Share your amp and speaker building projects with us!

[Rob]

cool!

Hey Mike,

Is this a speaker project you've been working away on while we haven't heard from you in a while? They look like a nice project. Big enough to interface with the room (that's where small speakers have no chance). I'd love to hear them! I guess I don't understand where the 15" woofer fits into this at 35 Hz since the horn opening I see at the bottom seems to be described as for the pair of midrange cones.

What amps are those in the bottom of the rack?

 

[timoteus]

I built these a couple of years ago. Since then I have built some Paraglows and a Seduction in black powdercoat, polished brass, and rosewood to match the speaker cabinets. I don't have pics of those though. I need a digi cam real bad.

 

[Rob]

Timoteus,

Ahhh, the Hedlund Horn. Very nice job. Thanx for sharing. What drivers 'ya using?

Sounds like you did a nice job on the amps too. Hope you can show pics soon.

 

[timoteus]

I am using the Lowther EX3. I got them when they were first released, six months later they went to the rolled edge whizzer. So now mine are either obsolete or a collector's item, take your pick. :scratch2:

 

[gonefishin]

Here is my Shiva MKIII in a 54l sealed cabinet, next to a pair of SEAS Njord speakers my friend and I built. I have possesion of these awesome speakers till his living arrangment are settled, not bad , in return for me helping him build them.

below is Lurch's HT system

 

[gonefishin]

below is Lurch's sub pic

 

[Lurch]

sub amp box

I did'nt like the idea of cutting a hole in my sub cabinet after spending alot of time bracing it so I made a quik box to house the amp in, also I plan on building a sonotube shiva and I can use the same amp to run one for ht and the other for Music.

 

[mikee.e]

Hello!

Hi! my name is mike elliston

a little about me=
i live in NZ im 20 years old,im studying ELectrotechnology at polytech.

Rob- how long is that horn with 12" ? it looks like a midbass with big mouth.

volvotreter-your horns are very awesome,when i get the time/money/space i will build horns like that,a friend in Australia Adrian Mack has made his own Tractix horns
adrians horns

his site isnt up to date yet,when its finished il post a link,he has JBL2370 HF with P audio comp drivers on them,and Eighteensound 18LW1400 for sub duty, and jbl2225s for midbass up to 300hz to meet his midrange Tractrix.

very nice looking
its easy to make an ugly speaker box


and also u may want to see what arrived a little over 2months ago

those are with my webcam ,i have camera being developed soon

built this box in 2hrs of working out holes,another 2hrs of frantic glueing! (for some reason my dad wanted to get it all done in one go before the glue set)made it kinda fun! and we forgot to glue the front port shelf port baffle-so i gotinside the speaker cut out put lots of woodglue down ont the top of that join :-Dil silicon it sometime.

at first i had it against the MDF,with 4screws,it didnt like that and puffed heaps of air out the sides..so did all screws up,then got some weatherstrip like shown in my site,and put that under woofer frame face.seems to work,i still dont trust it though..

i sometimes turn it up too loud for songs which only have high bass,then a song comes on with heaps of low stuff,and its annoying me in the other room (with less than 20watt haha)

thats 97db efficiency for ya! it was either this or a Shiva(cheap piece of distortion)but i wudve gotn one otherwise i reckon


2226 in 175L ebs 33hz tuned i currently have a little Sanken 30watt amp,with a restrictive 20va transformer powering it!
ouch!
but,its Plenty loud enough,and the response is on my website-
http://homepages.slingshot.co.nz/~mike.e

its a nice rolly offy overdamped response

im going to get a 240watt amp for it to realise its full potential
i definately enjoy the brilliant sound quality of it.
This is my first real sub.i bought this 2nd hand from a guy in Australia.

it actualy doesnt have any damping material inside it on the walls :-S
but i am planning to put some in.

it does have a rising response with higher frequencies,im thinking of filtering it at 24db/octave,especially because of the EBS tuning,and my 'turning it up' at the little sub amp volume.

its in a corner position in a 2.2mx4m room,tiny room with lots of rattles with that tiny amp! can only imagine 240watts!

and my next project-Basshorn!
which i have posted Here-

audio asylum link to my post


it uses the 12" lab12 woofer from eminence (Designed specifically for the labhorn which i studied in depth)
its only a 40hz corner horn as its my first horn and its only 250L or so.

ive spent the entire year, playing with hornresp,asking questions to a few horn fellows,and finding horn info online.

if u have any questions go right ahead,i may forget to check this forum as i havent been here before..


and Lately my interests include- reading about distortion and why should i want to build a basshorn-

www.linkwitzlab.com- this man g oes into great detail in his sealed box woofer, with FFT measurements of his output,i reccomend it,he then notes that subwoofers need 2nd and 3rd harmonics LOWER than 6% or else the 20hz fundamental tone will have equal apparent amplitude to our ears as the 40hz and 60hz distortions!! and thats with 20hz Sine,i really hate the thought of having all that other sound that shouldnt be there.


this really encourages me to avoid sealed at high SPL, do ported (like my 2226) and look into horns for maximal loading!

sorry for the long post,but sometimes theres alot to be said!

