Tapped Horn For Car

[mwmkravchenko]

OK. This afternoon I go and set the litle sub into the hands of a couple of kids. I know this is a relative term but when your old enough to be their dad you call them kids. I guess I'm in that leauge compared to some of the guys on the forum to. No substitute for experience they say. But there is also no substitute for a discriminating ear. One of these gentlemen has listened to a sub I built him for a couple of months so he has a good reference at home.

Will see what this little puppy does with some more up to date music. These fellows like rap and hip hop if I have my info correct. So this will be quite a departure from the pounding this sub has been getting from the Organ CD's I've tried. Not that an organ CD is easy on a sub. Some of the stops on a large pipe organ have as much power as a jack hammer at close range. It's just that people are asking how it sounds with.....

I have classical, instrumental, orchestral, choral, even country and western has been tried. But no pop so far other than what was on the radio.

A good excuse to give it a whirl and I'll report back in when I get back tonight.

If the guys are happy maybe I'll encourage them to post their own thoughts.

Mark

[mwmkravchenko]

Well the two gentlemen have given their verdict. I always knew this sub had taste. It hates rap!

But almost everything else it passed with flying colors. Rock, Punk, Techno, Classic Heavy Metal, Blues. You get the idea. From the frequency response it is fairly easy to see that as designed this little box works well down to 40hz. Much below that and it is not so happy. Stuffing may help a bit but that is still to be investigated.

Mark






Hey GM we have the same hairline but your box looks bigger.

[mwmkravchenko]

The three of us tried various tracks and then they were talking frequency response per box. I played the test CD generated with WaveGen ( 30 hz to 100hz in 5hz increments ) and we sat in the car innards vibrating and such. It's interesting to find the resonant modes in a small vehicle. With a couple of people in the car the response is actually flatter ( a word I hope ) lets go with more even. Plus 2 minus 1db. We were peaking out at 112db easily with all of us very uncomfortable. No ear plugs. That level was driven with the stock head unit playing music not tones with another 18 volume points to go. So can go louder yes. Do I want it no! The box could use it's own amp as most things that suck the power like a dedicated amp. The most we pumped in was 10 watts that's with one set of eyes on the SPL meter and my four on the voltmeter.

I'm being challenged to do something similar for an 8 inch driver. Any requests?



Mark

[DarpMalone]

Very cool project, Mark... As I read the thread, I was thinking, I'd love to build one for 8" woofers.

How about the SilverFlute W20's? I haven't heard the 8's, but the 5.25's and the 6.5's sound great and they're nicely priced.

D

[GM]

Originally posted by mwmkravchenko
Well the two gentlemen have given their verdict. I always knew this sub had taste. It hates rap!

Hey GM we have the same hairline but your box looks bigger.

Interesting, I wasn't aware rap had any low bass in their recordings. I mean the only rap I hear are the rap boom cars around here that sound like they die around a really loud/obnoxious ~50-60 Hz. The lowest sounding ones are the Mexican 'polka' boom cars/trucks/vans.

Not anymore, that's an old pic of me. I'm a 'cone head' now. Yeah, your box would barely fill up my HF horns Vb wise, not that there's any relevancy of course since they are both optimized for radically different apps.

GM

[mwmkravchenko]

The driver is a rather important part of the equation in this type of a an enclosure. The right balance gets you a very small box with some outstanding qualities. Here is what I propose. I have on hand a couple of eight inch drivers. I'll test them and see what is what with them. Then I'll crunch the numbers for a couple of days and iff something interesting comes together I'll post it.

The other thing I promised for the car crowd is a real tapped horn that will work all the way down to about 16hz. It was briefly described in the beginning of this thread until Henkjan asked for the wee little one. The designs use a high quality driver because they give high quality sound. I'm a bit spoiled in that department. Once you hear bass done right the vast majority of subs sound like boom boxes. The larger horn is going into my car as my own permanent source of low end. The current baby box is for sale.

So that is the reasoning why I stick to the good drivers like the SDX7. Remember the SDX7 speced has the volume displacement of two of the drivers that you have asked me to look at. That is two for the price of one. More simple you'd need four normal 6 1/2" driver to equal one SDX7. That is the reason why I picked it. I have five different 6 1/2 " drivers on hand right now. The SDX7 is by far the best capable of giving you the most clean sound.

So enough tooting the horn. ( couldn't resist ) I have a couple of 8" in stock and I will play with them and see what gives.

Mark

[mwmkravchenko]

You want one of the pre-cut boxes? I could check the shipping or maybe you have the means at home to do this?

Mark

[Henkjan]

Mark, thanks for the offer, but I have a decent table saw and excelent router at home... the joy of woodworking is what got me into building my own speakers.... just need to find some time now (have 2 other projects that must be finnished before august ends...)

[brsanko]

of course you realize that rap relies on the second and third order harmonic distortion and messy transient response inherient in bass reflex and acoustic suspension box designs to give it that "full" "thick" bass sound. So the cleaner your sound is the less "impressive" the bass will be in rap. But if your intelligent enough to design horn speakers, chances are you don't listen to much rap.

[mwmkravchenko]

Hi brsanko

You are correct on two counts. Rap does rely on boxes with with high distortion components. A no I can't really stand the stuff. As for inteligence level I leave that up to you to decide. This design is presented for people to build it and listen. If you enjoy a clean realistic bass you get it.

Mark