Good stuff Gyps!!!!! This is indeed a damn fun yet addicting hobby!!!! Wind therapy while enjoying some great tunes is livin the dream!!!

With that being said this is a good discussion for those that are sitting on their hard earned cash and looking to jump into the deep end. In most cases it really is imho optimum to specifically match ur amp to your speakers. This amp can and will serve a brother very well if paired with the right speakers on a sled.
Most folks are just not sure where they will end up with Speaks thus u will find that most of the guys will try and get the OPs in a position that will afford solid head room aka, room for growth in watts and in adding speakers in parallel, and also a level of head room performance that runs an amp in 3rd or 4th gear versus at the red line in overdrive for reliability.
The 150x4@4 dynamic / non constant watt amp really is a damn safe target for sled audio
as it opens up the speaker roster, wiring options and also reliability.
Baff is just a victim of the discussion. It's not that it won't work or that it cannot be done well with this amp, but more so is that it's probably not a ideal platform for a 4 speaker setup for many of the traditional power hungry Speaks that come into play in the sled audio world.
In a nutshell, u and I know how damn addicting the shix is so I think we should pay it forward by making sure that those that follow learn from our mistakes and get an amp that can be considered a "one and done" platform to build upon.
If an OP has a very clear vision of his finish line then that can narrow the amp selection focus but that's rarely the case for most that visit this forum just starting to put their big tie into the shallow end of the pool.
You picking up what I'm laying down? I think this is a very solid amp for some 4 speak sled setups but not for most of them that come into play. A killer amp bridged for a 2 speak setup!!!!

Fun stuff. And sorry for dragging u and Baff in the mud here but we are just sharing opinions so those that follow can pivot off what we are perpetually learning in this relatively new and rapidly advancing sled audio world.

Enjoy your Easter weekend brothers!!!!! This is fun stuff and we should all be damn grateful we are able to engage in this hobby and enjoy solid sled audio!!!!! Let's do our best to keep raising the bar!!!

T

 

Thanks T for explaining this in a way that I couldn't find the words for. Admittedly I've been a bit harsh on this amp but it's the passion for this audio bug that drives it. Very seldom will anyone, including myself, be satisfied with only 4 speaker setup and that's where this amp will bring things to a screeching halt. Always looking at the end game of things when newbies come here searching for answers because they have no clue just as we were once in the same boat. To any that I came across as brash I sincerely apologize. That is all.

 

 

Boy have I learned a lot since this thread originally posted. The beloved bt355 is adjustable and originally I thought it was taboo to touch those adjustments. I bought a focal sport because I thought I needed more power. Even with it, the sound wasn't right with the LL in play at factory settings. I tried different speakers, amp settings only to not have a good sound until I started playing with the line leveler settings. I found out that the line levelers are factory set around 90-100 on the filter and midway on the gains leaving a lot left on the table when it came to tuning the setup. With that setting, you are filtering the original signal going into the amp before even adjusting your tune on the amp. So if you put the hp filter in play on the amp, you are filtering the original signal from the hu twice. No wonder I was getting a bad sound. After playing with the line leveler settings I was able to get a ton more out of the amp and added the mid and bass I was missing with both hp filters in play. I also took out the focal and put back in the tm400 and was able to tune it for a better (warmer) sound that I could get with the focal. That is when I discovered that throwing a bunch of power at a coax doesn't make it sound better just louder and in some cases harsh as the highs will cause ears to bleed and the lows are nowhere to be found from being over powered. I tried a little PA rz4-1200 amp and after adjusting the line levelers and amp even it sounded good and had 100-110 db on my phone app. Most aftermarket speakers have an average rms around 100 so throwing 150+ watts at them just doesn't make the speakers sound as good just louder and in a lot of cases sound bad. There is a fine line with amp/speaker setups especially on a sled being in the open air and at speed. Again not all watts are created equal and leaving the line levelers at factory settings can leave a lot on the table.

 

The nice thing about the tm400 amp is it has an input clipping indicator (your red light) to let you know if the input signal is too much and you can adjust it to get all the signal you can from the hu thru the line leveler. I also run the rear channel on all pass for the 6x9's but I run the fronts at 70 on the hp filter so not to get distortion on the 6.5's and adjusted the line leveler filter flat to get all the signal to my amp. Db app on the phone showing 120+ db around 3/4 volume and that is enough to make my ears pound. In my opinion, this amp is perfect for most 4 speaker setups with 100 rms speaker specs once you get the tune right.

 

 

The line leveler is still flattening out the input to the amp. On the LL, the top is the hp filter and on the ends are the gains. The filter has a default setting. If you turn those clockwise, they will only turn about 1/4 turn and all signal is filtered out. Take them back to default and then back them down (counterclockwise) around 1/2 a turn from default. You can play a bit from that setting but not much as you will notice distortion in the lows. I found that backing the filter down around 1/2 turn is just about perfect for the right sound.

Now the gains on the end will be straight up and down on the screw. Turn those 1/4 turn clockwise and you will notice a huge difference in the volume without touching the amp gains. If after 1/4 turn you start to get distortion back the amp gains down and retune the amp. You will have to play with the LL gains (on the end) a bit along with the amp gains to get it right.

If you up the gains on the LL too much, I can see the amp going poof from too much voltage input. That is why the tm400 is such a good amp. It has an input clipping indicator to let you know how much input you can push. Setting the gains on the LL about 1/2 turn more was perfect for the tm400 so that setting cant be much different than other amps.

 

I would like to hear the BT Mike explanation regarding the control on the BT355.

My SMD DD1 did not agree at all with the BT355 settings u r recommending Gypsye. 1 o'clock to 1:15 is about as far as I was able to go and I did not jack with the filter per BT.

Lots of techniques in the industry but I would make certain we know exactly what is going on behind the curtain on the BT355 before squeezing the toothpaste out of this tube.

T

 

1/4 turn on the focal my be enough. I was able to turn the gains up about a third to half turn on the tm400, rz4-1200 and on a stinger amp. Did you back off the gains on the amp and retuned the amp when you upped the gains on the LL?

 

I ran the DD1 on HU, then HU and BT355, then HU, BT355, and amp. Identified max for all interested parties. Was not really backing one off and adding more to another. Just identifying the outside edge of the sandbox. Again, I did not jack w the filter on the BT355 thus I'm certain that if u change any of the variable ur gonna get different results.

Point being, guys should be pretty damn conservative when twinning dials a half turn here, a quarter turn there, and a third of a turn over there without knowing exactly what is taking place behind the curtain.

T