DIY Boat Speakers!

[juliovideo]

Interesting link. I haven't compared active versus passive crossovers myself, but passive crossovers I'm sure, present more of a challenge. Though, passives can be done very well. You also need to consider what type of speaker you want. A three way speaker with a 3 way active crossover would require 3 amplifier channels per side. Do they make 3 channel amps anymore?

:T Yep, they do here's one:

http://emotiva.com/xpa3.shtm

The Behringer DCX2496 I think would do a three way crossover and allow you to correct the frequency response. But, I've never used one, so I'm not sure on that.

Thanks, interesting amplifier ,.........I have been watching this site for some time and are good things.

http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm

...................and I also like this amplifier,but the problem is that I've seen in 220 volts. 8O

XINDAK - V60 Mono Block Tube Power Amplifier

http://www.xindak.com/english/products/showditail.asp?id=389

.........or.................

XINDAK - XA8800MNE Mono Power Amplifier

http://www.xindak.com/english/products/showditail.asp?id=265

Image not available




Link to retail site removed by moderator.

[Johnloudb]

That's looks like a good speaker page. I think this design might be worth considering for your enclosure. It has a 12" width.

http://www.troelsgravesen.dk/3WClassic.htm

Jantzen audio also sells the crossover and drivers as a kit.

"Complete kit available from Jantzen Audio.
Request exact price incl. shipping here: contact@jantzen-audio.com"

You'd need to adjust the internal volume of the your woofer enclosure to match his woofer enclosure volume.

It has a high sensitivity (90dB) and will work well with tube amps. I would stay away from SE (single ended) tube amps like the one you posted above though. They limit dynamics too much unless you have a very high sensitivity design. And they tend to give a bloated sound to the bass.

[juliovideo]

That's looks like a good speaker page. I think this design might be worth considering for your enclosure. It has a 12" width.

http://www.troelsgravesen.dk/3WClassic.htm

Jantzen audio also sells the crossover and drivers as a kit.

"Complete kit available from Jantzen Audio.
Request exact price incl. shipping here: contact@jantzen-audio.com"

You'd need to adjust the internal volume of the your woofer enclosure to match his woofer enclosure volume.

It has a high sensitivity (90dB) and will work well with tube amps. I would stay away from SE (single ended) tube amps like the one you posted above though. They limit dynamics too much unless you have a very high sensitivity design. And they tend to give a bloated sound to the bass.

Thanks John ,good combination ...........

http://www.troelsgravesen.dk/3WClassic.htm

SEAS Prestige CA22RNX (H1288) 8"

$87.75 x 4 = $ 351.00


SEAS Prestige MCA12RC (H1304) 4.5"

$57.80 x 2 = $ 115.60


SEAS Prestige 27TFFC (H0881) Textile Dome

$38.75 x 2 = $ 77.50

The total is $ 544.10 dollar..............is not bad



Another that looks good is,but more expensive speakers ................

http://www.troelsgravesen.dk/ektagrande.htm

[Johnloudb]

I noticed you added an extra 8" woofer to the 3W Classic design. And that's not a bad idea ... but you'd need a whole new crossover design. Given the extra volume of your cabinet you can still add a subwoofer to the 3W Classic speaker design. You'd use an active crossover in a bi-amp configuration, or use subwoofer plate amp with it.

That's what Dan N. did with his HOSS speaker:

https://www.htguide.com/forum/showthread.php?t=26065&highlight=Hoss

and

http://www.parts-express.com/projectshowcase/indexn.cfm?project=HOSS&searchFilter=Hoss&CFID=105 23900&CFTOKEN=16124345

He used the RSS265HF subwoofer which can be used in a small volume. I think this could also work with your cabinet design.

That ScanSpeak speaker design is only 8.5 inches wide, so I don't think that would work with your enclosure.

[Johnloudb]

I just want to clarify, that my thought was to use the 3W Classic with your cabinet and just add a built-in subwoofer to extend the low frequencies of the 8" woofer - not to replace the 8" with a 10" sub.

