Since the arrival of Corona Ive been bored and since planning my next DIY project for summer vacation, but due to uncertain financial future I scrapped my original plans for something cheaper: a small bookshelf based on some simple car-audio kits. It was fun to assemble this simple design and now I have something for the winter fireplace (as expected it sounds horrible). All jokes aside I will probably buy better drivers as I'm very happy with the wood work and definitely learned a lot in the process as preparation for next bigger projects.
Size outer: 30*20*18 cm
Cost:
Wood: 2pc of 300x2100x18mm pine = aprox 40 eur
Car audio kit 6,5" Biltema: aprox 55 eur
Glue and paint I had from before.
Size outer: 30*20*18 cm
Cost:
Wood: 2pc of 300x2100x18mm pine = aprox 40 eur
Car audio kit 6,5" Biltema: aprox 55 eur
Glue and paint I had from before.
An externally hosted image should be here but it was not working when we last tested it.
That looks like a solid enclosure construction - well done for that.
How would you describe the finish - distressed pine?
How would you describe the finish - distressed pine?
The drivers look pretty nice. You haven't described why it sounds horrible. Maybe all you need is a simple tweak...
Oon
Oon
The sound is bright and harsh, a little plastic if that makes any sense. The crossover have a -2dB switch for HF that I'm gonna try, then break them in for 20 hours, add a bass reflex and some better damping, and then see (hear). I didn't have high expectations in any case for the price put and the volume of the cabinet design. If the treble and mid soften up I can make a small subwoofer for the bass. If not ill find some other drivers, maybe some coaxials or full ranges.
The end grain sides look interesting, the front baffle not so much. Personally, I hate the way pine stains, better to give it lots of natural light (UV) and time to let it colour to that rich orange/brown.
Bright and harsh is usually symptom of insufficient baffle step correction. Need to apply typically -5dB attenuation to mids and highs above 800Hz or so. That drops speaker sensitivity overall to circa 82dB bit sounds much more balanced.
Not having seen your XO, something like 1mH and 6.8ohm in parallel on the woofer and attenuate the tweeter by -6dB with a divider 4.7/4.7 ohm 10w divider.
Not having seen your XO, something like 1mH and 6.8ohm in parallel on the woofer and attenuate the tweeter by -6dB with a divider 4.7/4.7 ohm 10w divider.
About pine stain I agree I have struggled to find a good looking solution but I feel this is as close as I can get with the methods I’ve tried: sanding torching sanding stain sand stain. I was hoping for more grayish look but maybe next project I’ll try oak instead and less black/brown tar oil maybe silver/gray instead.
Thanks for reminding me about the baffle step response phenomenon I didn’t think about that but this box is practically giving me free air response up to -3dB @ 825Hz and -6 at 200*. In a car hat shelf I guess this issue is neglectable and hence the crossover is designed with that in mind. The -2dB in HF will most likely not solve anything as I assume the crossover point is somewhere around 3000hz.
*please update me if I’m wrong about baffle step but it’s correct to calculate -3dB point as 1/2 x 330m/s / baffle width in meter and -6dB as 1/8 instead of 1/2? If I had a 3 way system with baffle of 40cm would it make sense choose a bass with 6dB higher sensitivity and cutoff around 300-400 where the -3 baffle would be?
Thanks for reminding me about the baffle step response phenomenon I didn’t think about that but this box is practically giving me free air response up to -3dB @ 825Hz and -6 at 200*. In a car hat shelf I guess this issue is neglectable and hence the crossover is designed with that in mind. The -2dB in HF will most likely not solve anything as I assume the crossover point is somewhere around 3000hz.
*please update me if I’m wrong about baffle step but it’s correct to calculate -3dB point as 1/2 x 330m/s / baffle width in meter and -6dB as 1/8 instead of 1/2? If I had a 3 way system with baffle of 40cm would it make sense choose a bass with 6dB higher sensitivity and cutoff around 300-400 where the -3 baffle would be?
