first crossovers, please take a look and double check me...

[Txgrizzly]

Guys,
here is my 1st attempt at making my own crossover so please be gentle. it is for a set of RS150MT with no "BSC"

1st link is the schematic
2nd pic is the tweeter xover
3rd pic is the mid/woofer xover

[cjd]

Looks right to me.

[JonMarsh]

When are you going to hook them up? Proof is in the pudding, they say... :W

[Txgrizzly]

I am hoping to cut and glue up the enclosures this weekend. i will probably assemble them early next week and give them a listen... if i like the way they sound i am going to build two more for my 7.1 surround set up i am building. i am still kinda tossed up on whether to put them in a sealed enclosure or ported. this will be used 80% HT and 100% surround duty if that makes sense. i have a Velodyne sub so the ULF's will be going to it but i dont know if they would match up better to the sub in a ported or sealed enclosure. any thoughts on it?
I know this is supposed to go into a .25cf sealed or a .50 ported but kinda sketchy on the length and diameter of the port to get the correct tuning.

[Dave Bullet]

Put a multimeter across the terminals to measure resistance before hooking them up to your amp. Just to ensure you don't have a short in there.

[Txgrizzly]

Dave, thanks for the advice. couple of questions.

1. which set of terminals - the input side or output
2. should i just be looking to make sure it shows an open or should there be some sort of impedence on the path?

[cjd]

Personally, I prefer sealed for things like HT, especially surround duty where crossing a little higher isn't quite as crucial (80-100Hz for these). The excursion limits are more an issue and the chance that you have output going to these below tuning frequency risks big bursts in that range and unloading a bit too much.

C

[Txgrizzly]

well i have the enclosures cut, glued and have started putting the finish on them. all in all i am pretty pleased with how they are turning out. i cant wait to hear them... then i get to decide on building two more of these for my 7.1 system or start over with a different design for the surrounds.. i have taken a couple build photos and will take some once i am complete. its hard to put down the sandpaper and pick up a camera though...

Added a pic

[Txgrizzly]

pic of one of cabinets added

[cjd]

Looking good.

[Dave Bullet]

Dave, thanks for the advice. couple of questions.

1. which set of terminals - the input side or output
2. should i just be looking to make sure it shows an open or should there be some sort of impedence on the path?

Hi there,
1. The speaker binding posts = the input side. (ie. speaker disconnected from your amplifier). That is you complete wiring up the drivers and crossover, then put the multimeter on the ohms setting and measure resistance across the terminals / binding posts (assuming on the back of your speaker enclosure) which you would connect wires to from your amplifier.
2. If it is open - then there is a break in the circuit. Look at the tweeter circuit first as capacitors block DC (which is what the multi-meter uses to test resistance). If it is closed - you'll get a reading. You do not want to see a short (ie. <1 ohm reading) - this will kill your amplifier. If you are building a nominally 8 ohm rated speaker. You should have a reading of about 6 ohm+. A nominally 4 ohm speaker will have a reading of about 3 ohm +. What you are measuring is essentially the woofer circuit (remember capacitors in series block DC)

Cheers,
Dave.

[Txgrizzly]

Thanks Dave i will do this before i hook them up... am getting ready to start mounting the drivers cross overs and insulate the cabinets today...i might get to hear these tonight if all goes well.

[cjd]

Just make sure you measure impedance with the speaker attached!

[Txgrizzly]

well i got the speakers together last night and the both measured 7.1 ohms at the binding posts so i guess i got pretty close.

now for my impressions:
1. the Mids and Highs are crisp and clean and the sound field is very large. they really fill the room.
2. i know these are not going to be bass heavy speakers but i really expected more bass out of them. i went with the sealed cabinet and insulated the inside with 1" sealed cell foam.
3. i have a pair of paradigm's that are the same size almost that are in ported cabinets and they have alot more bass.

Question:
1. will putting more loose padding up the bass any?
2. how much more bass could i expect if i went with the larger ported cabinet?

here are couple pics of one of the speakers. for some reason the pics came out blurry

[Dennis H]

set of RS150MT with no "BSC"

i really expected more bass out of them.

That's why you need to use BSC. A non-BSC crossover is like turning the bass control down.

[---k---]

Like Dennis said. Make sure you're listening to them up against the wall. Where you locate them will make a big difference in the bass. Placing them against the wall will raise the bass approximately 6db.

Adding fill will slight increase the bass extension, but can slightly reduce the output. You might want to try removing some of the padding to reduce the box size and create peaky more boomy bass. Some like this. Others like rather dry bass.

I've heard an another speaker designs with an RS150 in a ported box at DIY Iowa 2008. It produced surprising amounts of bass. Very satisfactory. So, it isn't the driver.

[Txgrizzly]

thanks guys, i will try the things you suggest. if i wanted to add a little BSC back into the crossover how would i do it? the crossover design is on the 1st post...

[Dennis H]

Who designed the crossover? Is there a version with BSC?

[Txgrizzly]

i found the post where he shows it with BSC its under the Missions accomplished titled RS150MT and its on about page 3 of the post. two of the coils, two of the resistors and 3 of the caps are different. there is also an extra resistor in the tweeter path. it would be easier i think to just build new crossovers if i went that route

[Dennis H]

Have you tried your receiver's auto-eq? It may be able to boost the bass up to where it should be.

[---k---]

CJD did the crossover. I skimmed the first two pages, I beleive this post has both the full BCS and the no-BSC parts list:

http://www.htguide.com/forum/showpost.php4?p=268212&postcount=47

There are schematics just a tad further down in the thread.

I think once you slam them up against the wall, you'll get more bass. Definitely try your receiver's EQ or just use the tone control. Seriously.

[Txgrizzly]

thanks guys... i put them against the wall and used a little bass in the tone control. they are still a little light on the bass but they are so clear and imersive that i dont want to screw with them... these are going to be pure surround speakers once i get my new home theatre built so i dont see that as going to be a problem. now i am looking at starting my next project. i want to build a Sonotube sub. i want to thank everyone who helped me on this project especially Thomas for answering all my stupid beginner questions.

Here is a better pic of the finished product.

[Dean100]

Those look great, very nice job for your first ones. You may get a bit more bass after they break in for a little while and as you say for surround duty they should be fine.

[Txgrizzly]

Thanks Dean, i have been doing wood working for a while and this falls right in with that hobby. my next speaker i am going to build is a SONOTUB sub... should be interesting. just now looking at parts lists and designs...

[---k---]

Wow. Those look great. If I didn't know any better, I would have thought that was a premade PE box.

For a surround, you really don't need the bass. But, if you ever want to play with them, there could be lots of things to tweak, such as the stuffing, the inductor size, or maybe padding the tweeter down a hair. Let them break in, enjoy them a bit, build some mains, then come back to this one.

[PoorboyMike]

2. i know these are not going to be bass heavy speakers but i really expected more bass out of them. i went with the sealed cabinet and insulated the inside with 1" sealed cell foam.

When you say sealed cell foam, do you mean that if you hold a piece up to your mouth that you can't blow air through it? If that is the case, the foam is just reducing your box volume, which would cause the low end response to roll off sooner.