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2 si ht 18s ... not too impressed

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18s impressed
12K views 48 replies 15 participants last post by  black_z 
#1 ·
I have finally have my room set up and woofers set in place running off a crown xls1502 at 4 ohm per channel .
I was expecting much more output then I have . The woofers barely move . They are housed in a 22.5" square cube each . With approx 5 lbs of stuffing in each sealed box . I've looked over everything many times and can't figure out why there is barely any movement/ split. Coming from them . Can anyone shine some light on this for me . ?
 
#3 ·
What Jman said. But if it really is an output problem and not just a lack of cone movement, then some details on your wiring / signal chain would be helpful. Common problems include something amiss in the amp’s menu, or Speakon connectors not wired correctly (if you’re using those).

Also, the speakers could be out of phase, meaning that the polarity is flopped on one of them. A good way to check for that is to disconnect one of the speakers. If you suddenly get sound, then that’s the problem.

Regards,
Wayne
 
#4 ·
Output is quite low . Reciever is a onkyo nr807 i have a pair of rca cables going from there to the amp . Then from the crown to the subs I am using the binding posts. I've tried plying with sub placement .. corner loading etc and no luck . I assumed a woofer with such soft suspension would move quite easily expecially seeing 525 watts .. I have turned all volumes up on the amp and signal from onkyo to crown up all the way . I will see a clip signal on the crown on the status bars and still not happy with output .
 
#5 ·
I suspect a polarity issue. Try disconnecting one speaker as I suggested and see if the output levels increase. If that gets you nothing, then the fact that you’re lighting the clip indicators tells me you have plenty of input signal from the receiver, which basically narrows the problem down to a bad amplifier. You could double-check that by connecting it to your receiver’s L/R pre-amp outputs and see how it does with your main channel speakers (be careful!).

Regards,
Wayne
 
#7 ·
It must be a wiring or signal problem if you aren't getting much output.

That being said, the SI HT 18 has a ton of Xmech. I find that my nu3000 clips (and my entire house is shaking) before much audible distortion or even see the woofer traveling all that far. That Crown won't likely be enough power to bottom out the SI very easily.
 
#9 ·
As states the amp is seeing plenty of signal . I know I've been over the wiring and checked imp . I have a competition car audio background. I'll go through it again tomorrow and try free air the woofers. Think it's possible that there is too much stuffing?
 
#10 ·
Seems like a lot of stuffing, but i don't think that's your issue. plus i've had many onkyos and never had the sub level above zero.
One sub itself could be wired wrong when built. Also those subs are very power hungry, and 525 rms for those, is pushing the bare minimum.

Try sub level zero, amp level midway, and run one sub bridged, that will double your power and should give you some idea if its an amp issue. Also as stated before, try the front L/R preouts and see what happens. Good luck, shouldn't be to hard to narrow down the problem.
 
#13 ·
I ended up working a double yesterday. I will try and get down and play today after work ...
This room is a new build never had subs in it . But basically a square room . 24 x 24 x8 ft ceilings with carpet .I'll keep you all posted on what I do today after work
 
#14 ·
Went downstairs to play a bit . Pulled one sub. Ran it free air . No change in movement . Ran one coil per woofer and even less movement . .wired back up both coils and back to where I was . Borrowed a friend's 300 watt plate Amp. Ran a woofer free air with it and in the box . Virtually no change from the plate Amp to the crown for output. So I have a friend that live out of town and is coming in on Saturday and bringing me his ht18 to try in my set up. Hope something comes of this . When the woofers plays outside the box it smells like a blown woofer . Buy the coils look like new . Fee years ago I had built up a fi bl motor to a 18. Ran it on a 300 watt plate Amp and it moved a lot of air . And had excursion unlike my ht18s .. so sitting still I guess in till Saturday when we test some more . Unless someone has more input or ideas .
Thanks
 
#17 ·
Went downstairs to play a bit . Pulled one sub. Ran it free air . No change in movement . Ran one coil per woofer and even less movement .
Running one coil cuts the motor force in half. Hence the reduced cone movement.

