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tuyen wrote:

When i change the cutoff of the 505tt to 200hz and 250hz, I experience that same 'hole' you mention about.  Hence why I was questioning if it is the 160hz le'clech horn causing this and if using the goto s150 horn with it's different horn profile would change it (eg. playing down to 200hz with a first order slope as recommended??).   I guess from your experiences, it doesn't.. Please note, I don't have any measuring tools though so I'm really just going by my ear which is quite pointless in terms of setting it up properly.  Will eventually get around to it.

Tuyen, you will not get around it. You need to understand that using phrases 200hz, 250hz, 160hz and so on without having very firm understanding what you are talking is absolutely foolish. Only the people who have a lot of experience with listening and measuring, listening and measuring, listening and measuring, the proper measuring I have to say and who interpreted and correlated results of listening and measuring, only those people can make comments frequency and amplitude that have any meaning. If you never did any rudimental measurement of your playback and I presume never did it with any other playback than what point of reference you use when you say Hz or dB? Let face it if you use quantization of any sort then you have to have some kind of idea what the coordinate system of quantization would be. Otherwise - it all absolutely pointless. I understand that you would like to be consistent with a type casting of a typical Goto user: to be clueless. Still, it looks like you’ve have made a number of steps to more sensible direction. So, get yourself RTA – it will be the very next and very mandatory step.

Kcct82 wrote:

Hi Romy, I've confirmed through Goto's Japanese dealer that a drop between 200-400hz is normal for 505TT, their suggestion was to double up on drivers or buy the more expensive versions... Looking at the measurements the 505TT is good for 400-1800hz only. Sound wise it is ultra clear and dynamic, I do miss that kick in brass instruments and snare drum rim shots. I'm deciding whether I should turn my midbass horn 90 degrees against the side wall and setup a 4 horn vertical rack more towards the middle of the room.

Yep, you have consulted with Goto's dealer – as he has any idea what he is talking about. Wishfully thinking! Did you even see any dealer who does? The 505TT driver as I understand was the WE-555 imitation.  Those small thought drivers can go down to 100hz and can give you the brass’ kick that you are looking for. However, the WE-555- like driver did it loaded in very long horn with over 9dB of horn gain. Goto S150 horn that you use I think a replica of WE-6A or WE-11A horns. However the 555 drive was able to go down to more or less 100 only in 13A, 16A and 17A horns. Look at the picture of the 11A horn and 17A hoe and you will see that they are in of VERY different length and mouths size.

http://www.moviemice.com/we/horns/index.php

So, you still can push your 505TT down but it would require a very different type of horn then what Goto offer with S150. If you go to this direction then you will face a few factors. The 505TT driver itself might be not good for using it so low. The type of bass that you have with such a long horn and suck high level of horn gain will be different, I will be no so clean and much prone to honk then you would get from more conventional loading. You will also find impossible to time-integrate this design idea with the rest of the system. So, I wonder why you are trying to push your 505TT with S150 horn down. Would it be more rational to have you upperbass horn to run a bit higher? If you look to fill the 200-400Hz then it is much more convenient to do with low pass filter of your upperbass horn.

tuyen wrote:

Is there any chance of sharing the measurements?    I agree with the your comment regarding the sound of them. Although in saying that, I have managed to only listen to a few other different compression drivers so far.   Is there somewhere I can find out more about your bass horn?  Is it much of an improvement over your bass reflex boxes you were using before?    I want to try building a similar front loaded horn for the 15" woofers one day..

Tuyen, I wonder what the measurements of others can do to you? I do not mean to be a jerk about it - I am serious. Yes, conductor can read the score and hear how it sounds. A person who did a lot of own measurements and has an understanding how different measurements correlate to what he/she hear can look at some of measurements and to a degree to predict not how the system sound but if the system has own issues. The whole point is to have the measurements, see the problem in the measurements, to hear how this problem manifests itself; then to correct of the problem by one way or other and see and hear the result. Without doing it many times you do not have a definition of what is acceptable and not acceptable in measurements.

Also, Tuyen, you need to understand that if we are taking about 200Hx then we are taking only about 50% of pressure that is coming from the driver and horn. The room aberration is very high at those frequencies and if it used creatively and knowledgeably then it can substantial change many things:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=4421

Sure, you fee to do whatever you wish but again, before committing your with mid or upper-bass horns do yourself a favor – get RTA, learn how to use it, get your current setup to sound properly, getting the best your current installation can push out itself. Only then begin to think about change or modification. To make your setup to sound as it has to be shall take for you a year or so. Do not make any new acquisitions until you will be able to get out your current setup what is able to do. I know it sounds NOW like foolishness to you but it will come to you….

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