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There's a baffle step compensation circuit calculator here: Loudspeaker Diffraction Loss and Baffle Step Compensation Circuits
4dB is a reasonable amount of attenuation once room reinforcement is taken into account.
4dB is a reasonable amount of attenuation once room reinforcement is taken into account.
Baing car speakers that are designed for infinite baffle, and the crossover being part of a kit will be too, so I think what the others have said about the baffle step comp is bang on the money.
Some baffle step compensation could help. A custom made crossover could completely change the sound. The likely distance between the tweeters and woofers in a car installation will be large so when placed close together like that you may also have phase issues if the crossover is not redone.
Tony.
Some baffle step compensation could help. A custom made crossover could completely change the sound. The likely distance between the tweeters and woofers in a car installation will be large so when placed close together like that you may also have phase issues if the crossover is not redone.
Tony.
Hi,
Hope things are burning in well, however while baffle step is going to help balance the sound a bit better, if it still sounds harsh, it is most likely a bad tweeter and won't be fixed by a tweak in the crossover. There is no way out of it, just simply have to buy a new tweeter...
Oon
Hope things are burning in well, however while baffle step is going to help balance the sound a bit better, if it still sounds harsh, it is most likely a bad tweeter and won't be fixed by a tweak in the crossover. There is no way out of it, just simply have to buy a new tweeter...
Oon
Hi all and thanks for all the tips, as vacation is over I haven’t had much time to play around with tweaks. Burning in doesn’t seem to help much so I think a different crossover with baffle step correction and treble damping would be a good idea. A better/softer tweeter may too be an option or just replace all components with a new kit that are suited for a box like this, but rather with a bass reflex. I’m happy with the wood work still and my head is starting to think about a new project, or in fact the project I originally had in mind. Small speakers have never done it for me I like big bass dark and warm sound in general, this project was just a way to spend some vacation time and learn a little more before investing for a bigger speaker.
Cheap tweeters can perform exceptionally well so long as you don't want a very low xover point. And some cheap tweeters will handle a low xover point no problem.
Unless the tweeter is a trainwreck of a design I can't see it needing to be replaced.
The woofer, on the other hand, could be an entirely different story. It's much easier to end up with a terrible woofer than tweeter. The hard stuff get right is the upper range of the woofer, the bit where it crosses to the tweeter without measurements we'll never know.
Carbon fibre has the potential to have horrible break up. Although the woofers magnet doesn't look ridiculously tiny, that counts in its favour, its qts might not be sky high.
Do not port these whatever you do. Car door speakers are not designed for this.
I'd imagine that these could be made to sound fairly decent with a proper crossover. Baffle step compensation and a 4th order acoustic crossover 2.5-3Khz would be my guess. Ideally you'd take the tweeter as low as possible with it still being happy but you'd need to know what you are doing for this. Although to be honest you're going to need good measurements to really make these sing anyway.
Unless the tweeter is a trainwreck of a design I can't see it needing to be replaced.
The woofer, on the other hand, could be an entirely different story. It's much easier to end up with a terrible woofer than tweeter. The hard stuff get right is the upper range of the woofer, the bit where it crosses to the tweeter without measurements we'll never know.
Carbon fibre has the potential to have horrible break up. Although the woofers magnet doesn't look ridiculously tiny, that counts in its favour, its qts might not be sky high.
Do not port these whatever you do. Car door speakers are not designed for this.
I'd imagine that these could be made to sound fairly decent with a proper crossover. Baffle step compensation and a 4th order acoustic crossover 2.5-3Khz would be my guess. Ideally you'd take the tweeter as low as possible with it still being happy but you'd need to know what you are doing for this. Although to be honest you're going to need good measurements to really make these sing anyway.
What 5th said 🙂 these speakers as they are (minus the crossover) still represent an excellent learning opportunity. changing drivers may get you a different sound but learning what is not right with the existing ones and how to fix it so that they sound better will be ultimately a much better learning outcome.
I would not just abandom them but learn how to make them work together much better than what the kit crossover car use is currently allowing.
Tony.
I would not just abandom them but learn how to make them work together much better than what the kit crossover car use is currently allowing.
Tony.