.wired back up both coils and back to where I was . Borrowed a friend's 300 watt plate Amp. Ran a woofer free air with it and in the box . Virtually no change from the plate Amp to the crown for output. So I have a friend that live out of town and is coming in on Saturday and bringing me his ht18 to try in my set up. Hope something comes of this . When the woofers plays outside the box it smells like a blown woofer . Buy the coils look like new . Fee years ago I had built up a fi bl motor to a 18. Ran it on a 300 watt plate Amp and it moved a lot of air . And had excursion unlike my ht18s .. so sitting still I guess in till Saturday when we test some more . Unless someone has more input or ideas .
Thanks
If you are not keeping the pole vent open (AKA: putting the pole vent against the floor) you are suffocating the cooling system for the coil, hence the coil smell. I do NOT recommend repeating the latter.

Are you certain you do not have a high-pass filter enabled in your system? Other comments about the leads/spider leads/terminals/etc are erroneous since you have music out of both woofers even when you hook up one woofer at a time. The problem is not on our end because of your report of the latter. If you have a steep high pass filter set at 30 Hz or 40 Hz it explains the lack of output. When you built/tested the fi subwoofer that you custom built was it the same impedance and did you use the exact same player, receiver, and amplifier setup compared to your SI HT-18 setup?
 
#18 ·
When I built the fi sub all the equiptment was the same minus the crown amp. But I had 30 minutes today in between my job so I went down stairs to think. My ignorance the other day got the best of me . I only check one coil on the woofers when I pulled the jumper out . I pulled woofer back out and check both coils this time and must have check bad coils on each sub. I have one working coil per woofer . But they all read out fine which is weird. .. I do block the woofers off the ground so the poll piece can breathe.. so much for being new woofers I bought that the guy was advertising . Does anyone know if nick sells recones still for the ht 18s ? Glad I found the issue but bumbed out same time ..
 
#19 ·
When I built the fi sub all the equiptment was the same minus the crown amp. But I had 30 minutes today in between my job so I went down stairs to think. My ignorance the other day got the best of me . I only check one coil on the woofers when I pulled the jumper out . I pulled woofer back out and check both coils this time and must have check bad coils on each sub. I have one working coil per woofer . But they all read out fine which is weird. .. I do block the woofers off the ground so the poll piece can breathe.. so much for being new woofers I bought that the guy was advertising . Does anyone know if nick sells recones still for the ht 18s ? Glad I found the issue but bumbed out same time ..
I do.
 
#21 ·
How do you have the subs wired you wrote 4 ohms per channel? Which subs do you have D2's or D4's? Another thing and I still do it just to verify well two things, go to 12vdc sub wiring its pretty much fool proof put in how many subs and what impedance the subs are. The SI HT18's are a great sub I started off with 2 of these powered by a nu3000 they rocked!! Another thing to check the polarity all you need is a 9 volt battery hook + to + and - to - see if the sub goes out or in when you connect. Another thing while I am thinking about it are you using speak-on connectors if so check the wiring on those. If you go to the AVS web site then go to the DIY section and check out the MartyCube section ( thousands of posts ) on the first page about half way down right past the Homer Simpson image you will see different wiring methods. I am not saying you are doing anything wrong but from my experience some of the most aggravating problems turned out to be the easiest to fix. Hope this helps!!
 
#22 ·
Okay my mistake I read you were using RCA's so skip the speak-on part. Nick had some good points he goes by Electrodynamic. I have found him to be extremely helpful when I have encountered a problem with any of the subs I have bought from him. With a DVC sub it has to be wired correctly or issues.Keep us posted.
 
#27 · (Edited)
I helped a friend build two minimartys and they are awesome. Very articulate and powerful bass with just an iNuke 3000 DSP. They are heavy, and large, but if you want to go the traditional box route, the minis are great.

ETA - they were actually the martycubes - and they are pretty killer.
 
#32 ·
The crown amps I have do have selectable input sensitivity .. I will get a clip signal on the unit when turned up . It ended up snowing last weekend so no sonotube build got started but I did decide I had nothing to lose by ported my 22" cube sealed cabinets I build . It did help with output . Still not seeing a lot of Xmas even with the new crown xls2502 Amp hooked up now
 
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