GoodSoundClub - Romy the Cat's Audio Site - Last words on foam and other updates

| Search | Login/Register

Home » Horn-Loaded Speakers» Designing and building a 5 channel horn loaded (looking for directions on my way) (74 posts, 4 pages)

Print Thread |

1st Post |

Page 3 of 4 (74 items)

Select Pages:

« 1 2 3 4 »

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Another time aligned 5-way horn project..	Thread moved...	Horn-Loaded Speakers Forum	189	874492	08-12-2015
»	New	Deep End DIY - Australian take one Macondo...	It is simple, but......	Horn-Loaded Speakers Forum	87	316392	01-20-2016
»	New	Jessie Dazzle Project..	Will this better to be auditable?...	Horn-Loaded Speakers Forum	172	1558583	08-03-2007
»	New	5-ways from Speedysteve7..	Hehe - no invite for you...	Horn-Loaded Speakers Forum	23	205336	05-20-2011

07-27-2016

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	41
Post ID:	22689
Reply to:	22688

Some comments about your response.

kodomo , I would like to make some comments about your response. The presumption that the mic was exact in the listening spot and the drivers are time-aligned and run “in-phase”. If any of the above conditions are not true then all bets are off and any below has no relativity to you.

Generally the response is Ok but I would pay attention to a little bulge you have from 7K to 12K. In case of average room (in term of acoustic) this shall be auditable. I understand that this is hoe your MF drivers works. Do, shut down your tweeter and try to listen a bit without it. Then, try to turn the entire playback a few degrees off your listening spot. For instance if your MF horns aimed now to your side of your head then aim them to the end of your shoulder. Do NOT turn juts MF horn but turn only the while system. Turning the MF only would bring a need to time-re-aligned the whole system, you do not want that.

So, as you turn slightly your system the imaging will be change bit try to discard it. The HF will be more gently rolling off and try to get use to it. This little “sparkle” at 10K shall give to you some pleasure but do try to tune yourself off it. If you feel that with loosing of that bulge at 10K you will be losing transients at your upper range then do not “fix” it by 10K bulge but rather by … loading the output stage of your SET slightly more idle. (It will change gain as well). As you find a good performance of your upper range with reduced bulge at 10K then put your tweeter back to the duty.

Rgs, Romy

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

07-29-2016

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	42
Post ID:	22693
Reply to:	22689

You are right

You are right Romy. When I toe them in a little more, that curve flattens. If I toe in and also sit about 10cm's higher, it is both flat and more extended...

These will be very important as I will be designing the final stand this winter. I am so happy I did everything adjustable to start with!

ps. I have also experienced that the lowest end (sub 50hz) has a major role on the perception of the whole sound spectrum. When I build "my" ideal room for this system, I will build another tapped horn for an even more homogenous foundation, even though they are cut at 30hz.

07-29-2016

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	43
Post ID:	22694
Reply to:	22693

Try to play with it more.

This little bulge at 10K is very interesting thing. It might be presented and in a way beneficial but much smaller then your. It would a great degree depend from the way how acoustic environment is done still if everything is done properly then +1 or half dB at 10K might be very nice to have. It is important do not have it too much and do not have it too narrow…. I would like to pay attention that toeing speakers is only a mechanism to test with bulge smoothing and it is not proper way to moderate the bulge become with toeing a lot of aspects of imaging are changing. If you would like a clean way to get rid of the budge (as testing) then drop at the mouth of the horn some kind an acoustic filter. You can get a plastic screen that used to prevent mosquitos to fly in windows. One layer over mouth will shave approximately 1.5dB back-proportionally to frequency. This way not proper way to USE system but it is a very effective way to listen playback DURIG experiments and tuning.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-09-2016

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	44
Post ID:	22705
Reply to:	22694

30ppi renticulated foam

I have found 30ppi renticulated foam in an online aquarium shop and ordered it. It's specs is the same with what Geddes used as plugs in his horns. I will try that on my cf1400hz le cleach with varying depth through layering. First just a thin layer at the throat, then some more and then 70% of the horn covered like Geddes suggests. I will try and note the differences and will try to measure its effects. It seems it will be very hard to measure as they are quite ineffective sound pressure wise (transparent dynamically?), but have an effect on tonality...

