BH Shopping List - Sound System (part 2)

Amplifier
1. How many Internal Amp you need?
- Min 2 pcs - As the internal Amp need to support > 100 tweeters and run 24 hours, normally people like to switch between this 2 amps every 3 hours.

For me I use 1 Amp to run around 100 tweeters for 24 hours. I use PC fan to cold down the Amp. I use another internal Amp to play pulling and colony sound.

One advantage of playing few different internal sounds is you might able to find good internal sound in shorter time. As we know internal sound is harder to prove whether is good or bad compared to external sound. So playing different internal sounds at the same time better changes to get 1 right. How to know? See whether birds like to make nest near the tweeters? Make sure the volume is control properly, not too loud.

Another advantage is in case 1 Amp broken, you have another one running.

2. How many External Amp
- Min 2 Amp. 1 Amp play external sound and another play Hexagonal and Bazooka. You can use lower power Amp as the number of tweeters connected to the amp is normally < 10pcs.

3. How Much
- Internal Amp - RM300 to RM600 - Depend the power of the Amp
- External Amp - RM200 to RM400


Speaker Wire
1. What is the diameter?
- The bigger the better. I can only manage to get 42x0.15mm thickness of wire. If you can get 50 treads and above would be good.

2. How long you need?
- I bought 3x100meter speaker wire for my new BH. Should be more that enough.

3. How much?
- Depend on the size and length and of course copper price. Right now around RM80 to RM100 for 100 meters cable.

BH Shopping List - Sound System (part 1)

To DIY BH yourself, you need to list out the shopping list yourself. Since I am now building my new BH, I will list down some of the items here. Let me start with Sound System.

1. How many internal tweeters you need for 1 floor say 20x70' shop lot? There are 3 groups,

a. Group 1 said 400 tweeters - because since birds like to make nest at or near tweeters, so the more the merrier.

b. Group 2 said 10 to 20 tweeters - because too many will confuse birds. This group use good tweeters so that the sound is crystal clear and the frequency range is fall within 1KHz to 16KHz. Bird will zoom in to this places.

c. Group 3 said around 100 tweeters - I am belong to this group. I always believe "Balance". Too many confess birds, too few doesn't sound like there are a few colonies in the BH. I will also make sure I added around 10 "Magic Bullet" at selective locations. So you will have ~ 100 tweeters playing baby birds and colonies sound and the good tweeters plying pulling sounds.

2. How many External Tweeters
- 2 External tweeters at the entrance between outside and your roving
- 2 External tweeters at the entrance between roving and nesting.
- 6 Hexagonal tweeters. For me I will use 4 Bullet Bazooka.


3. Whether to use good quality tweeters?
- External tweeter is a MUST.
- Internal tweeter depend on your budget. For me, as I only use 100 tweeters, I will use good tweeters as it only cost extra RM1K. You has better sound and less maintenance.

My New BH - Metal Door Design

If you have gone through my blog from beginning, my current BH design was done by a consultant. Sad to said that the design is very bad. It is very very difficult to do a major change once your BH is running. After all the modification, my BH nests increase every month but the growth still not up to my expectation. For now onward, I will not do any structure change and focus more on the sound system, micro and aroma. Because every major change in design will temporary affect the nest grow. Birds need to take time to get use to the new design.

Now is time to move on to my next BH. My brother in law asked me to JV with him to convert his shop lot to BH which is just next to my current BH. This is great. I can use all the knowledge that I have gained so far to design my "Preferred BH design" and compare to my current BH. 2 different BH design at same location.

I will try to post as many photo as possible through out the new BH renovation progress. Let me start with Metal Door Design. My Metal door has 3 lockers at the front and 2 lockers at the "Back". To excess the back locker, you need to first open the front locker in order to open the small little panel. Then you can open the locker at the back.

I have 2nd similar metal door between the staircase. I am going to use my first half of the staircase as control room where all the Amp will be located here. The upper half of staircase will be use for nesting area.

Function of Horn

Below is the article I copied from the Wikipedia.

A horn loudspeaker is a complete loudspeaker or loudspeaker element which uses a horn to increase the overall efficiency of the driving element, typically a diaphragm driven by an electromagnet. The horn itself is a passive component and does not amplify the sound from the driving element as such, but rather improves the coupling efficiency between the speaker driver and the air. The horn can be thought of as an "acoustic transformer" that provides impedance matching between the relatively dense diaphragm material and the air of low density. The result is greater acoustic output from a given driver.^[1]

The narrow part of the horn next to the speaker driver is called the "throat" and the large part farthest away from the speaker driver is called the "mouth".^[1]

Horns have been used to extend the low frequency limit of a speaker driver—when mated to a horn, a speaker driver is able to reproduce lower tones more strongly. The flare rate and the mouth size determine the low frequency limit. The throat size is more of a design choice. Horns have been known to extend the frequency range of a driver beyond five octaves.^[1]

Base on the Wikipedia explanation, now then I realized why the horn come with the minimum frequency spec. So if your speaker driver min freq is 2KHz and you need to lower that freq to 1KHz to cover the birds freq range, you need to consider getting a suitable horn.
Specifications: • Horn type: Exponential • Minimum frequency: 600 Hz • Nominal dispersion: 45° H x 45° V • Throat diameter: 1.0" • Mounting type: 1-3/8"-18 TPI •


Specifications: *Horn type: Bi-radial *Minimum frequency: 1,500 Hz *Nominal dispersion: 60° H x 40° V *Throat diameter: 1.0" *Mounting type: 1-3/8"-18 TPI *Dimensions: 6.34" W x 5.16" H x 4.16" D

BH Checklist

A lot of people asked me to send him the bird house checklist. I decided to attach a link below for everyone to download. The checklist is especially usefully for those new BH.

Download BH Checklist

Internal Bullet Tweeter

I have installed 2 Bullet Tweeters using another type of horn at 2 sides of the partition. The sound quality is really good. I purposely placed Styrofoam at the side of the tweeters. Hope the birds will rest there and enjoy the beautiful music.

Waterproof Cover for Bullet Bazooka

Last weekend when I checked my Bullet Bazooka, I found out that the water proof covers were torn already. One of the reason is that the cloth cannot withstand under hot sun and rain condition.

But if you looked at it carefully, I think the main reason is caused by bird cling on the cloth. The birds like the sounds from the Bullet Bazooka.

I need to think another method to make the bullet Bazooka water proof.