diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Subwoofers (http://www.diyaudio.com/forums/subwoofers/)
-   -   What's the best enclosure for this driver? (http://www.diyaudio.com/forums/subwoofers/146584-whats-best-enclosure-driver.html)

AllenB 27th June 2009 08:56 AM

What's the best enclosure for this driver?
 
2 Attachment(s)
I want to use a SS 18W8545k as a sub and it doesn't move enough air in a closed box. I like the sound of high efficiency boxes but I'm not looking for a full sized horn and I want f3 lower than 35Hz.

I've been duelling with hornresp for a couple of hours trying to get a useable response in a tapped horn but I can't find one, maybe it's just me or maybe this driver is no good and nothing I do will get it working in a tapped horn?? Should I keep trying with the tapped horn or try another enclosure?

AndrewT 27th June 2009 10:20 AM

a ported box should suit this lowish Q driver with a very low Fs for a 7inch. It even has reasonable sensitivity.

rcavictim 27th June 2009 10:51 AM

7" driver...SUBwoofer????? Yeah right. If it says subwoofer on the factory carton, that is just advertising spin.

David_Web 27th June 2009 11:27 AM

2 Attachment(s)
The low FS does make things hard. This is what I got with a little fiddling.
It bottoms out at around 100dB 2pi in 36L.
I'm sure someone could do better but it was a quick one.

GM 27th June 2009 02:45 PM

Re: What's the best enclosure for this driver?
 
Quote:

Originally posted by AllenB
I want to use a SS 18W8545k as a sub and it doesn't move enough air in a closed box. I like the sound of high efficiency boxes but I'm not looking for a full sized horn and I want f3 lower than 35Hz.
It sims fine once properly damped, but to get a <35 Hz F3 means a fairly big box to get a so-so efficiency in a conic expansion and a ~80% larger box to get a bit more with an expo expansion and 'full size' to make it 'sing', so how big is too big?

GM

bjorno 27th June 2009 03:02 PM

2 Attachment(s)
Hi
As a counter weight to David's IMO well done TH design a T-TQWT is presented here: See picture 1(2).

The T-TQWT has lower FR cut-off and uses less volume /length and is IMO far easier to damp and filter for good SQ above and below 80 Hz.

If equalized to flat pass band the TH will only gain 2.3 dB compared to the T-TQWT: See picture 2(2).

b

1(1)

bjorno 27th June 2009 03:03 PM

2 Attachment(s)
2(2)

AllenB 27th June 2009 10:06 PM

AndrewT, I might have done that if I couldn't get a tapped horn to work, but thanks.

rcavictim, it's doesn't say sub on the box. Maybe I shouldn't have called it that but I want to cross over below 100Hz.

David_Web and bjorno, so it can be done. I can now see I was looking at it the wrong way but now the TH is back on :)

GM, I suppose I could stretch a few cubic feet or so if it was worth it. What did you have in mind?

GM 27th June 2009 11:11 PM

2 Attachment(s)
Nothing special, just a bit larger TH to get what I consider an adequate amount of dynamic headroom with a little lower cutoff and <35 Hz F3. Like all THs, damping is required for flattest response over the widest BW:

GM

rcavictim 28th June 2009 12:44 AM

Quote:

Originally posted by AllenB

rcavictim, it's doesn't say sub on the box. Maybe I shouldn't have called it that but I want to cross over below 100Hz.



IMO sub-bass only occurs in the first octave (20-40Hz) and a bit below. From 40 Hz up is the realm of a regular woofer. Others might argue that the range described by sub-bass is actually the region below hearing which many texts believe to be 20 Hz.

It is pretty much impossible to move enough air much below 40 Hz to be usefully audible with a tiny driver only measuring 7" frame size. The piston is what maybe 5" diameter to the middle of the surround? It is absolutely impossible to move enough air to be heard at 20 Hz with such a small driver.

Low frequency loudspeakers have to be large. You can make up for lost diameter with increasing excursion up to a point but early on along this path you start seeing the rise of harmonic distortion and 'chuffing' sounds, neither which are related to high fidelity.

The concept of hi-fi seems to have been lost by the modern music and sound reproduction industry. My proof is the popularity of MP3 files and equipment that uses only that highly compressed format being the most encountered. Companies that market home theater in a box will sell you a 1000 watt!!! (more like 1000 milliwatts) system that has six tiny speaker boxes and runs on a wall wart. People have been told through marketing so long that is is the hot sh*t that they believe it. It is all you can find in the stores where the majority of well programmed , dutifull consumer sheeple shop. The companies can sell underperforming crap and laugh all the way to the bank. The only thing that matters any more is the shareholders and the fat CEO salary and bonuses. Customer satisfaction? If you aren't satisfied with our product, you must be using it wrong.

Please do not think I was picking on you at all Allen. It is just that with what you just read all bottled up inside me, when I read 7" and subwoofer in the same sentence it kinda' hit a nerve. ;)

Why are the rest of you here who really do know better leading Allen on?

Allen, you want low bass, sub-bass? Be prepared to buy some large drivers and make a lot of sawdust.


All times are GMT. The time now is 04:29 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2