Car subs to garage setup? - Page 2 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
Reply
 
Thread Tools
post #31 of 35 Old 05-11-2019, 12:30 PM
AVS Forum Special Member
 
Stephen Hopkins's Avatar
 
Join Date: Feb 2004
Location: Douglasville, GA
Posts: 4,220
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 438 Post(s)
Liked: 203
Quote:
Originally Posted by SlashtaCross View Post
The pulsing stops when I flip the switch on the amp that says "subsonic". When it's off the speakers pulsate slowly and when it's on they stop. Someone pointed out that my RCAs are incorrectly installed. Both on the amp and on the receiver. On the amp they should be wired to the LINE IN instead of LINE OUT and as for the receiver end I have been told to get a "1 RCA male to 2 RCA female y splitter adapter" and run my RCAs into 1 sub preout. I ran my subs directly to the receiver and they're still working thankfully. The question is could I have damaged my receiver by plugging in the rcas to both sub pre outs? Could I have messed up my amp with the rcas running from line out instead of line in?
Being hooked to line out instead of line in on the car amp would definitely be a problem, sorry I didn't notice it. As for 2 RCAs to both sub-outs vs 1 and a Y-splitter, there's absolutely no difference... this is old advice from back when most AVRs had a single sub-out and sometimes on mono sub-amps with stereo inputs, hooking one RCA to a single input might not have a high enough voltage to trigger the amp's auto-on circuitry. On modern lower-end receivers with dual sub pre-outs, it's just splitting the same signal, so a single cable with Y-splitter is pretty much doing the same thing electronically.

Is it possible that running the RCAs wrong messes something up? Possibly, but highly unlikely, especially on the AVR. If you have a 3.5mm to RCA adapter laying around, maybe try connecting a pair of headphones to the sub-outs, raise the AVR's crossover to 200hz, and see if you hear anything in the headphones with music playing, that should confirm the sub-out is fine. If it is, then hooking the same 3.5mm-to-RCA adapter to the line-in inputs on the car amp with a source (like your phone if it has a headphone jack) and listening for playback should then narrow it down to the car amp or power supply.

The fact that the subsonic filter eliminates the pulsing seems to point some low-frequency harmonic, possibly from the power supply failing or possibly from the amp. Now that the input cables are correct, are you getting playback with or without the subsonic filter on? Getting an exchange for the power supply from Amazon should be easy enough, so if replacing that doesn't fix it, the car amp probably kicked the bucket... at which point, just return the power supply for a refund and source a plate-amp or pro-audio amp.

BenQ TK800 | Silver Ticket 106" 16:9 1.0 Grey | Marantz SR6011 | B&W P6 | B&W CDMC SE | Sonance .5 THX SUR | MCM In-Ceiling Atmos | Ascendant Avalanche 12" in 6 ft^3 @ 18Hz w/ BASH 500w Plate Amp | Sony X800 | NVidia Shield TV Pro | XBox One 500gb | Nintendo Switch | Harmony Smart Control | SmartThings Hub | Google Home | AT&T Fiber 300 | YouTube TV | Netflix | HBO Now | Spotify
Stephen Hopkins is offline  
Sponsored Links
Advertisement
 
post #32 of 35 Old 05-11-2019, 02:05 PM - Thread Starter
Member
 
Join Date: May 2019
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 0
Quote:
Originally Posted by Stephen Hopkins View Post
Being hooked to line out instead of line in on the car amp would definitely be a problem, sorry I didn't notice it. As for 2 RCAs to both sub-outs vs 1 and a Y-splitter, there's absolutely no difference... this is old advice from back when most AVRs had a single sub-out and sometimes on mono sub-amps with stereo inputs, hooking one RCA to a single input might not have a high enough voltage to trigger the amp's auto-on circuitry. On modern lower-end receivers with dual sub pre-outs, it's just splitting the same signal, so a single cable with Y-splitter is pretty much doing the same thing electronically.

Is it possible that running the RCAs wrong messes something up? Possibly, but highly unlikely, especially on the AVR. If you have a 3.5mm to RCA adapter laying around, maybe try connecting a pair of headphones to the sub-outs, raise the AVR's crossover to 200hz, and see if you hear anything in the headphones with music playing, that should confirm the sub-out is fine. If it is, then hooking the same 3.5mm-to-RCA adapter to the line-in inputs on the car amp with a source (like your phone if it has a headphone jack) and listening for playback should then narrow it down to the car amp or power supply.

The fact that the subsonic filter eliminates the pulsing seems to point some low-frequency harmonic, possibly from the power supply failing or possibly from the amp. Now that the input cables are correct, are you getting playback with or without the subsonic filter on? Getting an exchange for the power supply from Amazon should be easy enough, so if replacing that doesn't fix it, the car amp probably kicked the bucket... at which point, just return the power supply for a refund and source a plate-amp or pro-audio amp.
I had another smaller amp and decided to try it out and see if there was any difference and viola I've got bass again. It's a 600w Kenwood KAC-729S. I ran the RCA inputs from the amp and only hooked in the right one into the receiver as per advice and my rights were booming just fine. So this means my other amp is junk now? No easy fixing it or whatever? If so I'd probably rather get a Plate-amp, due to the fact that others were saying my power switch probably was under powering my amp to begin with, even though I wouldn't know where to start. Got any recommendations?
SlashtaCross is offline  
post #33 of 35 Old 05-11-2019, 03:09 PM
AVS Forum Special Member
 
