my custome build bandpass box.

[wicked]

i build this box just for kicks. this thing was hitting 135 db with a jl audio sub 10 w3 v-2. car audio in home theater, why the hell not. turns out the bass was to much for my crappy rca home theater speakers to handle. had to go with an rca 10 inch sub. still hits hard and low. havent measured for db yet.http://www.flickr.com/photos/wicked photos/

 

[wicked]

sorry, bad link above. here it is again.

http://www.flickr.com/photos/wicked_photos/

 

[annunaki]

You can't really see the sub or the enclosure in your pictures.

 

[j_garcia]

135dB, but what did the response curve look like?

 

[Sniperslayer]

lol i like those captions for your pictures

 

[annunaki]

Being a bandpass for car audio it was probably all at 60hz. That is the most typical "boom" frequency for those types of applications. Bandpass can get very loud but are very difficult to design to achieve flat linear response over a large bandwidth.

 

[wicked]

i willl post better photos in the near future. as for cross over slope, it was tweeked to 60 hz, on average. the sub dimension for the box was quite easy to figure out. i work as an audio installer and fabricator part time. i figured why not home theater. what could be so different.

 

[annunaki]

For home theater, one would desire flat requency response over a large range, from say 20hz-80hz. In a car you have the cabin gain effects (to balance out response) that are not as strong in the home environment, thus you can get away with very peaky type response. Bandpass enclosures also tend not to be as detailed as their sealed or vented counterparts.

 

[j_garcia]

I don't think band pass really works in a car that well either; at least not if you want good response. You could probably get good results with that JL driver in a sealed box, and that would also make it easier to handle in an apartment.

 

[wicked]

thanks for the input. i agree with most of it. at the time of build, i was just looking to get deep low bass. the kind that rattles nose hair. as for the detaile in sound, i find it to be true with music, (rock). watching movies is a different thing in my opinion. for someone to notice precision and timing in bass from a bandpass takes a well trained ear. for movies, it makes it almost imposible. i could be wrong. what do you guys think?

 

[annunaki]

I don't think it takes a well tuned ear, they just are not as accurate. Look at the response curves of most bandpass loaded subs, they simply are not very linear, thus not very accurate (i.e. true to the source).

Don't get me wrong, there can be bandpass enclosures that can do well. However, they are few and far between. They are also very finicky to work with. A slight miscalculation by .05ft^3 can throw off response rather easily with a bandpass enclosure.

Using the same subwoofer in a properly tuned vented enclosure would yield much better results for home theater. Sure, it may not hit 135db at 60hz but it will give you nice even response over a broad frequency range. I can run that woofer through a simulation when I have some time to give you an idea on enclosure options.

 

[annunaki]

The 10W3 would do very well in a 4.0 ft^3 enclosure with dual 3" ports 17" long. This will tune the enclosure to 22hz. This should yield usable in-room response down to 19hz or so, maybe lower. This sub models really well. I would think it should do quite well in that environment.

 

[wicked]

new close up phots of bandpass box. yea, its a little out there.http://www.flickr.com/photos/wicked_photos/

 

[annunaki]

I thought you said the sub was a JL Audio W3? Was the box made for a W3 and you just put a different sub in it???

 

[wicked]

the box demention was for a 10 w3-v2. as noted in one of the pictures, i had to change it out for the time being. it got extremly loud for apartment use. even with the gain turned into the negatives the bass was a bit much. i need to get some good bookshelf speakers to balance out the loud bass from the jl. i was thinking of the new polk audio speakers. i heard them at frys electronics connected to an audiosource amp. they sound quite impressive to me.

 

[annunaki]

What you really need is a different enclosure for the JL.

In all seriousness, the bandpass enclosure is introducing a large hump in the frequency response of the sub. That is why it sounds like it is too much, because it is. A ported enclosure like I stated above (when used with the W3) would smooth the bump in response as well as allow it to play significantly deeper. I am sure the JL is a better sub than what you have in the enclosure currently. I use a 10W3-v2 in my daily driver. It is a very potent, accurate woofer.