08-29-2016

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	45
Post ID:	22757
Reply to:	22705

First results of my experience

The reticulated foam makes a difference and that is for sure. However it does lower the output. From about 1db up to 2.5db! depending on the amount you put inside your horns.
Is it transparent? It is not, as it creates and audible difference even if you lift the driver/horn combination back up to original level (level before installing the foam)
Does it eliminate homs (higher order modes as named by Geddes) or works in some other way? Well, I can not say and homs is a subject that people debate on its existence. However for me it is more like the sound loses its breathing space. Like treble ambience. If the system is not tuned good, if it sounds overly bright or something like that, these may tame, but for my system this seems like a worthless addition, as the system is not shouty or edgy. The system only exhibits this kind of edgy behaviour if the actual recording is made that way and I would maybe keep these for sake of listening to those recordings Smile

I have tried varying depths and levels on horns and will continue to do so for another month before finalising my views. These may work wonders for some poeple who push their horns capacity too much (further than 3db) or people who use edgy TAD or BMS drivers Smile

08-29-2016

Post does not mapped to Knowledge Tree

anthony
Posts 338
Joined on 08-18-2014

Post #:	46
Post ID:	22759
Reply to:	22757

Photos?

Do you have any photos of your experiments? I would be interested in the foam and how you are using it in the horns.

Cheers,

Anthony

08-29-2016

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	47
Post ID:	22761
Reply to:	22759

Aquarium filter foam

I have used an aquarium filter foam, it is exactly the same foam. It can be bought from aquarium stores but you have to shape it and cut it. You can layer them one on top each other and cover any horn up to 50cm diameter with the one I have found. Here is the link for what I got: http://tempuri.org/tempuri.html

09-22-2016

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	48
Post ID:	22785
Reply to:	22761

Last words on foam and other updates

After trying these reticulated foams for some time now, I ended up with using them only on the JMLC 1400 with the Radian 475 beryllium drivers. I had a smallish bump about where it worked. It flattened out and the sound changed a little. It sounded a more airy and open when the bump was there but I have judged that it was not natural. The sound is a little more controlled on the higher registers now. It is very easy to take them out as well, so when I feel like the string section needs more air (as if in a bigger concert hall) I can take them out Smile

This is how the setup is as of now. The floor is carpeted and underneath the carpet, I also have heavy felt lining. The ceiling is full of quadratic diffusors. This is the best I can get on listening. The interesting thing is the opposite works best for recording. Reflection on the floor and absorption on the ceiling.

The whole equipment rack is now detached from the listening room. It is on another concrete slab. I will be now working on my bass boxes a little more. As they are reflex boxes with absolutely no port noise, I am satisfied with them and will continue updating them. I will put 2mm Bitumen inside all three sides except the front plate. Then felt and opposite the drivers some acoustic foam too. I also have the shop cut the densest granite and put two layers of them on top of each other. They are to go under the bass boxes as they rest on carpet now. Each block is about 100kg's.

09-26-2016

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	49
Post ID:	22787
Reply to:	22785

Looks very good.

Looks like a sensible location of side defuses. My latest observation on the subject is contrary to what the audiophile wisdom recommend. Most audio people use a lot of absorbers and I had this tendency as well in past. In my new room I use mostly natural absorbers: drapery, furniture, carpet and try to minimize to use of explicit absorbers. I feel that parabolic defuses do the best under normal circumstances – they sound “live” but do not create harmonic signature. I picked and experimented with Auralex GeoFusors. They are a major rip off money wise and they should cost $6 each. Still, if to discard the financial side then acoustically they do work very well in my new room. This clip demonstrate the result very well, and it very much correlates with what I am was hearing during my experiments.

https://www.youtube.com/watch?v=DVsg8KitD0A

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

09-28-2016

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	50
Post ID:	22793
Reply to:	22787

View with diffusors on the ceiling

Side diffusors are 2 d parabolic with absorption at the back. They are very good, absorbing the lower registers and diffusing the higher. This way they do not suck the life out of the sound (over absorption of hf)
I also work with carpet and even ottomans positions and effects, they are audible and measurable.