[juliovideo]

I just want to clarify, that my thought was to use the 3W Classic with your cabinet and just add a built-in subwoofer to extend the low frequencies of the 8" woofer - not to replace the 8" with a 10" sub.

I like that idea, and would be a different design.

Other interesting things is to see HiVi designs, in fact I suppose by having the yellow color.

http://www.audiovideoforum.de/

http://www.parts-express.com/projectshowcase/indexn.cfm?project=MillenniumIII

http://www.parts-express.com/projectshowcase/indexn.cfm?project=MP3s

[juliovideo]

What do you think of ? ........................

Tweeters - SEAS Prestige 27TFFC (H0881) Textile Dome

Midranges - SEAS Prestige MCA12RC (H1304) 4.5"

Woofer - SEAS Prestige CA22RNX (H1280) 8"

Subwoofers - Dayton RSS265HF-4 10"

http://www.youtube.com/watch?v=koBWtYVRf-0&feature=related

[lunchmoney]

What do you think of ? ........................

Tweeters - SEAS Prestige 27TFFC (H0881) Textile Dome

Midranges - SEAS Prestige MCA12RC (H1304) 4.5"

Woofer - SEAS Prestige CA22RNX (H1280) 8"

Subwoofers - Dayton RSS265HF-4 10"

http://www.youtube.com/watch?v=koBWt...eature=related

All very nice drivers... but do you have a crossover design for them?

[juliovideo]

All very nice drivers... but do you have a crossover design for them?

Not yet, it's hard to find someone near me to help me in this, the alternative is to pay for design.

Actually I need is a schema, but I still have a period of perhaps several weeks to make a decision.

I acknowledge that there are ways where by few dollars I can get out of this hole,but I want to do everything,........ that's the challenge !!.....DIY

[Johnloudb]

All very nice drivers... but do you have a crossover design for them?

He does have a crossover design for the drivers, it's in this post:

https://www.htguide.com/forum/showpost.php?p=448411&postcount=48

It's from the 3W Classic kit on this page:

http://www.troelsgravesen.dk/3WClassic.htm

So, if Julio decides on this design, he's got a crossover design for it. I think Julio might have misunderstood you. The active part of the crossover for the subwoofer is a fairly trivial matter - many options for that.

[juliovideo]

He does have a crossover design for the drivers, it's in this post:

https://www.htguide.com/forum/showpost.php?p=448411&postcount=48

It's from the 3W Classic kit on this page:

http://www.troelsgravesen.dk/3WClassic.htm

So, if Julio decides on this design, he's got a crossover design for it. I think Julio might have misunderstood you. The active part of the crossover for the subwoofer is a fairly trivial matter - many options for that.

The same speakers with a different design (DIY Sonus faber "Stradivari Homage" ) http://www.sonusfaber.com/eng/home.html

............. and using alternative Midrange 5.5" and tweeters

http://www.troelsgravesen.dk/PMS.htm

We are almost there !!

----------

[HareBrained]

Julio,

You to take a breath and wait a minute.

Just like the reef systems you build, every aspect of a speaker is in some way affects the parts of the speaker. Would you put a shark in a fresh water tank, or a trout in a reef system? No. And you can't put the PMS into your cabinet.

The reason John suggested the 3W was because of the critical similarities of your cabinet and that cabinet. The PMS is a very wide baffle and the crossovers are designed for that very wide baffle. So unless you're starting over with new cabinets, you need to stick with the 3W. Or some of the other suggestions.

You can't just take bits and pieces from different speakers designs and throw them together, and expect success. You either need to learn a lot more about designing a speaker or you need to allow others (John) to guide you.

Personally, I like the drivers in the 3W and I would add the RSS315HF but that depends on the final volume of the cabinet. Also, I didn't see an dividers between the drivers. This will be important to ensure the larger drivers don't back-drive the others.

[juliovideo]

Julio,

You to take a breath and wait a minute.

Just like the reef systems you build, every aspect of a speaker is in some way affects the parts of the speaker. Would you put a shark in a fresh water tank, or a trout in a reef system? No. And you can't put the PMS into your cabinet.