 

[wicked]

thanks for the input. aside from actually building another box, what would you recomend for speakers (bookshelf) to balance out the loud bass. i would hate to build a hole new entertainment center just to acomidate a jl in ported or sealed inclosure. my expertise is in car audio. i have no clue about home theater speakers. i would like to put the jl back in, i just need some good loud speakers that will balance the mids and highs with the bass from the jl audio sub.

note: i did build another box for the jl w-3. it was sealed and placed at the corner of the room near the fire place. it sounded good, but the low frequencies i wanted out of the speaker was just not present like in the bandpass now. it was maybe pushing 120-130 htz, not inof for my listining taste, could be an amp issue, but thats a hole diff. story. again im into car audio so the bass im looking for is that low deep bass. not the one present on all home theater subs i have heard. point be made, i love the bass from the bandpass with the jl audio. just need balance in good mids and highs. what would you recomend?

 

[annunaki]

It sounds to me you like exagerated bass. I would still recommend a new enclosure for the JL and then add a simple eq to the setup to custom tailor the response you desire. A ported enclosure tuned to 22hz would be excellent for the sub (like mentioned previously). You will be able to get similar sound to your current setup for bass (when you introduce a bump in response with an eq) yet it will play even deeper and more accurately.

As for the speakers, if you are drowning them out with bass, the sub is probably just too loud. However, the speakers you have are not too hot to begin with.

There are a lot of good speakers out there. It depends upon the budget though. For a lower budget, I would look into the AV123 x-ls bookshelf speakers. Do 5 of them for a perfectly matched system. http://www.av123.com/products_product.php?section=speakers&product=82.1 Upgrade one pair at a time if you need to, and try to buy one as a single unit for a center speaker.


They have received many glowing reviews. THey should help out greatly over your current setup of RCA speakers. Build the new enclosure for the sub and add a basic eq and you would have an awesome slamming system.

 

[wicked]

thanks for the speaker link, it looks promising. i will consider those, i sure would like to hear them befor hand. also, i feel you just cant be sold on the fact that a bandpass pushes deeper and lower bass tone than a sealed or a ported box. i have no idea how you can even toy with the idea that i can get deeper bass on a ported box than a bandpass. their is just no way. not in my experience. but again, thanks for all the info.

 

[annunaki]

thanks for the speaker link, it looks promising. i will consider those, i sure would like to hear them befor hand. also, i feel you just cant be sold on the fact that a bandpass pushes deeper and lower bass tone than a sealed or a ported box. i have no idea how you can even toy with the idea that i can get deeper bass on a ported box than a bandpass. their is just no way. not in my experience. but again, thanks for all the info.

Please explain to me how you are constructing a bandpass that can play deeper than a ported enclosure tuned to 18hz-22hz. Most common bandpass designs are tuned to around 50hz or so. Physics will dictate they cannot play deeper. They almost always rely on being in a confined space to help emphasize the low end response below 40hz-50hz.

I have been building enclosures for about 11 years now, I have yet to come across a bandpass enclosure that plays deeper than a low tuned proted enclosure. The sheer size of a bandpass enclosure tuned to such frequencies would be impractical. Most band pass enclosures when properly done (without a large bump in response near 60hz) typically end up about 25% larger than a ported counterpart. Even then they still do not play as deep. Bandpass designs may yield great efficiency, but they lack some detail due to the woofer not being exposed to the ambient air. There is some delay, though minimal, in the air having to escape through ports only.

I am not discounting that a properly designed bandpass enclosure cannot be done, it is just they do not serve much practical purpose anymore. Not to mention most woofers now days are more or less designed for sealed, ported, or passive radiator applications.

My guess is you may not have heard heard a really well done, low tuned, ported enclosure with a fair amount of port area. Perhaps you have not enough experience with ported enclosures tuned accordingly to allow such deep low end extension.

Think about it this way, if bandpass offered such great advantages, don't you think most high end sub manufacturers would be using the design? The fact is they don't for many of the reasons I highlighted above. In car audio they have a purpose (though diminishing), for home audio, not so much.