Geofusors look nice, I might get one, experiment with it and if succesful work on replicating it via cnc with wood (why not)

09-28-2016

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	51
Post ID:	22794
Reply to:	22793

Ah, they are parabolic!

If they are parabolic then do not need to experiment with anything else – they look gorgeous. Juts for shits and giggles try to put between the equipment rack and speakers some kind of very fussy plants of 5-6 feet tall. It might not be to your taste from perspective of room décor but it might acoustically decouple your playback from the glass behind. Juts try to put something in there that transparent for LF and to see what will happen.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-06-2017

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	52
Post ID:	22909
Reply to:	21722

Bass boxes updates

You may remember that my bass reflex boxes were sitting on top of the carpet. I installed a few days ago, 4 brass spikes under each one, then their foots to sit on, and put them on the sandwich granite bases I made. Bases are 50kg each now!
I have also covered the opposite walls of the drivers inside the box with rockwool and covered that with felt.

This had a very good overall effect on sound. I was very happy with everything over about 200hz in my system for sometime. Now, I am very happy down to 20hz. Do not get me wrong, it was sounding fine and was blending well. Now, I have spacious sound at the bass frequincies too and the sounds start and stop and die in the room more naturally. Overall it sounds like the system had just thrown another veil over its sound that was covering some of the bass. The denser passages sound even better now.
As of now, I have finished everything I planned to do with my system and I am very happy with the result. Further than this will be new adventures. One of these could be the rebuilding of the basshorn out of wood with the exact specs of the one I use now. Another one might be the trial of jmlc 270hz horn instead of the tractrix 200 as it wont pose much of a problem height wise. The acoustic center will be 5cm's higher, but the wood horn and the new frame will take the system 7 cm's lower. So I can do them together in the future. If it does not work as good as I want, I will have an extra 110hz horn, 270hz horn, 1000hz horn. Maybe I can get another tweeter and build a second similar pair as a test platform or sell it to fund other projects Smile

01-07-2017

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	53
Post ID:	22910
Reply to:	22794

Ok, try this.

kodomo wrote:
Now, I am very happy down to 20hz. Do not get me wrong, it was sounding fine and was blending well. Now, I have spacious sound at the bass frequincies too and the sounds start and stop and die in the room more naturally. Overall it sounds like the system had just thrown another veil over its sound that was covering some of the bass. The denser passages sound even better now.

Kodomo, here is some sanity check for you. I do not object what you do, I just paint for you the pass I went and the way how I asked myself some questions. You feel comfortable with your bass session. This is perfectly valid state of mind. Do an experiment.

Fist switch your playback to mono, I mean use only ONE channel, let say left and play only mono recordings. The reality is that you can play even stereo recording’s one channel, but it would requires a degree of experience that you might not developed yet. Remember, this is not about music listening but about a very targeted audio listening. So, you flip you system to a mono mode with whatever means it comfortable to you using let say juts left channel of you playback. Now take a right channel bass amplifier and right channel bass speaker section and place them atop pf your left channel bass module. Make sure that the bass speakers are in-phase. Drop between 3 and 8 dB on each bass channel or even better use RTA to flatten bass response, while making sure that bottom and top bass modules (former left and right) run the same amplification gain. Now listen the result. You might feel a lot of improvement, including your HF response.try

What I am saying is that looking at your installation I see a conspicuously empty space above your current bass modules (those acoustic treatments are not relevant). If your woman do not insist to fill this space with a ficus and you have some money and time to burn then you might consider adding another 2 drivers per channel, doubling your current bass modules. Besides all things that you might expect from the experiment above there is a thing that you might know until you try. The thing is that for whatever reasons the little line-array that your bass speaker will form do work spectacularly well with Macondo-like configuration. There are of cause many textbook advantages of LF line-array but based upon my experience those advantages are particularly sweet while line-array used with speakers of your type.

Rgs, Romy

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-11-2017

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	54
Post ID:	22911
Reply to:	22910

Why not!

I got what you mean. It is one of those things I really would like to try as well. When I started my project, I was going to have an array of scanspeak drivers but I had problems with the distributor here. It was then I got the Tad's and went 16" instead of 10" and reduced the number of drivers.

