Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Building it myself, and now I'm confused
Building it myself, and now I'm confused
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 10th January 2019, 01:05 PM   #1
BryanDIY is offline BryanDIY  United States
diyAudio Member
 
Join Date: Jan 2019
Location: Georgia
Default Building it myself, and now I'm confused

I am new to the site and extremely new to DIY home audio builds. That being said, I decided that I wanted to build my own 2.1 soundbar, I know I could buy one but there's no fun in that and it's not original. So off to the internet to learn what I can about building a home audio system, and now I am even more confused.

What I have learned thus far is that there is far more information about audio than I could ever imagine and it has now all run into one giant block in my brain. Some generous friends have donated some old surround sound speakers in hopes of aiding me with my project and I now have ample speakers for the build.

What I have decided to go with for speaker selection is:
(2) Sony 2 3/4 drivers (1-826-417-11)
(2) LG 90w 4ohm 2 3/4 drivers
(1) LG 200w 3 ohm 7 1/2 sub

To me this is feasible, I can build the box and install the speakers, but that's the easy part to me. The problem that has me confused is the amp(s) needed to make this work. I do not know enough to build my own amp board, crossover, etc. So I was looking to buy the premade boards that I can simply solder the speaker wires. My brain now hurts from going through all the different boards and trying to consider what each can do and what I am going to install, and so on and so on.

I am looking for help from those of you far smarter than me to help me complete my newly formed passion for building my own custom soundbar. Please be gentle with my ignorance.
  Reply With Quote
Old 10th January 2019, 02:52 PM   #2
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
Simplest solution at this point is the Parts-express.com class D amps. $20-30, four terminals. These take a 19 v power supply, available from them or from many computer shops. You'll need a 2.5 mm receptacle to match the plug on the power supply, probably 2 or 3 if you buy 2 or 3 19 v power supplies. You'll need 3 or four 10 kohm audio taper pots for volume controls. You'll need a power switch, a fuse holder, a fuse. Or a circuit breaker. You'll need RCA jacks or 1/8" stereo phone jacks to connect to the TV. Oh, notice many TV's like my new Sanyo do NOT have 1/4 phone jacks for stereo audio feed. They have patented optical cable connector. You'll need a non-flammable box, all this stuff is ****ese and going up in flames is not unheard of.
Parts express also sells complete crossovers for 4 ohm speaker networks. Pick a crossover point, possibly 2000 hz although I am not an expert on 7.5" subs. My main speakers use 15" woofers which are crossed over at 2000 hz.
You'll need a soldering iron and tin-lead rosin core solder. Wear safety glasses, solder will splash. I like the unsolder sucker bulb from parts-express.
Previous US diy king that sold quality boards was mcmelectronics but newark just shut them down and has been busily discontinuing most products. Some things like the plate amps are still available but the catalogs are no longer published and you have to sweat the products out of the internet site, PIT*.
Warning, Class D amps have a certain sound and I don't have the power connector to make mine work yet so I don't know if I like it. I've got a LM1875 Class AB IC amp that I built that doesn't work yet either and has been overheating for a year, so I'm still trying to work up the nerve to take another dive into that project. That project is occupying the coffee table that the Class D amp will go on. My class AB 70 W/ch 6 transistor/channel amp is still working well, but that takes a hundred hours or so to build.
BTW to get around the Sanyo patented optical sound bar feed, I bought a mcmelectronics stellar labs video tuner with vidio out and stereo out RCA jacks. It has better sensitivity than the Sanyo TV. Actually I had it already since the previous CRT TV did not have a digital TV tuner. But mcmelectronics discontinued stellar labs, and I don't know if the tuner that newark replaced it with has those outputs or not. Buyer beware.
Have fun.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 10th January 2019 at 03:02 PM.
  Reply With Quote
Old 10th January 2019, 02:59 PM   #3
BryanDIY is offline BryanDIY  United States
diyAudio Member
 