Regards,
Mike in NZ

 

[omer]

Welcome to AK Mike, glad to have you aboard! :yippy:

 

[Rob]

Welcome!

Mikee.e,

Welcome to AK! It sounds like you are having lots of fun down under. That was lucky finding the JBL driver at a 2nd hand shop.

You asked about my large 50Hz horn. The driver is a 12CO1P Selenium. FS is 45.58 Hz. The horn is really a throw together and was made to be as big as I could get down the stairs into the home theater room without going too crazy, and also optimizing use of 4'x8' material sheet size. As it is I have to remove the back chamber and the driver (1/4-20 bolts) to get it into the house. The horn throat is 47" deep. Mouth dimentions are 25-1/4" x 70". The entire cabinet measures 5' 1" front to back.

I didn't do any flare calculating at all because I used a pre-existing curve of fiberglass for this project. I did everything pretty much by eye. I was looking at a 10 foot diameter molded fiberglass radome cover for a commercial microwave dish in my storage yard one day and it occured to me that if I cut 4 petals out of the surface I could make a large, apparently exponential, and truly bi-radial horn. Thus the project was born! Here is a photo where I have superimposed the fiberglass radome image with a reversed/inverted photo of same to produce the horn against the horn flare for the Altec 210 VOT horn. You can see that my horn will be longer in the throat with slower expansion than the Altec. Additionally the mouth size will be larger than the Altec, although less so than the increase in throat length. The fiberglass was flimsy once cut so before I cut into the radome I marked out my petals and reinforced them on the backside with heavy welded-wire steel mesh and automotive fiberglass short-strand reinforced polyester resin. Once installed the panels were further beefed up with lead shot mixed in the same resin. A total of nearly 10 gallons at $50.00/gallon of this polyester putty was added to make the horn flare sections non-resonant. I could have bought a pair of actual vintage classic Klipschorns for what I spent on materials for my speakers, but the Klipsch wouldn't have done the job in the space available. These were truly custom made for my theater room where a long throwing speaker was needed that would also work in the near field, and where the width between screen and wall was quite limited to less than 2 feet.

I still need to address an energy storage issue at ~375 Hz which I believe to be a standiing wave along the long sidewall of the throat, but besides this these horns turned out to be highly successful. Outdoors they go smooth down to 50Hz and then turn off like a switch. The in-room corner placement is better. The bass is very fast. BillFort, fellow AKer did a revue on his listening impressions during a visit shortly after I had completed these horns. http://www.audiokarma.org/forums//showthread.php?s=&threadid=1653&highlight=BillF+visits+RobTV

 

[Rob]

In case you are wondering what a radome is, here is the fiberglass radome I used. 10 feet in diameter.

 

[Rob]

Here are the four flare petals marked out and reinforced with steel mesh and resin prior to cutting open the radome. This prep work helped the four flare sections to retain their shape after cutting.

 

[mikee.e]

woah cool!

yeah i live in NZ,i was lucky to get that jbl from OZ~!!

its nice to meet some fellow music and audio lovers

because-
i started at diyaudio.com,then diysubwoofers.org(mikee12345 and mikeported)and audio asylum(toxicport.e) and several car audio forumsuke: where i blasted:uzi: away the as many lies myths untruths and modeled ppls subs



Caution rant! skip down to the end of the blue if u wish..
i have a huge list of funny things-
like - 'my mate said that square ports have no turbulence'
and ppl saying 'my 15" is tuned to 35hz,so probably urs tuned to 25hz will be fine''

just a general lack of t/s specs aswell jsut to make it more fun!
(www.termpro.com) and many -

'what about 2 of woofer x vs 2 or 1 of woofer y' ,if ppl used the search button they wud find it ....

infact i did 150 posts in less than 28days at one forum, it was SO many ppl needing winisd/modeling help,it was ridiculous

and just facts like-a 4inch port ISNT NEcessarily too big-depending on how much POwer ul use,not just cos 'my 15" uses a 4" port..

and ppl denying the use of electronic equivalent circuits and the basis of winisd in cars,which i eventualy proved why its useful to a degree..it was hard work i tell u..



ive decided i have enough links and posts,to actualy never type a new post again at those car audio forums,i can just post a link to the previously answered question! haah.

