...awedio, no, I'm not Fede, although I know who you're talking about 
anyway, the slot tweeter looks in fact very nice, the only problem is that selenium drivers are hard to find in europe (being brazilian... I've found the st324 in Italy, but it costs SEVENTY euros. SEVENTY.) and the beyma looks very nice, may probably be better than the selenium (after all, a 100$ tweeter, it will be for a reason), but it costs really too much for a marginal part of my project.
so, ok, forget the soft dome tweeter (although I might try a cheap SICA one, anyway, 25€ is not a big deal), are there other slot tweeters that I could consider? I could search the internet, but if maybe you already know of a good product...
anyway, the slot tweeter looks in fact very nice, the only problem is that selenium drivers are hard to find in europe (being brazilian... I've found the st324 in Italy, but it costs SEVENTY euros. SEVENTY.) and the beyma looks very nice, may probably be better than the selenium (after all, a 100$ tweeter, it will be for a reason), but it costs really too much for a marginal part of my project.
so, ok, forget the soft dome tweeter (although I might try a cheap SICA one, anyway, 25€ is not a big deal), are there other slot tweeters that I could consider? I could search the internet, but if maybe you already know of a good product...
Last edited:
in the meantime, I've made a (very) rough drawing of the project.
do you think the bracing is adequate? I actually think it may be overkill, for a bass guitar cabinet...
I'm going to buy some MDM-3 (by Monacor) for internal cabinet padding, I've read that it's a material that "fools" the speaker in making the cabinet seem bigger than it is, I'm only going to pad the sides and a small part of the rear panel though, just behind the drivers themselves, I've been advised to keep the area behind the ports free of padding or whatever. how much bigger am I supposed to make the cabinet?
do you think the bracing is adequate? I actually think it may be overkill, for a bass guitar cabinet...
I'm going to buy some MDM-3 (by Monacor) for internal cabinet padding, I've read that it's a material that "fools" the speaker in making the cabinet seem bigger than it is, I'm only going to pad the sides and a small part of the rear panel though, just behind the drivers themselves, I've been advised to keep the area behind the ports free of padding or whatever. how much bigger am I supposed to make the cabinet?
in the end, I've decided to use the Eighteensound 12W500 woofers. I found a decent price for them (240€ shipped for both).
cabinet size has been accurately calculated, I've considered port, drivers and bracing volume (with a 2-3 lt tolerance, based on my calculations, it doesn't make much of a difference, even because I'm designing my cab quite conservatively, at least by bass guitar cabinet standards), so, in order to build a 120 LT cabinet, it actually has to be about 135 LT (which should be about right, anyway, I'll slightly overestimate port length by 1-1.5 cm for each of the three ports, so, in case the enclosure volume turns out to be lower than planned, I won't risk overexcursion, just less-than-optimal performance, and besides, I can still modify the ports later).
that is, without padding. with padding, I know I'll have to adjust the size of the cabinet, but how much? I read a test where the Monacor MDM3 damping material actually seems to increase cabinet volume by approx. 14%, but the test was carried out padding the entire interior of the cabinet, I was only planning to apply damping on the sides and MAYBE two small patches behind the magnets, of the same size of the drivers.
regarding my previous question, does anyone have good experiences with high-output tweeters (around the €50 mark at the most)? it doesn't have to reach 20000Hz, by the way, I'd be happy with 15-18kHz
cabinet size has been accurately calculated, I've considered port, drivers and bracing volume (with a 2-3 lt tolerance, based on my calculations, it doesn't make much of a difference, even because I'm designing my cab quite conservatively, at least by bass guitar cabinet standards), so, in order to build a 120 LT cabinet, it actually has to be about 135 LT (which should be about right, anyway, I'll slightly overestimate port length by 1-1.5 cm for each of the three ports, so, in case the enclosure volume turns out to be lower than planned, I won't risk overexcursion, just less-than-optimal performance, and besides, I can still modify the ports later).
that is, without padding. with padding, I know I'll have to adjust the size of the cabinet, but how much? I read a test where the Monacor MDM3 damping material actually seems to increase cabinet volume by approx. 14%, but the test was carried out padding the entire interior of the cabinet, I was only planning to apply damping on the sides and MAYBE two small patches behind the magnets, of the same size of the drivers.
regarding my previous question, does anyone have good experiences with high-output tweeters (around the €50 mark at the most)? it doesn't have to reach 20000Hz, by the way, I'd be happy with 15-18kHz
I refer to the phenomenon described, for example, in this article I found on the web:
Port Calculation
(scroll right to the end, it's the last section)
I've read things about damping material virtually increasing the cabinet volume elsewhere, anyway.
Port Calculation
(scroll right to the end, it's the last section)
I've read things about damping material virtually increasing the cabinet volume elsewhere, anyway.
well, I think it was the expectation that you would be looking at making the cabinet smaller.
Go 10% if you like (smaller!) and then you can add more padding or stuffing if it tunes higher than expected. But consider, some padding that's only 1 inch or 3cm thick along the walls will not have much effect on "perceived volume". Fiberglass stuffing has the thermal retention properties to more significantly affect tuning. You can add that later if you think it's needed.
Go 10% if you like (smaller!) and then you can add more padding or stuffing if it tunes higher than expected. But consider, some padding that's only 1 inch or 3cm thick along the walls will not have much effect on "perceived volume". Fiberglass stuffing has the thermal retention properties to more significantly affect tuning. You can add that later if you think it's needed.
oh, sorry, I was thinking smaller and I wrote bigger, you're right of course. thanks for the info, anyway.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.