I will need another weekend to try this, as these bass boxes are quite heavy and I will need help to put them on top of each other Smile

I will let you know about the results. I can adjust the volume of these boxes independently so it will not be a problem to attenuate them.

I also got some great jazz mono recordings that I can test with. I can sum my digital front end to mono as well, so I can try a lot of stuff with deeper bass too.

My girlfriend loves that I am passionate about sound and she enjoys the system and the improvements I make, so I am lucky I guess...

01-11-2017

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	55
Post ID:	22912
Reply to:	22911

Like with anything else: the initiative is punishable.

Kodomo, I know that you will try it. Let me to pitch you another question to ask yourself while you will be experimenting with it. I, BTW, never was able to find a final answer to myself and I might advocate both approaches below.

Let pretend that you cross your bass drivers at 80 cycles and you decided to multiply the bass cabinets, having one 2 bass modules per a channel with 2 drivers per module. You have two option to do it. You can run all 4 drivers at 80Hz or you can run 2 drivers (of one module) crossed at 80Hz and another 2 driver (of a second module) to cross at let say 30Hz. By doing it you will introduce essentially bass and ULF module.

I said that I can advocate both approaches. The first one is better because it is easy. The second one is better because it gives enormous flexibility to write acoustic signature to the specific acoustic demands of the room with respect to given octave. You can go for different drivers, different enclosure topology, different filtration, different amplification…You can spend months experimenting with it… and this might be consider bad thing.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-12-2017

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	56
Post ID:	22914
Reply to:	22912

Bass and ulf

I am actually doing the bass and ULF with different modules and amps. My bass modules are the dual tad boxes driven with their dedicated monoblock solid state amplification. The tapped horn is working for ULF only as it is crossed at 30hz with 18db. I can adjust the ulf modules (tapped horn) filter, phase and amp and yes, it gives me a lot of room to experiment. The tapped horn is driven by a hypex class d amp. I have tried a lot of different crossover points and filter slopes there and ended up with the setting I have now. When I have the time, I plan on building an exact replica of my tapped horn to create better ulf in the room too.

01-12-2017

Post does not mapped to Knowledge Tree

audiogurujax
Posts 3
Joined on 01-12-2017

Post #:	57
Post ID:	22920
Reply to:	22785

Horn source

Hi I am interested in building a speaker using horns like these can you guide me to where to source them I been looking arround and cant find noone that is either manufacturing or shipping large tractrix horns in the USA.
Thanks
Eric

01-12-2017

Post does not mapped to Knowledge Tree

Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	58
Post ID:	22921
Reply to:	22920

Look into it more.

Eric, if you are considering building a speaker of Macondo topology then you might reexamine “using horns like these”. The subject of La-horns vs Tratrix in Macondo topology is well discussed at this site, you might give to it some consideration. > >

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-12-2017

Post does not mapped to Knowledge Tree

audiogurujax
Posts 3
Joined on 01-12-2017

Post #:	59
Post ID:	22922
Reply to:	22921

Where do I source

Thanks but where do I source Horns these big I cant find any manufacturer or store where I can buy neither La-horns or Tratrix of large diameter?

01-13-2017

Post does not mapped to Knowledge Tree

kodomo
Posts 69
Joined on 06-20-2015

Post #:	60
Post ID:	22925
Reply to:	22922

Polish manufacturer

You can contact autotech of Poland. They manufacture a lot of different horns. http://horns-diy.pl/en/

Page 3 of 4 (74 items)

Select Pages:

« 1 2 3 4 »

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Another time aligned 5-way horn project..	Thread moved...	Horn-Loaded Speakers Forum	189	874492	08-12-2015
»	New	Deep End DIY - Australian take one Macondo...	It is simple, but......	Horn-Loaded Speakers Forum	87	316392	01-20-2016
»	New	Jessie Dazzle Project..	Will this better to be auditable?...	Horn-Loaded Speakers Forum	172	1558583	08-03-2007
»	New	5-ways from Speedysteve7..	Hehe - no invite for you...	Horn-Loaded Speakers Forum	23	205336	05-20-2011