17 Attachment(s)
Re: 2018 Golf Sportwagen Simple Build
Ok, I'm overdue for an update. I FINALLY received my Biketronics amps in May. The cool story with one of them is that it started as a special request last fall. I knew that they offered a 4x250w and a 2x700w amp, and I found that both the Hypex UCD250 and UCD400 (of which Biketronics uses 2 in-parallel to get 700w at 2ohms) used the same rail voltage. So I asked if they could build me a 3-channel with 2x250w and 1x700w. Mike at Biketronics actually called me back to discuss further, he said they were considering it. Not only did they agree to build one for me, they decided to make it a regular product. That's pretty damn cool! The downside is that I waited a lllooooonnnnggg time to get my amps. Although they were able to prototype the new amp very quickly, a number of factors (some COVID-related and out of Biketronics' control) caused some delays. I'm not throwing shade at Biketronics, but it did take many, many months until these amps were in my hands.
The main reasons for me choosing Biketronics was the incredibly small form factor, the well-regarded Dynamic behavior of the Hypex UCD modules they use (Dynamics are a big deal to me in a daily driver system like mine), and the fact they made a new configuration that gave me exactly what I wanted from two amp chassis. They're also pretty efficient and a lifetime warranty doesn't hurt either! I may be a Canuck, but I appreciate how much local manufacturing they do with their amps (based in Moscow, Idaho).
I'll post a review on them in the near-ish future, but first I want to update the build log. So far I'm pretty damn happy with them, definitely a step up from my previous amps.
First pics are a few of the amps themselves. Biketronics did custom laser-etching on the lids for me, the logos were kindly designed for me by our own Blockrocker. He did a great job figuring out what I wanted based on my...er...unique preferences.
The "Goat Power" BT4210 is 4x210w (@4ohms), for my mids and tweets. It was originally supposed to be 4x180 but they uprated it, waiting on a response for Biketronics as to why.
Attachment 15959 Attachment 15963
The second amp is the new 3-channel. The "Panda Power" BT3725 is 250x2 (@4ohms) and 1x700 (@2oms), for my midbasses and sub.
Attachment 15958 Attachment 15964
A few other pics of both amps. It's hard to appreciate just how tiny these amps are until you see them in person, but here's a couple next to a CD for reference. I love how the bottom plate is etched with the signatures of the Biketronics staff. Also a pic of one next to my old amps (Alpine PDX-V9 5-channel and Kenwood KAC-M3004 4-channel).
Attachment 15960Attachment 15961 Attachment 15962Attachment 15968
With more room to work with in my amp enclosure due to the smaller amps, I took the opportunity to clean-up the wiring more to my liking. I also ditched the tech-flex, it's just not my style. I added a Knuconceptz Bassik fused distro block as well.
Attachment 15965Attachment 15967Attachment 15966 Attachment 15969
With an unusually warm June, I realized my amp compartment needed to breathe better. The DSP temp was getting toastier than I'd like (last summer I had the Dayton DSP-408, it didn't have a temp readout who knows how roasty it was getting...). So I added a couple of 80mm, 12v ball-bearing fans in a push-pull config. They're run off of an automotive relay which is triggered by the amp turn-on signal. So the fans only run when the amps are on. Between the fan-cooled amps and the extra cooling fans, fan noise is audible (even though they're under the cargo floor) when the car is off. But when it's running, they're not noticeable and this system is built for driving anyway. I've been averaging 10 degrees C cooler since adding the fans. The fans are also on a connector, so it's easy to remove that panel.
Attachment 15970Attachment 15971Attachment 15972
Attachment 15973Attachment 15974
As mentioned earlier, so far yeah I'm really happy with how they sound! The coles notes is that they have a very low noise floor, great dynamics, more clarity and control. Everything from top to bottom sounds more immediate, sounds seem to start and stop "faster" for lack of a better term. Surprising how different they sound from my previous amps, even though I took voltage readings to try to match levels to the previous amps. They have a couple of quirks which I've asked Biketronics about, but I'll cover that in a review. So I think they were worth the wait!
Re: 2018 Golf Sportwagen Simple Build
Even looking at the picture of the amps stacked next to the CD, these babies are almost inconceivably small. Practically the size of the DSP. Beautiful amps! Great choice GP.
Re: 2018 Golf Sportwagen Simple Build
Looking forward to seeing (and hearing) these in person.
Re: 2018 Golf Sportwagen Simple Build
Love the build. I signed up just because of your use of the flutes. I too have a VW wagon, though its a MKIV Jetta and while I do not have the under seat room. I find I have plenty of space in front of my seats, I also have a set of silver flutes sitting here :)
The smaller recommended ported enclosure from silver flute is a .25 with a 1.5x5 port. have you experimented with a smaller diameter port at all? I get the air is moving faster with your smaller box.
Re: 2018 Golf Sportwagen Simple Build
Quote:
Originally Posted by
JHeitt142
Love the build. I signed up just because of your use of the flutes. I too have a VW wagon, though its a MKIV Jetta and while I do not have the under seat room. I find I have plenty of space in front of my seats, I also have a set of silver flutes sitting here :)
The smaller recommended ported enclosure from silver flute is a .25 with a 1.5x5 port. have you experimented with a smaller diameter port at all? I get the air is moving faster with your smaller box.