at diyaudio.com, u must click'yes i have searched' before making a new topic

some ppl are just lazy ,or dont understand and want some oen else to do their box for them-
ive decided i will now,but only a 1min modeling in winisd,or il spend my entire life in that program ahahah!!

i have plenty of links to informative sites that sorts most ppl out

WELL thats my last months experience online,,

im really looking forward to these horns


/END RANT


that 50hz horn is so awesome!
massively tall and NO folds it will have great HF ability.

compare to mine which has many folds.i think the 40cm width will cause badness in response as well as folds and reflections and discontinuities...i only need 100hz anyway at the highest.

il be taking lots of pics when making later in the year!

ive modeled,and drawn up - now i have to take into account wood thicknesses (25MM)

it will be a great experience to build and measure and listen to a low distortion horn

and il learn,and decide,-should i build a 30hz or 26hz basshorn for my mate! who wants the biggest and bestest horn that he can fit,particurly as a couch,or a piece of furniture

anyway 4am must sleep now.il check out the other forums later!


btw ive only mentioned my sub-i have 1980s Philips tweeter and midrange 4" (2 per channeL) running off my dodgy sanwa 2x10watt icky mini system that il get rid of that at the first chance.


il have pictures out of my camera of all this later

and yes i love horns!

cheers all!

 

[Rob]

Once the petals had been cut I did a mock up and ran music through a 12" FR driver placed at the throat. By walking around the room and using only my ears I got a feel for the response pattern. The results were encouraging enough that I decided to proceed with the project.

 

[mikee.e]

my mates tractix midrange

Rob-really nice horn!
would adding a brace across the mouth help the resonance?

i couldnt see into the horn before my pc screen isnt bright..

cheers!

adrians tractix

 

[Rob]

Mike,

There are a total of six braces made of steel bar dampened with sheet lead wrap placed at strategic points between the sidewalls of the horn. The positions where they are placed were mapped by running an audio oscillator through a power amplifier and slowly sweeping the box while detecting the exact zone centers of the vibration modes that occured in the sidewalls by hand. The positions were located with great accuracy and without these damping bars the cabinet would have been putting out as much sound out the sides as from the front. These damping bars proved extremely effective. Note that the Altec 210 does not use them and also has parallel sides, something I avoided as well!

This picture shows some of the vibration dampers installed.

The energy storage 'boom' I have now at ~375 Hz (or maybe it's ~275 Hz, I forget) is not from sidewall resonance as in cabinet vibration. I believe it to be from an acoustical standing wave reflecting back into the horn from the straight sides of the mouth of the horn.

I haven't listened to these horns in the better part of a year as I have another set of developmental speakers in this room occupying my R&D efforts. My recollection of the horn boom issue is a bit fuzzy. I plan to attack it when these new speakers are out of there.

 

[mikee.e]

could you feel the resonant nodes and anti nodes?

have you seen the labhorn

i have heard of ppl using accelerometers-but it sounds tricky,but a similar method

i think my 40hz basshorn should be braced enough as its folded it sort of acts as a bracing to itself.

i have 3 braces ,corner reflectors 25mm mdf ( i think i should put it all around) it will be alot more heavier but its no use making a bad resonant horn

:

 

[THOR]

Rob, Triumph the Insult Comic Dog emailed me some comments he wanted me to post about your horn project I guess your email was down:

**Disclaimer the following interviews or statements in no way reflect THOR or his thoughts or opinions**

"Dear Rob,

That is an execellent project you have going on there..........................FOR ME TO POOP ON!!!!!

Sincerely,
Triumph the Insult Comic Dog"

 

[Rob]

Thor,

Triumph must be a teacher. There are those that can do, and there are those that cannot. The latter often become teachers.*

I could care less about what someone who cannot do has to say about my projects. They stand well on their own merits, and sometimes also on large casters.

*no actual teachers were harmed in this satirical diatribe.

 

[Rob]

Originally posted by mikee.e
could you feel the resonant nodes and anti nodes?

have you seen the labhorn

i have heard of ppl using accelerometers-but it sounds tricky,but a similar method

i think my 40hz basshorn should be braced enough as its folded it sort of acts as a bracing to itself.

i have 3 braces ,corner reflectors 25mm mdf ( i think i should put it all around) it will be alot more heavier but its no use making a bad resonant horn

:

You don't need instrumentation to feel when the outside of a large cabinet starts to vibrate in dimensional related resonance. It is very dramatic and occurs at even very low volume levels. Of course if the surfaces you need to examine for vibration are buried inside the folds of a horn as in your design the use of remote sensors like accelerometers is necessary if you wish to perfect the design to that level of detail.

I've seen the labhorn in pictures. Interesting. Looks like a spiral shell from an aquatic animal. The response graph on the linked website looked nice except for the suckout.