Biketronics Line Leveler - BT355 - What to Expect?
Ultimate HDF Member
Joined: Mar 2008
Posts: 5,788
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From: SW Florida
I think the loss of bass Rocket67 is experiencing is the LL filtering out the low FQ boost HD put in there to make there crappy speakers sound good.
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Joined: Mar 2015
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From: TEXAS
Originally Posted by InthewindMN
If I understood Mike from BT correctly I believe the LL hpf is set at 200, wouldn't anything below that on the amp be pointless since the LL already took it out or are they not the same filters?
T
I have mine dialed in about as good as I can get it now. Here is what I had..
PBR300x2, HP, Gain at a little over 5
Infinity Kappa 6.5"
BT line leveler set to default
With this setting there were songs that I could barely hear at 65+MPH and I could max the volume with no sign of distortion but much less bass than without the LL. The volume before was way louder so I was either going to get this working or remove the BT355.
Here are the settings now that give me the sound I expected without distortion:
PBR300x2 set to AP, gain about 6.5
Kappa's
BT355 set to defaults except the bass filter has been moved to just about max, since there is no marks to tell what Hz this is set at all I can say is I turned it until the bass where where I liked it. The radio settings were neutral when I set it.
Result, I can hear all songs now no matter what speed. Most I can listen comfortably at a little over half volume. I can crank volume to max without distortion. I have adjusted bass on HU to about 2 clicks over neutral and treble is 2 click.
I wear full helmet and use earplugs so it's really easy to hear any distortion on higher volumes and I am hearing zero now which tells me I can crank up the bass and treble more or I have a little room on the AMP gain. My guess is that the BT reduces the voltage significantly which allows higher gains on the amp. Since it does go to 10 I think I am safe at 6.5. I rode it all day yesterday and am very happy with the results. Songs that I had to typically turn down due to distortion were very clear even at higher volumes. I am sure I could move the gains on the LL and put the PBR back to 5 but it works really good so I am not going to mess with it.
PBR300x2, HP, Gain at a little over 5
Infinity Kappa 6.5"
BT line leveler set to default
With this setting there were songs that I could barely hear at 65+MPH and I could max the volume with no sign of distortion but much less bass than without the LL. The volume before was way louder so I was either going to get this working or remove the BT355.
Here are the settings now that give me the sound I expected without distortion:
PBR300x2 set to AP, gain about 6.5
Kappa's
BT355 set to defaults except the bass filter has been moved to just about max, since there is no marks to tell what Hz this is set at all I can say is I turned it until the bass where where I liked it. The radio settings were neutral when I set it.
Result, I can hear all songs now no matter what speed. Most I can listen comfortably at a little over half volume. I can crank volume to max without distortion. I have adjusted bass on HU to about 2 clicks over neutral and treble is 2 click.
I wear full helmet and use earplugs so it's really easy to hear any distortion on higher volumes and I am hearing zero now which tells me I can crank up the bass and treble more or I have a little room on the AMP gain. My guess is that the BT reduces the voltage significantly which allows higher gains on the amp. Since it does go to 10 I think I am safe at 6.5. I rode it all day yesterday and am very happy with the results. Songs that I had to typically turn down due to distortion were very clear even at higher volumes. I am sure I could move the gains on the LL and put the PBR back to 5 but it works really good so I am not going to mess with it.
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Joined: Aug 2014
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From: Lockport Illinois
Here are the settings now that give me the sound I expected without distortion:
PBR300x2 set to AP, gain about 6.5
Kappa's
BT355 set to defaults except the bass filter has been moved to just about max, since there is no marks to tell what Hz this is set at all I can say is I turned it until the bass where where I liked it. The radio settings were neutral when I set it.
[/QUOTE]
When you say you cranked the bass filter to almost max are you referring to the HPF? Also did you move the HPF clockwise or counterclockwise??
Did you recheck your output voltage on the amp to make sure you are not over driving the speakers?
PBR300x2 set to AP, gain about 6.5
Kappa's
BT355 set to defaults except the bass filter has been moved to just about max, since there is no marks to tell what Hz this is set at all I can say is I turned it until the bass where where I liked it. The radio settings were neutral when I set it.
[/QUOTE]
When you say you cranked the bass filter to almost max are you referring to the HPF? Also did you move the HPF clockwise or counterclockwise??
Did you recheck your output voltage on the amp to make sure you are not over driving the speakers?