The reason John suggested the 3W was because of the critical similarities of your cabinet and that cabinet. The PMS is a very wide baffle and the crossovers are designed for that very wide baffle. So unless you're starting over with new cabinets, you need to stick with the 3W. Or some of the other suggestions.

You can't just take bits and pieces from different speakers designs and throw them together, and expect success. You either need to learn a lot more about designing a speaker or you need to allow others (John) to guide you.

Personally, I like the drivers in the 3W and I would add the RSS315HF but that depends on the final volume of the cabinet. Also, I didn't see an dividers between the drivers. This will be important to ensure the larger drivers don't back-drive the others.

Thanks for the recommendation ,I have 15 minutes looking for the meaning of PMS and can not find it. 8O ............. about of reeftank....

Look this :T http://reefkeeping.com/issues/2009-03/totm/index.php

Every word I have been here with the help of an online translator, and my daughters at some point helped me to search on what I want to express(not now) , though I speak and read a little English.

The perfect plan is the design of 3 W for my budget, but the second woofer ?; I do not understand this part.

Thanks.

http://www.youtube.com/watch?v=0kNEo8OxrT8

------------------

[Johnloudb]

Hairbrained was referring to the "Poor Mans Strat" link you posted
( http://www.sonusfaber.com/eng/home.html ), when he said PMS. Like he says the width of that speaker is very wide and the shape is very different from your cabinet design. So that crossover wouldn't work well for you.

I agree with you, I think the 3W Classic ( http://www.troelsgravesen.dk/3WClassic.htm ) would be a terrific speaker design and work well with your box. The extra woofer is the active power subwoofer that we mentioned earlier. Hairbrained just suggested the RSS315HF 12" subwoofer instead of the RSS265HF 10" subwoofer I mentioned, and that Dan used in his HOSS speaker.

If you've decided not to use the subwoofer with your design that okay too. If you do use a subwoofer you need to add a board to seperate your speaker enclosure, so that the 8" driver in the 3W Classic and the subwoofer driver don't interact, as Hairbrained pointed out.

You also need to determine the total volume of you speaker cabinet and how much volume the subwoofer driver needs. This is done with speaker box design software. Anyway, once you decide on a speaker design, we can show you what you need to do next.

We certainly understand the challenge you face in communicating online in english. It's great you don't let that be an obstacle. :T

John

[juliovideo]

Hairbrained was referring to the "Poor Mans Strat" link you posted
( http://www.sonusfaber.com/eng/home.html ), when he said PMS. Like he says the width of that speaker is very wide and the shape is very different from your cabinet design. So that crossover wouldn't work well for you.

I agree with you, I think the 3W Classic ( http://www.troelsgravesen.dk/3WClassic.htm ) would be a terrific speaker design and work well with your box. The extra woofer is the active power subwoofer that we mentioned earlier. Hairbrained just suggested the RSS315HF 12" subwoofer instead of the RSS265HF 10" subwoofer I mentioned, and that Dan used in his HOSS speaker.

If you've decided not to use the subwoofer with your design that okay too. If you do use a subwoofer you need to add a board to seperate your speaker enclosure, so that the 8" driver in the 3W Classic and the subwoofer driver don't interact, as Hairbrained pointed out.

You also need to determine the total volume of you speaker cabinet and how much volume the subwoofer driver needs. This is done with speaker box design software. Anyway, once you decide on a speaker design, we can show you what you need to do next.

We certainly understand the challenge you face in communicating online in english. It's great you don't let that be an obstacle. :T

John

I understand now .......... thanks !

These are measures of the inside for the two woofers, ..................Some experts help me to calculate the total area?


thanks
















----------

[Johnloudb]

Julio, here it is. :T The total approximated volume for the woofers.


Image not available


I just estimated the area with rectangles that I thought came close to your specifications. I then calculated the area by adding up the different areas A. - F1,2. Area F1+F2 combine to form a rectangle which is easy to find the area of it. Below are the individual areas I calculated in Square Feet.


Image not available


I suggest you double check my work, just to be sure - I won't be held responsible for a mistake.

To get the individual areas first convert the lengths from inches to feet.

