JBL GTO 627 Compliance ?

I'm not a speaker designer/builder, but here's what I know:
  • Messing with the cross-over is pointless; as you've pointed out, it deals with the transition between the woofer and the tweeter, therefore at some high frequencies, e.g. 5KHz.
  • You need to work on the Qtc, the overall Q factor of the speaker/box combination, ideally 0.5-0.7 for a critically damped system. But since your speakers have a very high Qts and the volume of the box is fixed, the only course of action you have is to add LOTS of damping material inside the box. Expect a few dB's of difference at the most.
  • See also this discussion; it's about ported enclosures, but sealed boxes work the same way, with a softer roll-off below the resonance.
  • As an example illustrating the other extreme, at home I use a pair of subwoofers with 12" speakers, the Qts is 0.14 and the box is about 100 lt; it's a much over-damped system, I know, but I like it that way.
  • That being said, the younger folks often think otherwise: my kids hate my subwoofers, they want lots of bass!:)
 
Last edited:
Zung :

I agree with your recommendations, they are exactly what I intend to do with my other big project. Large in size and sealed, I hope to achieve good bass, although I know that they are not exactly the bass ones that our " children " like, the same thing happens to you. Young people prefer basses with blows, not definition and realism, they want to feel at the corporal level, and that we pay for the broken windows, of course.....:D

Well, I do not imagine them sitting for an hour without interruption listening to music, when I released my HF speakers after two years of patient work, I told my oldest son to choose something to listen to ... and he gave me a CD of Ramones, and in a live recording, to top it off.
I remember the face of disgust that he put ... I think he had me compassion ... Finally, after long audiophile explanations and some "normal" music, I think he understood the value of my work ... but I'm not very insurance....

The stages of life...;)

PD: Very good links! Thank you !
 
Last edited:
Compared to techno/electro/hardcore, The Ramones are actually not too bad. I attended their concert once, I was impressed by their physical workout in the dressing room before the show, and, during the concert, between songs, they were very kind to announce the next number: otherwise my untrained ears would think it's the same :)
 
Compared to techno/electro/hardcore, The Ramones are actually not too bad. I attended their concert once, I was impressed by their physical workout in the dressing room before the show, and, during the concert, between songs, they were very kind to announce the next number: otherwise my untrained ears would think it's the same :)

In fact all the themes are similar " musically" , :rolleyes:
but you can not evaluate an HF system with electronic music and also the live recording was very poor. The sound level of the crowd's screaming was almost the same SPL as Marky's.
Of course it is easier to achieve a good recording in an intimate, small environment, as in jazz trios, etc., but there are very good sound engineers, mediocre and very bad, (as in all professions)
There are good recordings of outdoor shows - with thousands of people - well done, but this was not the case.
Sorry for OT
 
More pics
 

Attachments

  • IMG_20180924_130521.jpg
    IMG_20180924_130521.jpg
    647.4 KB · Views: 62
  • IMG_20180924_130546.jpg
    IMG_20180924_130546.jpg
    128.1 KB · Views: 68
  • IMG_20180927_124658.jpg
    IMG_20180927_124658.jpg
    533.1 KB · Views: 64
  • IMG_20180927_124707.jpg
    IMG_20180927_124707.jpg
    827.9 KB · Views: 61
  • IMG_20180927_125001_BURST001_COVER.jpg
    IMG_20180927_125001_BURST001_COVER.jpg
    823.1 KB · Views: 64
  • IMG_20180927_124940.jpg
    IMG_20180927_124940.jpg
    636.2 KB · Views: 34
  • IMG_20180927_125030.jpg
    IMG_20180927_125030.jpg
    496.5 KB · Views: 36
More pics :
 

Attachments

  • IMG_20181003_135350.jpg
    IMG_20181003_135350.jpg
    820.3 KB · Views: 24
  • IMG_20181003_135331.jpg
    IMG_20181003_135331.jpg
    794.2 KB · Views: 32
  • IMG_20181003_135620.jpg
    IMG_20181003_135620.jpg
    688.7 KB · Views: 28
  • IMG_20181003_133921.jpg
    IMG_20181003_133921.jpg
    768 KB · Views: 25
  • IMG_20181003_131002.jpg
    IMG_20181003_131002.jpg
    515.3 KB · Views: 24
  • IMG_20181003_122839.jpg
    IMG_20181003_122839.jpg
    593.6 KB · Views: 36
  • IMG_20181003_165716_BURST002.jpg
    IMG_20181003_165716_BURST002.jpg
    412.4 KB · Views: 26
  • IMG_20181003_170408.jpg
    IMG_20181003_170408.jpg
    910.7 KB · Views: 22
Screwed and glued to the front panel :
 

Attachments

  • IMG_20181004_131448.jpg
    IMG_20181004_131448.jpg
    320.3 KB · Views: 24
  • IMG_20181004_125927.jpg
    IMG_20181004_125927.jpg
    791.6 KB · Views: 28
  • IMG_20181004_125641.jpg
    IMG_20181004_125641.jpg
    722 KB · Views: 38
  • IMG_20181003_175253.jpg
    IMG_20181003_175253.jpg
    749.1 KB · Views: 30
  • IMG_20181003_175130.jpg
    IMG_20181003_175130.jpg
    708.3 KB · Views: 26
  • IMG_20181003_170438.jpg
    IMG_20181003_170438.jpg
    913.5 KB · Views: 27
It is almost ready, just need to adapt the frame.

The sound: Clear voices, controlled bass, zero boomy.

They deliver their best performance if they are powered with good power, there is no car cabin gain here.

PS: to prevent overheating I used the paint suitable for high temperatures. I believe that 360 degrees Celsius of protection will be enough
 

Attachments

  • IMG_20181008_141431.jpg
    IMG_20181008_141431.jpg
    731.8 KB · Views: 72
  • IMG_20181008_144045.jpg
    IMG_20181008_144045.jpg
    781.3 KB · Views: 67
  • IMG_20181008_145045.jpg
    IMG_20181008_145045.jpg
    558 KB · Views: 64
  • IMG_20181008_150007.jpg
    IMG_20181008_150007.jpg
    757.7 KB · Views: 68