Yeah... Wasn't my point to hit that low either. But I think I will try them then. It's just so there is no gap between 3000-4000. I dunno what else to do really. Nothing fits together with each other
One thing with those piezos though is that you sacrifice dispersion.
Output power is limited by battery voltage. Nothing else. On a 12V battery that "2x100W" will output exactly the same as an amp6b or a lepai amp, ie. 2x16W. It would have higher quiscent current so it would consume more power but like almost everything else that's already asked and answered several times in this thread.
rubenn, is considering the same speakers and he found some piezo that might work. I can naturally not vouch for an untested design change. Well, I can actually guarentee it will not be as good in any way.
As of now, I have to compromise however, so yes the design will not be as thorough as the original boominator. This is also to be expected when your design is optimal.
Question though, how will these have less dispersion. I'm not so familiar with all hifi terms yet, but I guess that dispersion is "spredning"? I would have guessed they would have better dispersion due to the large horn? What determines good dispersion?
@jonasvj
As Saturnus said the answer to a tube port, which I guess you are looking for, is already posted on previous pages. However, you can calculate the width/length of the port in WinISD Pro (free program). Phaedras has used a 110 mm Ø tube and I'm gonna use a 75mm Ø tube. Length is way different on these two different ports.
Question though, how will these have less dispersion. I'm not so familiar with all hifi terms yet, but I guess that dispersion is "spredning"? I would have guessed they would have better dispersion due to the large horn? What determines good dispersion?
@jonasvj
As Saturnus said the answer to a tube port, which I guess you are looking for, is already posted on previous pages. However, you can calculate the width/length of the port in WinISD Pro (free program). Phaedras has used a 110 mm Ø tube and I'm gonna use a 75mm Ø tube. Length is way different on these two different ports.
This one: https://www.elextra.dk/main.aspx?page=article&artno=H15563
Tekniske detaljer:
- hold strøm Ih (A): 4.00
- trip strøm It (A): 8.00
- Maks. time til trip (at 5 x Ih): 12.7
- Maks. strøm Imax (A): 40
- Specificeret spænding Vmax (Vdc): 30
- typ. effekt Pd (W) : 2.5
- resistance tolerance:
- Rmin (ohm): 0,010
- Rmaks. (1 hour after tripping) (ohm) : 0,05
- Størrelse:
- A (max): 14.0
- B (max): 20.1
- C (typ): 5.1
- D (min): 7.6
- E (max): 3.0
- F (typ): 1.2
- operating strøm: 900mA ~ 9.0A
That's what I use too in order to not bother about having to open the amp to change the fuse should it ever blow.
Horn shape. The original piezos have 90x90 degrees, the motorolas and replicas have 100 degrees axial (meaning all directions). Those you're looking at have 90x40 degrees.
Ah I see what you mean now, after having a second look at them. Although, that's something I'm gonna have to live with. Also used this type of piezo last year, and that didn't bother me. But that piezo had a sensitivity of 92 dB/w/m, I put a 100 ohm resistor on it and that made the stereo sound quite bassy/muddy. Hoping for better results with this.
Yes, I would actually try with those first because I have some laying around.
Another question:
To make up for lack of dispersion, can you spare the resistor?
My thought was that the piezo would play a little louder to compensate - if this is even possible? The SPA-10PA's overall SPL is stated to be 95 dB/w/m and the piezo 96 dB/w/m. These might be off though.
Another question:
To make up for lack of dispersion, can you spare the resistor?
My thought was that the piezo would play a little louder to compensate - if this is even possible? The SPA-10PA's overall SPL is stated to be 95 dB/w/m and the piezo 96 dB/w/m. These might be off though.
The resistor doesn't actually attenuate the level. It sets the cut-in frequency. You see a piezo of that size has an impedance of over 1000 ohms at 2.5KHz, so it makes no difference for the output level if you put a 33 ohm resistor or a 100 ohm resistor in series. But no, you can't compensate for dispersion by playing louder. You're just going to have to live with it.
so if the voltage decide how high the volume output is, will it then be a good idea to buy an amp9 and use 24v when we need to play very loud at party in the evenings and then play 12 v during the day ?.
and when we use amp9 12 v will it play exactly as loud as an amp6 12v?
just need a yes or no to my questions
and when we use amp9 12 v will it play exactly as loud as an amp6 12v?
just need a yes or no to my questions
so if the voltage decide how high the volume output is, will it then be a good idea to buy an amp9 and use 24v when we need to play very loud at party in the evenings and then play 12 v during the day ?.
and when we use amp9 12 v will it play exactly as loud as an amp6 12v?
just need a yes or no to my questions
Amp9 cant run on 12v as far as I know. Will only be able to use it with 24v. But yes, the amp9 Will output louder than the amp6 and therefore also use a lot more power.
Yes it can
But it uses more power anyway since the idle power consumption is higher than for the Amp6.The Amp6 uses 60-80mA on idle and Amp9 220-240mA.
http://shop.41hz.com/shop/item.asp?catid=13&itemid=796
Last edited:
We paralleled the outputs so it was 2 outcoming channels into 2 sets of 2 paralleled HP-10W to make it 4ohms.
An you can make your own 12V/24V switch like this: http://www.instructables.com/id/SIMPLE-ParallelSeries-Select-Switch/
Even though that pretty illogical way to connect it. And by all standards not the "right way", it's actually the best way in this case because the amp9b is designed for 4 ohms loads and has better efficiency in 4 ohms.
For example: amp6b has 88%@8ohms and 84%@4ohms while the amp9b has 82%@8ohms and 90%@4ohms.