Example: Area F1,2 = (4"/12") X (6.75"/12") = 0.1875 Cubic Feet

Then just add up all the areas. This gives you a total cross-sectional area of the exclosure. To get the volume just multiply this area by the height (28.75"/12" = 2.40 Feet).


Image not available


Total Woofer Enclosure Volume = 3.1 Cubic Feet or 88 Liters.

You'll also need to section off part of the midrange enclosure since it's too big. Then you can use the left over volume for the woofers. I think you'll be able to add a 10" or a 12" sub in there with that extra volume left over from the top section of the speaker. But you'll need to make a hole in that divider between the woofer section and top section of the enclosure - just in the area outside of where the midrage enclosure is sectioned off. I think the midrange enclosure is 2 liters (as I remember - check that). Also 28.32 Liters = 1 Cubic Foot.

Have you decided to do a W3 Classic with a Subwoofer? No rush ... if you want to check the internet for other designs. Although, I kind of doubt you'll do better than this for your enclosure, but I haven't looked either.

[juliovideo]

I can say, with all these calculations ..........thanks my friend !

You know John, I have a few days ago the cabinet ready to put the side panels, but sixth sense told me to wait ! .

Now your talking to me to increase the capacity up to improve the volume of the woofers,I can do yet, and I can take 2 hours to complete.

Tomorrow I start this part .............. I was feeling bored , a joke.

Have you decided to do a W3 Classic with a Subwoofer? No rush ... if you want to check the internet for other designs. Although, I kind of doubt you'll do better than this for your enclosure, but I haven't looked either.

Surely yes ,what worries me is where to place the amplifier for the subwoofer, would be necessary ? or to make a pasive crossover ?

See other possible improvements for enclosure is good idea .

Greetings and thanks for your great help !

http://www.youtube.com/watch?v=IwWUOmk7wO0&feature=related

--------------

[ahaik]

John's calculations look good to me.
I did it just a little different and got close results to John.
I'll post it up just in case:

I looked at the four section as Trapizoids and to compansate for the arch I extended the smaller base of the Trapezoid by .25" (.125" on each side), see the lowest of the three images.

(Base1 +Base2 + 0.25) * Hight / 2
From top to bottom:
(9.5 + 2.75 + 0.25) * 4 / 2 = 25
(12.5 + 9.5 + 0.25) * 4 / 2 = 44.5
(12.625 + 12.5 + 0.25) *4 / 2 = 50.75
(12.625 + 11.25 + 0.25) * 4 / 2 = 48.25

Total Area = 25 + 44.5 + 50.75 + 48.25 = 168.5 sq inch

Vol = 168.5 * 28.75 = 4844.375 cu inch = 2.8 cu ft

[fbov]

If you want to measure the area directly, if only as a check, use a scale. Weigh a known area of the same material, weigh the sample and take the ratio. If the sample weighs twice as much as the known area, it's area is also twice as large.
Frank

[Johnloudb]

I can say, with all these calculations ..........thanks my friend !

You know John, I have a few days ago the cabinet ready to put the side panels, but sixth sense told me to wait ! .

Now your talking to me to increase the capacity up to improve the volume of the woofers,I can do yet, and I can take 2 hours to complete.

Tomorrow I start this part .............. I was feeling bored , a joke.

Surely yes ,what worries me is where to place the amplifier for the subwoofer, would be necessary ? or to make a pasive crossover ?

See other possible improvements for enclosure is good idea .

Greetings and thanks for your great help !

http://www.youtube.com/watch?v=IwWUOmk7wO0&feature=related

--------------

I'm glad you were joking!!

For the sub you'd need to go with an active crossover, because it's difficult and costly to design a passive crossover below 120Hz. You could make a passive high pass crossover for the 8" woofer, but you'd have get speaker design software to design the crossover.

How do you feel about bi-amping the W3 Classic? You would need two stereo amps, one for each channel. This would be used with the passive crossovers, so still the same. But, this way you could add an active crossover for the sub without it affecting the mids and treble. The active crossover would then just cross between the woofer and subwoofer. Of course you'd also need two subwoofer amps.