I am not sure what it's called but it was the adjustment on the BT355 that apparently is for bass. I turned it clockwise and the base improved so kept turning until I got it where I wanted it. It only goes like half a turn so it wasn't much. The AMP is set to about 80.
I never checked the voltage but the system achieves the same volume as before without distortion. I don't know about over driving the speakers but they don't sound like there is any issue. I have a spare set in the box so if they go I can just pop a new pair in. Based on what it sounds like, they don't seem to be over reaching their limits. I could make it even louder if I wanted, trying to be conservative. Note, mine does not distort even at max volume now. I have a volt meter I could check it with, just don't know how.
Since it's all back together I am going to run it and if it craps out I will replace it. I have had this system over a year and it's still going strong so I don't expect any dramatic changes in that but you never know.
I know there is probably a million ways to do this and what I have done may not be the best way but it does work and does not distort. Bass is good for an open air speaker set and voume on most songs is about 6/10 at 65-70MPH with a helmet and ear plugs so I would say it's pretty close to correct. I can move the base/treble settings on the HU to max and radio to max and probably do some damage...but I don't have any reason to do that. Just gonna enjoy as-is unless someone can tell me a better way.
Last edited by TexasMotorcycleRider; Dec 12, 2016 at 02:14 PM.
The least amount of gain you use on any amp the better. The higher you turn up the gain the harder the amp works. The harder the amp works the less life it will have. Not to mention the faster your distortion point will be reached. Just a little tip
I wasn't sure how to turn the gain up on the BT and didn't want to mess with the settings until I had a good idea of what they did. I am not 100% sure that I actually adjusted the HP filter, there are 4 adjustments on the BT and I didn't get any manual that showed what they are or what they are for. It would be nice to have info that can help get this thing set correctly.
I am deducting that the BT355 is the culprit reducing the signal to the point that with a 300 watt amp and 2 6.5" speakers in my face, some songs are loud enough to hear while riding down the road. I have seen a lot of post on this and other forums where people are having the same issue and some have even just taken the BT off and went back to using the high output wires.
What is worse? running the amp off speaker wires from a non-flashed HU with the gain at 5 or using the BT355 and setting the gain to 6.5? For comparison, the volume levels are about the same but with the BT there is no distortion. So, I can up the gains on the LL or up the gains on the amp, should net the same voltage to the speakers...right? Of course, we are talking electronics so nothing is as it seems.
Since I made the adjustments there is no distortion that I can hear. I was going to do the 75% (or approximately) volume and move the gains until it distorted and then back it iff but I was happy with the volume level before it ever distorted so I never went high enough to distort it.
Guess I need to get the volt meter and check at the amp. I found a post in here that had the square root of the ohms*RMS or something like that.....not sure if I want to do all that based on what it sounds like now.
Last edited by TexasMotorcycleRider; Dec 12, 2016 at 02:59 PM.
If you have the LL sitting on the table the adjustments on the bottom are the HPF filters (typically have and orange sticker on them) and the adjustments on the end opposite the wires are the gain. Some of the LLs will ship with the gain zeroed out some will have it cranked all the way up. Without the LL your going to slam you speakers with so much stuff they aren't supposed to handle you will pop your speaks at high volume.
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If you have the LL sitting on the table the adjustments on the bottom are the HPF filters (typically have and orange sticker on them) and the adjustments on the end opposite the wires are the gain. Some of the LLs will ship with the gain zeroed out some will have it cranked all the way up. Without the LL your going to slam you speakers with so much stuff they aren't supposed to handle you will pop your speaks at high volume.
I don't know why I didn't remember that....
Yes, I adjusted the gain, the one on the right....guess that means I need to adjust the other one (left) to match (DUH). Maybe with both turned up a bit I can back off the gain on the amp. It's really hard to tell sitting in front of the speakers which one is louder but there was definitely a difference when I turned the gain up so we'll see how matching both sides does.
I did not adjust the HPF (the ones with the orange sticker that has "HPF" on it. Those are to default still.
As far as the popping/distortion, that is exactly why I got the BT355 (LL) is because some songs really sounded great and some had distortion even on lower volumes. When I started wearing ear plugs I really noticed it a lot more due to the lack of wind noise in my ears probably helped that.
Thanks for the info...I absolutely have it completely wrong but that is why I keep coming back to this. I want to make sure I eventually get this right.
