Greetings.
I have a pair of Coral beta 10. I have a problem with the decision to build BHL original enclosure or to try TQWT box or something on your recommendation
I would like to have good bass as possible, my room is 25m2 and speaker placement is close to the wall.
I am attaching the link of the TQWT case for beta 10 from the German forum.
which I would like try to do
I ask for your opinion and help.
Hifi-Selbstbau - Coral Beta 10B
Best regards.
Miha
I have a pair of Coral beta 10. I have a problem with the decision to build BHL original enclosure or to try TQWT box or something on your recommendation
I would like to have good bass as possible, my room is 25m2 and speaker placement is close to the wall.
I am attaching the link of the TQWT case for beta 10 from the German forum.
which I would like try to do
I ask for your opinion and help.
Hifi-Selbstbau - Coral Beta 10B
Best regards.
Miha
1/ Given the age of the driver, one makes a big assumption that yours will be similar. As well, the T/S parameters us amateurs use produce less useful numbers than the factory kit.
2/ The TQWP you pont to is dedsigned using Classic methodology, ithas a vanishingly low chance of being near optimum. If such a box is not mass-loaded (restricted terminus) it can be discarded.
3/ for the same reason, any horn from before 2k is unlikely to be anywhere near optimum either.
Both of these quarter-wave enclosures needs to be specifically modeled for the driver. Perhaps one of our talented/experienced quarter-wave designers will suggest something.
About 150-160 litres sealed gives F10 about 30 Hz anechoic, the box size will be smallish compeared to a Voigt or horn
Going to a 300 litre reflex box that F10 gets near 20, but in room could be just too much.
The size of that vented box should give an idea of the small end of a horn or pipe.
dave
2/ The TQWP you pont to is dedsigned using Classic methodology, ithas a vanishingly low chance of being near optimum. If such a box is not mass-loaded (restricted terminus) it can be discarded.
3/ for the same reason, any horn from before 2k is unlikely to be anywhere near optimum either.
Both of these quarter-wave enclosures needs to be specifically modeled for the driver. Perhaps one of our talented/experienced quarter-wave designers will suggest something.
About 150-160 litres sealed gives F10 about 30 Hz anechoic, the box size will be smallish compeared to a Voigt or horn
Going to a 300 litre reflex box that F10 gets near 20, but in room could be just too much.
The size of that vented box should give an idea of the small end of a horn or pipe.
dave
I did model a MLTL for it for a friend (who did not build it yet, wood is ridiculous expensive here today due to covid). We did measure his drivers and took the average of both drivers (rather close) as model specs and came to a huge cabinet. 50cm wide, 30cm deep, 160cm height internal size with a 50x6cm slot port on the bottom of 5cm deep. In the modelling stuffing is needed a lot to mask resonances (but hard to model). And this all for an F3 response of 45Hz. Use this info at your own risk, as it's not build or tested yet, and modelled to the specs we had, which may be different than yours (as for the age of the drivers).
Back in my pre T/S days my tower designs were based on the classic Vas/1.44, Fb = Fs and damped to 'taste' and it sims the 'toe tapping, finger snapping' performance they were known for [AKA 'the west coast sound' of Altec, JBL] 
.
Frankly, T/S or not, would still do it today for its superior power handling over larger cabs, especially if tuned lower.
. Frankly, T/S or not, would still do it today for its superior power handling over larger cabs, especially if tuned lower.
Hi Miha,
The Coral Beta 10, if still in good shape, is a very good driver and a rare historic item. It deserves every effort to let it shine, but some necessary steps sadly are not that trivial.
First you need to find out if your units are still OK and are still a pair. This is best determined with a TSP measurement, which will also allow simulations of an enclosure afterwards, hoping that your units are still "similar" after all these years...
An easy way to measure TSP is DATS, you´ll need a non-magnetic clamping device as well.
After these first steps and measurements, we shall see.
Good luck and all the best
Mattes
The Coral Beta 10, if still in good shape, is a very good driver and a rare historic item. It deserves every effort to let it shine, but some necessary steps sadly are not that trivial.
First you need to find out if your units are still OK and are still a pair. This is best determined with a TSP measurement, which will also allow simulations of an enclosure afterwards, hoping that your units are still "similar" after all these years...
An easy way to measure TSP is DATS, you´ll need a non-magnetic clamping device as well.
After these first steps and measurements, we shall see.
Good luck and all the best
Mattes
Thank you all.
I am aware that they have historical value and that they are worth the effort for the best.
With my little knowledge of speakers it is best to contact an expert.I know a professional who repairs and restores speaker units, he is very good and accurate at his work.
I will ask him to do a test and make measurements.
After review by an expert I will let you know, then I will ask you for guidance.
For now thank you again.
Best regards.
Miha
I am aware that they have historical value and that they are worth the effort for the best.
With my little knowledge of speakers it is best to contact an expert.I know a professional who repairs and restores speaker units, he is very good and accurate at his work.
I will ask him to do a test and make measurements.
After review by an expert I will let you know, then I will ask you for guidance.
For now thank you again.
Best regards.
Miha
Hi Miha,
There has been quite some discussion around the Beta 10 not that long ago on this forum, the search function will get you there.
I myself never had the Beta 10, but had the Beta 8 for quite some time.
I personally think that even today it is quite difficult to surpass these drivers, and if you want to do that, you will pay a lot of money...
Sadly, I ´ve sold my Beta 8 long ago... what an idiot I was...
All the best
Mattes
There has been quite some discussion around the Beta 10 not that long ago on this forum, the search function will get you there.
I myself never had the Beta 10, but had the Beta 8 for quite some time.
I personally think that even today it is quite difficult to surpass these drivers, and if you want to do that, you will pay a lot of money...
Sadly, I ´ve sold my Beta 8 long ago... what an idiot I was...
All the best
Mattes