Join Date: Jan 2019
Location: Georgia
Indianajo- I was just on parts express looking at this amp :TPS3116D2 Class D 2.1 Bluetooth 4.0 Amplifier Board 2 x 50W + 100W with Filter and Volume Controls and looking at a 24v power supply. The amp does not get the 200 w for the sub but its where I got before you posted.
  Reply With Quote
Old 11th January 2019, 02:25 PM   #4
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
This is a bizarre forum to move this subject to. Speakers multi-way when you are asking about amplifiers? And no link left on the old parts forum. I couldn't find this, thought maybe you had deleted your post.
I don't recommend any bluetooth amp, bluetooth is reported to be sub high fidelity. Your TV would have to have bluetooth out, and mine doesn't. It may be that all popular amp boards have moved to bluetooth, the era of RCA jacks may be over. As all trail cameras now require a $800 Apple phone to download the data, no Micro-USB jacks anymore.
You have checked that your source TV has RCA jacks or a headphone jack?
Check the specs on the amp board that it will take 24 v. A 24 v transformer will produce 29.6 v open circuit which is too much for the class D TI IC I read. That is why I suggested the 19 v switcher supply for laptop computers. 24 v switcher supplies are rare. Linear regulators after transformers tend to blow up, go to maximum voltage.
Apexjr.com in LA also has amp boards I believe. I haven't bought any but I did buy some surplus from him.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 11th January 2019 at 02:31 PM.
  Reply With Quote
Old 11th January 2019, 02:37 PM   #5
BryanDIY is offline BryanDIY  United States
diyAudio Member
 
Join Date: Jan 2019
Location: Georgia
Quote:
Originally Posted by indianajo View Post
This is a bizarre forum to move this subject to. Speakers multi-way when you are asking about amplifiers? And no link left on the old parts forum. I couldn't find this, thought maybe you had deleted your post.
I don't recommend any bluetooth amp, bluetooth is reported to be sub high fidelity. Your TV would have to have bluetooth out, and mine doesn't. It may be that all popular amp boards have moved to bluetooth, the era of RCA jacks may be over. As all trail cameras now require a $800 Apple phone to download the data, no Micro-USB jacks anymore.
You have checked that your source TV has RCA jacks or a headphone jack?
Apexjr.com in LA also has amp boards I believe. I haven't bought any but I did buy some surplus from him.
I assume the moderator moved the posting to this location.

The bluetooth is only for playing music from another audio source like a phone or tablet. The TV has the RCA jacks, I double checked yesterday when you mentioned it because I had forgotten that this was an important feature for what I am wanting. I would use the RCA jacks for the TV and switch to the bluetooth for the other audio sources.

I had another idea as well, since I have the surround systems that the speakers came from, they are old, I was thinking about scavenging the audio boards, crossovers, and power supplies from them, adding the bluetooth and placing them in the soundbar.

I also thought about the fire hazard you mentioned and was thinking about using the fire retardant spray that is used in construction to spray the inside of the box. The box would be made of would and would soak in the fire retardant spray as was intended for construction purposes. I think this may help with the fire concern.