Or you could make the the W3 Classic sealed. I looked at the driver specs and it would have a 2nd roll off close to 60Hz sealed with a Qtc of 0.707. You could then use a second order crossover just on the sub. Maybe a 4th order on the sub would work with that too. This would be cheaper and wouldn't add any extra electronics in the signal path to the mid and high frequencies. Wait, this might need a bigger box.

Someone needs to do some box modeling, eventually. I wouldn't mind doing this ... I need the practice. You might check out LSP CAD Lite which I think is fairly easy to use. That's what I am using.

A passive, first order, line level crossover might work well with the vented W3, just before the amp . This is really easy to build, just a capacitor and and resistor for each channel, in a small box with connectors.

You could still use plate amps but mount them in a wood frame and put it on the floor next to the speaker. Or you could use a stereo amp, with a separate electronic crossover.

There's lots of possibilities, just depends on what you like and what you want to spend.

[Johnloudb]

John's calculations look good to me.


Vol = 168.5 * 28.75 = 4844.375 cu inch = 2.8 cu ft

Good to have that verified - I'm glad our numbers were close. :T Yours is probably closer, especially when you consider the volume taken up by the bracing.

[juliovideo]

I'm glad you were joking!!

For the sub you'd need to go with an active crossover, because it's difficult and costly to design a passive crossover below 120Hz. You could make a passive high pass crossover for the 8" woofer, but you'd have get speaker design software to design the crossover.

How do you feel about bi-amping the W3 Classic? You would need two stereo amps, one for each channel. This would be used with the passive crossovers, so still the same. But, this way you could add an active crossover for the sub without it affecting the mids and treble. The active crossover would then just cross between the woofer and subwoofer. Of course you'd also need two subwoofer amps.

Or you could make the the W3 Classic sealed. I looked at the driver specs and it would have a 2nd roll off close to 60Hz sealed with a Qtc of 0.707. You could then use a second order crossover just on the sub. Maybe a 4th order on the sub would work with that too. This would be cheaper and wouldn't add any extra electronics in the signal path to the mid and high frequencies. Wait, this might need a bigger box.

Someone needs to do some box modeling, eventually. I wouldn't mind doing this ... I need the practice. You might check out LSP CAD Lite which I think is fairly easy to use. That's what I am using.

A passive, first order, line level crossover might work well with the vented W3, just before the amp . This is really easy to build, just a capacitor and and resistor for each channel, in a small box with connectors.

You could still use plate amps but mount them in a wood frame and put it on the floor next to the speaker. Or you could use a stereo amp, with a separate electronic crossover.

There's lots of possibilities, just depends on what you like and what you want to spend.

thanks John ,Increase the capacity ..............









About Midrange of the enclosure is almost 2 Cubic Foot,I think that this area is very well for midrange.

What do you think of the new area, it's fantastic ?

[Johnloudb]

Yes, very fantastic! :T I hope you haven't glued those boards in yet ... it doesn't look like it. If so, it won't be difficult to fix. Very nice work though!

I noticed on the "3W Classic" web page he used a pre-made plasitic enclosure for the midrange driver:

"When ordering the drivers I included a ready-made enclosure for the small MCA12 drivers. I never used these plastic containers before, but it appears to do better than expected - and it saves an awful lot of time. The mid cab is lightly stuffed with MDM3 from Monacor."

It's not included in the kit though - does anyone know where you can buy these midrange enclosures?
But, you can build a small midrange enclosure if necessary. And use the rest of the volume for the woofers, which you'll need with a 12" RSS315.


Image not available


Also, you need to keep the driver layout exactly like he designed the W3 Classic.


Image not available


One problem is that the midrange is 200mm ( 7.87 inches) from the top of the speaker. So the second brace blocks the midrange, but you could cut out part of the front brace for the midrange enclosure. Or buy a midrange enclosure.

The 8" woofer can be mounted a just below second brace, since it's position is not as critical as the tweeter and midrange. I think we might get rid of the port and make it sealed. Then you can crossover to the Sub at 60Hz with a second order filter.