Stephen Hopkins's Avatar
 
Join Date: Feb 2004
Location: Douglasville, GA
Posts: 4,220
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 438 Post(s)
Liked: 203
Sounds like the other amp is toast and... it could have been due to the power supply, or it could have just been a cheap amp that's gathered some dust in a garage for a few years. If you don't want to risk toasting the Kenwood too, then I'd probably lean towards a plate amp. Check out what Parts Express has and see what fits your budget... I've had good luck with the BASH amps (I have a 500w still driving my Ascendant 12" XBL after 14-years, the same model they're still selling) and you can adjust their boost parameters by swapping out a couple of resistors. The Yung amps review pretty well also, but I would stick with one of the no-boost models unless you can model your drivers/enclosure in WinISD and see if/where/how-much boost you might need. The 300w Yung or BASH probably hit right in the price/performance sweet-spot.

https://www.parts-express.com/cat/su...amplifiers/332

This OEM Buyout amp also looks like a lot of power for the price... I wouldn't recommend it for most Home Theater builds because of the 35hz Subsonic filter but it would probably be perfect for this application. You'll just need to grab some Male XLR to Female RCA adapters and wire the 4 subs in a parallel+series configuration (each pair in series, then each set in parallel or vice-versa).

https://www.parts-express.com/b-52-a...000w--299-2336



I'm guessing your box probably already has each pair wired in parallel, so each binding post is 2ohm... so just wire the binding posts in series and you should have a net 4ohm load and the same net effect (in the picture below, each 2-ohm driver represents a pair of 4ohm 15s in your setup).


BenQ TK800 | Silver Ticket 106" 16:9 1.0 Grey | Marantz SR6011 | B&W P6 | B&W CDMC SE | Sonance .5 THX SUR | MCM In-Ceiling Atmos | Ascendant Avalanche 12" in 6 ft^3 @ 18Hz w/ BASH 500w Plate Amp | Sony X800 | NVidia Shield TV Pro | XBox One 500gb | Nintendo Switch | Harmony Smart Control | SmartThings Hub | Google Home | AT&T Fiber 300 | YouTube TV | Netflix | HBO Now | Spotify
Stephen Hopkins is offline  
Sponsored Links
Advertisement
 
post #34 of 35 Old 05-11-2019, 09:05 PM - Thread Starter
Member
 
Join Date: May 2019
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Liked: 0
Ok I've got a few questions with these different types of amps.

1. If I were to get a plate-amp is it most ideal to cut a hole in the box to install it? (Note* my subs are in 4 individual boxes that are screwed together into 1)

2. If I didn't want to cut a hole in my box then would a pro-amp be in the same price range or more?

3. You said a 300w would work well for me but is 300w gonna be plenty of power if I'm feeling spontaneous and wanna push the bass a little harder?

*EDIT - I went ahead and took my speakers out to see how they were actually wired and put together a little diagram. As for the picture of the terminal where the speaker wire is attached at the back of the box I plan to re-do that connection with a proper female disconnector.

It's crazy I've had these subs for years and used them quite a bit but I've never actually messed with any of the internals.

I'm not very savvy when it comes to this type of technical stuff so when ppl start talkin about ohms I'm lost. As you can see the speakers are wired in a totally different order than what you have posted. Which way is optimal in my case?

I'm considering purchasing one of these two plate amps if a rack style would be too costly:

https://www.parts-express.com/bash-5...w-rms--300-752

https://www.parts-express.com/bash-3...w-rms--300-750
Attached Thumbnails
Click image for larger version

Name:	Crutchf.jpg
Views:	3
Size:	206.4 KB
ID:	2565646   Click image for larger version

Name:	wiree.jpg
Views:	2
Size:	694.6 KB
ID:	2565648   Click image for larger version

Name:	sub.jpg
Views:	2
Size:	330.2 KB
ID:	2565650  

Last edited by SlashtaCross; 05-12-2019 at 12:45 AM.
SlashtaCross is offline  
post #35 of 35 Old 05-12-2019, 01:23 AM
AVS Forum Special Member
 
Stephen Hopkins's Avatar
 
Join Date: Feb 2004
Location: Douglasville, GA
Posts: 4,220
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 438 Post(s)
Liked: 203
Your wiring diagram has each pair of subs in parallel (each pair is a 2ohm load) which makes sense for a 2ch amp... the diagrams I was showing was how to wire the 4 drivers for a single-channel amp (like a plate amp). As for installing a plate amp, you could cut a hole in the box and install it that way (which is the traditional method) and drill some holes in your box to keep all the wiring internal, or you could just build a small box of some sort to hold the box and protect the exposed electronics.

A pro-amp can be had in the same price range... check out the Behringer KM750 I mentioned on Amazon. With something like that, you could just keep the subs wired the way they currently are since it's a 2ch amp and 2ohm stable when used in 2ch mode.

I'd give the B-52 amp I linked to another look... more powerful than the BASH amps, cheaper than the 500w BASH amp, and pretty well suited for this application (I think they were originally used in PA-style subs, so music use should be right in its wheelhouse). I'd still say 300w from the cheaper BASH should be plenty for this application... I doubt your American Legacy amp was actually putting out close to that, much less anywhere near its rated output.

BenQ TK800 | Silver Ticket 106" 16:9 1.0 Grey | Marantz SR6011 | B&W P6 | B&W CDMC SE | Sonance .5 THX SUR | MCM In-Ceiling Atmos | Ascendant Avalanche 12" in 6 ft^3 @ 18Hz w/ BASH 500w Plate Amp | Sony X800 | NVidia Shield TV Pro | XBox One 500gb | Nintendo Switch | Harmony Smart Control | SmartThings Hub | Google Home | AT&T Fiber 300 | YouTube TV | Netflix | HBO Now | Spotify
Stephen Hopkins is offline  
Sponsored Links
Advertisement
 
Reply Speakers

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off