Thanks! Apologies, wordy reply incoming...
I don't have a ton of experience with ported enclosures, but I think it all comes down to how low do you want it to play vs. how loud do you want it to play? Those Silver Flute enclosure specs seem more geared towards your typical bookshelf speaker where you're trying to get more bass extension. In winisd those box/port specs point to a roughly 55hz port tune. But this will cause the speaker to run out of linear excursion at a lower power level. You're usually not blasting small bookshelf speakers so that might not be an issue. In a car however...
My 'Flute enclosures are geared purely towards high-output midbass, the port tuning is 70hz and I currently have them high-passed at 78hz (24db/LR). Setup like this, they could theoretically take 230watts before running out of xmax (not sure if the voicecoil would survive that lol). But because of this small box/high port tune, they can't play very low. They do however have tons of output in the 78hz-165hz range that I'm using them for. They have good sensitivity and are VERY snappy. Tracks like Billie Jean by Michael Jackson and Da Funk by Daft Punk have a nice, sharp smack on the kick drum, they're just really fun to listen to (I admit I do like exaggerated midbass). They also model with surprisingly low group delay for a ported enclosure, which perhaps makes it easier to integrate with a sealed subwoofer? I think they'd perform better with a slightly larger enclosure, but I only had so much room (mine are around 0.145 cu.ft net).
Regarding port diameter, I think the tradeoff is that a smaller port can be shorter to give the desired tuning frequency but port velocity will be higher. If port velocity gets too high, you will hear port "chuffing" and will lose output do to port compression. In hifi circles I've read that 17 m/s is what's considered the approximate limit for audible port noise. My setup with 2" (1.85" internal diameter) ports requires the port to be 8.8" long and theoretically hits 17 m/s at around 170watts. If I use a 1.38" diameter port in winisd, the port length would only need to be 4.64" long, but would hit 17 m/s at only 55-ish watts. I think subs in a trunk can get away with a lot more port velocity/noise, but it may be worth considering with midbasses in front of your seats.
Please take all of this with a grain of salt, I'm not an expert by any means and am basing most of this off of things I've read and theoretical modelling in winisd pro alpha. But I do enjoy my midbass setup, for something I decided to try out of curiosity it turned out way better than I expected!
Re: 2018 Golf Sportwagen Simple Build
Makes sense. Silver flutes spec sheet says that recommended box puts the F3 at 70hz. I've never ran them through winisd as I've just started considering keeping the midbass out of the doors. I too would be crossing them around 80ish so it's interesting to see it models well for that range in your smaller box. I don't have nearly enough power so the bigger box would help on that end. I also gravitate to exaggerated midbass, just works well with the music I like. Thanks for the reply and I look forward to updates!
7 Attachment(s)
Re: 2018 Golf Sportwagen Simple Build
I'm long overdue for an update. Made some tweeter and sub changes, I'm not quite done with the tweets so I'll start with the subs.
The Evo 12 was nice, but it just never gave me the sense of being "the one". I've been casually modelling a lot of different subs over the past few months, the Scanspeak Discovery 10" (basically a Peerless XXLS variant) jumped out at me when modelled as a pair.
https://solen.ca/wp-content/uploads/26w4558t00.pdf
With a medium depth and no rear pole vent, I began to realize I might be able to fit two 10's under my cargo floor in a 1.1 cu.ft (net) sealed enclosure. I've never tried two 10's in any of my systems, so I decided to give it a go!
The pair have around 40% more cone area than my previous 12. They have decently high efficiency, low inductance, low moving mass and a really low FS for a 10. They don't have a ton of xmax or power-handling, but the pair are a good match with my sub channel (700watts @2ohms) and they theoretically don't hit xmax in this enclosure at that power level.
Attachment 16477Attachment 16478
I also felt like having another go at developing my carpentry skills. The enclosure partially sits inside the spare tire, it's not a work of art but it's probably the best enclosure I've ever made so hey, that's progress haha.
Attachment 16479Attachment 16480
Went with Rustoleum's Aged Iron texture paint again, for something that hides under the cargo floor I couldn't justify the effort of carpeting it.
Attachment 16481Attachment 16482
I know two 10's is nothing crazy, but it is pretty hilarious-looking when they're crammed under the cargo floor. Fully stealth and no loss of cargo space for this guy!
Attachment 16483
They're still breaking in and I've got a ways to go with tuning them, but damn I'm really happy with them so far. Finally I have more output capability than I want, so I have the sense of effortless dynamics that I've been looking for. They're also incredibly well-controlled, it's hard to describe but they just start/stop immediately, no overhang or "tail" to a kick drum hit. The have much better low-extension than the 12 did (to be fair, I think that 12 needed a much larger enclosure than I had it in) and way better upper bass/lower midbass performance. So far I've needed way less EQ than the 12 did to get them in the ballpark.
I really like them. I'm not looking to do hair-tricks with them, just looking for a decent amount of oomph with effortless clarity and control. These are doing a really good job of meeting those desires so far!