The other option would be to add a small passive 2nd order filter that connects to the amp. I can show you how to build it. It's easier than putting a speaker crossover together. Then you use a 4th order crossover with the subwoofer.

Subwoofer ---> Required Volume (sealed for Qtc = 0.707 "Butterworth")

12" RSS315 ---> 1.9 Cubic Feet
10" RSS265 ---> 0.93 Cubic Feet

Woofer
8" CA22RNX ---> 1.7 Cubic Feet (sealed), 1.3 Cubic Feet (ported)

I'll do some box modeling of in the next couple days, and see how this will work out. I'll also model both subs sealed and ported to see which you want to go with.

Once I know a little more about how the woofer and subwoofer response looks in the box volume, you can start planning construction and buying parts.

Does this sound okay so far?

[juliovideo]

John Perfect ,.......about of the glue ,you're right in the photo still had no glue .

This is a DIY from Spain, the thread it has 20 pages.......enjoy !!

DIY Sonus Faber Cremona

Translated to English http://translate.google.com/translat...hl=en&ie=UTF-8

spanish http://www.mundohi-fi.com/portal/ind...b&tid=8&pid=13

[Johnloudb]

Julio,

That's a really nice build ... no doubt, your inspiration for this design! Well, I've modeled the 10" Subwoofer for a Butterworth alignment in a sealed box. The LSP CAD Lite software is not very flexible and will only let you model for a specific alignment. A Butterworth alignment requires a box of about 1 cubic foot. You have about 1.4 cubic feet for the sub enclosure. So, this is good. The rest of the volume will be used for the 8" woofer.

A 12" Sub won't work, it's too big physically for your box, and needs more volume.


Image not available


The frequency response:


Image not available


Your box volume gives you something between a Butterworth and a Bessel alignment. Which is good.

Ported enclosures are more tricky to design and the only place you could fit a port would be on the bottom of the speaker, with the speaker elevated slightly above the ground. This sub works good in a sealed box (-3dB at 42Hz) and you can use an equalizer to extend the response lower if you want.

I'll model the 8" woofer next. And design a passive filter for it.

Impedance Response:


Image not available

[juliovideo]

Interesting what you say,....................I have had good experience with this foam to use inside the box,for me is the best ;I buy some time this foam for a speaker in s a m s a s h ........I did change this only and gave me a nice low-frequency dry and clean.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-900

Image not available


-------------

[Johnloudb]

That would be nice for lining the inside of the speaker walls. You will also need a certain amount of poly fill to dampen resonances in the woofer and midrange enclosure. You can experiment with the amount to see what works best.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-317

I modeled the Seas 8" woofer and it needs about a 1.7 cubic foot enclosure, sealed. It had an -3dB point of 50Hz. So, I'll try to model a passive second order crossover tonight, to use at the main amp input.

[juliovideo]

That would be nice for lining the inside of the speaker walls. You will also need a certain amount of poly fill to dampen resonances in the woofer and midrange enclosure. You can experiment with the amount to see what works best.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-317

I modeled the Seas 8" woofer and it needs about a 1.7 cubic foot enclosure, sealed. It had an -3dB point of 50Hz. So, I'll try to model a passive second order crossover tonight, to use at the main amp input.

Thanks John ................About the cables to connect between croossover and speakers, what you recommend me? or what would be the best.

http://www.parts-express.com/wire-cable.cfm

..........thanks of advance.


-----------------

[juliovideo]

Today I found the piece to weld the components in the crossover......... :T


Search for USA "connector, lug type terminal strip"


http://www.alliedelec.com/Search/pro...01A004136617F#


Image not available


Search for UK,....."Soldering tag strips"

http://uk.rs-online.com/web/

Item 433-775, approx. 2-3 US$/ea. Minimum is 10 pcs.

UK:
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=043377 5

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=043378 1



----------------------

[Johnloudb]

Julio,
Here is the second order passive high pass circuit schematic:


Image not available


Values the components are as follows:

Capacitors -
C1 = 0.318uF
C2 = 0.0318uF

Resistors -
R1 = 10k
R2 = 100k (amp input impedance)

R2 is just the input impedance of the amp. For these values to work your amp must have 100k ohm input impedance. This is usually published with the amplifier specifications.

