Rony,

I am not exactly understand what you are trying to do and what kind of cabinet are you trying to attach in the back of that horn. Perhaps I misread you. There are two types of Altecs 515: the G-like and B-like – they are very different type of drivers. There are other letter, A, C, E but they all still comply with the two types above, whish one you use? Generally pushing the Altecs 515 all the way up 800Hz is too ambitions, I feel they begin loosing at much lower frequency, but it would be all depends what is your next channel and what it will be able to do at the bottom…

One thing I would like to note. I do not think that it make send to ask about obvious or potential problems in your situation. I know a lot about upperbass sound and particularly horns and juts because I do know a lot I assures you that a sensible specific implementation at a give location might override the design problems and shortcomings – come it is almost bass! So, the most accurate question would be not what is wrong with your horn and what you feel is wrong with the sound is produces. Perhaps from there it would be more reasonable to recognize where you stay your expectation in upperbass and how the given implementation might or might not serve you.

Ronny,

You can look among those two threads.

http://www.romythecat.com/Forums/ShowPost.aspx?postID=6436

http://www.romythecat.com/Forums/ShowPost.aspx?postID=3710

I do not feel that for midbass horn a surface makes any difference at all. It rather the surface hardness instead of the surface finished smoothness. I would personally like the textured finish – better sound at HF, better match across all channels and very easy to retouch it if damaged.

I do not know who your horn makers but from what you say I do not like them. The people who propose clear lacquer finish do not charge for form but for the finishing job on the horn. Also, to make horns from either red oak or cherry wood I am sure will look sexy, particularly stained and lacquer but it is about look not about the purpose.  The look might be an important thing but we do not need to discuss the look - everyone desire for themselves. I just would love to know that your horn maker spend as much efforts assuring the your horn to sound better as much as he intend to spend on it’s appearance.

BTW, if you intend to leave them rough though and finish them yourself then be advised that it is not so simple and it does require some techniques, infrastructure and tools…

Hi, Marcus

As I understand it is 15” loaded into 110-150Hz horn, MF compression driver in 350-400Hz horn, Ribbon tweeter and a pair of tapped horns? Looks good.

If it were up to me than I would paint the entire baffle with tweeter and MF in black– in my view it would make the whole speaker more organic. This is however just visual part. There is some functional, more important part.

The tweeters are mounted flat at the baffle and it is not very good. Do you do not want to have any flat surface around tweeter as it give some HF reflection fog. I am sure that the tweeters are time-aligned, so you can’t move them. You however might cover the front of baffle around tweeter with some think soft material to minimize the reflections. The throat for your upperbass horn looks a bit too large but it is what it is. The tapped horns look very nice but they must be outside the upperbass not inside. Moving then out you will gain a LOT of imaging.  You also, if you crossover point on tweeter not too low, might want to exchange the position of MF and HF channels. Ribbon tweet are hobble MF drivers, do not believe the people who say contrary. The only reason I see for you to put the tweeter in such a prominent position is because you drive it too hard and it crossed too low. With 400Hs horn that you use you might get good 10K out of your MF and if so then I do not think that your tweeter needs to be in your ears level anymore.

Anyhow, good work, keep the speakers further from the back wall and play with toeing-in and out.

Marcus,

here is absolutely nothing wrong in what you describe. I absolutely assure you that any single person initially end up with the results similar to what you describe. Most of them stop there and do not understand that they got very bad results and I very much assure you that dominating majoring of the shiny DIY playback that depicted within Web do sound very similar to the result you got.

Anyhow, now as you built the bone of your acoustic system it is the time to make it to sound appropriately. It might take for a while as you will not be dealing only with sound of playback but rather with self-education and moderation of own expectations. His is normal.

I know about the subject too much in order to advise you anything specific. Get phase tester, get RTA, get recordings that feel comfortable and start to experiment. As the speaker bone built to make the speaker to sound well is truly fun – it is like riding a wild horse… Have fun and keep the eyes on the ball…

Macman wrote:

Hi Romy, Its an Altec 416-8A driver in a ~100 Hz exponential horn, Jbl 2441 in 350Hz tractix, Aurum Cantus G1 tweeter and Eminence Definimax 4012 HO in ~30Hz Tapped horn. I just hooked it up and the highs are promising but I thought the lower end (200 hz and below) would be this setups stongest register but that has yet to show itself. Hopefully this will be something that is modifiable. I still dont have a good set of electronics but I think you would be able to hear the potential even so. The altec driver when I got it, was used in an altec valencia. I had some time to listen to it during the building process and the bass that it was able to deliver was astounding. Really tight and fast. I thought that it would exell in the midbass horn but the "kick" just isnt there. The throat is 8" in diameter which I belived would work efficiently. I will catch you up on the "padding" around the tweeter, I just couldn´t come up with another solution for the tweeter placement. The tweeter and the 2441 is currently crossed over at 7kHz and I think it works out pretty good. The 2441 doesn´t appear to do a very good job at the higher Frequencies. As It seems now the biggest letdown is the TH. The transient response is nowere to be seen and the sound is just loud and muffled. The dynamics is awful and the fast bass that I was looking for isnt there. I don´t know if I made some mistakes when I made it. I used a 12" because I wanted to have a driver that moved a lot of air so I could feel the bass as well as hear it. I know John knows THs well, maybe he have some thoughts. (the possition of the THs inside the other drivers is just temporary). Regards Marcus

Macman wrote:

Just realised that I had dual highpass filters on the TH, which more or less cut off frequencies below 50Hz entirely. A lot better now, still much to be made of course.

This is very normal. People get the “building plans”, render it in wood and presume that it has to be assurance of some kind of “good sound”. There is nothing further from truth. As the bone of the speaker structure is built you just start to make your speaker. If you are sensitive to what you do then you will go over many events, from very useful self-realizations to openly stupid actions – that all normal and it comes with the game. You need to find a way to properly load and cross your 416 driver.  I am sure your 2441 driver is a piece of crap. All vintage drivers are crap- and they need to be serviced, cleaned, aligned and calibrated to perform properly. Do not be in harry to make any concussions unit you make each channel to operate at its best and make the whole system to sound in uncompromised way. It will take some time and some efforts but that is OK.

noviygera wrote:

I have an Edgar 80hz midbass with a 15" EV driver. I am not happy with the sound I am getting, as well, and I believe it is in part due to the 15", as well as a not proper horn enclosure. But somehow I am sure that for the 100-500hz range a smaller size driver will be more appropriate to integrate with a midrange section, especially if you are using a good compression driver.

I think a conversation about size of the driver has very little relevance. A common colloquialism says: it is not about size but how it is being used. In horns the colloquialism works perfectly fine: it is not about size of driver but the size of the throat it loaded into. The problem with Edgar-like 80hz midbass and the Macman’s 100Hz horn is not the large driver but large throat that has low mouth to  throat ration and do not provide sufficient horn equalization. It still might be made to work very well but it still will have some fundamental restraints.