around 95dB/w and I'd like to make these speakers go as deep as my Royd Doublets, i.e. in the 36Hz region.

Disclaimer: I ain't never done nuffink link this before!

John

PS. Father-in-law is now a certified wooden yacht builder (and an ex-sparkie) so access to woodworking tools for the cabinetry is possible. I'm wondering about using marine ply for construction too, given the fact he has a shed full of it :D
 
36Hz! Id forget compact cabinet then! Joking aside, they'd be dam big horns to go that low and you'd need a favourable room.

Ive not gone this route yet but I have spent the past year researching the wonderful world of full range. If you want to PM me I'll give you a host of links.

Before you crash into the Lowthers why not consider one of the Fostex? Many people rate these at about 80% of the Lowther performance but at a much much cheaper price. Something like the 8" 206 or 207 would fit the bill. There are plenty of horn designs for these but plenty of people prefer a quarter wave transmission line. www.diyaudio.com is the best place to start you search, theres a wealth of info on there and many like-minded people.
 
If it has to be a horn, and it's your first speaker, I'd consider something simple, but proven. I have owned and heard quite a few full range drivers now, and the Fostex Sigma series is the most capable at its price point IMHO.

However, as they are real horn drivers, they have to be implemented the right way. For example, if you choose a wrong sized compression chamber for the FE108EZ, it will sound crap. You will get eery phase effects and weird colouration. So, I'd advise to stick to a tried and tested design with these.

Take a look at this plan. It's designed for the 168EZ, the medium size unit.*) It has two great advantages:
* You already have a cutting plan
* There are no iffy angles involved

The 168EZ is the best compromise between treble and bass performance for most people, this is why I would start with this one.

If you're looking for something really substantial, I have a plan for some huge Lowther horns; they are easy to build, but have a WAF that is below zero. The horn would fit the PM6* series.

Best regards,

Oliver

*) Yes, I know, this can be seen a chain of resonant chambers rather than a horn.

P.S.: I seriously doubt you would be able to reach a -3dB point of 36Hz with a horn of acceptable size.
 
Hi folks. OK, so -3dB at 36Hz is out (who am I to argue?) but I would still like to play with the idea of building horn speakers. Part of this is the fact that I don't have to muck around with crossovers, and part due to the fact that I would like high efficiency. I've lots of links now (thanks, guys) and I'm going to have a good read and think about what might work in my room.

Cheers,

John
 
John,

Rebuilding a crossover is much simpler than rebuilding a cabinet though. When you say you have flea-power, just how few watts do you have and how loud do you need to go? Personally, I couldn't live with the limited frequency range and coloration of 'full-range' single driver designs but their dynamic nature can be quite captivating. You might like to hear a few designs where possible before committing to rolling your own.

James
 
"I'm thinking of a single full range driver, Lowther DX3 or DX4 say, and as compact a cabinet as I can get, corner placement."

I suppose you expect to buy a reliable Fiat also.
 
James, I have 8 watts of push-pull valve power. Not a lot but it drives my 89dB, 6ohm Royds well enough - so I suppose the power isn't the issue. I just have an irrational lust for a pair of horn speakers! In terms of volume, it'd be nice to have the capability of >100-110dB, which I don't think I have with the Royds.

J. Vigne: Nah, I wouldn't buy any Fiat even if it were reliable...
 
hi JTC

I dont think you'll get the frequency response you're looking for from a small full range driver like a fostex or a lowther. Even the larger speakers like the Beauhorn Virtuosos dont go near that level.

If you want low bass you could look at adding a sub.

You could try speaking to Thorsten (3dsonics) on zerogain, who's quite knowledgeable on the subject.

There are loads and loads of lowther based speakers to copy, and kits to build.

You could always cop out, and buy something second hand or vintage.

There are also loads of website dedicated to high sensitivity systems/ speakers.

If it were my first build, I'd definately start with a kit for simplicity's sake. You could try a PFM search for 'Jordan' - which were SSB's recent Lowther based project for example.
 
bottleneck said:
[...]I dont think you'll get the frequency response you're looking for from a small full range driver like a fostex or a lowther.[...]
Click to expand...
FWIW, I don't think it's that much a question of the driver's diameter, but the size of the cabinet (and, of course, other 'minor details', such as the driver's fs, etc.).

In order to get a low -3dB point (35-40Hz) you need something really substantial, like a Klipsch Horn or a Schmacks Horn.

If I had the room for this, I'd use one of these buggers as a sub and a pair of Lowthers along with it.

A sidenote: The Fostex drivers produce a more substantial bass than the Lowthers. They are less 'holographic' in their hear-through clarity, but can stomp if forced.
 
I have some experience of Lowther drivers and cabinets and can recommend the Hedlund horn as being the best I have ever heard in my system. I built a pair of these monsters with my son a few years back in 25mm mdf and they do produce ample bass and image very well. They are however not the easiest of cabinets to build and do dominate visually. When my son left home to live in rented accomodation we built a pair of folded quarter wave cabinets which were a step backwards from the Hedlunds. I moved on to Quad 57s which are without doubt one of the finest speaker designs ever made. Unfortunately again with zero wife aceptance factor. I then spent months auditioning conventional speakers, borrowing many pairs from long suffering dealers and lugging them upstairs into my listening room. I was in total dispair of ever finding something to match the quality of the Quads that my wife would tolerate. Eventually I ended up with a pair of JM Lab 926 electras which have the clarity and speed of the Quads but give better bass definition.
Meanwhile my son moved and scrapped the quarter wave cabinets and he reinstalled his DX2s in a pair of Lowther Acousta cabinets we had lying round in the carport. These are quite pleasant but do need stuffing in the corners of the room to give half decent bass.
I came across the Martin King website http://www.quarter-wave.com/ where he has gone about designing a cabinet specifcally for the Lowther DX drivers which incorporates a baffle step correction circuit which brings the legendary Lowther frequency response down to a more correct level. This intreged me and as I had a pair of PM2C drivers tucked away I went mad and built a pair of cabinets and correction circuits to try. The results were very good and the speakers are close to the JM lab electras in bass response but wipe the floor with them in terms of imaging and air and space and prescence. The cabinets are now at my sons where they surpass his DX2s in the Acousta cabinets.
Speakers are the most subjective component in any system and personal taste is paramount. I would suggest you try to get to listen to a few single driver speakers to see if their qualities rock your boat. Many many people swear by Lowthers and put up with their shortcomings. My experience with Martin Kings design demonstrates that the shortcomings can be overcome to a large extent with a relativly compact design so you can enjoy the speed, clarity and ambience of these drivers without compromising too much on ragged frequency response.
Enjoy your quest for the perfect speaker and experience the pleasure of building something for yourself. Have a look at James's speakers on this forum as inspirational material and as a wonderful demonstration of someones journey towards nirvana. Just don't forget nirvana is a temporary state and eventually you will move on back to the beginning.
Iain
Iain
 
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