In the schematic the voltage source V1 represents the preamp output. The meter VM1 represents the amplifier input.

You can adjust the circuit to work with amps with an input impedance as low as 47k ohms. In the 47k ohm case, both caps should be doubled in value, and the resistance values should be halved.

Example:

Capacitors -
C1 = 0.636uF
C2 = 0.0636uF

Resistors -
R1 = 5k ohm
R2 = 50k ohm (close enough )

The capacitors aren't standard values, but you can get close by paralleling additional caps of different values. Once you know the input impedance of main amp, I'll fine tune the circuit for you.

Here is the response of second order high-pass filter. This response combined with the second order roll off the Seas 8" woofer will give a forth order high-pass filter. And this should work well with a subwoofer crossover that has a 4th order low-pass filter circuit.


Image not available


Do you have an amplifier for the speakers? I'd recommend bi-amping ( two stereo amps ) the speakers, instead of using 2 plate amps for the subs. For about the same cost of buying two subwoofer plate amps, you can get a high quality amp like an Emotiva (www.emotiva.com) to drive the subs. You could then buy a separate subwoofer crossover to work with it. I think this would give better results than Dayton plate amps. An Emotiva UPA-2 (185 RMS watts per channel into 4 ohms) plus an inexpensive sub crossover would be less than cost as 2 plate amps.

http://emotiva.com/upa2.shtm

Anyway, these are just suggestions. I'm not sure what to suggest on specific cables until you know what electronics you'll be using. Those Dayton cables should work well.

[Johnloudb]

I have a question? Does cascade two 2nd order Butterworth filters give a 4 order Linkwitz-Riley? This filter is supposed to be a 4th order Butterworth but it is down -6dB at the 50Hz corner frequency. The circuit design was created using a circuit template in Spice. Anyway, a butterworth is supposed to be -3dB at the corner frequency. Maybe, just because it's a passive filter it can't perfectly approximate a butterworth?

My goal was a 4th order Linkwitz-Riley crossover, using the combined woofer response with the passive filter. Maybe I should just adjust the corner frequency so it is down -3dB at 50Hz? Or, maybe I'm splitting hairs and shouldn't worry about it?

[mackintire]

Does cascade two 2nd order Butterworth filters give a 4 order Linkwitz-Riley?

Yes I believe it does.

A 4th order Linkwitz-Riley crossover is -6db at the crossover point AND 24 dB/octave rolloff rate after the crossover point.

[Johnloudb]

Thanks!

I think I'll experiment with the passive filter a bit and see if I can get a better response.

[Dennis H]

For about the same cost of buying two subwoofer plate amps, you can get a high quality amp like an Emotiva (www.emotiva.com) to drive the subs.

Since these are boat speakers, shouldn't we be recommending 12 volt components? There are plenty of amps and active crossovers available in the car world. Or have I misunderstood that they are going to be used on a boat?

[juliovideo]

Since these are boat speakers, shouldn't we be recommending 12 volt components? There are plenty of amps and active crossovers available in the car world. Or have I misunderstood that they are going to be used on a boat?

The speakers will take the form of a boat, but not for a boat.



--------------------

[Dennis H]

Ah, thanks, my bad.

[juliovideo]

Ah, thanks, my bad.

I have thought to make the vertical lines like this photo..........





........will be different from this photo






:T


-----------------------

[juliovideo]

Do you have an amplifier for the speakers? I'd recommend bi-amping ( two stereo amps ) the speakers, instead of using 2 plate amps for the subs. For about the same cost of buying two subwoofer plate amps, you can get a high quality amp like an Emotiva (www.emotiva.com) to drive the subs. You could then buy a separate subwoofer crossover to work with it. I think this would give better results than Dayton plate amps. An Emotiva UPA-2 (185 RMS watts per channel into 4 ohms) plus an inexpensive sub crossover would be less than cost as 2 plate amps.

http://emotiva.com/upa2.shtm

Anyway, these are just suggestions. I'm not sure what to suggest on specific cables until you know what electronics you'll be using. Those Dayton cables should work well.

Thanks john , I not have still an amplifier for these speakers ,thanks for the recommendation. :T ..............I appreciate all your analysis is very helpful to me.




-----------------

[Johnloudb]

Thanks john , I not have still an amplifier for these speakers ,thanks for the recommendation. :T ..............I appreciate all your analysis is very helpful to me.

-----------------

I'm glad you find my advice helpful. I have to watch myself ... In the past, I've given too much advice sometimes and try to take over peoples projects. So, just tell me to "bug off" if I suggest too much.


Well, I got a good looking response for the 2nd order high-pass filter. It approximates a Butterworth filter with a 50Hz corner frequency pretty well. :T It's down -4dB at 50Hz with a second order roll off.


Image not available


I only had to change the value of C2 from 0.0318uF to 0.060uF


Image not available


Values of the components are as follows:

Capacitors -
C1 = 0.318uF
C2 = 0.060uF

Resistors -
R1 = 10k
R2 = 100k (amp input impedance)

Tomorrow, I'll write down some stuff showing how to adjust the filter for different amps, and how to get the capacitance values above from standard capacitors. It's real easy.

[juliovideo]

I'm glad you find my advice helpful. I have to watch myself ... In the past, I've given too much advice sometimes and try to take over peoples projects. So, just tell me to "bug off" if I suggest too much.

You are just like me , I am watching a reciprocity beyond what I expected, actually I help dozens of people in forums, both in the marine aquarium as FTA satellite.

There are people who know, but maybe not go beyond a broad explanation for many reasons.

When I help someone, I give all possible details.........I know what it is to be blind, because I was 20 years of my life in a prison called Communist Cuba, and when I could escape from that place I could see the light of the world.

I thank to USA you for accepting me as political refugees and learn the values of democracy......and educate my two daughters to serve this country.

Thanks to you and all members





''''''''''''''''''''''''''''''''''''

[Johnloudb]

That's really great that you made it to States ... good for you! :T

Here's some equations regarding caps and resistors that you'll find helpful in combining standard values to get the ones you need. If you already know this, disregard.


Image not available

Image not available


Here's and example filter for an amp with 100k ohm input impedance (using standard values):


Image not available


R1 = 10k ohms in this case. You can even omit R2a in this case since the amp has 100k ohm input impedance. If you decide to use two Emotiva amps to power your speakers, they have a 47k ohm input impedance, which will work fine. Just double the capacitor values and make R1 5k ohms. You can then omit R2a again.

Emotiva amps have received very good reviews from members on this site. They are probably hard to beat for the money. But, definitely please yourself. You could even use a tube amp to drive the highs/mids and a solid state amp to drive the low frequencies.

Well, I think this speaker design is done!! Keep us updated with you progress and if you have any questions please ask.

Oh, yeah, you can find project boxes, capacitors, PCB boards and RCA connectors for your second order high pass filter at Parts Express. Or, also Parts Connexion has lots of stuff. You can spend a fortune on caps and wire and stuff ... but don't! It's doesn't have much affect on the sound if any. If you have any questions about the high pass second order filter let me know, and I point you in the right direction.

I look forward to seeing the finished Sailboat Speakers!!!

[juliovideo]

I look forward to seeing the finished Sailboat Speakers!!!

Thanks John





-----------------------

[juliovideo]

My DIY cables :dancenana:

;b>














Parts


WBT 0800 Silver Solder 4% Silver

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=093-586

Belden RJ45 CAT-5e Crossover Cable
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&it em=270323593127#ht_2140wt_1165

EXPANDABLE SLEEVING

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=082-352

Nakamichi Speaker AMP Lock In Banana Plug 24K
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&it em=180331933618#ht_921wt_1165


.................... Home Depot 3M tape (black and red) and Heat Shrink Tubing.


----------------------

[Johnloudb]

Nice work there Julio! Pretty cables!! :T

[juliovideo]

Nice work there Julio! Pretty cables!! :T

Thank you John






---------------------------