I only thought about the audio boards from the old surround systems because I wasn't finding an amp that came close to what I was needing for the speakers, considering my very limited knowledge in that area. The surround audio boards were designed to push those speakers so it made sense to repurpose them from what they were to my desired sound bar. I know it is kind of cheating, but in a sense, it is not. Thoughts?
  Reply With Quote
Old 12th January 2019, 01:34 AM   #6
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
My idea for fire resistance is metal boxes. PVC when subjected to fire makes phosgene gas, which was used against soldiers in WWI. Wood enclosures like many build on solid state forum just add to the fire size when ignited. A metal enclosure also keeps your local AM radio station from coming through your new amp if you protect your inputs with parallel capacitance. A grounded metal enclosure keeps electrons squirting out of failed components from touching your precious fingers. I use steel recipe files and tool boxes for enclosures sometimes. The input fuse I recommended previously limits the size of the fire.
I worked on a music device last week where the designers put a circuit breaker in big enough to take the 1/4 hp 12 VDC motor without straining. But the logic boards didn't have a separate fuse for their power supply, so when the back of a connector on the PowerSupply board pushed through a transformer lead, 2 sq inches of the power supply board burned to cinders. Probably the chopper transistor and maybe also the inverter transformer burned. Fortunately the steel case limited the fire size. The swell engine is inside a organ chamber full of hardwood chests & supports it took 2 years to build. We're waiting for a call from the vendor as to whether they have PS boards anymore. Else a new $2500 "swell engine" from these highly respected dummies, or a home build swell engine I could maybe build for $175 parts.
Repurposing amps is cool: finding out what power supply they were designed for takes some detective work. Solid state you can kind of estimate the watts by halving the rail supply voltage and calculating (V^2)/2=P. Rail V is guarenteed to be less than the rated voltage on the big caps after the rectifier. Power is subject to heat sink and fan limitations of course. Also power supply sag under max power caused by wimpy transformer windings of consumer gear rated in "music power".
My supply of old amps includes 1 Watt wonders using DIP packages with a heat sink on the end and the like trash. Underwhelming. I also have a 30 W PNP push pull organ amp that buzzes horribly if the input signal goes over 1.1 VAC. Blows the power supply regulator too. Germanium zener diodes were a lost cause.
Best amp project I did was improving the heat sink and fan of "the worst amp ever sold", the dynaco ST-120, where it doesn't burn output transistors any more. That had a stellar stiff power transformer and *****y heat sinks.
Reason I mentioned apexjr, he was touting a 200 W sub amp board. But 200 W is only 3 db louder than 100 W and maybe not worth pursueing.
I've bought some Peavey amps to repair & upgrade, but they won't fit under my TV. This is my LM1875 TV stereo amp in the picture with the top cover off. 25 W/ch, I have efficient Peavey 1210 speakers to be driven by this. Failed checkout, over heats left channel IC.
Have fun.
Attached Images
File Type: jpg ICampboardinstalledbig.jpg (415.0 KB, 95 views)
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 12th January 2019 at 01:50 AM.
  Reply With Quote
Old 13th January 2019, 08:07 PM   #7
BryanDIY is offline BryanDIY  United States
diyAudio Member
 
Join Date: Jan 2019
Location: Georgia
I was going to make the soundbar out of hardwood and spray the inside of it with the fire retardant. You don't think since the speakers were originally with the surround sound systems that I can simply swap the guts from one to the now soundbar? Also, I was doing some more "shopping around" and have thought about this part list for the major parts:

Dayton Audio XO3W-375/3K 3-Way Speaker Crossover 375/3,000 Hz
Mean Well MW NES-350-24 24 VDC 14.6A 350W Regulated Switching Power Supply
WINGONEER TDA7498 2X100W Dual Channel Class D Audio Amplifier Board, DC 24V
WINGONEER TDA7498E 2x160W Dual Channel Audio Amplifier Board, Support BTL Mode 1X220W Single Channel, DC 24V

Thoughts?
  Reply With Quote

Reply


Building it myself, and now I'm confusedHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
USB to I2S : too much confused Dibya Digital Line Level 3 24th October 2018 05:14 AM
Interested in Building a Set of Headphones, but Confused Where to Start. krfkeith Planars & Exotics 0 17th March 2012 06:37 PM
Help Confused jwatts Subwoofers 2 26th June 2006 12:12 PM
I'm Confused and I need your help. Paprika Solid State 12 22nd September 2003 08:49 AM
I'm building a new system, but I'm confused about some issues. Corn-Picker Everything Else 19 23rd October 2002 05:40 PM


New To Site? Need Help?

All times are GMT. The time now is 09:53 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki